Global Journal of Environmental Science and Management

ORIGINAL RESEARCH ARTICLE Environmental Management

Life cycle assessment of coconut plantation, copra, and charcoal production

T. Puspaningrum; N.S. Indrasti; C. Indrawanto; M. Yani

Volume 9, Issue 4 , October 2023, Pages 653-672

https://doi.org/10.22034/gjesm.2023.04.01

Abstract

BACKGROUND AND OBJECTIVES: Coconuts and their derivatives, such as copra and charcoal, are leading commodities of Indonesia contributing to local consumption and exports. Life cycle assessment is a tool for evaluating the inputs, outputs, and potential impacts of a product system throughout its life ... Read More BACKGROUND AND OBJECTIVES: Coconuts and their derivatives, such as copra and charcoal, are leading commodities of Indonesia contributing to local consumption and exports. Life cycle assessment is a tool for evaluating the inputs, outputs, and potential impacts of a product system throughout its life cycle and is associated with product sustainability. The cradle-to-gate life cycle assessment of copra and coconut shell charcoal aims to determine the impacts of coconut, copra, and charcoal production from copra byproducts quantitatively and identify scenario improvements to reduce the impacts and enhance sustainability.METHODS: Field observations were conducted in tall coconuts in Agrabinta, South Cianjur, and in copra and coconut shell charcoal factories in Sukabumi, West Java, Indonesia. The life cycle assessment method comprises the following four stages: goal and scope definition, inventory analysis, impact assessment, and interpretation. The scope of this study was based on land preparation, nurseries, planting, fertilization, harvesting of mature coconuts, transportation of mature coconuts, copra production, transportation of coconut shells, and charcoal production. Ten impacts were calculated using the Center of Environmental Science of Leiden University Impact Assessment baseline method with Simapro software.FINDINGS: This study obtained ten impact categories, not only the global warming potential impact similar to most studies of perennial crop products in Indonesia. Normalization results showed that the category with enormous impacts on humans from coconut cultivation and copra processing activities had terrestrial ecotoxicity potential. The largest impact on charcoal production was on the human toxicity potential. Separated coconut factories from plantations have a high impact because of high fuel transportation. Four recommendation scenarios were formulated: 1) utilization of smoke from pyrolysis into liquid, 2) implementation of organic coconut cultivation practices, 3) integration of coconut plantations with copra and charcoal processing plants and processing smoke into liquid, and 4) combining scenarios 1, 2, and 3. In scenario 3, seven of ten impacts showed the lowest value among other scenarios. This scenario potentially decreases the impact from 68.35 to 99.62 percent. The human toxic potential of coconut shell charcoal decreased from 2.92 × 105 to 109.43 kilogram 1,4-dichlorobenzene equivalent, terrestrial ecotoxicity potential decreased from 59 to 19 kilogram 1,4-dichlorobenzene equivalent, and the global warming potential decreased from 1753.55 to 93.03 kilogram carbon dioxide equivalent.CONCLUSION: Life cycle assessment can evaluate the impacts of copra and coconut shell charcoal from the coconut cultivation to the production stages. Opportunities for improvement can be identified from the interpretation and hotspots. Scenario analysis results showed the potential of developing integrated coconut agroindustry with coconut plantations, copra factories, and charcoal factories to produce liquid smoke in one location. This integration markedly reduces the impact due to the reduction of transportation fuel and emissions and the treatment of air pollution from pyrolysis.

ORIGINAL RESEARCH ARTICLE Environmental Engineering

Coagulants for water based on activated aluminum alloys

R.G. Sarmurzina; G.I. Boiko; B.K. Kenzhaliyev; U.S. Karabalin; N.P. Lyubchenko; P.V. Kenyaikin; Zh.B. Ilmaliyev

Volume 9, Issue 4 , October 2023, Pages 673-690

https://doi.org/10.22034/gjesm.2023.04.02

Abstract

BACKGROUND AND OBJECTIVES: The reduction of fresh water deficit and water-related morbidity is the most important problem of the state’s national security. The effective treatment of natural water in industrialized areas from natural and anthropogenic pollutants is the main ecological task. Coagulation ... Read More BACKGROUND AND OBJECTIVES: The reduction of fresh water deficit and water-related morbidity is the most important problem of the state’s national security. The effective treatment of natural water in industrialized areas from natural and anthropogenic pollutants is the main ecological task. Coagulation is one of the effective methods used to treat water chemically to purify it. Aluminum polyoxychlorides have gained popularity because of their advantages over coagulants—aluminum and iron sulfates. No production of aluminum polyoxychloride occurs in Kazakhstan despite the need for coagulants (the minimum need is assessed at about 11 thousand tons). The work is aimed at theoretical justification and experimental proof of a principally new approach to the development of aluminum polyoxychloride production technology based on activated aluminum alloys containing metal activators, such as gallium, indium , and tin from 0.5 to 5 percent weight. In addition, the goal is solving environmental issues associated with improving the drinking water quality and related to environmental pollution with wastewater.METHODS: The microstructures, phase components, and elemental compositions of alloys and reaction products were studied by scanning electron microscopy/energy dispersive X-ray spectroscopy. The thermal effects of alloys were investigated usin thermogravimetry methods. Oil content in wastewater was determined by spectrophotometry. Oil particle dimensions and wastewater zero potentials were determined using electrophoretic light scattering method and residual turbidity by turbidimetry. Water quality assessment was included in the purified water analysis and comparison with the sanitary and epidemiological standards established for drinking water supply and wastewater intended for water discharge.FINDINGS: The structures and compositions of activated aluminum alloy containing metal activators - gallium, indium, and tin - from 0.5 to 5 weight percent and aluminum polyoxychlorides based on it were studied using modern instrumental methods. The efficiency of the treatment of natural and oil-contaminated wastewater with aluminum polyoxychloride was assessed. The treated water parameters were within the norms established for drinking water supply and wastewater disposal by Sanitary Rules and Norms 2.1.4.559-96. The efficiency of potable water treatment reached 90–99 percent.CONCLUSION: An effective and technologically simple method is developed for producing aluminum polyoxychloride. It involves dissolving an activated alloy in 1–5 percent hydrochloric acid, with an aluminum content of 98.5–85 percent. Alloy processing is carried out at temperatures ranging from 60 to 65 degree celsius. The temperature rises from 20 to 25 degree celsius to the specified optimum without heat supply from the outside due to the interaction among reagents. The process is completed in 2–3 hours. The results confirm that aluminum polyoxychloride is an effective coagulant for drinking and wastewater treatment. The treated water is within the established limits in terms of hydrogen potential, chemical oxygen demand, and turbidity. The water treatment method can be easily implemented.

ORIGINAL RESEARCH ARTICLE Environmental Management

Climate change mitigation and adaptation through livestock waste management

E. Frimawaty; A. Ilmika; N. A. Sakina; J. Mustabi

Volume 9, Issue 4 , October 2023, Pages 691-706

https://doi.org/10.22034/gjesm.2023.04.03

Abstract

BACKGROUND AND OBJECTIVES: Farmer characteristics are recognized in this study. The characteristics, perceptions, willingness to adopt climate change mitigation, and awareness of livestock farmers toward livestock waste management are the main points for determining appropriate climate mitigation rules.METHODS: ... Read More BACKGROUND AND OBJECTIVES: Farmer characteristics are recognized in this study. The characteristics, perceptions, willingness to adopt climate change mitigation, and awareness of livestock farmers toward livestock waste management are the main points for determining appropriate climate mitigation rules.METHODS: This study was conducted in Enrekang and Barru Regencies of South Sulawesi. International Business Machines - Statistical Package for the Social Sciences 27 was used for this study. In descriptive statistics, data were compiled, and the age, long husbandry experiences (year), number of family member, number of farming assistant, gender, education, farmer group participation status, side job, type of business, cattle ownership status, number of cattle (head), and weight total of cattle’s manure (kilogram per day) were examined qualitatively. A chi-square test was used to compare the experimental results (perception and knowledge of livestock manure management) with practical livestock manure management.FINDING: This study found that the average age of farmers in the study area is 45 and 11.2 percent received have high formal education level from a university. Most of the cattle are male at 86.7 percent. Poor manure management system at 76.30 percent manure un-managed and un-appropriate farmer groups with more than 60 percent of the farmers un-joined farmer’s group. Almost 50 percent of the cattle farmers are willing to learn manure management. Nevertheless, this study found that the respondents’ knowledge and practical manure management, as well as the respondents’ knowledge (0.837) and perception (0.343) of practical manure management, do not have any significant connection.CONCLUSION: This study determines the full condition of cattle farmers in Barru and Enrekang Regencies. Barriers include low level of education, age of farmers, lack of manure management, and lack of willingness to join farmers group. Nevertheless, drivers, such as willingness to adopt manure management and high levels of experience in cattle farming, were also found. Enriching the knowledge and perception of farmers is essential in managing livestock wastes to mitigateof climate change.

ORIGINAL RESEARCH ARTICLE Environmental Science

Relationship between bacteria and nitrogen dynamics in wastewater treatment oxidation ponds

S. Saneha; T. Pattamapitoon; S. Bualert; O. Phewnil; W. Wararam; N. Semvimol; K. Chunkao; C. Tudsanaton; M. Srichomphu; U. Nachaiboon; O. Wongsrikaew; P. Wichittrakarn; C. Chanthasoon

Volume 9, Issue 4 , October 2023, Pages 707-718

https://doi.org/10.22034/gjesm.2023.04.04

Abstract

BACKGROUND AND OBJECTIVES: The bacterial community plays a crucial role in the nitrogen cycle. Oxidation ponds act as a natural treatment system for wastewater and are designed to promote the growth and activity of certain bacterial species that remove contaminants from the water. The nitrogen cycle ... Read More BACKGROUND AND OBJECTIVES: The bacterial community plays a crucial role in the nitrogen cycle. Oxidation ponds act as a natural treatment system for wastewater and are designed to promote the growth and activity of certain bacterial species that remove contaminants from the water. The nitrogen cycle in these ponds involves the conversion of nitrogen compounds through biological processes by bacteria. The presence or absence of certain bacterial species can greatly influence the efficiency of the nitrogen cycle in these ponds. This research investigates the relationship between bacteria and nitrogen dynamics, the key components of wastewater treatment, in oxidation ponds. This work aims to identify the bacterial community composition in oxidation ponds, investigate the role of bacteria in the transformation and removal of nitrogen compounds from wastewater in oxidation ponds, and evaluate the impact of environmental factors on the microbial communities and nitrogen dynamics in oxidation ponds. This study was carried out in the oxidation wastewater treatment at the King’s Royally Initiated Laem Phak Bia Environmental Research and Development or LERD Project, in Phetchaburi, Thailand.METHODS: Wastewater samples were collected from the 1st–5th oxidation ponds at a depth of 30 centimeter from the water surface and analyzed for various quality parameters including temperature, dissolved oxygen, potential of hydrogen, biochemical oxygen demand, nitrates, ammonia, and total kjeldahl nitrogen. Next-generation sequencing by Illumina Miseq was used to examine the 16S ribosomal ribonucleic acid of bacteria in the collected samples. Correlation test was used for statistical analysis.FINDINGS: The temperature, potential of hydrogen (1st to 5th ponds), and dissolved oxygen (2nd to 5th ponds) in the oxidation ponds were within the standard value. Fifteen bacterial phyla were identified in the five oxidation ponds, with phylum Proteobacteria accounting for the highest population comprising 47.56% of the total bacterial population.CONCLUSION: Genera Novosphingobium (phylum Proteobacteria), Ammonia-11 (phylum Verrucomicrobiota), and Vicinamibacteraceae (phylum Acidobacteriota) have the strongest relationships with ammonia, nitrate, and total kjeldahl nitrogen (R2 = 0.9710, 0.986, 0.8124). The bacterial population is a crucial factor in nitrogen nutrient and water quality. Novosphingobium is involved in the removal of ammoniafrom wastewater, Verrucomicrobiota act as denitrifiers, and Vicinamibacteraceae increases the total kjeldahl nitrogen levels.

ORIGINAL RESEARCH ARTICLE Environmental Management

Health risk assessment and microplastic pollution in streams through accumulation and interaction by heavy metals

A.M. Sabilillah; F.R. Palupi; B.K. Adji; A.P. Nugroho

Volume 9, Issue 4 , October 2023, Pages 719-740

https://doi.org/10.22034/gjesm.2023.04.05

Abstract

BACKGROUND AND OBJECTIVES: The threat posed by microplastics to humans through fish consumption is potentially great due to microplastics’ capacity to adsorb heavy metals. The Code and Gajahwong streams have suffered from plastic and heavy metal pollution as the major rivers in Yogyakarta, Indonesia. ... Read More BACKGROUND AND OBJECTIVES: The threat posed by microplastics to humans through fish consumption is potentially great due to microplastics’ capacity to adsorb heavy metals. The Code and Gajahwong streams have suffered from plastic and heavy metal pollution as the major rivers in Yogyakarta, Indonesia. However, little is known about the cumulative danger caused by the association of the microplastic and heavy metals. A thorough analysis of the extent of the health risks that people who consume fish from these rivers may experience is urgently needed. Hence, this study aimed to study microplastic pollution accumulated by fish in Code and Gajahwong streams, analyze the interactions with heavy metals, and assess the potential health risks.METHODS: Fish sample collection was conducted in three stations by considering the severity of plastic pollution. Microplastics were extracted from the gills, digestive tract, muscle, and water and then characterized based on the number, size, shape, color, and type of polymer. Potential health risks were evaluated based on the potential ecological risk index, polymer hazard index, pollution load index, estimated daily intake, target hazard quotient, total target hazard quotient, and target cancer risk.FINDINGS: Microplastics have contaminated the streams and fish and were dominated by small-sized green fibers and low-density polyethylene polymer. The pollution was related to human activities around the streams. The highest accumulation in fish was found in the digestive organs. Lead and cadmium have been associated with microplastics. The calculation of the potential ecological risk index and polymer hazard index showed that the medium risk of microplastic contamination in both streams. Based on the values of estimated daily intake, target hazard quotient, total target hazard quotient, and target cancer risk, short-term consumption of fish from the streams carries a low risk, but it will increase over time and pose a serious harm in the long term.CONCLUSION: Given that most of the microplastics found were associated with lead and cadmium, they can increase the risk to human health due to the transfer of microplastics through food chains. Mitigation efforts involving various stakeholders, community involvement, and continuous education must be continuously pursued. This study significantly contributes to the current problem of environmental pollution by means of microplastic threats associated with heavy metals and provides a thorough health risk assessment applicable to other rivers and mitigation efforts that must be exerted to achieve sustainability.

ORIGINAL RESEARCH ARTICLE Environmental Science

Exploring the dynamics of seasonal surface features using coastal and regional ocean community model

D. Jaishree; P.T. Ravichandran; D.V. Thattai

Volume 9, Issue 4 , October 2023, Pages 741-752

https://doi.org/10.22034/gjesm.2023.04.06

Abstract

BACKGROUND AND OBJECTIVES: Studying the monthly variations in the surface features of the Bay of Bengal is a complex task that involves numerous large-scale ocean-atmosphere dynamics. This study identified the bay’s changing circulation patterns over recent decades as a crucial study area requiring ... Read More BACKGROUND AND OBJECTIVES: Studying the monthly variations in the surface features of the Bay of Bengal is a complex task that involves numerous large-scale ocean-atmosphere dynamics. This study identified the bay’s changing circulation patterns over recent decades as a crucial study area requiring in-depth research. Understanding the changes in circulation patterns provides valuable insights into the Bay dynamics. It helps identify the potential impacts of climate change, ocean currents, and other factors on the bay’s ecosystem. This study aims to understand the seasonal variability of the Bay of Bengal’s surface circulation features using a high-resolution numerical Coastal and Regional Ocean Community simulations model. METHODS: To conduct the study in the Bay of Bengal, the Coastal and Regional Ocean Community model, a numerical ocean model, was utilized. The high-resolution numerical model for ocean circulation is three-dimensional and uses hydrostatic primitive equations in generalized curvilinear coordinates. Simulations were conducted over 8 years using a grid comprising 256 x 249 horizontal surface points to model a range of ocean-atmospheric parameters. This grid provided an approximate resolution of 10 kilometers.FINDINGS: The findings are based on the model’s enhanced performance compared to previous study results. It was observed that the sea surface temperature remains above 28 degrees Celsius throughout the bay except in winter. During the monsoon season, surface salinity was observed to be reduced in the Bay of Bengal’s northern region and western and eastern boundaries. Surface eddies along the western bay extend to deep waters before the onset of monsoon. The net heat flux in the bay has been determined as positive before monsoon, negative post-monsoon, and mixed during the monsoon season.CONCLUSION: This analysis focuses on the ocean surface layer with more prominent dynamics. Various surface parameters were calculated, and discussions on surface temperature, salinity, D20, D26, and net heat flux across seasons have been presented.

ORIGINAL RESEARCH ARTICLE Environmental Engineering

Microplastic contamination and growth pattern of oyster; Crassostrea gigas in a coastline

L. Kasmini; A.S. Setia Batubara

Volume 9, Issue 4 , October 2023, Pages 753-764

https://doi.org/10.22034/gjesm.2023.04.07

Abstract

BACKGROUND AND OBJECTIVES: Oysters (Crassostrea gigas) are one food source commonly consumed by the community and an important commodity with high economic value. Environmental issues, such as microplastics, have become a worldwide concern for its implications for aquatic organisms, especially oysters. ... Read More BACKGROUND AND OBJECTIVES: Oysters (Crassostrea gigas) are one food source commonly consumed by the community and an important commodity with high economic value. Environmental issues, such as microplastics, have become a worldwide concern for its implications for aquatic organisms, especially oysters. This study aims to identify the microplastics and growth patterns of oysters in Aceh Province, Indonesia's north and east coasts. This study aims to determine which oysters are suitable for consumption and food health based on research locations along the east-north coast of Aceh Province.METHODS: The locations in this study include nine regencies/cities, which are directly facing the Malacca Straits. Microplastic isolation from oysters using 10 percent potassium hydroxide and incubation process were done to dissolve the organic materials. The growth pattern was analyzed to determine the growth rate of oysters at each study location.FINDINGS: The results of this study showed that oysters in all sampling locations were contaminated with microplastics, with a high prevalence of 48 percent found in Langsa, followed by Aceh Timur and Pidie each (40 percent), Banda Aceh (38 percent), Aceh Utara (32 percent), Aceh Besar and Bireun (30 percent), Lhokseumawe (12 percent), and Aceh Tamiang (8 percent). The analysis of the growth patterns revealed that the growth of oysters at each location was not optimal (b <3 or negative allometric).CONCLUSION: In 500 oyster samples collected, 139 were contaminated with microplastics. The most dominant type of microplastic contaminating oysters is fiber up to 170 particles, followed by films 28 particles, and fragments 19 particles. Negative allometric growth pattern might correlate with microplastics that contaminate the waters and enter the oyster's digestive organs. The results of this study reveal that oysters consumed by people have been contaminated with microplastics, so stakeholders must carry out socialization for early prevention to be realized.

ORIGINAL RESEARCH ARTICLE Environmental Management

Mapping and identifying heavy metals in water use as chemicals of potential concerns in upper watershed

N. Fahimah; I.R.S. Salami; K. Oginawati; S.J. Yapfrine; A. Supriatin; Y.N. Thaher

Volume 9, Issue 4 , October 2023, Pages 765-788

https://doi.org/10.22034/gjesm.2023.04.08

Abstract

BACKGROUND AND OBJECTIVES: Excessive presence of heavy metals in water sources can reduce water quality and harm human health. However, research on heavy metals from water sources for sanitation and hygiene purposes and drinking water in the Upper Citarum Watershed remains limited. This study focuses ... Read More BACKGROUND AND OBJECTIVES: Excessive presence of heavy metals in water sources can reduce water quality and harm human health. However, research on heavy metals from water sources for sanitation and hygiene purposes and drinking water in the Upper Citarum Watershed remains limited. This study focuses on the distribution of heavy metals and chemicals that have potential health risks.METHODS: Ten heavy metals, namely, lead, cadmium, chromium, copper, cobalt, iron, mercury, manganese, arsenic, and zinc, were analyzed. Groundwater samples were collected from 160 locations, and drinking water samples (for respondents who do not drink groundwater) were collected from 98 locations. Heavy metal concentrations were detected using inductively coupled plasma optical emission spectrometry.FINDINGS: The levels of arsenic, cadmium, cobalt, iron, mercury, manganese, and lead exceeded the quality standards for drinking water, while those of arsenic and cobalt did not exceed the quality standards for water hygiene and sanitation. Arsenic and cobalt quality standards were more stringent for drinking water compared with those for water hygiene and sanitation. Lead–cadmium and iron–manganese in groundwater showed a positive Spearman correlation (p<0.05) and may originate from the same source. Copper and zinc did not exceed the quality standard in 100% of drinking water samples. Iron and zinc in groundwater differed significantly due to variations in topography and soil type (p<0.05). This study reveals that 6 out of 10 heavy metals are chemicals of potential concern and are sorted based on potential risks to health, that is, arsenic > mercury > lead > cobalt > manganese > cadmium. Ingestion is the main pathway for potential risk, and children are more likely to be at risk than adults.CONCLUSION: Stakeholders and decision makers must immediately implement sustainable actions to protect public health. Evaluation of water sources, technology, maintenance processes, and water quality should be conducted before and after technology use from Refill Drinking Water Depots to ensure that raw and processing water meets the quality standards.

ORIGINAL RESEARCH ARTICLE Environmental Engineering

Bioenergy potential of Chlorella vulgaris under the influence of different light conditions in a bubble column photobioreactor

S. Dhanasekar; R. Sathyanathan

Volume 9, Issue 4 , October 2023, Pages 789-804

https://doi.org/10.22034/gjesm.2023.04.09

Abstract

BACKGROUND AND OBJECTIVES: Recent investigations indicated that continuous use of fertilizers and pesticides in agricultural fields not only deteriorated soil health but also caused a deleterious effect on surface and groundwater bodies. Treating such wastewater using microalgae has shown higher nutrient ... Read More BACKGROUND AND OBJECTIVES: Recent investigations indicated that continuous use of fertilizers and pesticides in agricultural fields not only deteriorated soil health but also caused a deleterious effect on surface and groundwater bodies. Treating such wastewater using microalgae has shown higher nutrient removal and biomass efficiency. Moreover, microalgae are proven to be miniature factories that augment the huge potential of biofuel. The aim of this study is to evaluate the different light intensities required for Chlorella vulgaris algae to remove nutrients from synthetic agricultural wastewater in a fabricated bubble column photobioreactor. Additionally, the research findings focus on assessing the degradation of organic pollutants and biomass generation under different light conditions.METHODS: In this study, synthetic agrochemical wastewater was treated in a bubble column photobioreactor with blue, red, sunlight, and white light conditions. The treatment was conducted in a batch process with a hydraulic retention time of 21 days, using light intensity of 1800–2800 luminescence and a temperature maintained at 25–28° degrees Celsius.FINDINGS: Under different lighting conditions, the blue light condition exhibited a higher biomass concentration of 3.99 gram per liter, with an estimated heat energy value of 1.278 kilojoule per liter. Moreover, in the blue light condition, scanning electron microscopy analysis showed no significant changes in the shape of Chlorella vulgaris and energy-dispersive X-ray analysis elemental composition exhibited the lowest oxygen-to-carbon ratio (1.03). Fourier transform infrared spectroscopy was used to illustrate the functional group of microalgae under different lighting conditions. The lipid, protein, carbohydrate, and amino acid contents were 3329–3332, 2116–2139, 1636–1645, and 545–662 per centimeter, respectively. The higher biomass potential from the wastewater treatment shows significant benefit in terms of feedstock and biofuel production.CONCLUSIONS: The present investigation identified the nutrient reduction and biomass productivity to be more in blue light condition for Chlorella vulgaris algae. The investigation also assessed the potential of lipid, carbohydrate, and protein content in Chlorella vulgaris, which indirectly evaluates the biofuel potential of the species.

ORIGINAL RESEARCH ARTICLE Environmental Management

Healthcare waste characteristics and management in regional hospital and private clinic

S. Ajbar El Gueriri; F. El Mansouri; F. Achemlal; S. Lachaal; J. Brigui; A. Fakih Lanjri

Volume 9, Issue 4 , October 2023, Pages 805-818

https://doi.org/10.22034/gjesm.2023.04.10

Abstract

BACKGROUND AND OBJECTIVES: Good health and a safe environment are essential for sustainable development, including the appropriate management of healthcare wastes. The study intends to assess the generation rate and management methods of healthcare waste in the regional hospital center and a private ... Read More BACKGROUND AND OBJECTIVES: Good health and a safe environment are essential for sustainable development, including the appropriate management of healthcare wastes. The study intends to assess the generation rate and management methods of healthcare waste in the regional hospital center and a private clinic in Tangier, Morocco, with a focus on potential risks to health workers from infectious diseases.METHODS: The study collected data on healthcare waste generation over a period of two months by measuring and analyzing general and hazardous waste using an electronic scale. The data was presented as averages in kilograms per bed per day and as percentages. A questionnaire was provided to 100 healthcare workers. It included questions on their sociodemographic characteristics and their knowledge and attitudes regarding healthcare waste management.FINDINGS: The case study revealed that the healthcare waste production in the two institutions varied, with the private clinic producing 0.76 kilograms per day per bed and the regional hospital center producing 1.84 kilograms per day per bed. The survey also discovered that the hazardous fraction of waste generated in the regional hospital center was 40 percent, which was much higher than the World Health Organization’s estimation. The daily amount of hazardous waste generated increased from 260.49 kilograms to 436.81 kilograms post-COVID-19. The survey found gaps in knowledge, attitudes, and daily challenges in waste management practices among the health workers in both facilities.CONCLUSION: The survey findings suggest that the healthcare waste management methods in Tangier are unsafe and may endanger the health workers and patients. The study found that the lack of monitoring and control contributed significantly to noncompliance with good practices. These findings can be used by the regional divisions of the Ministry of Health to develop specific protocols for managing sanitary emergencies and perform routine observation and training at all levels in the two facilities studied.

CASE STUDY Environmental Science

The antibacterial and antifungal potential of marine natural ingredients from the symbiont bacteria of mangrove

D. Pringgenies; W. Ari Setyati; F. Feliatra; D. Ariyanto

Volume 9, Issue 4 , October 2023, Pages 819-832

https://doi.org/10.22034/gjesm.2023.04.11

Abstract

BACKGROUND AND OBJECTIVES: Mangroves are known to contain tannins, flavonoids, and quinones, which have the potential to be antibacterial, effective even against multidrug-resistant bacteria. Mangroves also have antifungal and antiviral properties. Although, mangroves are known for their use as medicinal ... Read More BACKGROUND AND OBJECTIVES: Mangroves are known to contain tannins, flavonoids, and quinones, which have the potential to be antibacterial, effective even against multidrug-resistant bacteria. Mangroves also have antifungal and antiviral properties. Although, mangroves are known for their use as medicinal ingredients, information regarding symbiont bacteria’s antibacterial and antifungal potential is still scarce. Therefore, this study aimed to examine symbiont bacteria in the fruit and leaves of Xylocarpus granatum as additional raw materials for anti-acne cosmetic creams and moisturisers.METHODS: Symbiont bacteria were isolated using the pour plate method through Zobell 2216E and incubated for 2 x 24 hours at 27.5 Celcius degree. Afterwards, 13 isolates were successfully isolated and characterised based on their morphology. Further, everal tests were conducted, including the antibacterial test, antifungal test, molecular identification, and gas chromatography-mass spectrometry. The pathogenic bacteria used in the antibacterial test were Staphylococcus aureus, Vibrio harveyi, and Vibrio alginolyticusFINDINGS: The antibacterial test results showed that eight isolates were capable of producing an inhibition zone against S. aureus, seven isolates were positive for antibacterial activity against Vibrio harveyi, and 10 isolates were positive for antibacterial activity against Vibrio alginolyticus. The pathogenic fungi used in the antifungal test were Malassezia furfur and Candida albicans. The antifungal test results demonstrated that six isolates could produce inhibition zones against Malassezia furfur and Candida albicans. Furthermore, molecular identification was carried out on six potential isolates based on the antibacterial and antifungal tests, which were X2.52, X1.65, X1.64, X1.53, X1.54, and X1.63. The molecular identification results revealed the occurrence of four species in the Xylocarpus granatum mangroves, namely, Sinomicrobium oceani, Proteus mirabilis, Pseudomonas khazarica, and Alcaligenes aquatilis.CONCLUSION: The study found that the mangrove symbiont bacteria had antibacterial and antifungal potential. The compound with the highest concentration in six isolates was 9-octadecenoic acid, methyl ester. This type of content has antibacterial potential and is also predicted to have antifungal potential.

CASE STUDY Environmental Science

Prediction models of iron level in beef muscle tissue toward ecological well-being

K. Narozhnykh

Volume 9, Issue 4 , October 2023, Pages 833-850

https://doi.org/10.22034/gjesm.2023.04.12

Abstract

BACKGROUND AND OBJECTIVES: Elemental status is associated with the biochemical processes occurring in the body. Beef, consumed worldwide, is an excellent source of iron in terms of quantity and bioavailability, providing up to 18 percent of the daily requirement. The level of iron in muscle tissue affects ... Read More BACKGROUND AND OBJECTIVES: Elemental status is associated with the biochemical processes occurring in the body. Beef, consumed worldwide, is an excellent source of iron in terms of quantity and bioavailability, providing up to 18 percent of the daily requirement. The level of iron in muscle tissue affects beef quality. Current methods used to assess iron content in cattle muscles are laborious and complex. Accordingly, the current study aimed to develop a fast and simple method to assess the elemental status of animals in vivo and in a minimally invasive way based on an effective model for iron-level prediction by using blood-analysis results toward ecological well-being. This method can overcome the shortcomings of currently used approaches.METHODS: Samples of diaphragmatic muscle weighing 100 grams, as well as blood samples, were obtained from Hereford cattle bred under typical conditions of an industrial complex in the south of Western Siberia, Russia. Elemental analysis was performed by atomic absorption method with electrothermal atomization. Regression analysis was conducted to estimate the relationships between iron level in the muscle tissue of Hereford cattle and independent values (blood parameters). An optimum model for predicting the iron level was established. The coefficients of regression models were calculated using the least squares method, and the values of the dependent variable corresponded with the Gaussian ones. A high correlation existed between independent variables.FINDINGS: An optimum model for predicting the iron level in the muscle tissue of Hereford cattle was established. It contained three predictors, namely, number of erythrocytes, color index, and globulin, as a result of selection based on internal and external-quality criteria. The model meets the necessary assumptions: the residuals are normally distributed, no autocorrelations exist, and the observations are influential. Furthermore, no signs of multicollinearity exist between the main effects of the model (variance-inflation factor = 1.2–1.7).CONCLUSION: The model can be used for the intravital analysis of iron level in the muscle tissue of cattle. In contrast to currently used methods, the approach proposed can be used for intravital analysis of the level of iron in muscle tissue, which is the most important advantage of the developed approach. The results can be used in ecology to assess ecological well-being and determine the allowable load of iron in animals. For veterinary medicine, the resulting model enables the evaluation of the iron level in the muscle tissue of Hereford cattle during their lifetime. Studying the effect of different factors on meat quality may allow to decrease or avoid useless measures used in farming, such as the excessive use of feed additives. In turn, these measures can decrease resource exploitation and increase farming productivity. Therefore, the results can guide the further development of sustainable farming.

CASE STUDY Environmental Management

Sustainability index analysis of the black soldier fly (Hermetia illucens) cultivation from food waste substrate

A.D. Santoso; T. Handayani; R.A. Nugroho; A.I. Yanuar; N. Nadirah; E.S. Rohaeni; E. Widjaja; M.A.M. Oktaufik; U. Ayuningtyas; Y.P. Erlambang; R. Herdioso; M.N. Rofiq; R. Hutapea; A.L. Sihombing; B. Rustianto; I.M.A.D Susila; D. Irawan; D. Iskandar; S. Indrijarso; G.D. Widiarta

Volume 9, Issue 4 , October 2023, Pages 851-870

https://doi.org/10.22034/gjesm.2023.04.13

Abstract

BACKGROUND AND OBJECTIVES: Most food waste is dominated by domestic activities consisting of large numbers of organic pollutants, such as nitrogen and phosphate potentially hazardous to the environment. Domestic waste can be used as a feed source in black soldier fly cultivation with utility in pollutant ... Read More BACKGROUND AND OBJECTIVES: Most food waste is dominated by domestic activities consisting of large numbers of organic pollutants, such as nitrogen and phosphate potentially hazardous to the environment. Domestic waste can be used as a feed source in black soldier fly cultivation with utility in pollutant removal, animal feed production, and compost fertilizer. Therefore, this study aimed to determine sustainability of larvae from black soldier fly cultivation by calculating and analyzing index.METHODS: Data collection was conducted using the scientific judgment of experts and business actors in black soldier fly through Focus Group Discussion and the filling out of questionnaires consisting of 31 attributes connected with environment or ecology, economics, social, and technology dimensions. Furthermore, the data were calculated using the multi-dimensional scale approach with rapid appraisal software. Sustainability status and leverage attributes were analyzed by Monte Carlo analysis, and alternating least-squares algorithm.FINDINGS: Sustainability index for larvae of black soldier fly production was 89.69 percent. The result suggested that the technique in several stages of operation including waste collection, cultivation, harvesting, and commercialization contributed to sustainability development when the elements of strength of each dimension are considered. From the analysis of the four dimensions, economic dimension had 100 percent or maximum leverage value. The environmental and social dimensions had the same leverage values of 92.02 percent, while the technological dimension had 74.74 percent. The results indicated that management experiences and techniques, potential for odor generated, family member involvement, productivity level, and managers level, warrant further attention to improve sustainability of black soldier fly production.CONCLUSION: Production, productivity, land conversion, and population were identified as significant or dominating factors impacting the supply framework of black soldier fly production by the intended investigation inside the display ponders. Therefore, study should be encouraged to effectively integrate black soldier fly biomass as a value-added component in an ideal environmental, social, economic, and technical system. The results are significant in providing insights into the possibility of feasible black soldier fly biomass production in Indonesia, which can inform government policies and programs.

CASE STUDY Environmental Management

The impact of fruit and vegetable waste on economic loss estimation

B. Parsafar; M. Ahmadi; Gh.R. Jahed Khaniki; N. Shariatifar; A. Rahimi Foroushani

Volume 9, Issue 4 , October 2023, Pages 871-884

https://doi.org/10.22034/gjesm.2023.04.14

Abstract

BACKGROUND AND OBJECTIVES: Receiving nutrients from fruits and vegetables are essential for public health. However, a large amount of waste is produced during producing, supplying, and consuming these fruits and vegetables. Water, fertilizers and pesticides used for the production of agricultural ... Read More BACKGROUND AND OBJECTIVES: Receiving nutrients from fruits and vegetables are essential for public health. However, a large amount of waste is produced during producing, supplying, and consuming these fruits and vegetables. Water, fertilizers and pesticides used for the production of agricultural products can affect the soil and their cultivation environment and finally lead to environmental pollution. Therefore, this study aimed to investigate the amount of fruit and vegetable waste caused by corruption and evaluate its economic loss and health damage.METHODS: The data were collected using the observation technique aided by observation tools and weighing tests to physically analyze and determine the quantity and quality of waste from Tehran’s fruit and vegetable distribution centers. In each center, the waste obtained from fruits and vegetables was stored in special waste tanks at the end of the day, and the waste was transported to outside the center by special waste disposal vehicles. The economic loss of unusable fruits and vegetables was calculated according to the weight of their waste in the fields of agricultural product supply. The data were analyzed using statistical software SPSS, ANOVA statistical test, and Excel software.FINDINGS: The results revealed that the amounts of fruit and vegetable wastes were 12 percent and 24 percent, respectively, accounting for a total loss of 54,891,539 USD. The highest quantity of fruit waste (15 percent) was observed in summer, and the economic loss due to fruit waste was higher in this season. Also, the amounts of vegetable waste in summer and spring were equal to 28 percent and 24 percent, respectively, indicating the higher economic loss due to vegetable in these seasons.CONCLUSION: The results showed that the economic loss due to vegetable waste was greater than the economic loss due to fruit waste. The amount of vegetable waste was 24 percent, representing a high economic loss. The generation and disposal of these wastes caused a great economic loss and health problems due to their unpleasant odor, release of leachate into the environment, and landfill pollution. Therefore, it was recommended to follow appropriate production principles and supply operations. Moreover, a comprehensive waste disposal management, as a practical measure, should be used to prevent and control these problems. The use of modern technology in harvesting, transporting and supplying fruits and vegetables could reduce their lesion, and subsequently reduce the economic loss.

CASE STUDY Environmental Engineering

Harbor water pollution by heavy metal concentrations in sediments

L. Sulistyowati; Y. Yolanda; N. Andareswari

Volume 9, Issue 4 , October 2023, Pages 885-898

https://doi.org/10.22034/gjesm.2023.04.15

Abstract

BACKGROUND AND OBJECTIVES: The Belawan Harbor is the third largest port, which is located in an estuary, causing the port water area to be vulnerable to pollution, especially heavy metals. Conflicts between the community and the port authorities often occur due to pollution. Heavy metals are dangerous ... Read More BACKGROUND AND OBJECTIVES: The Belawan Harbor is the third largest port, which is located in an estuary, causing the port water area to be vulnerable to pollution, especially heavy metals. Conflicts between the community and the port authorities often occur due to pollution. Heavy metals are dangerous contaminants for waters, and total organic carbon in waters is needed but will cause eutrophication if the concentration is excessive in the environment. The level of heavy metal pollution in the waters of the Belawan Harbor and the factors that cause the pollution should be analyzed, because the level of heavy metal pollution has not been measured in the sediments of harbor waters. This study can be used as a reference for the actions of related agencies in dealing with heavy metal pollution in waters.METHODS: Sampling of sediments was performed at 10 locations, starting before the harbor activity began and moving toward the open sea. Sampling was conducted using Van Veen grab. Heavy metal concentrations were analyzed in the laboratory using the atomic absorption spectrometer method to assess the essential heavy metal copper and non-essential heavy metal lead, cadmium, and mercury. Heavy metal pollution in sediments was assessed by analyzing sediment pollution index. The multivariate statistical analysis on the relationship among factors was conducted using Pearson correlation matrix method, principal component analysis, and cluster analysis.FINDINGS: The environmental quality standards used indicate average concentration of heavy metals; lead (28,869 milligram per kilogram) and copper (8,003 milligram per kilogram) are below the quality standard. The mercury concentrations are undetectable (<0.00011 milligram per kilogram) at each station. By comparison, the concentration of cadmium (1,455 milligram per kilogram) exceeded the Interim Sediment Quality Guidelines from the Canadian Council of Ministers of the Environment. Results of the index analysis show that the average value of the pollution factor of copper is −0.177 (low contamination), that of lead is −1.433 (moderate contamination), and that of cadmium is −4.850 (high contamination); the geoaccumulation index value of copper is −5.328. (not polluted), that of lead is −0.190 (unpolluted), and that of cadmium −1.657 (moderately polluted). As mercury concentration in sediments is relatively low, it is not considered when calculating pollution levels. Overall, on the basis of a pollution index of 1.033 (1 < pollution load index ≤ 2), this condition indicates that the waters of the Belawan Harbor are categorized as not polluted to lightly polluted. The highest total organic carbon is at the estuaries of the Belawan and Deli Rivers. The sediment fraction is 72.2 percent sandy, 16.4 percent sludge, and 11.4 percent clay substrate.CONCLUSION: Pollution in the waters of the Belawan Harbor is in the category of not polluted to slightly polluted. Although the pollution is still in the light category, this must be of particular concern to the relevant agencies, especially the local government, to make the right policies to overcome this pollution immediately. Pollution problems increase with the anthropogenic activities around coastal areas, as well as activities in the Belawan and Deli River watersheds, because the pollutant will flow from the upstream to the estuary area.

CASE STUDY Environmental Management

The influences of environmental awareness on green performance

M.H. Mansour

Volume 9, Issue 4 , October 2023, Pages 899-914

https://doi.org/10.22034/gjesm.2023.04.16

Abstract

BACKGROUND AND OBJECTIVES: Despite the various environmental challenges the hotel sector faces, there is a significant need to resolve them by applying sustainable techniques like green human resource management. As a result, there is a pressing need to investigate how green human resource management ... Read More BACKGROUND AND OBJECTIVES: Despite the various environmental challenges the hotel sector faces, there is a significant need to resolve them by applying sustainable techniques like green human resource management. As a result, there is a pressing need to investigate how green human resource management may improve environmental performance. This study investigates the causal linkage among environmental awareness, green human resource management, green behaviours, green performance, and servant leadership.METHODS: The data were collected via Questionnaires obtained from employees working in hotels in Amman, Jordan (52.5 per cent response rate). To evaluate the model, Smart Partial Least Square was employed to conduct validity and reliability testing and develop structural equation modeling.FINDINGS: According to the results, Environmental awareness mediated the effects of green human resource management and green behaviours on green performance. Green HRM was found to have a direct and substantial impact on Green Performance (β = 0.109, p < 0.005). A positive and statistically significant relationship between Green Behaviors and Green Performance was also found (β = 0.338, p < 0.000). Additionally, Green HRM has a favorable and significant effect on Environmental Awareness (β = 0.176, p < 0.0001). Furthermore, Environmental Awareness is positively and significantly influenced by Green Behaviors (β = 0.743, p < 0.000). Green performance positively relates to environmental consciousness (β = 0.186, p < 0.000).CONCLUSION: Based on social cognition, social exchange, and social learning theory, this study contains theoretical insights, practical implications, and positive recommendations for hospitality managers and scholars. Current research is critical because it emphasizes environmental stewardship in industries that directly connect to and influence the environment, such as tourism and hospitality. The study does not examine environmental performance and behavior in general but instead evaluates pro-environmental behaviors in depth by considering green behaviour.

CASE STUDY Environmental Management

Effects of citizen participation on urban water management based on socioeconomic factors

F. Mardianti; D.E. Purba

Volume 9, Issue 4 , October 2023, Pages 915-932

https://doi.org/10.22034/gjesm.2023.04.17

Abstract

BACKGROUND AND OBJECTIVES: In this era of globalization, clean water management is considered a complex problem requiring the strategic management of various aspects. Citizen participation in managing polluted waters is a critical, determining factor in preventing water crises. This study predicts the ... Read More BACKGROUND AND OBJECTIVES: In this era of globalization, clean water management is considered a complex problem requiring the strategic management of various aspects. Citizen participation in managing polluted waters is a critical, determining factor in preventing water crises. This study predicts the socioeconomic factors influencing citizens’ behaviors in polluted water management.METHOD: A survey on Jakarta’s clean water was conducted with 503 respondents in 2022. Three interest variables were studied: first action taken during contamination, water nuisance level, and willingness to pay for clean water. Control variables were also explored, including daily income, education level, age, marital status, and gender. Data were analyzed using logistic regression.FINDINGS: In general, socioeconomic factors influence citizens’ behaviors in dealing with polluted water. The specific findings regarding the probabilities for the first action on the basis of asking for immediate action from local authorities, namely, by asking other citizens, waiting for information from other citizens, and looking for sources of water pollution were –2.21, –3.50, and 0.61, respectively. The results also revealed the probabilities of nuisance level (0.07), willingness to pay for clean water (0.0495), daily income (–0.02), educational level (–0.429), and age (0.01). The probabilities for married citizens (–2.845) and men (–0.268) were lower than those for unmarried citizens and women, respectively.CONCLUSION: The findings of this study can be used to predict the management of water pollution among Jakarta citizens, as well as serve as a reference for related stakeholders. Socioeconomic factors can affect citizens in various aspects of life, including participation in water management. However, not all socioeconomic factors are directly proportional to citizen participation. In fact, other socioeconomic indicators are inversely proportional to what are expected based on theoretical assumption. Finally, educational level and income do not always translate to behavioral changes linked to water pollution management.

CASE STUDY Environmental Management

Health risk assessment through probabilistic sensitivity analysis of carbon monoxide and fine particulate transportation exposure

E. Ernyasih; A. Mallongi; A. Daud; S. Palutturi; S. Stang; R. Thaha; E. Ibrahim; W. Al Madhoun

Volume 9, Issue 4 , October 2023, Pages 933-950

https://doi.org/10.22034/gjesm.2023.04.18

Abstract

BACKGROUND AND OBJECTIVES: The rising number of vehicles used for transportation, which is attributed to the steady increase in population, is known to be a major contributor of air pollution, which, in turn, can have adverse effects on the environment and human health. Therefore, in this study, we aimed ... Read More BACKGROUND AND OBJECTIVES: The rising number of vehicles used for transportation, which is attributed to the steady increase in population, is known to be a major contributor of air pollution, which, in turn, can have adverse effects on the environment and human health. Therefore, in this study, we aimed to evaluate the concentration of carbon monoxide and fine particulate matter in the air and their potential health risks and further examine the use of probabilistic methods to simulate the sensitivity of people living in communities and school children to these pollutants.METHODS: This study collected carbon monoxide and fine particulate matter samples from 32 stations near community houses and 14 sites near schools located along roads. Hazard quotient and target hazard quotient calculations were used to estimate the non-carcinogenic health risks associated with exposure to these substances for both community adults and school children. Finally, Monte Carlo simulations were applied to analyze the sensitivity and uncertainty risks. FINDINGS: As per the results, the highest level of carbon monoxide was recorded in station 22, with 6729 microgram per cubic meter, while the lowest was in station 24, with 1037 microgram per cubic meter. Station 10 had the highest concentration of fine particulate matter at 116 microgram per cubic meter, as opposed to station 2 with the lowest level at 10 microgram per cubic meter. In children, the hazard quotient value for carbon monoxide was found to be highest at 3.013, with the lowest at 0.614. Similarly, the highest level of target hazard quotient for carbon monoxide in children was 7.370, whereas the lowest was 1.522. For fine particulate matter, the highest risk level was 0.180. Additionally, the highest, and lowest levels of target hazard quotient for fine particulate matter were 0.311 and 0.037, respectively. Deterministic and probabilistic approaches were used to assess the risks these pollutants impose on adults and school children based on their daily inhalation rate. The results revealed that the 5th and 95th percentiles of cancer risk for carbon monoxide in adults were 2.85 and 6.11, respectively, indicating medium risks. However, for fine particulate matter, the 5th, and 95th percentiles were 0.09 and 0.19, respectively, signifying lower risks. For school children, the percentiles for carbon monoxide and fine particulate matter were 1.20 and 2.50, respectively, demonstrating higher risks.CONCLUSION: As per the results, it was determined that the hazard quotient risk for carbon monoxide in adults exceeded the standard, >1, thus posing a risk. Only three stations had hazard quotient values lower than 1, which is deemed of safe level. Most of the fine particulate matter risk assessment results had hazard quotient values lower than 1, indicating a safe level. However, all other 30 stations had exceeded the World Health Organization standard (>1), thus demonstrating risks. The likelihood of the inhabitants being at risk increased as the frequency of discrete exposure occurrences increased; this is evidenced by target hazard quotient calculation results for both carbon monoxide and fine particulate matter at the 32 monitored station areas. These results warrant that future research should focus on reducing carbon monoxide and fine particulate matter in the environment by fostering awareness among local and national stakeholders as well as the academe; this may allow South Tangerang to become a center of excellence for green schools in the area.

CASE STUDY Environmental Management

Consequences of changing regional integration on environmental development, agricultural markets, and food security

L.A. Omarbakiyev; S.M. Kantarbayeva; A.K. Nizamdinova; S.T. Zhumasheva; G.Zh. Seitkhamzina; A. Saulembekova

Volume 9, Issue 4 , October 2023, Pages 951-966

https://doi.org/10.22034/gjesm.2023.04.19

Abstract

BACKGROUND AND OBJECTIVES: Geopolitical risks have made significant changes in the integration ties between the countries of Central Asia, which has affected the sustainable development of the agro-industrial complex and food security. The adoption of urgent measures to improve food security, on the ... Read More BACKGROUND AND OBJECTIVES: Geopolitical risks have made significant changes in the integration ties between the countries of Central Asia, which has affected the sustainable development of the agro-industrial complex and food security. The adoption of urgent measures to improve food security, on the one hand, is a necessary condition for the development of the Republic of Kazakhstan, but on the other hand, it can lead to a decrease in the level of environmental security in the country if the possible consequences in the reintegration process are not considered. Therefore, this article aimed to examine the sustainable agriculture practices implemented in Kazakhstan’s agro-industrial complex to improve food security and reduce the environmental impact of agriculture.METHODS: To collect information, a mixed research strategy combining qualitative and quantitative methods was used. The collection of information was carried out in the summer of 2022 and consisted of three stages. In the first stage, statistical information was collected; in the second stage, a correlation analysis was carried out; and in the third stage, a survey of 40 experts was conducted.FINDING: The data obtained indicate that the efficiency of Kazakhstan’s agricultural production strongly and directly depends on the level of the country’s integration into the united Eurasian Economic Union market. Due to the geographical features of Kazakhstan’s location, it is necessary to develop areas that are primarily focused on the internal capabilities of the country. Internal changes will help the industry increase international competitiveness and efficiency while promoting sustainable development and ensuring food security and environmental safety.CONCLUSION: The article determined that it is necessary to prioritize developing multilateral partnerships to address transportation and logistics challenges in the export and import of agricultural products, and reduce dependence on the import of seeds, breeding products, fodder, and agricultural machinery. However, to effectively promote these areas, it is necessary to improve food security through the introduction of sustainable agriculture practices, such as crop diversification, conservation agriculture, integrated pest management, and drip irrigation.

ORIGINAL RESEARCH ARTICLE Environmental Management

Farmers' motivation and obstacles in the smallest available agricultural region

D.P. Darmawan; G.M.K. Arisena; A.A.A.W.S. Djelantik; A.A.K. Krisnandika; N.L.M.I.M. Dewi; N.T. Lukpitasari Korri; N.M.C. Sukendar

Volume 9, Issue 4 , October 2023, Pages 967-982

https://doi.org/10.22034/gjesm.2023.04.20

Abstract

BACKGROUND AND OBJECTIVES: The high need for tourism-supporting infrastructure has impacted the increasing conversion of land functions in Denpasar City, Indonesia. The lack of agricultural areas in Denpasar City has motivated farmers to continue farming. Farmer motivation to do farming will collide ... Read More BACKGROUND AND OBJECTIVES: The high need for tourism-supporting infrastructure has impacted the increasing conversion of land functions in Denpasar City, Indonesia. The lack of agricultural areas in Denpasar City has motivated farmers to continue farming. Farmer motivation to do farming will collide with obstacles in carrying out agricultural activities in Denpasar City. The purpose of this study was to examine the motivations and obstacles faced by farmers in carrying out agricultural activities. This research is relevant to the journal scope of Sustainable Agriculture Management, Urban, and Built Environmental Management.METHODS: This study was carried out in Denpasar City in Indonesia, where each sub-district in Denpasar City will be selected by one Subak. The selection of Subak was based on the Subak with the most farmers in each sub-district in Denpasar City. The selected subak were Pakel 1 Subak, Kerdung Subak, Temaga Subak, and Margaya Subak. The population in this study was 672 people. The respondents in this study were 87 people. The data collection method was carried out using structured and in-depth interviews using questions and points while face-to-face between the interviewer and the respondent, via a prepared questionnaire. This study uses two variables with 41 indicators. The analytical methods used to point to objectives one, two, and three are descriptive quantitative and descriptive qualitative methods. Goal four is “Build a model for dealing with obstacles to farming in urban areas.” The fourth objective was analyzed descriptive qualitative based on the results of the analysis of objectives one, two, and three.FINDINGS: The study results show that the motivation to continue farming is caused by demands to work, not having another job to get help from other parties, a healthy work environment, the ability to take lessons from previous farming experience affect product quality, and work in nature. The obstacles for farmers to continue farming are the bargaining position of farmers in selling products, market information obtained by farmers is still minimal, and market absorption of the products produced is not maximized.CONCLUSION: Based on the results of the research, several things deserve to be concluded. The number of dependents of a farming family is more than six because there are still children of farmers already working but still being supported by their parents for their primary needs, and most of the farmers do farming in an area of 0.21 – 0.60 hectares. The motivation to keep farming is caused by the demands to work, not having another job to get help from other parties, a healthy work environment, and the ability to take lessons from the previous farming experience affecting product quality and work in nature. The obstacles for farmers to continue farming are the bargaining position of farmers in selling products, market information obtained by farmers is still minimal, and market absorption of the products produced is not maximized.

CASE STUDY Environmental Management

The effect of income and smallholder characteristics on cultivation, harvesting, and post-harvest management of natural rubber

. Nurliza

Volume 9, Issue 4 , October 2023, Pages 983-994

https://doi.org/10.22034/gjesm.2023.04.21

Abstract

BACKGROUND AND OBJECTIVES: Indonesia is the second largest natural rubber producer, which it gets primarily from smallholders. However, smallholders are less and less competitive because of unsustainable agricultural practices, while there is huge potential for sustainable natural rubber. This study ... Read More

CASE STUDY Environmental Management

Heavy metals contamination in geothermal medicinal plant extract; Chromolaena odorata Linn

A. Abubakar; H. Yusuf; M. Syukri; R. Nasution; M. Yusuf; R. Idroes

Volume 9, Issue 4 , October 2023, Pages 995-1004

https://doi.org/10.22034/gjesm.2023.04.22

Abstract

BACKGROUND AND OBJECTIVES: Medicinal plants growing in geothermal areas have been reported to possess relatively high concentrations of bioactive secondary metabolites, which have been attributed to the adaptive heat stress response. Nonetheless, the exploitation of their medicinal benefits is limited ... Read More BACKGROUND AND OBJECTIVES: Medicinal plants growing in geothermal areas have been reported to possess relatively high concentrations of bioactive secondary metabolites, which have been attributed to the adaptive heat stress response. Nonetheless, the exploitation of their medicinal benefits is limited by potentially life-threatening concentrations of heavy metals. Chromolaena odorata Linn, also called seurapoh, is a well-known medicinal plant that can absorb and accumulate heavy metals from the soil. This present study aimed to investigate the contents of mercury, lead, cadmium, and arsenic in the ethanolic extract of Chromolaena odorata Linn leaves collected from a geothermal area in Aceh Province, Indonesia.METHODS: Three hot springs, namely Ie-Suum, Ie-Jue, and Ie-Brouk, located in the same geothermal area, Seulawah Agam, were selected as the sampling points, and three samples of Chromolaena odorata were collected at each point. Extraction was carried out by means of maceration employing ethanol solvent. The heavy metal contents of each extract were determined using priorly validated atomic absorption spectrometry and graphite furnace atomic absorption spectrometry. The maximum thresholds of each heavy metal from the Indonesian Agency for Drug and Food Control were adopted during data interpretation.FINDINGS: The results revealed the presence of trace levels of arsenic (0.0482 ± 0.004 – 0.0639 ± 0.007 milligram per kilogram) and lead (0.0219 ± 0.004 – 0.0672 ± 0.006 milligram per kilogram), which did not exceed Indonesian maximum safety thresholds (≤5 and ≤10 milligram per kilogram, respectively). Mercury in all samples was not observable (limit of detection = 0.018 milligram per liter). Cadmium was observed in almost all samples with a concentration range of 0.0219 ± 0.005–1.1472 ± 0.006 milligram per kilogram, which exceeded the maximum threshold (0.3 milligram per liter).CONCLUSION: Heavy metal contamination in the ethanolic extract of geothermal Chromolaena odorata leaves has been attributed to volcanic activities. Among the heavy metals of concern, cadmium was the only one with a concentration exceeding the safety limit. The presence of cadmium in the extract at a high concentration could cause its translocation to the human body, eventually leading to multiple organ damage. Therefore, the extract of Chromolaena odorata leaves collected from a geothermal area should be consumed with caution for possible cadmium intoxication.

CASE STUDY Environmental Engineering

Dechlorination of selected polychlorinated biphenyl congeners using metal-impregnated pulverized shrimp shell catalyst from waste

D.B. Aviantara; F. Suciati; G. Hadiko; N.S. Indrasti; M. Yani

Volume 9, Issue 4 , October 2023, Pages 1005-1018

https://doi.org/10.22034/gjesm.2023.04.23

Abstract

BACKGROUND AND OBJECTIVES: Polychlorinated biphenyls are pervasive contaminants that are receiving attention worldwide. Due to their well-known propensity to have harmful impacts on both humans and the environment, polychlorinated biphenyls have been internationally banned for use. In this study, dechlorination ... Read More BACKGROUND AND OBJECTIVES: Polychlorinated biphenyls are pervasive contaminants that are receiving attention worldwide. Due to their well-known propensity to have harmful impacts on both humans and the environment, polychlorinated biphenyls have been internationally banned for use. In this study, dechlorination of five polychlorinated biphenyl congeners, 2,2′,5,5′-tetrachlorobiphenyl, 2,2′,4,5,5′-pentachlorobiphenyl, 2,2′,3,4,4′,5′-hexachlorobiphenyl, 2,2′,3,4,4′,5′-hexachlorobiphenyl, 2,2′,4,4′,5,5′-hexachlorobiphenyl, and 2,2′,3,4,4′,5,5′-heptachlorobiphenyl, are evaluated. The chlorines from polychlorinated biphenyl congeners were removed using a heterogeneous catalyst synthesized via microwave-assisted impregnation of zinc metal onto pulverized shrimp shell waste.METHODS: The five polychlorinated biphenyl congeners were dechlorinated through treatments combination of time (1–4 hours), heat (150–250 degree celsius), and catalyst proportion (1–5 percent weight/weight basis). The dechlorination trials followed the Box–Behnken experimental design and then analyzed using response surface methodology. Levels of the remaining polychlorinated biphenyl congeners were monitored by using a gas chromatograph equipped with an electron capture detector.FINDINGS: The results of the trials demonstrated that among the five polychlorinated biphenyl congeners, only 2,2′,3,4,4′,5,5′-heptachlorobiphenyl did not respond to the provided treatments. Three congeners, namely, 2,2′,5,5′-tetrachlorobiphenyl, 2,2′,4,5,5′-pentachlorobiphenyl, and 2,2′,4,4′,5,5′-hexachlorobiphenyl, showed positive response, and one congener 2,2′,3,4,4′,5′-hexachlorobiphenyl showed negative response to the provided treatments. These findings suggested that chlorine attached to the para position of the biphenyls ring was easier to remove. The efficiency calculation of total polychlorinated biphenyl concentrations after treatments was approximately 25 percent. Such a low degree of effectiveness may be caused by the catalyst becoming inactive, either chemically through the deposition of chlorines that have been removed from the biphenyl ring or mechanically by the leaching of zinc from the surface of the pulverized shrimp shell due to insufficient mechanical strength. Optimization via response surface methodology produced optimal results for dechlorination at 150 degree celcius for 2.4 hours with 5 percent additional catalyst.CONCLUSION: The total amount of polychlorinated biphenyls that remained after dechlorination was not significantly impacted by the treatment combination of temperature, duration, and weight of the catalyst. However, the treatments had significant effects on the chlorine removal at the para positions of the biphenyl ring. In this case 2,2′,5,5′-tetrachlorobiphenyl, 2,2′,4,5,5′-pentachlorobiphenyl, and 2,2′,4,4′,5,5′-hexachlorobiphenyl congeners have positive responses and 2,2′,3,4,4′,5′-hexachlorobiphenyl congener has a negative response. For polychlorinated biphenyl congeners having more than six chlorines, no chlorine removal was observed.

CASE STUDY Environmental Engineering

Preventing water pollution using importance-performance analysis and terrain analysis

L. Sulistyowati; N. Andareswari; F. Afrianto; A. Rais; M.F. Hafa; D. Darwiyati; A.L. Ginting

Volume 9, Issue 4 , October 2023, Pages 1019-1032

https://doi.org/10.22034/gjesm.2023.04.24

Abstract

BACKGROUND AND OBJECTIVES: The monitoring of the Brantas watershed showed a light-polluted status. This study began by identifying the priority of regional problems using importance-performance analysis. Furthermore, a hydrological analysis was conducted to determine the pollutant area of the Brantas ... Read More BACKGROUND AND OBJECTIVES: The monitoring of the Brantas watershed showed a light-polluted status. This study began by identifying the priority of regional problems using importance-performance analysis. Furthermore, a hydrological analysis was conducted to determine the pollutant area of the Brantas watershed by applying terrain analysis. When terrain analysis in hydrology is combined with participatory community information, it can provide valuable insights into water pollution and help prioritize remediation efforts. Integrating local knowledge with scientific data can improve decision-making and increase the effectiveness of water management strategies.METHODS: The methodological approach employed in this study included importance-performance analysis to determine priority problems in Batu City and terrain analysis as a hydrological analysis to determine the pollutant area in the Brantas watershed. The importance-performance analysis assessment data were obtained from 197 respondents representing the occupations of the people of Batu City. The terrain analysis data were derived from the surface elevation data in the form of a digital elevation model.FINDINGS: According to the importance-performance analysis community assessment, urban trash management was one of the crucial yet low-rated features. The terrain analysis results demonstrated that business and industrial activities were distributed in locations with high flow accumulation values, indicating that the water pollution in Batu City was triggered by the presence of business and industrial activities in the watershed accumulation areas. Along the upstream Brantas watershed, 460 business and industrial activities were discovered. Therefore, the results of importance-performance analysis and terrain analysis had a correlation. They were also closely related to the assessment results of the contaminated Brantas watershed.CONCLUSION: The following are some recommendations for the watershed's quality improvement: 1) cooperation among the Government, communities, and the private sector for addressing water pollution issues; 2) the development of environmentally friendly technologies in water treatment; and 3) education and outreach to communities about the importance of preserving water resources. As a city experiencing rapid urban development, environmental degradation constitutes a risk to be borne. Accordingly, Batu City must continue to develop good environmental management for the sake of nature conservation because the urban system is a unit formed by the social economy and ecological environment subsystem.

REVIEW PAPER Environmental Management

Effectiveness of the voluntary disclosure of corporate information and its commitment to climate change

F.G. Arredondo Trapero; E.M. Guerra Leal; J. Kim

Volume 9, Issue 4 , October 2023, Pages 1033-1048

https://doi.org/10.22034/gjesm.2023.04.25

Abstract

BACKGROUND AND OBJECTIVES: Although governments and companies have been implementing various measures, such as technological innovation, new emissions regulations, and policies to reduce greenhouse gas emissions, it seems that global warming is not decreasing. In order to reduce greenhouse gas emissions, ... Read More BACKGROUND AND OBJECTIVES: Although governments and companies have been implementing various measures, such as technological innovation, new emissions regulations, and policies to reduce greenhouse gas emissions, it seems that global warming is not decreasing. In order to reduce greenhouse gas emissions, the commitments of companies were considered to be the key for climate change. However, since the Paris Climate Agreement, there has not been an accurate evaluation of the efforts and contributions of companies toward emission reductions. This study investigated the effectiveness of companies in Climate Action and tested its impact on greenhouse gas emissions at the country and per capita levels.METHODS: This study focuses on companies of the countries from the main Latin American economies (Mexico, Chile, Brazil, Colombia, and Argentina) and their major trading partners (the United States of America, Canada, China, Korea, Germany, and Japan). There are 894 companies from Latin America and 3680 companies that represent their trading partners of referred countries in Climate Action. This study used two data sources, the commitment of companies from Global Climate Action and the annual greenhouse gas emissions levels of each country from an open-access data platform called Our World in Data.FINDING: The findings demonstrate a significant and positive relationship between changes in greenhouse gas emissions from 2021 and 2020 and the number of companies participating in Global Climate Action (Pearson = .718*, significance = .013) and per capita (Pearson = 0.827** significance = 0.002). Correlations indicate there is a higher level of commitment to climate action but with marginal contributions to greenhouse gas emissions reduction. Previous expectations were that greater corporate involvement in climate action would reflect a link to greenhouse gas reductions, but this was not the case. Additionally, the reduction in greenhouse gas emissions during the pandemic was due to the economic slowdown and was not necessarily because of the climate action efforts of companies and governments to reduce emissions. The findings demonstrated a negative and significant correlation at the country level during the pandemic (Pearson = −0.629 significance = .038). The lack of effective results for reducing (from 2020 and 2021) greenhouse gas emissions justifies the relevance of increasing transparency and accountability for both companies and countries. The acceleration of the production system reflected in an increase in greenhouse gas emissions is not keeping pace with the commitments and the reported achievements on Global Climate Action.CONCLUSION: This study contributed to justifying efforts for a better way to follow up international efforts to reduce greenhouse gas emissions. Transparency and accountability are key to effectively achieving greenhouse gas reductions and curbing the impending climate crisis.

Environmental Management

Impact of COVID-19 large scale restriction on environment and economy in Indonesia

R.E. Caraka; Y. Lee; R. Kurniawan; R. Herliansyah; P.A. Kaban; B.I. Nasution; P.U. Gio; R.C. Chen; T. Toharudin; B. Pardamean

Volume 6, Special Issue (Covid-19) , 2020, , Pages 65-84

https://doi.org/10.22034/GJESM.2019.06.SI.07

Abstract

COVID-19 has a severe and widespread impact, especially in Indonesia. COVID-19 was first reported in Indonesia on March 03, 2020 then rapidly spread to all 34 provinces by April 09, 2020. Since then, COVID-19 is declared a state of national disaster and health emergency. This research analyzes ... Read More

Environmental Science

Using multivariate generalized linear latent variable models to measure the difference in event count for stranded marine animals

R.E. Caraka; R.C. Chen; Y. Lee; T. Toharudin; C. Rahmadi; M. Tahmid; A.S. Achmadi

Volume 7, Issue 1 , January 2021, , Pages 117-130

https://doi.org/10.22034/gjesm.2021.01.09

Abstract

BACKGROUND AND OBJECTIVES: The classification of marine animals as protected species makes data and information on them to be very important. Therefore, this led to the need to retrieve and understand the data on the event counts for stranded marine animals based on location emergence, number of individuals, ... Read More

Decolorization of mixture of dyes: A critical review

V.K. Gupta; S. Khamparia; I. Tyagi; D. Jaspal; A. Malviya

Volume 1, Issue 1 , 2015, , Pages 71-94

https://doi.org/10.7508/gjesm.2015.01.007

Abstract

Water plays a vital and essential role in our ecosystem. This natural resource is becoming scarce, making its availability a major social and economic concern. Use of a large variety of synthetic dyes in textile industries has raised an hazardous environmental alert. About 17 - 20% of freshwater pollution ... Read More

Environmental Management

The dramatic impact of the Coronavirus outbreak on air quality: Has it saved as much as it has killed so far?

R.J. Isaifan

Volume 6, Issue 3 , July 2020, , Pages 275-288

https://doi.org/10.22034/gjesm.2020.03.01

Abstract

The outbreak of coronavirus disease (COVID-19) was first reported from Wuhan, China, on December 31st, 2019. As the number of coronavirus infections has exceeded 100,000 with toll deaths of about 5000 worldwide as of early March, 2020, scientists and researchers are racing to investigate the nature of ... Read More The outbreak of coronavirus disease (COVID-19) was first reported from Wuhan, China, on December 31st, 2019. As the number of coronavirus infections has exceeded 100,000 with toll deaths of about 5000 worldwide as of early March, 2020, scientists and researchers are racing to investigate the nature of this virus and evaluate the short and long term effects of this disease. Despite its negative impacts that obliged the World Health Organization to declare COVID-19 epidemic as a Public Health Emergency of International Concern, the rate of mortality of this infection has not exceeded 3.4% globally. On the other hand, the mortality rate caused by ambient air pollution has contributed to 7.6% of all deaths in 2016 worldwide. The outbreak of COVID-19 has forced China to lockdown its industrial activities and hence dropped its NO2 and carbon emissions by 30 and 25%, respectively. This work reports on the first case study that compares the air quality status before and after the crisis. It sheds light on the facts related to the demographics of deaths by gender, age and health status before infection. The historical data on air quality, estimates of annual deaths and its economic burden have been presented and analyzed. The actual daily deaths due to COVID-19 have been obtained from the official records of the daily Situation Reports published by World Health Organization as of March 11th. The rate of mortality due to COVID-19 was impacted by two factors: age and health status. Results show that 75% of deaths were related to cases that had underlying present diseases with the majority aged of 80+ years. The reported figures were compared with the average daily mortality due to poor air quality which reached up to 3287 deaths due to high levels of NO2, O3 and PM. The air quality status before the crisis was compared with the current situation showing that COVID-19 forced-industrial and anthropogenic activities lockdown may have saved more lives by preventing ambient air pollution than by preventing infection.

Removal of ammonium ions from wastewater: A short review in development of efficient methods

V.K. Gupta; H. Sadegh; M. Yari; R. Shahryari Ghoshekandi; B. Maazinejad; M. Chahardori

Volume 1, Issue 2 , 2015, , Pages 149-158

https://doi.org/10.7508/gjesm.2015.02.007

Abstract

Ammonium ions wastewater pollution has become one of the most serious environmental problems today. The treatment of ammonium ions is a special concern due to their recalcitrance and persistence in the environment. In recent years, various methods for ammonium ion removal from wastewater have been extensively ... Read More

SPECIAL ISSUE Environmental Science

Environmental microbial communications in gram-positive and gram-negative bacteria

P. Srikanth; D. Sivakumar; J. Nouri

Articles in Press, Accepted Manuscript, Available Online from 19 August 2023

https://doi.org/10.22034/GJESM.2023.09.SI.01

Abstract

Microorganisms are present in nature and shape an enormous a half of our micro- and macro-environment. Quorum sensing is the process of intercellular conversation that enables microbes to perceive their surroundings and change their behaviour, allowing them to remain like cellular organisms. Both Gram-positive ... Read More Microorganisms are present in nature and shape an enormous a half of our micro- and macro-environment. Quorum sensing is the process of intercellular conversation that enables microbes to perceive their surroundings and change their behaviour, allowing them to remain like cellular organisms. Both Gram-positive and Gram-negative microorganisms use quorum sensing frame work for communicating with every other, though there may be distinct quorum sensing pathways available in Gram-positive and Gram-negative microorganisms. The scope of quorum sensing extends to inter-nation communication, mediate through numerous newly diagnosed extra-cell signal molecules known as autoinducers. The concentration of these signalling substances rises above a critical level when the population density does, causing particular gene expression patterns in the microorganisms. This may result in coordinated behaviours, including the development of biofilms, the generation of virulence factors, or other group activities. Without the ability to detect and react to the presence of their neighbours, microbial communities would not be able to adjust to changing environmental conditions or carry out collective actions that are essential for survival. Among those autoinducers, five major principal signal molecules are perturbed about side the classical quorum sensing system. The larger part of quorum sensing recognizing inhibitor takes bacterial quorum sensing share identifying as the even-handed and simply blocks the larger part recognizing plan of pathogenic organisms, which can demolish the pathogenicity of microorganisms without applying explicit squeezing factor, and doesn't execute the regular organisms or then again intrude with their standard physiological activities. To talk with each other, bacteria mix, release, and total minimal diffusible signal molecules, known as pheromones or autoinducers a pheromone (recognizing) depends upon its edge centre. Specific receptors found on the surface of the bacterial cell are required for the identification of pheromones or autoinducers. The proteins that can bind to diffusible signalling molecules often make up these receptors. These receptors bind to signalling molecules when their concentration rises over a predetermined threshold, setting off a signalling cascade that causes the bacteria to respond in concert. The prevailing article will speak about checking out basic variations between numerous quorum sensing systems in gram passitive and gram negative bacteria, and it is important to understand the communications of microorganisms in nature better. QS sensing will help as a regular language for signal communication of various microorganisms, yet the path where all proteins get the signals and turn on downstream sign transduction has changed phenomenally.

SPECIAL ISSUE Environmental Engineering

Adaptation variation of easiness on environmental, social, and governance components in the selected sustainability developments

F.R. Sutikno; N.A. Sasongko; I.N. Djarot; H.S. Dillon

Articles in Press, Accepted Manuscript, Available Online from 13 June 2023

https://doi.org/10.22034/GJESM.2023.09.SI.02

Abstract

BACKGROUND AND OBJECTIVES: Environmental, Social, and Governance reporting is universally recognized as a pivotal component embraced by the industry to address climate change and serve as a safeguard to the physical and social environments of society. In the absence of global standards, organizations ... Read More BACKGROUND AND OBJECTIVES: Environmental, Social, and Governance reporting is universally recognized as a pivotal component embraced by the industry to address climate change and serve as a safeguard to the physical and social environments of society. In the absence of global standards, organizations have developed standardized reporting frameworks for companies. This study provides an adaptation easiness measurement and a wide range of environmental, social, and governance disclosure components extracted from several standards. Multiple standards and a broader range of scaling measurements were used in this study to observe the characteristics of each industry where each environmental, social, and governance component is specific. The objective of this study is to investigate how companies in Indonesia comply with various environmental, social, and governance standards, given the importance of identifying variations of easiness on environmental, social, and governance on sustainability reports.METHODS: Using multi-source analysis, content analysis, and exploratory data analysis, this study identified whether industries in Indonesia adopt selective patterns in the components included in their sustainability reports.FINDINGS: This study identified 26 environmental, 8 social, and 23 governance popular components, which are components with high environmental, social, and governance report applicability and company adaptability. The environmental components that is easy to adapt primarily center around formal environmental, social, and governance framework data, in social component revolves around customary practices in corporate social responsibility, and in governance component emphasizes corporate reputation. By employing industry-specific environmental, social, and governance components, this study identifies three distinct groups, enabling the formulation of tailored policies to effectively address the unique needs of each group.CONCLUSION: This study exposes several findings on how companies in Indonesia adopt different components of environmental, social, and governance reports according to their needs, regulations, and analysis complexity. The novelty of this study combined the use of unified comparison components, a wider range of scaling measurements, and specific environmental social, and governance components per-industry type.

SPECIAL ISSUE Environmental Management

Effects of effluent recirculation on two-stage anaerobic digestion in treatment of biodegradable municipal solid waste

P.V. Dinh; T. Fujiwara; A.N. Peni; C.K. Tran

Articles in Press, Accepted Manuscript, Available Online from 09 August 2023

https://doi.org/10.22034/GJESM.2023.09.SI.03

Abstract

BACKGROUND AND OBJECTIVES: Advantages such as high stability and high biogas production when recirculating the effluent stream in two-stage anaerobic digestion systems have been demonstrated on a variety of substrates, but there is limited information regarding the use of this practice on organic municipal ... Read More BACKGROUND AND OBJECTIVES: Advantages such as high stability and high biogas production when recirculating the effluent stream in two-stage anaerobic digestion systems have been demonstrated on a variety of substrates, but there is limited information regarding the use of this practice on organic municipal waste. Therefore, this study aimed to investigate how effluent recirculation affects the two-stage anaerobic digestion of biodegradable municipal solid waste.METHODS: Firstly, biodegradable municipal solid waste substrate was fermented under conditions of 12 percent initial total solids and a temperature of 36 degrees Celsius for 5 days. After that, the substrate continued to be diluted using tap water or the effluent stream with a rate of 2:1. In the case of using the effluent stream, the experiment was further performed with dilution rates of 3:1, 1:1, and 1:2. Then, the liquid part was collected and pumped into the methane reactor at an organic loading rate of 7.64 grams of total solids per liter per day at 36 degrees Celsius. The methane reactor was an up-flow reactor that contained both granular sludge and suspended sludge. The effectiveness of the experimental stages was evaluated through biogas production and chemical oxygen demand removal.FINDINGS: In the fermentative reactor, using the effluent stream to dilute solid-state feedstock helped keep the reactor stable at pH 5.5 without alkali addition. In the case of using tap water for dilution, it required a dose of 115.8 grams and 75.3 grams of sodium hydroxide per kilogram of volatile solids to attain pH conditions at 6.5 and 5.5, respectively. Maintaining the reactor at pH 6.5 increased the concentration of fermentation products compared to pH 5.5, including 5.9 percent total chemical oxygen demand, 5.5 percent soluble chemical oxygen demand, and 10.6 percent total volatile fatty acids. In the case of recirculating the effluent stream in the methane reactor, increasing the dilution rate from 0.5 to 3.0 resulted in a methane yield of 227.5-278.9 milliliter per gram of volatile solids and 85-93 percent chemical oxygen demand removal. The methane reactor’s best digestion performance was attained at recirculation rate 2. Methane formation mainly occurred in granular sludge via the hydrogenotrophic pathway. Methane formation in suspended sludge occurred in a secondary manner, mainly via both the hydrogenotrophic and acetotrophic pathways. Among methanogen families, Methanobacteriaceae was found to have the highest relative abundance (7.5 percent in granular sludge and 0.8 percent in suspended sludge).CONCLUSION: Recirculating the effluent provided significant benefits, including the ability to stabilize the hydrolysis process and increase the methane yield. A recirculation rate of 2 to obtain a total chemical oxygen demand of 35.2 grams per liter was the best condition for methanogenesis. Acetotrophic methanogens were better adapted to difficult conditions than hydrogenotrophic methanogens. The formation of methane mainly occurred in granular sludge via a dominant hydrogenotrophic pathway. Methane formation in suspended sludge occurred in a secondary manner, mainly via both the hydrogenotrophic and acetotrophic pathways. Among methanogen families, Methanobacteriaceae was found to have the highest relative abundance.

SPECIAL ISSUE Environmental Science

Using benthos a bioindicator to assess the efficiency constructed wetland community wastewater treatment system

K. Seethong; K. Chunkao; N. Dampin; W. Wararam

Articles in Press, Accepted Manuscript, Available Online from 24 June 2023

https://doi.org/10.22034/GJESM.2023.09.SI.04

Abstract

BACKGROUND AND OBJECTIVES: The increasing population and urban growth have led to a higher demand for water in various sectors, resulting in a significant amount of wastewater. Constructed wetlands mimic natural wetlands, using the interaction between plants, soil, and microorganisms to treat wastewater ... Read More BACKGROUND AND OBJECTIVES: The increasing population and urban growth have led to a higher demand for water in various sectors, resulting in a significant amount of wastewater. Constructed wetlands mimic natural wetlands, using the interaction between plants, soil, and microorganisms to treat wastewater efficiently. This study assesses the diversity, species composition, and distribution of benthic organisms in a community wastewater-filter grass system and explores the relationship between water quality and benthos.METHODS: Water samples were collected from plant plots between December 2021 and March 2022. On-site measurements included temperature, dissolved oxygen, salinity, and pH, whereas laboratory analysis encompassed the biochemical oxygen demand, ammonia, nitrate, total phosphorus, orthophosphate, and suspended solids. Soil samples were taken before and during planting at 2-week intervals, evaluating organic matter, pH, electrical conductivity, salinity, phosphorus, potassium, calcium, magnesium, and plant growth indicators. Benthos sampling involved polyvinyl chloride pipe cores at a depth of 5 cm from the soil surface. Statistical tests were performed to analyze the water quality data.FINDINGS: The study observed a decrease in Chironomid abundance in both constructed wetland systems, indicating their effectiveness in treating wastewater. A comparison of system types revealed that the 5-day detention–2-day dry release system exhibited higher Chironomid abundance than the continuous flow system, and the biological oxygen demand maximum decreasing rate was 95%. The ammonia and nitrate maximum decreasing rates were 97% and 94%, respectively, indicating greater wastewater-treatment efficiency. The study also identified diverse benthic organisms, particularly chironomids, as bioindicators for assessing wastewater conditions.CONCLUSION: The continuous flow system and the 5-day detention–2-day dry release system of constructed wetlands can reduce the organic compounds and increase the oxygen levels in the plant plots. The interaction among plants, soil, and microorganisms is critical in wastewater treatment. In addition, the study highlighted the diversity and abundance of benthic organisms, particularly chironomids, which were more prominent in the continuous flow system. Consequently, the 5-day detention–2-day dry release system was more efficient in treating wastewater than the continuous flow system.

SPECIAL ISSUE Environmental Management

Sustainable development model toward environmentally friendly hospital

F, Aini; A. Irianto; S. Amar

Articles in Press, Accepted Manuscript, Available Online from 01 August 2023

https://doi.org/10.22034/GJESM.2023.09.SI.05

Abstract

BACKGROUND AND OBJECTIVES: This study aims to create an environmentally friendly hospital at West Pasaman regional public hospital by implementing a sustainable development model, which consists of the green hospital, green building, green innovation, and green human resource management. The researchers ... Read More BACKGROUND AND OBJECTIVES: This study aims to create an environmentally friendly hospital at West Pasaman regional public hospital by implementing a sustainable development model, which consists of the green hospital, green building, green innovation, and green human resource management. The researchers previously discussed the physical aspects of the building, efficiency related to energy saving and hospital waste management. However, from several references obtained, it has not yet been discussed what is the extent of the benefits derived from the entire implementation of the green hospital. Thus, this study contributes to creating an environmentally friendly hospital model mediated by a green hospital and it is influenced by green building, green innovation, and green human resource management.METHODS: The study method uses a survey, which uses a questionnaire as a data collection tool. The population in this study consisted of employees, visitors, and the community around West Pasaman regional public hospital. The selection of the sample in this study was based on the proportionate cluster random sampling approach, which was analyzed using the structural equation modeling–partial least square method.FINDINGS: There are ten findings for analysis at the West Pasaman regional public hospital. First, green building has a significant effect of 0.187 on the green hospital. Second, green innovation has a significant effect of 0.230 on the green hospital. Third, green human resource management has a significant effect of 0.235 on the green hospital. Fourth, green building has a significant effect of 0.263 on the environmentally friendly hospital. Fifth, green innovation has a significant effect of 0.192 on the environmentally friendly hospital. Sixth, green human resource management has a significant effect of 0.197 on the environmentally friendly hospital. Seventh, the green hospital has a significant effect of 0.241 on the environmentally friendly hospital. Eighth, green building has a significant effect of 0.045 on the environmentally friendly hospital mediated by the green hospital. Ninth, green innovation has a significant effect of 0.055 on the environmentally friendly hospital mediated by the green hospital. Tenth, green human resource management has a significant effect of 0.057 on the environmentally friendly hospital mediated by the green hospital.CONCLUSION: Implementation of the sustainable development model as a form of environmental management policy at the West Pasaman regional public hospital is optimally needed in order to achieve an environmentally friendly hospital. This study recommends employees, visitors the community around the West Pasaman regional public hospital to increase the green hospital, green building, green innovation, and green human resource management in achieving an environmentally friendly hospital.

SPECIAL ISSUE Environmental Science

Carbon dioxide net assimilation exchange in a young pecan nut orchard during the growth cycle

A. Zermeño-Gonzalez; E.A. Jimenez-Alcala; J.A. Gil-Marin; H. Ramirez-Rodriguez; M. Cadena-Zapata; A.I. Melendres-Alvarez

Articles in Press, Accepted Manuscript, Available Online from 19 August 2023

https://doi.org/10.22034/GJESM.2023.09.SI.06

Abstract

BACKGROUND AND OBJECTIVES: Pecan nut trees (Carya illinoensis K), due to their condition as woody and long-living species, in addition to the contribution of nuts for consumption, may also have an essential role in assimilating carbon dioxide and sequestering atmospheric carbon. This study aimed to determine ... Read More BACKGROUND AND OBJECTIVES: Pecan nut trees (Carya illinoensis K), due to their condition as woody and long-living species, in addition to the contribution of nuts for consumption, may also have an essential role in assimilating carbon dioxide and sequestering atmospheric carbon. This study aimed to determine the carbon dioxide net ecosystem exchange of an orchard of young pecan nut trees in northern Mexico, and its relationship with the growth months of the trees.METHODS: The study was carried out from March to November 2017 in a six-year-old pecan nut tree orchard containing trees of the Western Schley and Wichita varieties. The orchard is drip-irrigated with buried tape. The carbon dioxide net ecosystem exchange between the canopy of the orchard trees and the atmosphere was determined with eddy covariance measurements using a three-dimensional sonic anemometer and an open-path infrared carbon dioxide analyzer.FINDINGS: The highest daytime carbon dioxide net ecosystem exchange rate corresponded with the peak absorption rate of photosynthetically active radiation absorbed by the trees' canopy. It was observed between 11:00 and 14:00 hours throughout the growth months of the trees. The highest carbon dioxide net ecosystem exchange rate was observed in June, at 7 micro mol square meter per second. The relationship between the carbon dioxide net ecosystem exchange and the photosynthetically active radiation absorbed by the trees’ canopy through the growth months was described using a rectangular hyperbolic function. From March to September, the carbon sequestration of the young pecan nuts was 0.962 tons of carbon per hectare.CONCLUSION: The highest carbon dioxide diurnal assimilation rate was observed in May, at 5 717.95 millimoles per square meter. Despite the young age of the pecan trees, the orchard has a retention capacity of 0.962 tons of carbon per hectare for the months evaluated. The young pecan orchard significantly contributes to the assimilation and retention of atmospheric carbon that will increase with the growth of the trees, due to greater leaf and biomass development.

SPECIAL ISSUE Environmental Management

Life cycle assessment of paper products based on recycled and virgin fiber

J. Simamora; E.I. Wiloso; M. Yani

Articles in Press, Accepted Manuscript, Available Online from 01 August 2023

https://doi.org/10.22034/gjesm.2023.09.SI.07

Abstract

BACKGROUND AND OBJECTIVES: Virgin wood fiber and recycled waste paper are the main raw materials for paper production. Virgin wood-fiber paper appears less favorable than recycled paper, as recycled paper generally consumes more natural resources. Some indicators raise questions about the product being ... Read More BACKGROUND AND OBJECTIVES: Virgin wood fiber and recycled waste paper are the main raw materials for paper production. Virgin wood-fiber paper appears less favorable than recycled paper, as recycled paper generally consumes more natural resources. Some indicators raise questions about the product being recycled, including the amount of solid waste produced during production and carbon emissions, which can occasionally be higher than for paper made from virgin fiber, as it may require more energy to operate. This study presents a comparative life cycle assessment of paper production in Indonesia using wood fibers and recycled fiber materials. This life cycle assessment study aimed to compare two comparable products, namely duplex board with 93 percent recycled fiber and folding boxboard with 100 percent wood or virgin fiber raw materials.METHODS: Both products were represented as one metric ton of the final product. The study utilized a cradle-to-grave system and combined primary data from a paper factory in Indonesia with secondary data from the Ecoinvent database, representing processes in background systems. Various impact assessment methods were employed to evaluate the environmental impact, including the Greenhouse Gas Protocol, the Centre for Environmental Studies, International Reference Life Cycle Data System, and the United Nations Environment Program, Society for Environmental Toxicology, and Chemistry toxicity model. All inventory and impact assessments were performed using SimaPro software.FINDINGS: The current study revealed that duplex board is environmentally preferable to folding boxboard across all the impact categories assessed. The results of the impact assessment of global warming potential fossil, acidification, particulates, fossil abiotic depletion, and human toxicity-cancer for duplex board were 1,848.26 kilogram carbon dioxide equivalent, 8.12 kilogram-sulfur-dioxide-equivalent, 2.12 kilogram particulate matter 2.5-equivalent, 14,668.06 megajoule, and 0.0000017 comparative toxic unit, while for folding boxboard 2,651.25 kilogram carbon- dioxide-equivalent, 13.95 kilogram sulfur-dioxide-equivalent, 3.27 kilogram particulate matter 2.5-equivalent, 22,395.81 mega-joule, and 0.0000021 comparative toxic unit, respectively. All impact magnitudes were measured in functional units per 1 ton of paper product.CONCLUSION: The study has revealed the environmental impact of paper products produced in Indonesia. Paper products made from recycled fibers are a more environmentally favorable option when than those produced from virgin fibers. Through further contribution analysis, it was determined that the main contributor to all impact categories in both production systems was fossil-based energy input. Efforts to improve the environmental performance of the two products should focus on enhancing the energy efficiency of the system and incorporating non-fossil fuel energy sources into the production process.

SPECIAL ISSUE Environmental Management

Sustainable healthy settlement on a small island as a cultural heritage area

I. Martias; R. Rifardi; A. Agrina; I. Suprayogi

Articles in Press, Accepted Manuscript, Available Online from 08 August 2023

https://doi.org/10.22034/GJESM.2023.09.SI.08

Abstract

BACKGROUND AND OBJECTIVES: Penyengat Island is a small island in the Riau Archipelago Province, Indonesia, with a coastal settlement that embodies traditional Malay values. This island holds significance due to the historical connection to the Malay royal civilization along the Malacca Strait, which ... Read More BACKGROUND AND OBJECTIVES: Penyengat Island is a small island in the Riau Archipelago Province, Indonesia, with a coastal settlement that embodies traditional Malay values. This island holds significance due to the historical connection to the Malay royal civilization along the Malacca Strait, which includes Indonesia, Malaysia, and Singapore. Therefore, this research analyzes the status and determinants of the sustainability of healthy settlement arrangements in the coastal area of Penyengat Island as a cultural heritage site.METHODS: The study utilizes the multi-dimensional scaling-rapid appraisal for sustainability approach, employing the modified rapid appraisal for fisheries ordinance software technique for settlement analysis. Data collection was performed using a survey and literature review. The survey was conducted through field observations and interviews with respondents, while a literature review was carried out through secondary data collection related to settlements and cultural heritage. The data analysis was performed using multi-dimensional scaling, modified from the rapid assessment appraisal method for fisheries.FINDINGS: The study reveals that the sustainability index status for the ecological and institutional legal dimensions in Penyengat island is sustainable. In contrast, the economic and socio-cultural dimensions recorded low sustainability, while the green infrastructure dimension was deemed unsustainable. Several attributes significantly influenced the sustainability of healthy settlement arrangements in the coastal area of Penyengat Island, including household waste management, lighting in houses, noise levels, residential density, clean water supply, corporate social responsibility (CSR) funding, occupation, income growth, technological innovation, tourist numbers, public perception of the distance between cultural heritage and settlements, social conflicts, implementation of mutual cooperation, community group management, handling cross-program problems, education and training, settlement regulations, community organization regarding settlements, socialization of regulations, cultural heritage organizations, hedgerows, additional vegetation, tree canopy expansion, and rain gardens. The multi-dimensional scaling analysis indicated that the ecological dimension of sustainability ranged from 51.71 to 60.67, corresponding to the moderate status in Rukun Warga 1 to 5. The economic dimension ranges from 40.46 to 48.23, indicating a less advanced status in Rukun Warga 1 to 5. The socio-cultural dimension ranges from 48.97 to 51.78, representing sufficient status in Rukun Warga 1 and less sustainable in Rukun Warga 2 to 5. The institutional, legal dimension ranges from 50.18 to 71.24, with a sufficiently continuous status in Rukun Warga 1 to 5. Lastly, the green infrastructure dimension ranges from -0.12 to 6.72, a non-continuous status in Rukun Warga 1 to 5.CONCLUSION: The sustainability status of healthy settlement arrangements on Penyengat Island is relatively good. While Penyengat Island has made significant strides in achieving sustainable settlement arrangements, the green infrastructure dimension requires attention. Enhancing sustainability in this dimension involves addressing socio-cultural aspects and improving the institutional and legal framework. In summary, Penyengat Island can progress toward a more sustainable and resilient future by fostering community involvement, strengthening governance structures, and implementing sustainable practices.

SPECIAL ISSUE Environmental Science

Biological control of bacterial wilt in pathumma; Curcuma alismatifolia

S. Promsai; Y. Tragoolpua; N. Thongwai

Articles in Press, Accepted Manuscript, Available Online from 02 September 2023

https://doi.org/10.22034/GJESM.2023.09.SI.09

Abstract

BACKGROUND AND OBJECTIVES: In Thailand, bacterial wilt is one of the most severe diseases that affects pathumma, also known as Curcuma alismatifolia Gagnep. Biological control was proposed to control this disease with antagonistic bacteria. The current study was conducted to screen for antagonistic microorganisms ... Read More BACKGROUND AND OBJECTIVES: In Thailand, bacterial wilt is one of the most severe diseases that affects pathumma, also known as Curcuma alismatifolia Gagnep. Biological control was proposed to control this disease with antagonistic bacteria. The current study was conducted to screen for antagonistic microorganisms capable of inhibiting the pathogenic bacteria and to evaluate the beneficial effect of antagonistic bacteria on pathumma in vivo.METHODS: Antagonistic bacteria were isolated from soil samples obtained from several locations in Thailand and screened for antibacterial activity. Next, the optimal conditions for the growth of antagonistic bacteria were determined. The production of anibacterial substances were then characterized. The potential of antagonistic bacteria to reduce the growth of plant pathogens was evaluated under greenhouse conditions. FINDINGS: In total, 102 bacterial isolates were isolated using tryptic soy medium. After evaluating their capacity to inhibit the growth of the wilt-causing bacteria using the paper disc diffusion assay, it was found that three bacterial isolates, Bacillus subtilis SP15, Pseudomonas mosselii SP38, and Pseudomonas mosselii SP46 showed high ability to inhibit growth of the wilt-causing bacteria Enterobacter asburiae JK1, JK2, JK3, JK4, E. dissolvens JK5 and E. hormachei JK6. The optimal conditions for all antagonistic bacterial isolates were 25 or 30 degrees Celcius, at potential of hydrogen 7-8 in modified tryptic soy medium containing 0.5 percent (weight /volume) glucose or sucrose and 1.5 or 2 percent (weight/volume) peptone. The antagonists were able to produce siderophores and phenazines. Under greenhouse experiments, the mixed cultures of antagonistic bacterial isolates could reduce the wilt disease incidence, and the number of pathogenic bacteria declined compared with the diseased control plants. In addition, it was discovered that soil materials provided the best carrier materials for the successful formulation of the mixed culture of antagonistic bacteria.CONCLUSION: This study revealed that the selected antagonists were beneficial for controlling wilt disease in pathumma. This is the first scientific study on the control of wilt-disease causing Enterobacter spp. in C. alismatifolia Gagnep. in Thailand using antagonistic bacteria. It is expected that these antagonistic bacteria be useful in wilt disease management in the field for friendly and sustainable agriculture

SPECIAL ISSUE Environmental Management

Environmental impact technology for life cycle assessment in municipal solid waste management

M.A. Budihardjo; I.B. Priyambada; A. Chegenizadeh; S. Al Qadar; A.S. Puspita

Articles in Press, Accepted Manuscript, Available Online from 27 June 2023

https://doi.org/10.22034/GJESM.2023.09.SI.10

Abstract

Municipal solid waste management has evolved from direct disposal to recycling and resource recovery, driven by sustainability. Life cycle assessment has played a crucial role in analyzing the environmental implications of different waste management strategies and selecting the most ecologically feasible ... Read More Municipal solid waste management has evolved from direct disposal to recycling and resource recovery, driven by sustainability. Life cycle assessment has played a crucial role in analyzing the environmental implications of different waste management strategies and selecting the most ecologically feasible options. Establishing best practices in municipal solid waste management based on competent life cycle assessment work is essential for policymakers to make informed decisions. This study reviewed 34 life cycle assessment studies on solid waste management systems in Asian countries, examining their life cycle stages, assessment techniques, and key outcomes. The analysis highlights include functional units, various life cycle assessment models (such as SimaPro and GaBi), life cycle impact assessment methods, impact categories, and alternative waste management methods. It is necessary to prioritize recycling, resource generation (such as decomposition, incineration, and anaerobic digestion), and waste reduction over landfilling to attain a high level of environmental friendliness. However, it is essential to observe that technologies necessitating large upfront investments and skilled labor are better suited for high-income countries. Conversely, low-income countries should prioritize waste reduction through recycling, waste depots, and methods that correlate with their existing capabilities to reduce the amount of waste sent to landfills. By sharing existing methods, developing integrated municipal solid waste management systems can be accelerated in low-income nations, which can have a substantial positive economic impact. Therefore, decision-makers should consider social, economic, and environmental impacts when selecting an appropriate refuse management strategy for their nation. This analysis provides valuable insights into the scope of life cycle assessment studies and contributes to the selection of sustainable municipal solid waste management systems. These findings can be utilized by life cycle assessment practitioners, stakeholders, and Asian governments to inform policy development and decision-making processes.

SPECIAL ISSUE Environmental Engineering

Management strategies for the efficient energy production of brackish water desalination to ensure reliability, cost reduction, and sustainability

A. Bdour; A. Hejab; L. Almakhadmeh; M. Hawa

Articles in Press, Accepted Manuscript, Available Online from 28 August 2023

https://doi.org/10.22034/GJESM.2023.09.SI.11

Abstract

BACKGROUND AND OBJECTIVES: Energy efficiency plays a crucial role in the success and sustainability of desalination technologies. Energy considerations are intricately linked with every aspect of planning, management, and operation in water desalination. This study aims to evaluate and enhance energy ... Read More BACKGROUND AND OBJECTIVES: Energy efficiency plays a crucial role in the success and sustainability of desalination technologies. Energy considerations are intricately linked with every aspect of planning, management, and operation in water desalination. This study aims to evaluate and enhance energy requirements, energy efficiency, and the economic feasibility of the Hashemite University photovoltaic brackish water reverse osmosis desalination plant at Hashemite University.METHODS: This study’s aims were achieved by conducting an energy audit and detailed assessment to identify the energy efficiency considerations that should be integrated into the facility’s planning, management, and operation strategies. To ensure accurate and reliable data collection and enable a comprehensive analysis of the plant’s energy performance, portable energy analyzers and loggers were employed to measure energy consumption, and measurements and verification techniques were recommended and implemented to establish the required baseline. A regression model was utilized to determine the potential energy savings resulting from energy conservation measures. This involved determining the expected savings by calculating the area between two curves: the new actual consumption of the brackish water reverse osmosis plant after implementing energy conservation measures and the curve generated by the model representing the usual consumption in the absence of energy conservation measures.FINDINGS: This study underscores the challenges faced by desalination, particularly regarding intensive energy consumption. It also presents innovative ways to achieve sustainability by emphasizing energy efficiency, integrating renewable energy, and advocating for a holistic water management approach. It was determined that the maximum specific energy consumption of the Hashemite University photovoltaic brackish water reverse osmosis plant was 0.625 kilowatts per cubic meter. This reflects the actual consumption and energy performance of the plant, which was found to be 192 percent more efficient than the estimated specific energy and 144 percent more efficient than the calculated specific energy. No energy conservation measures were implemented at this stage, as the plant was already operating efficiently. The measured data shall be considered as a baseline for future investigations and monitoring and evaluation of the plant. Many challenges were identified during the current work, including the low quality of raw water and minimal demand for freshwater, which resulted in lower operation hours outside of sun peak hours, while the direct utilization of photovoltaic energy is recommended.CONCLUSION: Renewable energy and energy recovery were recognized as potential sources for energy savings to achieve sustainable and long-term feasible operation and cost recovery at the Hashemite University photovoltaic brackish water reverse osmosis plant. The feasibility of the plant showed a fast payback period of up to 1.1 years. Utilizing clean solar photovoltaic energy to power the brackish water reverse osmosis plant led to a considerable reduction of greenhouse gases (mainly carbon dioxide). The estimated amount of carbon dioxide reduction during the project’s lifetime was 1,289,600 kilograms. The integration of solar energy showed promise for further enhancing energy efficiency and sustainability. This study contributes to making the desalination sector more environmentally friendly and economically viable, which is of paramount importance in addressing global water scarcity concerns.

SPECIAL ISSUE Environmental Management

Sustainability index analysis of organic fertilizer production from paunch manure and rice straw waste

A.D. Santoso; F.D. Arianti; E.S. Rohaeni; B. Haryanto; M.D. Pertiwi; L.P. Panggabean; A. Prabowo; S. Sundari; S.P. Wijayanti; I.N. Djarot; F.D. Kurniawati; F.L. Sahwan; T. Prasetyo; A. Barkah; T.A. Adibroto; R. Ridlo; I. Febijanto; A.A. Wasil; S. Lusiana; R. Rosmeika; R.B. Heryanto

Articles in Press, Accepted Manuscript, Available Online from 25 August 2023

https://doi.org/10.22034/GJESM.2023.09.SI.12

Abstract

BACKGROUND AND OBJECTIVES: Substantial quantities of livestock waste and organic pollutants, such as nitrogen and phosphate, which pose environmental risks are generated from agriculture activities. A combination of paunch manure and rice straw is used as organic fertilizer. Therefore, this study confirmed ... Read More BACKGROUND AND OBJECTIVES: Substantial quantities of livestock waste and organic pollutants, such as nitrogen and phosphate, which pose environmental risks are generated from agriculture activities. A combination of paunch manure and rice straw is used as organic fertilizer. Therefore, this study confirmed sustainability of organic fertilizer from paunch manure and rice straw waste.METHODS: Data were collected through focus group discussions and the closure of questionnaires which contained 29 attributes related to environmental, economic, social, and technological dimensions. The data collected was analyzed using the Multidimensional Scaling method, Rapfish software, and Monte Carlo analysis to ascertain the level of sustainability status and leverage attributes, and examine scoring errors and variations.RESULTS: Sustainability index for organic fertilizer production was 74.55 percent. The result showed that the method contributed to the growth of sustainability in various operational phases, including the processing and commercialization of organic fertilizer. According to analysis of the four dimensions, the environmental dimension held the highest leverage value at 90.1 percent, followed by social, economical, and technological dimensions at 70.50 percent, 63.69 percent, and 73.93 percent, respectively. This study identified seven leverage attributes that are very influential to sustainability of organic fertilizer production. These include water use and raw material efficiency, potential business scale increase, market absorption, the potential for public unrest, the manager or worker level of expertise in the manufacture of organic fertilizer as well as the process used to determine its quality and output.CONCLUSION: The proposed inquiry conducted within the context of this study identified the pivotal factors that influenced organic fertilizer supply framework as the quality, quantity, and market absorption of organic production. As a result, the o use of agricultural waste as a valuable addition to a perfect social, economical, and technological development system needs to be encouraged. The study is significant because it offered information about the viability of producing organic fertilizer in Indonesia, which the government and other stakeholders may use to guide their policies and programs.

SPECIAL ISSUE Environmental Management

Barriers to sustainable green innovation in meeting the challenges of the global economy of firms

A. Escobar; J. Luna; A. Caraballo

Articles in Press, Accepted Manuscript, Available Online from 05 September 2023

https://doi.org/10.22034/GJESM.2023.09.SI.13

Abstract

BACKGROUND AND OBJECTIVES: Sustainable innovation is crucial, because it is a key strategy for ensuring the long-term survival of companies in a world with limited resources. Consequently, understanding the barriers faced by companies in achieving sustainable innovation, such as high initial cost, lack ... Read More BACKGROUND AND OBJECTIVES: Sustainable innovation is crucial, because it is a key strategy for ensuring the long-term survival of companies in a world with limited resources. Consequently, understanding the barriers faced by companies in achieving sustainable innovation, such as high initial cost, lack of technical knowledge, or unclear regulations, is important for developing appropriate policies, strategies, and solutions that promote and facilitate its adoption.METHODS: This study aims to analyze the relevant and most important scientific evidence and research topics on barriers to sustainable innovation through a bibliometric analysis combined with concurrence networks and cluster analysis using VOSViewer.FINDINGS: Research on barriers to innovation was developed on a larger scale in 2012 with an average growth of approximately 43 percent until 2022. During this period, the study on green innovation has been predominant and on the social component of sustainable innovation to a lesser extent. Asia, specifically China, is leading the research on this topic mainly on the environmental component of sustainable innovation. In terms of barriers, the majority of the literature focus on financial constraints. The research agenda focus on the following areas or clusters: sustainability, barriers to sustainable innovation, and social innovation.CONCLUSION: The major barriers to sustainable innovation are financial and government regulations. The current research tackles the environmental component of sustainable innovation. Therefore, future research should focus on market and knowledge barriers in developed and less developing countries and on the social component of sustainable innovation. Potential areas of research (which are underexplored) exist and can be important for future research on enhancing knowledge about barriers to sustainable innovation: applied research that considers regional effects and country-specific analysis, in particular in developing countries. Research on the social component of sustainable innovation could be relevant. Social innovation is essential, because it addresses concrete societal problems and promotes collective action and inclusion in novel ways within companies.

SPECIAL ISSUE Environmental Engineering

Modeling of peatland fire risk early warning based on water dynamics

B. Kartiwa; . Maswar; A. Dariah; . Suratman; N.L. Nurida; N. Heryani; P. Rejekiningrum; H. Sosiawan; S.H. Adi; I. Lenin; S. Nurzakiah; Ch. Tafakresnanto

Articles in Press, Accepted Manuscript, Available Online from 31 August 2023

https://doi.org/10.22034/GJESM.2023.09.SI.14

Abstract

BACKGROUND AND OBJECTIVES: To minimize the potential risk of land fires, climate monitoring and hydrology characterization are crucial factors in managing peatlands. Therefore, this study aimed to investigate the relation between climate variability and water dynamics to develop a peatland fire early ... Read More

SPECIAL ISSUE Environmental Management

Adoption and implementation of extended producer responsibility for sustainable management of end-of-life solar photovoltaic panels

S.E. Kabir; M.N.I. Mondal; M.K. Islam; I.A. Alnaser; M.R. Karim; M.A. Ibrahim; K. Sopian; M. Akhtaruzzaman

Articles in Press, Accepted Manuscript, Available Online from 12 September 2023

https://doi.org/10.22034/GJESM.2023.09.SI.15

Abstract

BACKGROUND AND OBJECTIVES: Extended producer responsibility has been a policy tool for managing solar photovoltaic waste in European Union countries for approximately a decade. Furthermore, EPR has been widely used in many countries for electronic waste and other forms of waste management. Several studies ... Read More BACKGROUND AND OBJECTIVES: Extended producer responsibility has been a policy tool for managing solar photovoltaic waste in European Union countries for approximately a decade. Furthermore, EPR has been widely used in many countries for electronic waste and other forms of waste management. Several studies have recommended this tool to sustainably manage solar photovoltaic waste in countries transitioning to large-scale solar energy usage. Nevertheless, implementing a policy tool varies depending on numerous factors, particularly context differences in developed and developing countries. The research on adopting and implementing this tool for solar photovoltaic waste management is limited in developing countries. Bangladesh requires appropriate regulations to manage the impending waste, which will soon encounter substantial end-of-life solar photovoltaic panel volumes. Therefore, this study investigated the adoption and implementation of the extended producer responsibility policy tool within the context of Bangladesh.METHODS: A comprehensive literature review was conducted to identify the enabling and challenging factors influencing the implementation of this tool. Subsequently, a Likert Scale-based questionnaire incorporating the enabling and challenging factors was framed. A survey targeting stakeholders in the solar photovoltaic sector was then performed. Data analysis involved univariate and bivariate analyses, and Bangladesh was selected as a representative developing country for this study.FINDING: The results revealed that stakeholders in the solar PV industry significantly emphasized (mean > 3) all enabling factors associated with extended producer responsibility for adoption in their country to manage end-of-life photovoltaic panels. This observation signified the importance of adopting and implementing extended producer responsibility to manage the impending disposal of end-of-life solar photovoltaic panels. Among the enabling factors, the public expense reduction (mean = 3.97), user acceptance (mean = 3.89), eco-design encouragement (mean = 4.02), and the local recycling facility with secondary material market establishments (mean = 3.89) emerged as the most crucial factors. The solar photovoltaic waste-specific regulations (mean = 3.72), the absence of a pre-established collection network (mean = 4.20), and weak institutional capacity (mean = 4.03) were identified as challenging factors requiring special attention during this tool adoption. The inter-item correlation matrix analysis for enabling and challenging factors also demonstrated high significance. Moreover, Cronbach's alpha for enabling and challenging factors were 0.885 and 0.749, respectively. This outcome suggested a good and acceptable internal consistency level among the factors.CONCLUSION: Adopting extended producer responsibility was essential in developing countries to ensure the sustainable management of end-of-life solar photovoltaic panels. Nonetheless, successful implementation required addressing specific domestic concerns, such as the absence of a pre-existing waste take-back system and weak institutional capacity. Regulators should also proactively take measures to leverage enabling factors, including gaining users' acceptance, reducing costs, and potentially tapping into secondary material markets. Consequently, this study can assist in formulating appropriate regulations regarding the sustainable management of hazardous end-of-life solar photovoltaic panels. The findings can be utilized in Bangladesh and other countries encountering similar challenges, contributing to environmental preservation and eco-friendly development.

SPECIAL ISSUE Environmental Engineering

Bibliometric analysis for sustainable food waste using multicriteria decision

. Syafrudin; I.B. Priyambada; M.A. Budihardjo; S. Al Qadar; A.S. Puspita

Articles in Press, Accepted Manuscript, Available Online from 30 August 2023

https://doi.org/10.22034/GJESM.2023.09.SI.16

Abstract

Sustainable food waste management is globally concerning, thus necessitating cutting-edge approaches and a thorough understanding. To address this complicated problem effectively, bibliometric analysis and multicriteria decision-making can be combined. Therefore, multicriteria decision-making methods ... Read More Sustainable food waste management is globally concerning, thus necessitating cutting-edge approaches and a thorough understanding. To address this complicated problem effectively, bibliometric analysis and multicriteria decision-making can be combined. Therefore, multicriteria decision-making methods have become critical tools for navigating the intricacies of sustainable solution development. This study explored the complex field of sustainable food waste management by conducting a comprehensive bibliometric analysis of multi-criteria decision uses in this field. Using bibliometric methods, a methodological examination of the scientific literature was performed to identify important trends, contributions, and gaps in research on sustainable food waste. Decision-makers can be further empowered by using multicriteria decision-making to assess interventions across various dimensions, including environmental effects, economic viability, and social acceptability, highlighting the interdisciplinary nature of this strategy and promoting interactions between researchers, decision-makers, and stakeholders. These guidelines directly followed the development of policies, business practices, and consumer behavior, indicating a more sustainable food system. The combination of bibliometric analysis and multicriteria decision-making offered a formidable instrument to reduce food waste, enhance resource efficiency, and spur progress in global sustainability initiatives in a world where sustainable behavior is crucial. The study results in decision-makers evaluating interventions and strategies holistically by concurrently considering the food waste dimension, a multicriteria model, economic factors, environmental factors, social factors, policy considerations, and technical feasibility are just some of the factors considered in this study. This analysis highlights the growing commitment to comprehensive solutions that focus not only on waste reduction but also on resource efficiency, environmental stewardship, and societal well-being as sustainable food waste management gains traction on global agendas.

SPECIAL ISSUE Environmental Management

Analysis of environmental health risks from exposure to polyethylene terephthalate microplastics in refilled drinking water

S. Kasim; A. Daud; A.B. Birawida; A. Mallongi; A.I. Arundana; A. Rasul; M. Hatta

Articles in Press, Accepted Manuscript, Available Online from 13 September 2023

https://doi.org/10.22034/GJESM.2023.09.SI.17

Abstract

BACKGROUND AND OBJECTIVES: Microplastic pollution has a far and wide presence in the surroundings. It can be encountered in the sea, wastewater, freshwater, food, air, and water sources. It is even present in refilled drinking water. This study aims to analyze environmental health dangers of the exposure ... Read More

SPECIAL ISSUE Environmental Management

The role of pro-environmental behavior in the development of sustainable tourism

N. Zulvianti; H. Akmal; M.R. Putra

Articles in Press, Accepted Manuscript, Available Online from 18 September 2023

https://doi.org/10.22034/GJESM.2023.09.SI.18

Abstract

BACKGROUND AND OBJECTIVES: Sustainable tourism is tourism development that has a long-term impact on the environment, society, culture, and the economy for the present and the future. The benefits are felt by local people and tourists. The achievement of this research is the implementation of pro-environmental ... Read More BACKGROUND AND OBJECTIVES: Sustainable tourism is tourism development that has a long-term impact on the environment, society, culture, and the economy for the present and the future. The benefits are felt by local people and tourists. The achievement of this research is the implementation of pro-environmental behavior, which is supported by tourist satisfaction and electronic word of mouth toward sustainable tourism as a form of environmental management policy in West Sumatra. This research aims to show three direct effects: first, the effect of satisfaction and electronic word of mouth on the sustainability of tourism; second, the effect of satisfaction on electronic word of mouth; and third, three moderating effects of pro-environmental behavior, namely, moderating the influence of tourist satisfaction on tourism sustainability, moderating the influence of electronic word of mouth on tourism sustainability, and moderating the influence of satisfaction with electronic word of mouth.METHODS: This study is a quantitative study involving 420 tourists as respondents who visited West Sumatra from January to April 2023. Data analysis used partial least square–structural equation modeling. Structural equation modeling is a field of statistical study that can test a series of relationships that are relatively difficult to measure simultaneously. Partial least square is a component or variant-based structural equation model.FINDINGS: After analyzing the data, it was determined that of the six hypotheses proposed in this study, five were accepted and one was rejected. The rejected hypothesis states that with a significance level of 0.199 > 0.05, pro-environmental behavior does not moderate the effect of electronic word of mouth on the sustainability of tourism. These findings clarify that the impact of electronic word of mouth on the sustainability of tourism is not mitigated by pro-environmental conduct.CONCLUSION: When implementing sustainable tourism, not only economic factors are taken into account but also the preservation of nature and culture. Therefore, the stability of tourism in the future can be guaranteed without adversely impacting the environment.

ORIGINAL RESEARCH ARTICLE Environmental Management

Economics and cost effectiveness of a rain garden for flood-resistant urban design

D. Rinchumphu; N. Suriyanon; N. Phichetkunbodee; S. Munlikawong; C. Wanitchayapaisit; S. Sitthikankun

Articles in Press, Accepted Manuscript, Available Online from 18 April 2023

https://doi.org/10.22034/gjesm.2024.01.01

Abstract

BACKGROUND AND OBJECTIVES: Rapid urbanization negatively affects the hydrologic cycle and makes cities vulnerable to disastrous flash floods. It can additionally cause erosion and water pollution in natural ecosystems. Global climate changes have exacerbated such issues, further upsetting hydrologic ... Read More BACKGROUND AND OBJECTIVES: Rapid urbanization negatively affects the hydrologic cycle and makes cities vulnerable to disastrous flash floods. It can additionally cause erosion and water pollution in natural ecosystems. Global climate changes have exacerbated such issues, further upsetting hydrologic patterns. Therefore, many regions have considered the rain garden as green infrastructure, which can help mitigate urban runoff. However, design guidelines and the means of assessing rain garden cost effectiveness in the Global South are limited. Furthermore, as many countries in the Global South experience a tropical climate, design guidelines developed in the temperate Global North may not be directly transferable. The need for more information on design and cost effectiveness can make designers and decision makers hesitate to implement such a new strategy. The main objective of the present study is to create a design approach and simultaneously specify the cost of the infiltration rate of the rain garden in urban areas.METHODS: This study focuses on the ability of rain garden design to determine accurately the cost of materials used for construction. Sand and gravel are used in different sand ratios in the filter media layer, namely 1:1, 1:2, 1:3, and 1:4. The storage layer uses gravel only and has only one design. The aim is to determine the change in infiltration rate with an increase in the amount of sand. Knowing the amount of sand can determine the cost per infiltration rate.FINDINGS: The results showed that the most efficient design was a rain garden with a soil:sand ratio of 1:4, which increased the infiltration rate per cost by 2.00 millimeters per hour per United States Dollar per square meter. The lowest efficiency option was a soil:sand ratio of 1:1, which increased the infiltration rate per cost by 1.33 millimeters per hour per United States Dollar per square meter.CONCLUSION: This study will serve as a guide for designers to design a rain garden area according to the needs of the area, having determined the construction cost per infiltration rate. However, spatial requirements, construction costs, and social factors may influence future decisions on rain garden design and must be studied further.

ORIGINAL RESEARCH ARTICLE Environmental Engineering

Green synthesis of titanium dioxide photocatalyst using Lactobacillus bulgaricus for processing palm oil mill effluent

L. Agustina; M. Romli; P. Suryadarma; S. Suprihatin

Articles in Press, Accepted Manuscript, Available Online from 11 July 2023

https://doi.org/10.22034/gjesm.2024.01.02..

Abstract

BACKGROUND AND OBJECTIVES: To improve photocatalytic degradation perfomance, photocatalyst particles with a larger surface area preferred. The effectiveness of titanium dioxide as a photocatalyst depends on the synthesis method used. The method affect the particle size, crystallinity and phase composition ... Read More BACKGROUND AND OBJECTIVES: To improve photocatalytic degradation perfomance, photocatalyst particles with a larger surface area preferred. The effectiveness of titanium dioxide as a photocatalyst depends on the synthesis method used. The method affect the particle size, crystallinity and phase composition of the produced catalyst. This study aims to develop a green synthesis process of nano- titanium dioxide photocatalysts for the advanced treatment of palm oil mill effluent.METHODS: The green synthesis of titanium dioxide nanoparticles used de Man-Rogosa-Sharpe broth media containing Lactobacillus bulgaricus culture and titanium oxyhydroxide metal oxide. The factors investigated were the molarity of titanium oxyhydroxide (0.025 molar; 0.035 molar and 0.045 molar) and temperature (40; 50 and 60 degrees Celsius). The synthesized photocatalyst was characterized using a particle size analyzer to determine the particle size. The produced photocatalyst with a nanoparticle size range of 1-100 nanometer was further characterized using scanning electron microscopy-energy dispersive X-ray and X-ray diffraction. The photocatalyst was tested for advanced treatment of palm oil mill secondary effluent. The factors investigated in this test included the irradiation time and titanium dioxide photocatalyst dosage. The treatment performance was evaluated in terms of effluent quality and pollutant elimination efficiency.FINDINGS: Nano titanium dioxide photocatalysts have been synthesized through titanium oxyhydroxide metal oxide biologically using Lactobacillus bulgaricus. The synthesis process at a temperature of 60 degrees Celsius and a 0.025 molar metal oxide solution produced a titanium dioxide photocatalyst with a size of 33.28 nanometer. The content of titanium and oxygen constituents in the photocatalyst was confirmed to be 39.06 percent and 47.95 percent respectively, with 67.6 percent titanium dioxide crystallinity in a theta degree of 25.4. This indicates that the green synthesis has produced an anatase diffraction nano titanium dioxide photocatalyst. Testing the titanium dioxide photocatalyst to treat palm oil mill secondary effluent yielded in elimination efficiency of 16.16-27.27 percent for chemical oxygen demand and 11.05-21.95 percent for biological oxygen demand. Phenol, which is toxic and difficult to degrade biologically, could eliminated significantly (up to 81.12 percent) using a photocatalyst dose of 1 gram per liter at a time irradiation of 2.5 hour.CONCLUSION: The biological synthesis of nano titanium dioxide photocatalysts is affected by temperatures and metal oxide concentrations. The photocatalytic process for advanced treatment of palm oil mill secondary effluent shows that this synthesis process effectively eliminates phenols. Some compounds such as lignin, amino acids, and pectin are not significantly mineralized using this process.

ORIGINAL RESEARCH ARTICLE Environmental Engineering

Efficient biosorption of cadmium by Eucalyptus globulus fruit biomass using process parameters optimization

M. Samimi

Articles in Press, Accepted Manuscript, Available Online from 20 July 2023

https://doi.org/10.22034/gjesm.2024.01.03..

Abstract

BACKGROUND AND OBJECTIVES: Industrial wastewater usually contains metal ions which are hazardous to human and aquatic organisms. Nowadays, the application of inexpensive biomaterials in adsorptive removal of metal ions, such as plant biomass, has been widely considered. In this study, the efficiency ... Read More BACKGROUND AND OBJECTIVES: Industrial wastewater usually contains metal ions which are hazardous to human and aquatic organisms. Nowadays, the application of inexpensive biomaterials in adsorptive removal of metal ions, such as plant biomass, has been widely considered. In this study, the efficiency of Eucalyptus globulus fruit biomass for biological adsorption of cadmium ions from aquatic environments has been evaluated.METHODS: After drying, the collected biosorbent was ground and powdered. The dried biomass, after screening with particle size of less than 45 micrometers, was used in all experiments. The effects of operating factors, such as biosorbent to cadmium ratio, pH value of the solution and residence time of biomass and metal, on the amount of analyte adsorption were evaluated by response surface methodology. The optimum conditions for maximum metal uptake by Eucalyptus globulus fruit biomass were also evaluated using the Box-Behnken Design model. Kinetic studies were statistically described to investigate the metal adsorption process.FINDINGS: Validation experiments showed the accuracy of the model proposed for determining the optimum conditions for the cadmium biosorption process. Based on the experimental data, the values of coefficient of determination, adjusted coefficient and predicted coefficient used in the model were determined as 0.9948, 0.9855 and 0.9245, respectively. Using the model, the maximum cadmium ion adsorption by biomass was obtained at 93.65 percent, biosorbent-to-metal ratio of 9:1, pH value of 6, and contact time of 80 minutes.CONCLUSION: In the present study, the Eucalyptus globulus fruit biomass, under optimal operating conditions, proved to be an efficient sorbent for cadmium uptake from aqueous environments. The results from the experimental data of the adsorption studies were consistent with pseudo-second-order kinetics (maximum capacity of 128.2 milligram per gram), indicating that the chemical adsorption of cadmium on the used biomass occurring in monolayers.

ORIGINAL RESEARCH ARTICLE Environmental Science

Silver-based plasmonic nanoparticles for biosensor organophosphate pesticides using a single film containing acetylcholinesterase/choline oxidase

D. Hermanto; N. Ismillayli; H. Muliasari; R. Wirawan; S.R. Kamali

Articles in Press, Accepted Manuscript, Available Online from 24 May 2023

https://doi.org/10.22034/gjesm.2024.01.04..

Abstract

BACKGROUND AND OBJECTIVES: To address the potential harm caused by the intensive use of pesticides in pest control in agriculture, there is a need for accurate and efficient methods to detect and monitor pesticide residues. Therefore, this study aimed to develop a biosensor that can detect organophosphate ... Read More BACKGROUND AND OBJECTIVES: To address the potential harm caused by the intensive use of pesticides in pest control in agriculture, there is a need for accurate and efficient methods to detect and monitor pesticide residues. Therefore, this study aimed to develop a biosensor that can detect organophosphate pesticides highly toxic to humans and the environment. METHODS: Biosensor organophosphate pesticides using a single film containing acetylcholinesterase/choline oxidase have been designed using silver-based plasmonic nanoparticles as a colorimetric indicator. In the presence of acetylcholinesterase, acetylcholine is hydrolyzed to choline and acetic acid, then choline oxidase catalyzes the oxidation of choline to hydrogen peroxide and betaine. Hydrogen peroxide reacts with the silver nanoparticles, and the discoloration of the brown solution occurs due to the oxidation of silver+.FINDINGS: As a biosensor indicator, silver nanoparticles were extremely accurate, sensitive, and stable over a long period of storage. Transmission Electron Microscope images confirmed the reduction in size of nanoparticles from 16.82 ± 4.36 to 9.63 ± 2.29 nanometers. The analyte profenofos, one of the organophosphate pesticides, inhibits the activity of acetylcholinesterase, thereby reducing the concentration decrease of silver nanoparticles by releasing less hydrogen peroxide. Optimum conditions for biosensors were achieved with a potential of Hydrogen of 7, buffer, and acetylcholinesterase concentrations of 7 and 70 millimolar, respectively, with an incubation time of 5 minutes. Biosensor response showed a linear range at profenofos concentrations of 0.05-2.00 milligrams per liter, with limits of detection and quantization of 0.04 and 0.13 milligrams/liter, respectively. Biosensor also has excellent sensitivity, reproducibility, and stability, with a Relative Standard Deviation of 2.5 percent and a stable response of up to 4 months. Subsequently, using a biosensor in the chilli as a sample resulted in a profonefos level of 0.04 milligrams per liter, making it safe for consumption. CONCLUSION: Biosensor measurement outcome aligned with the gas chromatography-mass spectrometry result, which is the accepted standard method for detecting profenofos. Additionally, the proposed biosensor offers several advantages such as ease of use, fast, low-cost, and on-site analysis. Hence, this method is suitable for monitoring and controlling pesticide residues, particularly organophosphate, in agricultural products and the environment.

ORIGINAL RESEARCH ARTICLE Environmental Science

Analyzing cellulolytic bacteria diversity in mangrove ecosystem soil using 16 svedberg ribosomal ribonucleic acid gene

I. Dewiyanti; D. Darmawi; Z.A. Muchlisin; T.Z. Helmi

Articles in Press, Accepted Manuscript, Available Online from 14 June 2023

https://doi.org/10.22034/gjesm.2024.01.05..

Abstract

BACKGROUND AND OBJECTIVES: Soil is an essential abiotic component serving as a habitat for numerous organisms, including cellulolytic bacteria commonly found in mangrove ecosystems. This bacteria could produce active enzymes needed to improve environmental quality by accelerating the organic matter decomposition. ... Read More BACKGROUND AND OBJECTIVES: Soil is an essential abiotic component serving as a habitat for numerous organisms, including cellulolytic bacteria commonly found in mangrove ecosystems. This bacteria could produce active enzymes needed to improve environmental quality by accelerating the organic matter decomposition. The unique mangrove environment may contain new types of cellulolytic bacteria with new characteristics. Despite several mangrove areas being explored as sources of cellulolytic bacteria, there is currently unexplored data on its diversity in Aceh Province, Indonesia. Accordingly, it is necessary to analyze the molecular biological approach, namely the 16 svedberg ribosomal ribonucleic acid gene, to identify the diversity of cellulolytic bacteria and analyze the phylogenetic relationships between them.METHODS: Bacteria isolates were collected from mangrove soil at six research locations with three replications. A purposive sampling method was applied to determine the research location. Isolates from soil samples were streaked and purified in carboxymethyl cellulose as selective media for cellulolytic bacteria. Molecular identification adopted 16 svedberg ribosomal ribonucleic acid gene sequencing, and the sequencing data were matched with GenBank data. Phylogenetic analysis and genetic distance between species were evaluated using molecular evolutionary genetics analysis.FINDINGS: Thirteen isolates were sequenced, and nine species of cellulolytic bacteria dominated by the Bacillus genus were identified. These species exhibited an identity value of 97.77-100 percent when compared to data from GenBank, and B. velezensis was found to have a close relationship with B. amyloliquefaciens at a value of 0.002 percent. Interestingly, the non-rehabilitated mangrove areas had more bacterial species than the rehabilitated ones. Two Bacillus genus had different nucleotide bases, proving they were distinct species.CONCLUSION: Nine cellulolytic bacteria species were identified; the two closely interspecies genetic distance related were B. velezensis and B. amyloliquefaciens, whereas the farthest were Bacillus sp1. and Bacillus sp2. Small genetic distances of interspecies indicate a close relationship between species. In comparing the two sampling sites, the non-rehabilitated mangrove contains higher bacterial cellulolytic species than the rehabilitated and Bacillus-dominated site. The findings provide valuable insights into the diversity of cellulolytic bacteria in mangrove ecosystems. The abundance of bacterial species could serve as sources of cellulase enzymes with different characteristics, essential in an environmental aquatic management.

ORIGINAL RESEARCH ARTICLE Environmental Management

Evaluation of municipal waste collection performance using operational data

G.M. Hoang; H.T.T. Ung; N.T.L. Le; T.D. Nguyen

Articles in Press, Accepted Manuscript, Available Online from 27 June 2023

https://doi.org/10.22034/gjesm.2024.01.06..

Abstract

BACKGROUND AND OBJECTIVES: Developing countries'' governments face challenges in municipal solid waste collection, such as rapidly increased volume of waste, physical and social obstacles to collection routes, or funding shortages. The lack of practical evaluation of the waste collection performance ... Read More BACKGROUND AND OBJECTIVES: Developing countries'' governments face challenges in municipal solid waste collection, such as rapidly increased volume of waste, physical and social obstacles to collection routes, or funding shortages. The lack of practical evaluation of the waste collection performance is considered a gap in improving the waste collection system in these countries. This study aims to assess the efficiency of current municipal solid waste collection by analyzing operational data that can help enhance the collection.METHODS: The geographical information system and the geographical position system data of all active trucks were collected for 14 consecutive days using the digital map. Data on waste volume collected by trucks, waste volume at collection points, and operational time of trucks throughout a working day were collected by survey. The operational efficiency indicators, including the deadhead rate, waste collected per distance unit, stopping time rate, and costs, are estimated to evaluate the effectiveness of municipal solid waste collection services.FINDINGS: The results indicate that solid waste collection efficiency of 1.67 tons/kilometers is low for high-density population areas. The deadheading rate of approximately 20 percent shows that the collection route operated by drivers is meandering and inefficient. Although using small trucks (6–7 tons) for transporting waste to landfills over a long distance is inefficient, small vehicles are used more than large ones. Ineffective utilization of transfer stations could lead to high idle time, accounting for approximately 37.6 percent of a collection trip. The regulated estimating method for transportation costs is not comprehensively developed, which may cause mistakes in choosing collection vehicles for operation and transfer station usage.CONCLUSION: The research findings assess the performance and identify ineffective factors that require improvement of waste collection, aiming to enhance the solid waste management system. Waste collection routes of Hoan Kiem district must be designed using empirical data. The distance-based coefficients should be developed for all collection vehicles with different loading capacities to better estimate collection and transportation costs in Hanoi, helping decision-makers utilize the current transfer station more effectively and appropriately in choosing collection vehicles for operation.

ORIGINAL RESEARCH ARTICLE Environmental Engineering

Wetland degradation monitoring using multi-temporal remote sensing data and watershed land degradation index

I. Ridwan; S. Kadir; N. Nurlina

Articles in Press, Accepted Manuscript, Available Online from 30 July 2023

https://doi.org/10.22034/GJESM.2024.01.07..

Abstract

BACKGROUND AND OBJECTIVES: The condition of the watershed area, particularly the Tabunio Watershed, is one with priority treatment due to the condition of the land where it is located, which qualifies for the “very high recovery” category with a critical land area of 19,109.89 hectare. Moreover, ... Read More BACKGROUND AND OBJECTIVES: The condition of the watershed area, particularly the Tabunio Watershed, is one with priority treatment due to the condition of the land where it is located, which qualifies for the “very high recovery” category with a critical land area of 19,109.89 hectare. Moreover, the diminishing water absorption also results in flooding during the rainy season and drought in the dry season. Environmental damage in the Tabunio Watershed is exacerbated by the existence of traditional gold mining and has become a concern for many parties. With this in mind, the perceived increase in natural disasters, such as floods, landslides, and droughts from year to year requires an evaluation of land degradation in the Tabunio Watershed.METHODS: The objective of this study was to monitor and simulate the spatial and temporal aspects of land degradation in the Tabunio Watershed. It was suggested that a complete land degradation index be developed to capture the spatial and temporal aspects of land degradation between the years 2005 and 2020. This index integrates land use land cover, vegetation coverage, soil erosion, and soil moisture content.FINDINGS: The proposed comprehensive land degradation index in this study demonstrated that (a) the land degradation index, which successfully monitored the spatio-temporal aspect of land degradation (kappa coefficient > 0.73 and overall accuracy > 86 percent), is regarded as having high accuracy. (b) In comparison to the individual indices, the land degradation index is capable of revealing land degradation in a more comprehensive manner. (c) land degradation index is readily transferable and applicable to other study areas due to the fact that all of its land degradation indices can be quickly extracted from remotely sensed imagery. (d) land degradation index can be used in a wide variety of contexts, which also accounts for the provision of quantitative predictions with regard to the possibility of land degradation. (e) The rate of land degradation will generally increase from 2005 to 2020, with 2010 being the most extreme year.CONCLUSION: The proposed comprehensive land degradation index method is capable of describing the spatial and temporal aspect of land degradation from 2005 to 2020 in the watershed area. Moreover, the proposed approach shows that the level of land degradation from 2005 to 2020 normally increases, recording the extreme years as the 2010s. In addition, in most years, the amount of land degradation was moderate, only few of which had severe or extreme degradation. As a consequence of this, some land degradation management measures ought to be created in advance, guaranteeing the protection of this vital region, which is a source of freshwater. The study provides a substantial understanding of the effect of land degradation on sustainable environment management and development in the watershed.

ORIGINAL RESEARCH ARTICLE Environmental Science

Exploring the upper ocean characteristics of a bay using coastal and regional ocean community model

D. Jaishree; P.T. Ravichandran

Articles in Press, Accepted Manuscript, Available Online from 10 July 2023

https://doi.org/10.22034/gjesm.2024.01.08..

Abstract

BACKGROUND AND OBJECTIVES: The innovativeness of this study lies in achieving a comprehensive understanding of the seasonal variations and oceanic characteristics of the Bay of Bengal by addressing the complex interplay of large-scale ocean-atmosphere dynamics. The study aimed to understand the upper ... Read More BACKGROUND AND OBJECTIVES: The innovativeness of this study lies in achieving a comprehensive understanding of the seasonal variations and oceanic characteristics of the Bay of Bengal by addressing the complex interplay of large-scale ocean-atmosphere dynamics. The study aimed to understand the upper ocean characteristics of the Bay of Bengal by analyzing the surface variables such as salinity and temperature using a high-resolution model simulation. To accomplish this, advanced high-resolution numerical simulations were employed, utilizing the coastal and regional ocean community model. This model was crucial for investigating and analyzing the circulation features throughout the entire Bay of Bengal, contributing knowledge and insights about the coastal and regional oceanographic community.METHODS: To investigate the temporal variability of the upper ocean in the Bay of Bengal, climatological simulations were performed over eight years using the coastal and regional ocean community model. Including a three-year spin-up phase facilitated the adjustment of the model to initial conditions and the attainment of equilibrium, ensuring its fidelity to real-world conditions. The follow-up analyses and comparisons were performed five years after the spin-up phase. The primary objective of this study was to examine the temporal evolution of the kinetic energy throughout the eight-year simulation. The volume-averaged kinetic energy was computed, revealing a gradual increase throughout the simulation, with particularly pronounced enhancements observed during the monsoon period. A Taylor diagram was used for predicting the model with the other data sets.FINDINGS: The analysis is performed above the surface and sub-surface oceanic layers with prominent dynamics. The temperature and salinity for the surface and sub-surface layers were validated and analyzed for their seasonal variations. The simulations were validated against the existing satellite, reanalysis, and in situ data.CONCLUSIONS: The innovativeness of this study lies in its successful demonstration of the seasonal variability of temperature and salinity in the Bay of Bengal. Through extensive validations, it establishes the model to accurately simulate the climatological surface features of the Bay of Bengal. This study highlights the effectiveness of numerical models when combined with observations, and the data were reanalyzed, showcasing their utility as valuable tools for studying oceanic conditions. The utilization of a Taylor diagram further supports the validation and excellent performance of the model compared to other available datasets. During the simulation, there is a high correlation (0.96) between the evolution of the salinity and temperature values obtained from the model and the corresponding data from the World Ocean Atlas. This indicates a strong agreement between the model-based simulations and the assimilated data, as supported by the notable correlation values of 0.96 for salinity and temperature. These findings reinforce the existing knowledge regarding the influential role of monsoon winds in shaping the circulation patterns within the Bay of Bengal. Overall, this study contributes to advancing our understanding of the ocean dynamics of the region and underscores the importance of considering seasonal variations for comprehensive oceanographic research, coastal management, climate modeling, and future studies in the Bay of Bengal.

ORIGINAL RESEARCH ARTICLE Environmental Engineering

Application of fuzzy logic in decision-making process for relocation of floating net cages in river fish farming

R. Pramana; B.Y. Suprapto; Z. Nawawi

Articles in Press, Accepted Manuscript, Available Online from 09 August 2023

https://doi.org/10.22034/gjesm.2024.01.09..

Abstract

BACKGROUND AND OBJECTIVES: Land-based aquaculture operations, at present, are intensively conducted to meet the ever-growing demand for food consumption. Floating net cages are one of the traditional methods commonly used by Indonesian fishermen for river fish farming. Increased human activities ... Read More BACKGROUND AND OBJECTIVES: Land-based aquaculture operations, at present, are intensively conducted to meet the ever-growing demand for food consumption. Floating net cages are one of the traditional methods commonly used by Indonesian fishermen for river fish farming. Increased human activities along the Musi River and coastline have resulted in pollution and waste in the river waters and fluctuating water quality. Yet, floating net cage owners still manually assess the water quality. This study aims to develop an early warning system for water quality and create a decision-making program as a reference for fishermen to relocate floating net cages when the river water quality deteriorates.METHODS: The device was tested at 39 locations within a radius of approximately 3400 meters, and the distance between locations varied between 55 and 334 meters. The river was divided into three sections: the river coast, the middle section, and the other river coast. Water quality sensors were placed at a depth of 0–20 centimeters from the surface of the Musi River, with measurement durations at each location ranging from 1 to 40 minutes. Direct measurements of the Musi River's water quality were obtained by monitoring the water quality using an internet-based computer application. A decision-making Python program utilizing fuzzy logic was then executed to evaluate the suitability of the river water quality for fish cultivation. The program's input variables comprise water temperature, potential of hydrogen, and dissolved oxygen sensor data. Meanwhile, the program output recommends floating net cage owners to either "Stay in position" or "Move." Water quality warnings that exceed the upper and lower threshold limits are displayed using light-emitting diode indicators and a buzzer.FINDINGS: Overall, the water quality values of the Musi River at the test locations generally indicated stable and suitable conditions for river fish cultivation. The average water quality values were 29.20 degrees Celsius for temperature, 3.98 milligrams per liter for dissolved oxygen, and a potential of hydrogen of 6.42. From all the data obtained during the decision-making program, 36 locations suggested that the floating net cages should "Stay in position." Meanwhile, the three remaining locations were recommended to "Move" as they exhibited poor water quality, with potential of hydrogen values below 6. Field observations indicated that these locations were situated near residential areas, factories/industries, and tributaries, which are highly susceptible to waste and pollution. The output of the decision-making program correlated with the issued warnings by the water quality warning indicators when the pH value exceeded the lower threshold limit.CONCLUSION: The fuzzy logic method implemented in the Python program for decision-making regarding the relocation of floating net cages in river fish farming revealed the fluctuating water quality conditions of the Musi River within a specific time duration. These conditions correlated with the proximity of the water bodies to pollution sources such as residential areas, factories, and tributaries. The program's output classified the status of the floating net cages into two conditions: "Stay in position" or "Move." The decision-making application to relocate floating net cages for fish farming in rivers provides a solution for fishermen as the resulting program decisions give the same indication as the reading value of the water quality sensor.

ORIGINAL RESEARCH ARTICLE Environmental Engineering

Factors affecting cadmium toxicity to rice germinated in soils collected from downstream areas of abandoned zinc mines

P. Chanpiwat; A. Numprasanthai

Articles in Press, Accepted Manuscript, Available Online from 11 August 2023

https://doi.org/10.22034/gjesm.2024.01.10..

Abstract

BACKGROUND AND OBJECTIVES: Cadmium contamination in rice grains with a maximum concentration 19 times the national food standard at sites downstream of zinc mines in Thailand has been reported since 2005. These cultivated rice grains are consumed by local residents and have increased the risk of renal ... Read More BACKGROUND AND OBJECTIVES: Cadmium contamination in rice grains with a maximum concentration 19 times the national food standard at sites downstream of zinc mines in Thailand has been reported since 2005. These cultivated rice grains are consumed by local residents and have increased the risk of renal dysfunction in residents. Decreasing negative health effects by reducing cadmium accumulation in rice should be considered. Since the soil characteristics affecting the toxicity and accumulation of cadmium in rice cultivated in cadmium-contaminated soils have never been reported, this study was conducted to investigate the soil characteristics affecting the plant availability and mobility of cadmium in paddy soils and the impacts of these soil characteristics on rice seed germination and accumulation in rice.METHODS: The study area is the Mae Tao Subdistrict, Mae Sot District, Tak Province, located downstream of abandoned zinc mines in northwestern Thailand. A total of 36 paddy fields that were reported to produce rice grain with cadmium contents exceeding the national standard for cadmium in rice (0.4 milligrams per kilogram) were randomly selected for composite soil sample collection. The physicochemical characteristics of the soils, including soil texture, redox potential, cation exchange capacity, potential of hydrogen, organic matter, total cadmium concentration, and chemical speciation and concentration of plant-available cadmium, were analyzed. The toxicity of cadmium to rice and the cadmium accumulation ability in rice were assessed through the germination of Khao Dok Mali 105, a popular rice variety for cultivation and consumption in the study area.FINDINGS: Total cadmium concentrations of 0.20 to 89.87 milligrams/kilogram were found in the soils, with 64 percent of all samples containing values greater than the national background value in agricultural soils. Up to 74.2 percent and 99.5 percent of total cadmium was found in the forms of mobile- and plant-available cadmium, respectively. Plant-available cadmium caused significant reductions in the number of seeds germinated and root length. Cadmium toxicity to rice was positively affected by the concentrations of exchangeable, plant-available and total cadmium. The concentrations of plant-available, exchangeable, carbonate-bound, and total cadmium strongly affected the accumulation of cadmium in germinated roots. Cluster analysis showed that plant-available cadmium was the main factor responsible for high cadmium accumulation in rice.CONCLUSION: Based on the overall analyses of soil characteristics affecting the mobility and plant availability of cadmium in soils and its toxicity and accumulation in germinated rice, the immobilization of plant-available cadmium in soils by adding organic matter-rich amendments to soils is recommended. In addition, oxidizing soil conditions should be maintained during rice cultivation to reduce the phytoavailability of cadmium in soils.

ORIGINAL RESEARCH ARTICLE Environmental Science

Impact of environmental and geographical position on the chemometric classification of ethanol extracts from Isotoma longiflora leaves

E. Imelda; K. Khairan; R.R. Lubis; T. Karma; R. Idroes

Articles in Press, Accepted Manuscript, Available Online from 28 June 2023

https://doi.org/10.22034/gjesm.2024.01.11..

Abstract

BACKGROUND AND OBJECTIVES: Isotoma longiflora L is commonly used as a medicinal plant by the local community in Indonesia, and its geographical position determines its bioactive compounds and hence its efficacy. Ethanol extracts of Isotoma longiflora leaves from various locations in Aceh Province were ... Read More

ORIGINAL RESEARCH ARTICLE Environmental Engineering

Torrefaction of bamboo pellets using a fixed counterflow multibaffle reactor for renewable energy applications

W. Hidayat; B.A. Wijaya; B. Saputra; I.T. Rani; S. Kim; S. Lee; J. Yoo; B.B. Park; L. Suryanegara; M.A.R. Lubis

Articles in Press, Accepted Manuscript, Available Online from 14 September 2023

https://doi.org/10.22034/gjesm.2023.04.02.

Abstract

BACKGROUND AND OBJECTIVES: The decreasing availability of fossil fuels requires the adoption of renewable energy sources that facilitate the mitigation of greenhouse gas emissions. Meeting Indonesia’s goal of achieving a 23 percent mixed energy composition by 2025 through co-firing demands a substantial ... Read More BACKGROUND AND OBJECTIVES: The decreasing availability of fossil fuels requires the adoption of renewable energy sources that facilitate the mitigation of greenhouse gas emissions. Meeting Indonesia’s goal of achieving a 23 percent mixed energy composition by 2025 through co-firing demands a substantial increase in the availability of renewable energy sources. Bamboo is a valuable biomass resource because of its fast growth rate and potential for energy production. Innovative processes like torrefaction are necessary to improve the quality of biomass due to its challenging low density and hydrophilic properties. The objective of this study is to evaluate the characteristics of torrefied bamboo pellets made from Gigantochloa pseudoarundinacea by using a fixed counter-flow multi-baffle reactor. This study aims to investigate the properties and viability of torrefied G. pseudoarundinacea pellets for solid fuel applications to fill existing knowledge gaps about this technology’s potential.METHODS: A fixed counter-flow multi-baffle reactor was used to torrefy G. pseudoarundinacea bamboo pellets. The baffles in the reactor column held the pellets, while hot gas flowed through them. Torrefaction was conducted at 280 degrees Celsius with a 3–5 minutes resident time, and the gas flow rate was 4.25 cubic meters per minute. Torrefied pellets at the column bottom were counted as the first cycle. Three cycles of torrefaction were used, and each cycle was evaluated. The second and third cycles used torrefied pellets from the first and second cycles. The physical, chemical, and bioenergetic properties of the pellets before and after torrefaction were evaluated.FINDINGS: The bamboo pellets’ physical, chemical, and thermal properties changed significantly after torrefaction. Torrefaction at 285 degrees Celsius produced 78.5 percent of the production yield, according to thermogravimetric and derivative thermogravimetric analyses. Lightness, red/green, and yellow/blue chromaticity decreased, indicating darker, better solid fuel pellets. Torrefaction in the third cycle reduced moisture content by 99.8 percent. The lower moisture content reduced fungal growth, and improvinged biomass transport and storage. Torrefaction also raised the bamboo pellets’ calorific value and physical and mechanical properties. The highest calorific value of 21.62 megajoules per kilogram was obtained after the third cycle of torrefaction, and it was 16.6 percent higher than that of raw pellets. Torrefaction improved pellet grindability and combustion by decreasing density and compressive strength. Torrefaction increased ash, volatile matter, and fixed carbon. The ultimate analysis showed increased carbon and reduced nitrogen, hydrogen, and oxygen, improving solid fuel quality, energy density, and combustion emissions. According to a Fourier-transform infrared analysis, torrefaction caused extractive and hemicellulose degradation and lignin increase. The chemical analysis showed that temperature and residence time degraded hemicellulose and increased lignin in the torrefied pellets.CONCLUSION: The torrefaction process using a fixed counter-flow multi-baffle reactor demonstrated the enhanced properties of G. pseudoarundinacea bamboo pellets for their application as solid fuel. The study’s findings contribute to the comprehension of torrefaction and the enhancement of conditions for producing superior biomass products. These findings have implications for exploring the potential applications of torrefaction in diverse industries and energy sectors.

ORIGINAL RESEARCH ARTICLE Environmental Science

Role of Cylindrospermopsis sp. in vertical nitrogen changes observed in tropical oxidation wastewater treatment ponds

M. Srichomphu; O. Phewnil; T. Pattamapitoon; Ratcha Chaichana; K. Chunkao; W. Wararam; N. Dampin; P. Maskulrath

Articles in Press, Accepted Manuscript, Available Online from 28 June 2023

https://doi.org/10.22034/gjesm.2024.01.09

Abstract

BACKGROUND AND OBJECTIVES: As a producer within the ecological food chain, phytoplankton provides the base energy and oxygen to the environment through photosynthesis and higher tropic levels. These benefits can be applied in five consecutive nature-by-nature oxidation ponds for the treatment of community ... Read More BACKGROUND AND OBJECTIVES: As a producer within the ecological food chain, phytoplankton provides the base energy and oxygen to the environment through photosynthesis and higher tropic levels. These benefits can be applied in five consecutive nature-by-nature oxidation ponds for the treatment of community wastewater coming through a high density polyethylene pipeline from the Phetchaburi Municipality located at the King’s Royally Initiated Laem Phak Bia Environmental Research and Development Project, Ban Laem District, Phetchaburi Province (Universal Transverse Mercator 47P 1442725 North 617774 East). This study focuses on the vertical distribution of the phytoplankton Cylindrospermopsis sp. and its relationship with nitrogen compounds in oxidation ponds.METHODS: Samples were collected from a community wastewater treatment system at various depths (30, 60, 90, 120, and 150 centimeters) below the water surface in April 2019 between 11:00 and 13:00 hours and analyzed for their chemical and physical properties. The analysis revealed a vertical relationship between Cylindrospermopsis sp. and wastewater. In the density of phytoplankton which were collected by measuring 20 liters of water and filtered using a 36-micron plankton net, calculated and counted under a high magnification microscope, as the species are classified according the taxonomy.FINDINGS: The results of the wastewater quality were as follows: the content of suspended solids was 65–81 milligram per liter, water temperature was 31.8–33.2°C, potential of hydrogen was 8.7–9.2, total nitrogen content was 4.0–5.3 milligram per liter, ammonium content was 0.03–0.06 milligram per liter, nitrate content was 0.09–0.12 milligram per liter, total phosphorus content was 0.9–1.3 milligram per liter, and phosphate content was 0.4–0.5 milligram per liter. In the density of phytoplankton, a significant correlation was observed between the population of Cylindrospermopsis sp. and water depth (R2 = 0.9324). The number of populations at the depths of 30, 60, 90, 120, and 150 centimeters were 3.2 × 107, 1.6 × 107, 1.1 × 107, 5.5 × 107, and 1.1 × 108 cells per cubic meter, respectively.CONCLUSION: The different densities of Cylindrospermopsis sp. found at different depths throughout the treatment pond are related to the nitrogen dynamics of the water body. The results of this study revealed that organic nitrogen, including ammonium, was assimilated and converted to inorganic nutrients, which promoted the growth of other phytoplankton species. The correlation between Cylindrospermopsis sp. and total nitrogen and ammonium showed significance at R2 = 0.7268 and 0.797, respectively, with a confidence level of 0.05. Therefore, to ensure treatment effectiveness, the depth of wastewater treatment ponds should be considered during their construction because phytoplankton regulation plays an important role to maintain the overall treatment efficiency.

ORIGINAL RESEARCH ARTICLE Environmental Engineering

Machine learning using random forest to model heavy metals removal efficiency using a zeolite-embedded sheet in water

N.D. Takarina; N. Matsue; E. Johan; A. Adiwibowo; M.F.N.K. Rahmawati; S.A. Pramudyawardhani; T. Wukirsari

Articles in Press, Accepted Manuscript, Available Online from 23 July 2023

https://doi.org/10.22034/gjesm.2024.01.03

Abstract

BACKGROUND AND OBJECTIVES: Zeolite has been recognized as a potential adsorbent for heavy metals in water. The form of zeolite that is generally available in powder has challenged the use of zeolite in the environment. Embedding powder zeolite in a nonwoven sheet, known as a zeolite-embedded sheet can ... Read More BACKGROUND AND OBJECTIVES: Zeolite has been recognized as a potential adsorbent for heavy metals in water. The form of zeolite that is generally available in powder has challenged the use of zeolite in the environment. Embedding powder zeolite in a nonwoven sheet, known as a zeolite-embedded sheet can be an alternative to solve that. Another challenge is that information and models of zeolite-embedded sheet removal efficiency are still limited. The novelty of this study is, first, the development of a zeolite-embedded sheet to remove heavy metals from water, and second, the use of the random forest method to model the heavy metal removal efficiency of a zeolite-embedded sheet in water.METHODS: The heavy metals studied were copper, lead and zinc, considering that those are common heavy metals found in water. For developing the zeolite-embedded sheet, the methods include fabrication of the zeolite-embedded sheet using a heating procedure and heavy metals adsorption treatment using the zeolite-embedded sheet. The machine learning analysis to model the heavy metal removal efficiency using zeolite-embedded sheet was performed using the random forest method. The random forest models were then validated using the root mean square error, mean square of residuals, percentage variable explained and graphs depicting out-of-bag error of a random forest.FINDINGS: The results show the heavy metal removal efficiency was 5.51-95.6 percent, 42.71-98.92 percent and 13.39-95.97 percent for copper, lead and zinc, respectively. Heavy metals were reduced to 50 percent at metal concentrations of 10.355 milligram per liter for copper, 171.615 milligram per liter for lead and 4.755 milligram per liter for zinc. Based on the random forest models, the important variables affecting copper removal efficiency using zeolite-embedded sheet were its contents in water, followed by water temperature and potential of hydrogen. Conversely, lead and zinc removal efficiency was influenced mostly by potential of hydrogen. The random forest model also confirms that the high efficiency of heavy metals removal (>60 percent) will be achieved at water potential of hydrogen ranges of 4.94–5.61 and temperatures equal to 29.1 degrees Celsius.CONCLUSION: In general, a zeolite-embedded sheet can adsorb diluted heavy metals from water because there are percentages of adsorbed heavy metals. The random forest model is very useful to provide information and determine the threshold of heavy metal contents, water potential of hydrogen and temperature to optimize the heavy metal removal efficiency using a zeolite-embedded sheet and reducing pollutants in the environment.

ORIGINAL RESEARCH ARTICLE Environmental Management

Flood susceptibility mapping based on watershed geomorphometric characteristics and land use/land cover on a small island

B.H. Narendra; O. Setiawan; R.A. Hasan; C.A. Siregar; , Pratiwi; N. Sari; A. Sukmana; I.W.S. Dharmawan; R. Nandini

Articles in Press, Accepted Manuscript, Available Online from 21 July 2023

https://doi.org/10.22034/gjesm.2024.01.07

Abstract

BACKGROUND AND OBJECTIVES: Flooding is the most frequent hydrological disaster which greatly impacts humans and the environment. Lombok, a small tropical island, experiences severe flooding almost yearly. Flood susceptibility mapping is important to determine the priority watershed in implementing flood ... Read More BACKGROUND AND OBJECTIVES: Flooding is the most frequent hydrological disaster which greatly impacts humans and the environment. Lombok, a small tropical island, experiences severe flooding almost yearly. Flood susceptibility mapping is important to determine the priority watershed in implementing flood mitigation action, including improving the spatial planning in watershed management. Several methods of determining flood susceptibility require the support of long data series and a variety of monitoring equipment in the field where not every region has the resource capacity. Compared to other methods that require the support of long data series and a large number of evenly distributed monitoring equipment, the geomorphometric parameters and land use/cover in a watershed are closely related to the hydrological responses and are potentially applicable in flood susceptibility mapping. This research aimed to classify the watershed flood susceptibility on a small island based on the geomorphometric characteristics and land use/land cover of the watershed.METHODS: This study was carried out on Lombok Island, located in southern Indonesia, representing a small island in the tropical region. Watershed classification was carried out using 24 geomorphometric variables and land use/land cover, representing aspects of the river network, geometry, texture, and watershed relief. The principal component analysis approach was carried out to determine the most significant variable, and the weight of each variable was determined using the weighted sum approach method. Then, compound values were calculated based on the weighted values and preliminary ranking to indicate the flood susceptibility levels, which were divided into five classes.FINDINGS: The analysis found that the variables most related to flood events are the total number of rivers, relief ratio, elongation ratio, river density, stream frequency, and dry agricultural land use. These most related geomorphometrics indicate that the watersheds with higher flood susceptibility have low rock permeability, relatively low infiltration capacity, and relatively high surface runoff, thus triggering flooding. The flood susceptibility mapping classified 16 watersheds as having very high flood susceptibility. This research shows that analysis of the geomorphometric characteristics and land use/land cover can be relied upon to determine the flood susceptibility level, which is useful in spatial planning and flood disaster mitigation.CONCLUSION: Geomorphometric characteristics and land use/land cover can be used to determine a watershed's hydrological characteristics or behaviour. Based on the geomorphometric characteristics of the watersheds on Lombok Island, some identifying variables that are highly related to flood processes were obtained. Based on these characteristics, watersheds with high and very high flood susceptibility levels have low rock permeability, relatively low potential infiltration capacity, and relatively high surface runoff potential. Flooding still occurs despite good forest cover because the geomorphometric characteristics of the watershed also play a major role in flood events.

ORIGINAL RESEARCH ARTICLE Environmental Science

Root growth and arbuscular mycorrhizal fungi on woody plants for vegetative stabilization of tropical slopes

I.G. Tejakusuma; E.H. Sittadewi; T. Handayani; T. Hernaningsih; W. Wisyanto; A. Rifai

Articles in Press, Accepted Manuscript, Available Online from 18 May 2023

https://doi.org/10.22034/gjesm.2024.01.10

Abstract

BACKGROUND AND OBJECTIVES: Plant growth is improved by arbuscular mycorrhizal fungi, although they have not been researched for slope stability. These fungal inoculations and bamboo interventions may promote root development toward the slip plane. Thstudy looks at how tree roots react to planting ... Read More

CASE STUDY Environmental Science

Modeling regional aboveground carbon stock dynamics affected by land use and land cover changes

A.D. Malik; M.C.W. Arief; S. Withaningsih; P. Parikesit

Articles in Press, Accepted Manuscript, Available Online from 23 May 2023

https://doi.org/10.22034/gjesm.2024.01.19

Abstract

BACKGROUND AND OBJECTIVES: Land use and land cover changes are affected by massive construction, urban expansion, and exploitative agricultural management. These pressures threaten the potential of aboveground carbon storage in Rancakalong District, West Java, Indonesia. In that massive construction ... Read More BACKGROUND AND OBJECTIVES: Land use and land cover changes are affected by massive construction, urban expansion, and exploitative agricultural management. These pressures threaten the potential of aboveground carbon storage in Rancakalong District, West Java, Indonesia. In that massive construction and agricultural expansion are ongoing, it is critical to detect the potential changes in carbon stocks in the region. This study evaluated the impact of land use and land cover changes on aboveground carbon stock potential in Rancakalong District, West Java, Indonesia, by incorporating several ground-based carbon inventories into geographic information systems and remote sensing approaches. The spatiotemporal dynamics of the aboveground carbon stocks were assessed using Integrated Valuation of Ecosystem Services and Tradeoffs models.METHODS: Aboveground carbon stocks were estimated using the integrated approach of field inventory and geographic information systems. Land use and land cover changes were assessed from remotely sensed imagery data recorded in 2009 and 2021 using the maximum likelihood classification method in the geographic information as a collection of layers and other elements in a map 10.6 package. Tree height and diameter were collected within the purposively distributed plots with a size of 30 × 30 square meters. Vegetation biomass was assessed using an allometric equation, and aboveground carbon stock data were extrapolated to the landscape scale using a linear regression model of measured carbon stocks and the Normalized Difference Vegetation Index derived from recent satellite imagery.FINDINGS: Vegetated areas were predominant in 2009 and 2021. Vegetation covered 51 percent of the total area in 2009, increasing to 57 percent in 2021. Regarding agricultural area, mixed gardens and drylands decreased between 2009 and 2021. Meanwhile, paddy fields were the only agricultural land use to increase between 2009 and 2021. The bare land and built-up expansion related to the observed land clearing for the Cisumdawu Highway mainly came from the conversion of mixed gardens, paddy fields, and drylands. The results show that the land use and land cover changes in Rancakalong District have caused a reduction in aboveground carbon stocks by 11,096 tons between 2009 and 2021. The highest reduction in aboveground carbon stocks occurred in mixed gardens, while a slight increase in aboveground carbon stocks occurred in forests, shrubs, and paddy fields. The results highlight the contribution of mixed gardens to carbon storage as they are visually similar to forests in the structure and composition of vegetation.CONCLUSION: Land use and land cover changes directly affected the aboveground carbon stock potential in Rancakalong District, indicated by an 11,096-ton reduction in the stocks. This shortage of carbon stock potential was mainly attributed to the massive reduction in mixed garden areas between 2009 and 2021 by 12 percent, which caused a significant decrease in aboveground carbon stocks. The application of the Integrated Valuation of Ecosystem Services and Tradeoffs model is efficient in analyzing the effect of land use and land cover change on aboveground carbon stock dynamics and can be widely used in environmental engineering studies involving remote sensing approaches.

CASE STUDY Environmental Management

An analysis on the economic development and deforestation

E.S. Siregar; S.U. Sentosa; A. Satrianto

Articles in Press, Accepted Manuscript, Available Online from 06 June 2023

https://doi.org/10.22034/gjesm.2024.01.21

Abstract

BACKGROUND AND OBJECTIVES: This study aimed to investigate endogenous variables namely, economic development and deforestation, in North Sumatra, and examine their determinants. Both variables are substantial in a country community welfare with harmonized environmental sustainability as a legacy for ... Read More BACKGROUND AND OBJECTIVES: This study aimed to investigate endogenous variables namely, economic development and deforestation, in North Sumatra, and examine their determinants. Both variables are substantial in a country community welfare with harmonized environmental sustainability as a legacy for future generations.METHODS: In this quantitative study, secondary data in the form of time series data from 1991 to 2020 with a total of 30 years were analyzed. The novelty of this study is its aim to combine deforestation variables and their determinants in a research model related to economic development. In this study, the determinants of economic development used were education, health, mineral resources and forest resource, whereas those of deforestation, were forest resource, institutional factors, population density, and economic development.FINDINGS: The data analysis revealed that the economic development in North Sumatra was significantly influenced by education, health, and mineral resources, excluding forest resources. Simultaneously, the determinants influenced economic development by 74.15 percent. Education contributed 27 percent, health 71 percent, mineral resources 12 percent and forest resources 29 percent to economic development. Forest resources and institutions had a significant influence on deforestation in North Sumatra, whereas population density and economic development did not have a significant effect. Simultaneously, the determinants influenced deforestation by 77.24 percent. Partial, forest resources and institutions were identified and significant effect but population density does not significantly affect it. Forest resources contributed 14 percent to deforestation, institutional factors 72 persent, population density 3 percent and economic development 57 percent.CONCLUSION: The findings of this study, indicated that education and health have a major effect on economic development whereas forest resources do not however, forest resources significantly affect deforestation. This means that an increasing environmental damage removes forest cover. Thus, it is recommended that the government increase human resource in terms of education and health, which are essential in prioritizing human resource development as a fundamental factor. It is also important to set the limit to long-term natural resource exploitation, consider environmental damages, and improve institutional quality. The government needs to explore alternative sources that are more sustainable and environmentally friendly, such as ecotourism, and renewable energy. Renewable energy can be a reliable source of energy that will help reduce reliance on fossil fuels while also minimizing environmental impacts.

CASE STUDY Environmental Science

Cocoa farmers' characteristics on climate variability and its effects on climate change adaptation strategy

I. Idawati; N.A. Sasongko; A.D. Santoso; M. Septiani; T. Handayani; A.Y.N. Sakti; B.D. Purnamasari

Articles in Press, Accepted Manuscript, Available Online from 01 November 2023

https://doi.org/10.22034/gjesm.2024.01.20.

Abstract

BACKGROUND AND OBJECTIVES: Climate change has a greater influence on agriculture through local climate variability than global climate patterns. The impact of climate change on agricultural productivity and shifts in crop patterns varies significantly across regions. Its impact is closely tied to the ... Read More BACKGROUND AND OBJECTIVES: Climate change has a greater influence on agriculture through local climate variability than global climate patterns. The impact of climate change on agricultural productivity and shifts in crop patterns varies significantly across regions. Its impact is closely tied to the technical abilities of farmers in managing their cocoa farming businesses. Technical skills encompass the proficiency of farmers in adopting adaptive cocoa cultivation techniques for planting, maintaining cocoa plants, as well as handling harvest and postharvest processes. The technical capability is interconnected with factors such as crop dependency on rainfall patterns, availability of infrastructure for quality inputs, soil degradation and fertility, nutrient levels, limited farmers’ resources, and technology penetration. Given the significant impact of climate change on cocoa farmers, it becomes crucial to enhance their adaptive capacity to address these challenges. Therefore, this study aimed to analyze the relationship between the characteristics of farmers and their adaptive capacity in responding to the impact of climate change.METHODS: Data were collected from 960 populations from two regencies, 4 districts, and 8 villages using the stratified sampling technique through interviews with 282 respondents. The sample size was determined using the Slovin formula through in-depth interviews with five key informants. The data collected were descriptively and statistically analyzed using the Excel program, which involved generating frequency distribution tables. Furthermore, the Mann-Whitney test, utilizing Statistical Product and Service Solution version 24, was employed to conduct a comparative analysis.FINDINGS: This result showed that the characteristics of farmers in the two areas were relatively the same in terms of age, non-formal education, number of family dependents, and perceptions of the climate. In terms of age, most farmers fell within the mature group of 36-48 years, with an average age of 44.63, considering in low category. The low productive age of farmers (44.63), along with their non-formal education, including training in climate field schools and integrated pest management field schools, as well as the number of dependents and their perceptions of climate change, emerged as significant parameters impacting farmers'''' decision-making processes. These factors also influenced their ability to cope, adapt, and seek new approaches to manage and mitigate the effects of climate change on their farming operations.CONCLUSION: The relationship between farmers’ characteristics and adaptive capacity showed that the larger the land owned by farmers, the higher the managerial adaptability of farmers with lower technical ability.

ORIGINAL RESEARCH ARTICLE Environmental Management

Presence of microplastics contamination in table salt and estimated exposure in humans

D.A. Syamsu; D. Deswati; S. Syafrizayanti; A. Putra; Y. Suteja

Articles in Press, Accepted Manuscript, Available Online from 21 September 2023

https://doi.org/10.22034/gjesm.2024.01.22.

Abstract

BACKGROUND AND OBJECTIVES: Microplastics are plastic fragments measuring less than 5 millimeters which are formed from degraded plastic materials and have the potential to pollute the environment. Due to their widespread presence in the marine environment, microplastics have become a significant global ... Read More BACKGROUND AND OBJECTIVES: Microplastics are plastic fragments measuring less than 5 millimeters which are formed from degraded plastic materials and have the potential to pollute the environment. Due to their widespread presence in the marine environment, microplastics have become a significant global threat. The presence of microplastics is often considered as causing pollution in various environments, especially aquatic ecosystems such as rivers and oceans. Microplastics contamination can even be found in consumed salt, thus raising concerns about its impact on human health. However, information on the presence of microplastics in salt is still very limited. This study aims to determine the abundance and characteristics of microplastics as contaminants in salt and assess the human exposure to microplastics in Indonesia.METHODS: A total of 21 samples of salt products were taken from various brands available in Padang City and Jambi City, Indonesia for analysis. Microplastics extraction was carried out by removing the organic materials contained in the salt samples using 30 percent hydrogen peroxide and then filtering them with a 0.45 micrometer pore filter. A stereomicroscope was used to detect the abundance, shape, size, and color of microplastics, while the Attenuated Total Reflection-Fourier Transform Infrared Spectroscopy was utilized to identify the polymer type of the microplastics. Furthermore, human exposure to microplastics can be predicted by calculating the estimated dietary intake and taking into account the daily salt intake.FINDINGS: Microplastics were detected in significant amounts (p<0.05) in all salt samples, ranging from 33 to 313 particles/kilogram. The types of microplastics most commonly found in the samples were fragments (67.49 percent), fibers (23.82 percent), films (6.08 percent), and pellets (2.61 percent). The types of polymer identified include polyethylene, polypropylene, polyethylene terephthalate, and polyester. The dominant microplastics were 100-300 micrometers in size (47.3 percent) and black in color (52.88 percent). It is estimated that adults in Indonesia will be exposed to 60.225-571.225 microplastics/year if they consume 5 grams of salt/day or 120.45-1142.45 microplastics/year if they consume 10 grams of salt/day.CONCLUSION: Of the 21 salt samples analyzed, all were detected to contain microplastics. Inadequate and unhygienic salt production and contaminated seawater used as raw material contribute to microplastics contamination of salt, thus posing a risk to human health. By calculating of daily salt intake of the Indonesian population, it is possible to estimate their daily and annual exposure to microplastics. The results of this study contain useful information for the efforts to prevent microplastics contamination by relevant stakeholders and the provision of education and socialization about the proper salt production process in accordance with food safety standards as to reduce or even eliminate microplastics in salt. In addition, this study can provide valuable data on human exposure to microplastics in salt products that can assist policymakers in making standard references for microplastics.

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ORIGINAL RESEARCH ARTICLE Environmental Science

Evaluation of mineral and near-infrared forecasting of wheat yield varieties using spectrophotometric techniques

H.A. Pardhe; N. Krishnaveni; B.K. Chekraverthy; S. Patel; S. Naveen; V. Rashmi; P.C. Govinden

Articles in Press, Accepted Manuscript, Available Online from 12 September 2023

https://doi.org/10.22034/gjesm.2023.04.17.

Abstract

BACKGROUND AND OBJECTIVE: Iron, an essential micronutrient, significantly contributes to growth, immune health, and cognitive development in human health. Inadequate dietary iron intake leads to iron deficiency anemia, affecting nearly 1.6 billion people, especially pregnant women and preschool children. ... Read More BACKGROUND AND OBJECTIVE: Iron, an essential micronutrient, significantly contributes to growth, immune health, and cognitive development in human health. Inadequate dietary iron intake leads to iron deficiency anemia, affecting nearly 1.6 billion people, especially pregnant women and preschool children. Biofortification and fortification of iron in wheat is an acceptable and cost-effective strategy to alleviate iron deficiencies. This study aims to address iron deficiencies through the strategy of fortification and biofortification of wheat varieties. The study places specific emphasis on the proximate composition and iron/mineral content of different wheat varieties. To achieve these objectives, different spectrometric methods were employed to analyze the wheat samples.METHODS: Proximate and mineral quantification were carried out following standard Association of Official Analytical Chemists methods using ultraviolet-visible spectrophotometry, atomic absorption spectrometry, inductive coupled plasma-mass spectroscopy, and prediction was carried out using near-infrared spectra combined with chemometrics.FINDINGS: The samples had moisture content (1.1 - 4.5 percent), protein (18.0 - 22.6 percent), fat (0.3 - 0.6 percent), gluten (6.3 - 10.3 percent), fiber (0.3 - 1.4 percent), alcoholic acidity (0.04 - 0.08 percent), ash (0.9 - 1.7 percent), and carbohydrate (71.1 - 75.2 percent). Iron was determined and compared by spectrophotometric methods. Iron concentration ranged from (0.7 to 6.3 milligrams/100 grams) in ultraviolet-visible analysis, (0.7 to 6.74 milligrams/100 grams) in atomic absorption spectrometry, and (0.81 to 6.8 milligrams/100 grams) in inductive coupled plasma-mass spectroscopy. The obtained results were compared with the standard "Food Composition and Food Safety Standard Authority of India" and predicted using near-infrared spectra combined with chemometrics.CONCLUSION: The work aims to investigate the nutritional content of various wheat varieties, particularly focusing on iron content, which could potentially have implications for improving dietary strategies and addressing nutritional deficiencies. The biofortified varieties (HI-8663 and HI-1605) were found to have high iron content when compared to normal wheat. The acquired results bridge the intricate relationship between plant-based diets, micronutrient deficiencies, providing valuable insights into combating iron deficiencies in public health with the potential achievement of improved nutritional understanding, optimized wheat selection, advanced analytical techniques, education, awareness, and iron deficiency mitigation.

REVIEW PAPER Environmental Engineering

A state of the art review on geotechnical reinforcement with end life tires

M. Shariati; M. Afrazi; H. Kamyab; S. Rouhanifar; E. Toghroli; M. Safa; Sh. Chelliapan; H. Afrazi

Articles in Press, Accepted Manuscript, Available Online from 19 September 2023

https://doi.org/10.22034/gjesm.2024.01.25.

Abstract

This study provides a comprehensive exploration of the utilization of scrap tires in geotechnical engineering, focusing on their applications, mechanical behavior, environmental impact, and potential challenges. The utilization of waste tires in engineering applications is of paramount importance, offering ... Read More This study provides a comprehensive exploration of the utilization of scrap tires in geotechnical engineering, focusing on their applications, mechanical behavior, environmental impact, and potential challenges. The utilization of waste tires in engineering applications is of paramount importance, offering a sustainable solution to the escalating challenge of waste tire management. The accumulation of discarded tires poses significant environmental and economic concerns globally, with traditional disposal methods often leading to environmental degradation, fire hazards, and increased land use. By harnessing the inherent properties of scrap tires, such as their durability and energy-absorbing characteristics, geotechnical engineering presents a promising path for repurposing these materials. This review examines how integrating scrap tires into geotechnical projects, such as retaining walls, slopes, and drainage systems, can offer sustainable alternatives while addressing environmental concerns. The paper extensively analyzes the mechanical behavior of sand-rubber mixtures through laboratory investigations. Factors including rubber proportions, aspect ratios, and interaction mechanisms are dissected to understand their influence on shear strength, deformation behavior, and modulus properties. These insights pave the way for optimizing the performance of sand-rubber mixtures in engineering applications. Additionally, the article delves into modeling approaches that simulate the intricate behavior of these mixtures, facilitating better design and analysis. The economic feasibility of incorporating scrap tires is investigated, emphasizing the cost-effectiveness achieved through reduced material costs and enhanced infrastructure durability. The environmental benefits of diverting rubber waste from landfills are discussed, highlighting the alignment with sustainability goals and regulations. Despite the advantages, engineering challenges associated with rubber particles' behavior are acknowledged, and potential solutions are explored. Through a comprehensive synthesis of research findings and practical implications, this review aims to provide a deep understanding of the potential of scrap tires in geotechnical engineering. It concludes by advocating for further research and innovation to harness the full potential of scrap tires, ultimately contributing to a more sustainable and resilient built environment.

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ORIGINAL RESEARCH ARTICLE Environmental Engineering

Generalization of artificial neural network for predicting methane production in laboratory-scale anaerobic bioreactor landfills

M.J. Zoqi

Articles in Press, Accepted Manuscript, Available Online from 20 September 2023

https://doi.org/10.22034/gjesm.2023.04.21.

Abstract

BACKGROUND AND OBJECTIVES: Leachate recirculation has become a global practice for anaerobic digestion of municipal solid waste. Implementation of artificial neural networks for modeling and prediction of this process still remains challenging. Additionally, there has been a lack of research regarding ... Read More BACKGROUND AND OBJECTIVES: Leachate recirculation has become a global practice for anaerobic digestion of municipal solid waste. Implementation of artificial neural networks for modeling and prediction of this process still remains challenging. Additionally, there has been a lack of research regarding the generalization capacity of neural networks using the data from other studies. This study aimed to enhance methane production rates and decrease biostabilization time in municipal solid waste treatment. It addressed the research gap in applying and generalizing neural networks to predict biogas production based on laboratory-measured parameters. METHODS: Two distinct systems were utilized for leachate treatment. System 1 involved collecting the leachate delivered by a new municipal solid waste reactor and transferring it to a recirculation tank. System 2 consisted of passing the fresh municipal solid waste leachate through a degraded municipal solid waste and then returning the obtained liquid back to the waste reactor. The experimental data were employed to develop an artificial neural network to predict methane content and cumulative biogas production. The model was trained and optimized using the experimental data. The effectiveness and generalizability of the optimal neural network were evaluated by using it for the unseen data from other studies, ensuring its ability to make accurate predictions beyond the training dataset. FINDINGS: The results demonstrated that in System 1, ammonium and chemical oxygen demand concentrations in the leachate progressively increased to high levels. In System 2, the average removal efficiencies for chemical oxygen demand and ammonium were found to be 85 percent and 34 percent respectively. The methane yield in biogas reached 59 liters per kilogram of dry weight, with a corresponding methane fraction of 63 percent. The neural network model showed an excellent performance, with validation performances of 0.716 and 0.634. The overall performance of the dataset resulted in correlation coefficients of 0.9991 and 0.9975. Finally, high correlation coefficients of 0.88 and 0.82 were achieved by incorporating the test data from other studies. CONCLUSION: Leachate recirculation enhanced the reduction of chemical oxygen demand and the production of methane in bioreactors. Ammonium concentrations initially increased and later decreased due to waste adsorption and bacterial assimilation. The artificial neural network applied for predicting the cumulative methane production from municipal solid waste displayed a robust generalizability when tested on the data from other studies. The neural network was not significantly affected by changes in waste chemical properties, laboratory conditions, and recirculation rate. However, it showed a significant sensitivity to variation of waste mechanical properties.

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Journal Metrics gjesm.net/journal/metrics
Journal date created	2015
JCR 2022 Impact Factor (IF)	3.4
SJR 2022 Quartile	Q1
SJR 2022	0.56
SNIP 2022	0.960
CiteScore 2022	7.5
CiteScore Tracker 2023	6.5
Scopus - ID	21100854451
Scopus h-index	34
WOS h-index	30
Google h-index	43
Journal Citation Indicator (JCI)	0.55
WOS Total Citations	3699
Scopus Total Citations	4770
Google Total citations	7730
Google i10-index	201
Google h5-index	27
Google h5-median	40
Published volumes	9
Published issues	35
Published articles	456
Contributing countries	45
Acceptance rate	10%

Volume 9 (2023)

Volume 8 (2022)

Volume 7 (2021)

Volume 6 (2020)

Volume 5 (2019)

Volume 4 (2018)

Volume 3 (2017)

Volume 2 (2016)

Volume 1 (2015)

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