Environmental Engineering
M.F. Nikshoar; M.A. Rowshanzamir; S.M. Abtahi; S. Soleimanian-Zad
Abstract
BACKGROUND AND OBJECTIVES: Soil frost heaving causes significant destruction to road pavements, railways, pipelines, and other lifeline infrastructures. The conventional methods for dealing with the soil frost heave are primarily based on using the materials whose production and use are harmful to the ...
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BACKGROUND AND OBJECTIVES: Soil frost heaving causes significant destruction to road pavements, railways, pipelines, and other lifeline infrastructures. The conventional methods for dealing with the soil frost heave are primarily based on using the materials whose production and use are harmful to the environment. Due to the recent ecological concerns, developing novel alternative methods has received much attention. This study aims to investigate the possibility of using the microbially induced calcite precipitation method to control soil frost heave for less pollution introduction to the soil.METHODS: In this study, the Sporosarcina Pasteurii bacterium was used for calcite precipitation. The influence of three factors in four levels, including bacteria concentration, cementing solution concentration, and curing time, was investigated based on a plan set by Taguchi design of experiment method. The results were obtained by analysis of means and analysis of variance statistical methods and compared with the conventional frost heave reduction methods.FINDINGS: The results were presented in terms of heave ratio. Based on the testing results, the heave ratios (frost heave ratios of the treated to untreated samples) were obtained to be in the range of 0.21 to 0.42. The results showed that bacteria concentration was the most influential factor in the total frost heave of the treated soil. The influence of curing time was in second place, and the effect of cementing solution concentration was relatively less. The minimum frost heave was achieved in 108 colony-forming units per milliliter bacteria concentration, 0.6 mole per litre cementing solution concentration, and 21 days of curing.CONCLUSION: The findings indicated that the used method could be efficiently used to reach the desired objective. The heave ratios obtained by this method were promising to a great extent compared to the conventional methods. The reduction of frost heave due to the application of this method was attributed to the precipitated calcite within the soil voids and was justified by the scanning electron microscopy images of the treated soil samples. This study proved that the proposed method might be utilized as a potential ecological-friendly approach in the future researches.
Environmental Engineering
Z. Farajzadeh; M.A. Nematollahi
Abstract
BACKGROUND AND OBJECTIVES: The rank of Iran in terms of pollutant emissions, which mainly originate from the consumption of energy products, is much higher than the rank of gross domestic product, placing Iran the fourth in the production and consumption of gas and oil, among the cases with the highest ...
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BACKGROUND AND OBJECTIVES: The rank of Iran in terms of pollutant emissions, which mainly originate from the consumption of energy products, is much higher than the rank of gross domestic product, placing Iran the fourth in the production and consumption of gas and oil, among the cases with the highest emission intensity in the world. Different driving forces account for the high emission intensity. This study decomposes the changes in the aggregate emission intensity of the selected pollutants into a broader scope of driving forces including energy, urbanization, output, labor, and trade-related variables. The examined pollutants were far beyond carbon dioxide, including nitrogen oxides, sulphur dioxide, and carbon monoxide, emitted from energy product consumption. The aim of this study was to investigate the emission intensity of the selected pollutants and their components. METHODS: Decomposition analysis was done to decompose the emission intensity into a broader scope of the driving forces far beyond what examined in the literature. For this purpose, two well-known artificial neural networks, multilayer perceptron, and wavelet-based neural network were applied to forecast the emission intensity of the selected pollutants and their components.FINDINGS: The emission intensity of nitrogen oxides and sulphur dioxide illustrated a decreasing trend. In contrast, a general increasing trend with significant fluctuation was observed for carbon monoxide and carbon dioxide emission intensity. Among the components, energy structure, population-labor ratio, and trade openness showed an intensity decreasing effect, while urban per capita output, urbanization, energy intensity, and industrial output-trade ratio contributed to higher emission intensity of the pollutants. Moreover, the multilayer perceptron and wavelet-based neural networks were recommended to examine the predictability of the emission intensity and its components.CONCLUSION: It was found that intensive and extensive growth and energy structure were the most significant driving forces of the emission intensity. The forecast results indicated that the emission intensity of nitrogen oxides, sulphur dioxide, and carbon monoxide might be predicted by the applied networks with a prediction error of less than 0.2 percent. However, the prediction error for carbon dioxide emission intensity was much higher.
Environmental Engineering
A. Mallongi; A.U. Rauf; R.D.P. Astuti; S. Palutturi; H. Ishak
Abstract
BACKGROUND AND OBJECTIVES: The increasing population and anthropogenic activities in coastal areas affects the presence of mercury in coastal waters. Therefore, this study aims to 1) assess the ecological and human health risk of mercury contamination in coastal water; 2) analyze the effectiveness of ...
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BACKGROUND AND OBJECTIVES: The increasing population and anthropogenic activities in coastal areas affects the presence of mercury in coastal waters. Therefore, this study aims to 1) assess the ecological and human health risk of mercury contamination in coastal water; 2) analyze the effectiveness of polymer sulfur as an absorbent for mercury.METHODS: A total of fifteen water samples were obtained from the coastal areas of Makassar and were analyzed using cold vapor atomic absorption spectrophotometry. Ecological and human health risks were assessed using established assessment methods by the United States Environmental Protection Agency. The uncertainty and sensitivity tests for independent variables in human health risk were assessed by the Monte Carlo Simulation method. Furthermore, polymer sulfur was used as a promising technique for capturing and reducing the level of mercury in the water column.FINDINGS: The results showed that the mean concentration of mercury was very high and exceeded the values established by the World Health Organization, United States of Environmental Protection Agency, and Indonesian National Standards, indicating elevated risks to the ecosystem and human health in the future. Additionally, the Monte Carlo simulation model revealed that the non-carcinogenic risk caused by mercury exposure in adults and children was greater than 1 (Total Hazard Index>1), indicating the health adverse effects for both receptors. From the simulation results, the concentration of mercury at 23.3% and exposure time of 21.3 percent were the most influential and dominant factors in non-cancer risk for adults and children, respectively. Therefore, mercury concentration needs to be reduced in coastal areas. The application of polymer sulfur is effective for reducing mercury concentration in water with a percentage reduction range of 39 – 100 percent and p-value of 0.001.CONCLUSION: Mercury contamination of coastal water in Makassar city poses ecological and health risks. The application of polymer sulfur is an effective way for reducing mercury in the water column.
Environmental Engineering
A.S. Patimah; A. Prasetya; S.H.M.B. Santosa
Abstract
BACKGROUND AND OBJECTIVES: The research aimed to evaluate the water quality of the Cangkring River in Tuban Regency, East Java Province, Indonesia, at the segment near the oil and gas fields (Mudi Pad A, B, and C).METHODS: Water samples were collected from January to September 2021 at seven locations ...
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BACKGROUND AND OBJECTIVES: The research aimed to evaluate the water quality of the Cangkring River in Tuban Regency, East Java Province, Indonesia, at the segment near the oil and gas fields (Mudi Pad A, B, and C).METHODS: Water samples were collected from January to September 2021 at seven locations along the river segment and tested ex-situ using six parameters, including physical, chemical, and microbiological. The pollution index formula was used to calculate, determine, and analyze the river water quality status. Samples at three locations were further tested with 13 additional chemical parameters due to potential contamination by other substances as they were located the closest to the production site and office area.FINDINGS: Sample analysis with six parameters showed a pollution index value of 0.558 or within the predefined standard at one location (SW6) and 1.080–2.721 at the other six locations, indicating slight pollution. Another test at three selected locations (i.e., SW1, SW2, and SW7) with 13 additional parameters increased the pollution index to 5.556–6.170 (moderate pollution). This status change was due to the high presence of nitrite and ammonia in the water samples.CONCLUSION: The oil and gas industry near the Cangkring River has strictly complied with the regulations in treating their produced water. However, it still contains a high amount of nitrite and ammonia, moderately polluting the river water. Therefore, it is necessary to regularly test the river water near oil and gas fields to ensure its quality and safety.
Environmental Engineering
M.R. Maulana; S. Saiful; Z.A. Muchlisin
Abstract
BACKGROUND AND OBJECTIVE: The occurrence of plastic waste pollution in waters has become a major issue globally. One of the waters which tend to be polluted with plastic waste such as bags, food wrappers, and unused fishing nets, is the Krueng Aceh River, which is located in the center of Banda Aceh ...
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BACKGROUND AND OBJECTIVE: The occurrence of plastic waste pollution in waters has become a major issue globally. One of the waters which tend to be polluted with plastic waste such as bags, food wrappers, and unused fishing nets, is the Krueng Aceh River, which is located in the center of Banda Aceh city, Indonesia. Microplastics in the rivers potentially contaminate the fish through the food chains, and are then transferred to humans once consumed. The two species of fish that are frequently caught by fishermen in the Krueng Aceh River and consumed by the local people are mullet Mugil cephalus and bagok catfish Hexanematichthys sagor. Both have the potential of being contaminated with microplastics that enter the river. Therefore, this study aims to analyze the status of microplastic pollution in mullet M. cephalus and bagok catfish H. sagor harvested downstream of the Krueng Aceh River, Banda Aceh, Indonesia.METHODS: The fish samples were caught in three locations, namely in the river estuary, residential, and agricultural areas. A total of 50 mullets and 46 bagok catfish were employed for analysis. Microplastics were analyzed in the digestive tract using a microscope, while waste in the carcass was detected using the fourier transform infrared analysis.FINDINGS: In mullet, the highest number of microplastic particles were found in fish samples caught in river estuary (16 particles/fish on average), followed by the sample from residential areas (10 particles/fish on average). Meanwhile, the lowest abundance of microplastic was recorded in sample near agriculture areas (5 particles/gram body weight). In bagok catfish, microplastic abundance in samples from the river estuary and residential areas was almost the same, and it ranged from 7-8 particles/fish. The lowest particle number was in bagok catfish caught in the region near agricultural areas. This study indicated fiber as the most dominant microplastic in the two fish species at all sampling locations. It also had three colors in the alimentary tract of mullet and bagok catfish, namely red, blue, and black, which was predominant. The fourier transform infrared spectrum showed several wavenumber peaks signifying alkane compounds’ presence, which are microplastic characteristics. Based on the peak values, the presence of two polymer types was suspected, namely polyethylene, and polypropylene.CONCLUSION: Fiber and film microplastics were found in the digestive tract of mullet and bagok catfish, where the number of particles was most abundant in the mullet. The fourier transform infrared test was also detected the presence of microplastic pollutants in both species. This indicates that mullet and bagok catfish in Krueng Aceh River have been contaminated by microplastics and are not safe for consumption.
Environmental Engineering
L. Salvaraji; R. Avoi; M.S. Jeffree; S. Saupin; H.R. Toha; S.B. Shamsudin
Abstract
BACKGROUND AND OBJECTIVE: Air pollution is associated with population growth and economic advancement. Severe cardiovascular complications that require extensive medical service are aggravated by air pollutants. This study illustrates the trend and correlation of cardiovascular disease hospital admission ...
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BACKGROUND AND OBJECTIVE: Air pollution is associated with population growth and economic advancement. Severe cardiovascular complications that require extensive medical service are aggravated by air pollutants. This study illustrates the trend and correlation of cardiovascular disease hospital admission with air pollutants in Sabah for the past 9 years (2010–2019). The additional information obtained from this study will be useful to enhance proper environmental management and reduce air pollution in the cities of Sabah.METHOD: Ecological study design was utilized with cardiovascular disease hospital admission and ambient air pollutants in Sabah retrospective data. Data were collected from four districts with established continuous air quality monitoring stations. Collected data were analysed spatially and statistically. Autoregressive integrated moving average modelling was implemented to forecast the cardiovascular disease hospital admission.FINDING: Kota Kinabalu recorded the highest hospital admissions for cardiovascular disease, followed by Sandakan, Tawau and Keningau. The cardiovascular disease hospital admission prevalence rate in Kota Kinabalu was 12.45 per 1,000 population, followed by Sandakan, Tawau and Keningau (4.54; 4.18; and 5.88 per 1,000 population) in 2019. The cardiovascular hospital admissions increased in Kota Kinabalu, Sandakan and Tawau. The nitrogen dioxide (<0.04 ppm), carbon monoxide (<9 ppm), ozone (<0.05 ppm) and PM10 (<100 µg/m3) gases detected are below the national standard limit levels. In the later years of the series, the ozone and fine particulate gases intensify. Carbon monoxide has the highest positive correlation with cardiovascular disease hospital admission compared to other air pollutants. The autoregressive integrated moving average (0,1,1) with carbon monoxide and ozone as external regressors is the model with minimum Akaike information criterion.CONCLUSION: The carbon monoxide concentration in ambient air illustrates a potential risk for the increasing cardiovascular disease hospital admission number in Sabah. The study findings provide evidence-based source for the healthcare management team, policymakers, and community to sustain clean and safe ambient air.
Environmental Engineering
F.M. Torres-Bejarano; M. Verbel-Escobar; M.C. Camila Atencia-Osorio
Abstract
BACKGROUND AND OBJECTIVES: One of the negative impacts of polluting activities on aquatic ecosystems is the loss of its natural self-purification ability, for this reason, the purpose of this research was to evaluate the Sinú river capacity to assimilate wastewater discharges.METHODS: Monitoring ...
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BACKGROUND AND OBJECTIVES: One of the negative impacts of polluting activities on aquatic ecosystems is the loss of its natural self-purification ability, for this reason, the purpose of this research was to evaluate the Sinú river capacity to assimilate wastewater discharges.METHODS: Monitoring of several water quality parameters was carried out in the river at different seasons and a numerical method was used to simulate different scenarios through the Environmental Fluid Dynamics Code model. The model calibration process was tested applying the Root Mean Square Error and after calibrating the model, scenarios of increase and decrease of discharge concentrations and flows, and river flows were simulated. Finally, the results were compared to water quality reference limits.FINDINGS: Results show that the model accurately represented the real conditions of the studied river section for all the evaluated parameters. Also, assimilative capacity was affected mostly by the scenario in which the river flow was decreased by 50%, and the flows and discharges concentrations were increased five times; causing parameters such as ammonia nitrogen, chemical oxygen demand, phosphates, and total nitrogen, to exceed the established reference limits with maximum concentrations of 2.7 mg/L, 30.9mg/L, 0.98 mg/L and 6.3 mg/L; respectively. Higher concentrations of water quality parameters were mostly found in the dry season since lower velocities and river flows promote less pollutants mixing and dilution processes.CONCLUSION: The model spatiotemporal simulations showed the effect of the wastewater discharges on the Sinú River assimilative capacity and made it possible to find those scenarios where water quality parameters exceeded the reference limits, becoming an essential tool for water management and the development of strong water quality objectives by stakeholders and environmental authorities.
Environmental Engineering
M. Dede; S.B. Wibowo; Y. Prasetyo; I.W. Nurani; P.B. Setyowati; S. Sunardi
Abstract
BACKGROUND AND OBJECTIVES: Water resources carrying capacity is dynamic and can be influenced by catastrophic volcanic eruptions. The eruption of Mount Merapi in 2010 changed the landscape and community livelihoods due to the redistribution of a large volume of volcanic materials. This study aims to ...
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BACKGROUND AND OBJECTIVES: Water resources carrying capacity is dynamic and can be influenced by catastrophic volcanic eruptions. The eruption of Mount Merapi in 2010 changed the landscape and community livelihoods due to the redistribution of a large volume of volcanic materials. This study aims to analyze water resources carrying capacity before and after the major 2010 eruption of Mount Merapi.METHODS: The value of water resources carrying capacity is derived from that of water availability and the domestic water needs per capita per year. The model uses a grid of 100 x 100 meter cells to determine the spatial distribution of water resources carrying capacity in Krasak watershed, and this analysis considers the years 2008, before the eruption, and 2021, after the eruption. The population distribution data have been previously mapped by referring to statistical data and land use at the village level, while water availability is calculated considering rainfall, potential evaporation rate, and runoff.FINDINGS: Water resources carrying capacity in Krasak watershed has undergone changes related to the distribution of volcanic material and human activities. The water resources carrying capacity for both periods experienced a surplus, although there has been an average decrease of 331.50 cubic meters per year for each grid cell. Water resources carrying capacity analysis shows a decline, especially in the midstream and downstream. Based on T-Test, there are significant changes in the water resources carrying capacity at 2008 and 2021 (p-value 0.047 and 95% confidence level).CONCLUSION: Water resources carrying capacity increased only in some locations that occurred ecosystem succession after the eruption, although areas near the peak are decreased by sand and stone mining. The spatial-gridded model proved capable of analyzing this phenomenon.
Environmental Engineering
E. Fares; B. Aissa; R.J. Isaifan
Abstract
Background and objectives: Global energy needs have gradually shifted toward photovoltaic solar energy, especially in the Gulf region because of the high solar-irradiance potential. However, one of the main challenges for this technology in the region is soiling, which has been reported to degrade the ...
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Background and objectives: Global energy needs have gradually shifted toward photovoltaic solar energy, especially in the Gulf region because of the high solar-irradiance potential. However, one of the main challenges for this technology in the region is soiling, which has been reported to degrade the power output of photovoltaic modules significantly. Anti-soiling coatings are promising technologies to minimize the effect of dust on photovoltaic solar panels. Accordingly, this study aimed to synthesize aluminum, zinc, titanium, and tin oxides using mixed-based and nanoparticle-based precursors through inkjet printing techniques and investigate their potential in anti-soiling applications for PV panels.Methods: Four metal oxides, namely, aluminum, zinc, titanium, and tin oxides, were synthesized and deposited using the inkjet printing technique for anti-soiling application. Ultraviolet-visible spectroscopy, field emission scanning electron microscope, X-ray diffraction, X-ray photoelectron spectroscopy, and contact angle measurements were performed to characterize these thin films.Finding: The optical transmittance of the substrate using the nanoparticle ink revealed better optical properties than that using the mixed-based ink. Compared with nanoparticle samples, a homogeneous crack and a defect-free layer were observed with dense nanoparticles in all mixed inks (except for aluminum oxide ink). The contact angles indicated that the synthesized films were super-hydrophilic/hydrophilic coatings. The results of the outdoor testing revealed that up to 60% less dust was deposited on the best-performing film (aluminum oxide mixed-based ink) compared with bare glass. Conclusion: The outdoor experiment revealed that mixed-based thin films were better in reducing dust deposition than nanoparticle-based thin films and bare glass. This enhancement might be due to the decreased antireflection property along with a morphological contribution related to the presence of nanoparticle voids, which reduce the spectra scattering and minimize its deterioration, thus demonstrating better anti-soiling properties. The results of the outdoor test revealed that aluminum, zinc, and titanium oxides are promising materials for anti-soiling coating applications for both ink types. However, tin oxide coatings are not recommended for anti-soiling applications, as they showed the highest dust deposition rate near the bare glass performance.
Environmental Engineering
Suhaemi .; D.G. Bengen; C.P.H. Simanjuntak; A.F. Koropitan
Abstract
BACKGROUND AND OBJECTIVES: The Misool Islands are lined up regularly from west to east, the southern part of Raja Ampat Archipelago, Papua - Indonesia. The geomorphology is distinctive, and the coral reef substrate causes turbulence. Misool waters are located in the Papuan bird's head seascape, passed ...
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BACKGROUND AND OBJECTIVES: The Misool Islands are lined up regularly from west to east, the southern part of Raja Ampat Archipelago, Papua - Indonesia. The geomorphology is distinctive, and the coral reef substrate causes turbulence. Misool waters are located in the Papuan bird's head seascape, passed by Pacific water masses. The assessment status of Misool waters as a conservation area does not include hydrodynamic aspects in the decision processes. The present study is fundamental for determining and changing essential areas for conservation. The main objective of this study is to the pattern of hydrodynamic processes and investigate the features of the water mass in the Misool waters.METHODS: An acoustic doppler current profiler was deployed to measure currents every 15 minutes for ten water column layers. Investigation of waters characteristics was using Conductivity-Temperature-Depth equipment. A three-dimensional computational model was performed using MIKE3.FINDINGS: The water mass around the Misool Islands are more influenced by the local oceanographic processes than the water masses from the Pacific Ocean. The study site is characterized by the mixed tide, prevalence to semi-diurnal based on observational tidal data. Wind and baroclinic properties generate non-significant currents, resulting in low horizontal and vertical stratification. Intensification of tidal currents occurs along the shallow part in northeastern and part of the channel between Misool Islands and the mainland of Papua.CONCLUSION: The interaction of barotropic tides, geomorphology, and coral reef triggers the unstratified water mass. Strong currents and turbulence on the northeast side produce homogeneous waters. The water mass in Misool waters is originated from the local dynamic.
Environmental Engineering
S. Rahman; M. Ramli; F. Arnia; R. Muharar; M. Ikhwan; S. Munzir
Abstract
BACKGROUND AND OBJECTIVES: The increase in the number of vehicles has several negative impacts, including traffic congestion, air pollution, noise levels, and the availability of parking spaces. Drivers looking for parking spaces can cause traffic jams and air pollution. The solution offered at this ...
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BACKGROUND AND OBJECTIVES: The increase in the number of vehicles has several negative impacts, including traffic congestion, air pollution, noise levels, and the availability of parking spaces. Drivers looking for parking spaces can cause traffic jams and air pollution. The solution offered at this time is the development of a smart parking system to overcome these problems. The smart parking system offers a parking availability information feature in a parking area to break up congestion in the parking space. Deep learning is a successful method to solve parking space classification problems. It is known that this method requires a large computational process. Th aims of this study are to modified the architecture of Convolutional Neural Networks, part of deep learning to classify parking spaces. Modification of the Convolutional Neural Networks architecture is assumed to increase the work efficiency of the smart parking system in processing parking availability information.METHODS: Research is focusing on developing parking space classification techniques using camera sensors due to the rapid advancement of technology and algorithms in computer vision. The input image has 3x3 dimensions. The first convolution layer accepts the input image and converts it into 56x56 dimensions. The second convolution layer is composed in the same way as the first layer with dimensions of 25x25. The third convolution layer employs a 3 x 3 filter matrix with padding of up to 15 and converts it into 10x10 dimensions. The fourth layer is composed in the same way as the third layer, but with the addition of maximum pooling. The software used in the test is Python with a Python framework.FINDINGS: The proposed architecture is the Efficient Parking Network or EfficientParkingNet. It can be shown that this architecture is more efficient in classifying parking spaces compared to some other architectures, such as the mini–Alex Network (mAlexnet) and the Grassmannian Deep Stacking Network with Illumination Correction (GDSN-IC). EfficientParkingNet has not been able to pass the accuracy of Yolo Mobile Network (Yolo+MobileNet). Furthermore, Yolo+MobileNet has so many parameters that it cannot be used on low computing devices. Selection of EfficientParkingNet as a lightweight architecture tailored to the needs of use. EfficientParkingNet's lightweight computing architecture can increase the speed of information on parking availability to users.CONCLUSION: EfficientParkingNet is more efficient in determining the availability of parking spaces compared to mAlexnet, but still cannot match Yolo+MobileNet. Based on the number of parameters, EfficientParkingNet uses half of the number of parameters of mAlexnet and is much smaller than Yolo+MobileNet. EfficientParkingNet has an accuracy rate of 98.44% for the National Research Council parking dataset and higher than other architectures. EfficientParkingNet is suitable for use in parking systems with low computing devices such as the Raspberry Pi because of the small number of parameters.
Environmental Engineering
G.R. Puno; R.C.C. Puno; I.V. Maghuyop
Abstract
BACKGROUND AND OBJECTIVES: Fine topographic information is a key input parameter for a detailed flood simulation and mapping. This study aimed to compare the accuracy statistics of the flood models developed using the digital elevation datasets with different resolutions from the light detection and ...
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BACKGROUND AND OBJECTIVES: Fine topographic information is a key input parameter for a detailed flood simulation and mapping. This study aimed to compare the accuracy statistics of the flood models developed using the digital elevation datasets with different resolutions from the light detection and ranging and interferometric synthetic aperture radar systems.METHODS: The study applied the Hydrologic Engineering Center-Hydrologic Modeling System and Hydrologic Engineering Center-River Analysis System models workable within the geographic information system to simulate and map flood hazards in Maapag Watershed. The models’ validity and accuracy were tested using the confusion error matrix, f-measurement, and the root means square error statistics.FINDINGS: Results show that using the light detection and ranging dataset, the model is accurate at 88%, 0.61, and 0.41; while using the interferometric synthetic aperture radar dataset, the model is accurate at 76%, 0.34, 0.53; for the error matrix, f-measurement, and root mean square error; respectively.CONCLUSION: The model developed using the light detection and ranging dataset showed higher accuracy than the model developed using the interferometric synthetic aperture radar. Nevertheless, the latter can be used for flood simulation and mapping as an alternative to the former considering the cost of model implementation and the smaller degree of accuracy residual error. Hence, flood modelers particularly from local authorities prefer to use coarser datasets to optimize the budget for flood simulation and mapping undertakings.
Environmental Engineering
M. Ramli; M. Mardlijah; M. Ikhwan; K. Umam
Abstract
BACKGROUND AND OBJECTIVES: A solar panel is a device that converts solar rays into electricity. It is a step to reduce emissions from fossil energy, which is to replace it with renewable energy. It requires a control system to ensure that the position of the solar panel is always perpendicular to the ...
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BACKGROUND AND OBJECTIVES: A solar panel is a device that converts solar rays into electricity. It is a step to reduce emissions from fossil energy, which is to replace it with renewable energy. It requires a control system to ensure that the position of the solar panel is always perpendicular to the sun''s rays. This study aims to modify the fuzzy set based on fuzzy entropy in the control system that has been developed. The modifications made are expected to increase the efficiency of solar panels in harvesting energy.METHODS: Type II fuzzy sliding mode control is used, along with a modified fuzzy set based on the entropy value. Before modification, the system containing the fuzzy set generates a histogram of entropy and voltage performance, which is the initial value and the comparison value. The algorithm alters the footprint of the uncertainty limit. This change results in a new fuzzy set, which results in a new histogram and voltage. The final step is to compare the initial and final parameters based on the results of the modifications.FINDINGS: The solar panels require only 7.3x10-5 degrees of movement per second. This is a very slow movement for a dc motor with a maximum voltage of 12 volts. The simulation produced a stable speed of 7.297x10-5 on the unmodified system and 7.295x10-5 on the modified system. The modified system experiences a slight delay towards the stable point because the fuzzy entropy method reduces the dominance of set point positions in the system.CONCLUSION: The modified fuzzy set is good at controlling the solar panel driving motor based on the output voltage value. On both controllers under consideration, the voltages follow the same pattern. However, it experienced a control mismatch at the point towards the set point. Finally, by changing the foot of uncertainty and adjusting it proportionally according to control needs, the control system based on fuzzy sets with fuzzy entropy can be further developed.
Environmental Engineering
E.N. Hidayah; R.B. Pachwarya; O.H. Cahyonugroho
Abstract
BACKGROUND AND OBJECTIVES: The existence of organic matter is one of the main issues for wastewater reclamation since chlorination is applied most frequently before use wastewater reclamation for many purposes. One of the eco-friendly and effective methods is using innovative material through resin immobilized ...
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BACKGROUND AND OBJECTIVES: The existence of organic matter is one of the main issues for wastewater reclamation since chlorination is applied most frequently before use wastewater reclamation for many purposes. One of the eco-friendly and effective methods is using innovative material through resin immobilized heterogeneous photocatalyst, which is based on the principle of advanced oxidation processes. Resin immobilized photocatalyst has been using for pollutant reduction, however lack of studies focused on dissolved effluent organic matter and its impact on the formation carcinogenic as by-product of water or wastewater treatment. This study aims to characterize organic matter by resin immobilized photocatalyzed titanium dioxide and zinc oxide and to determine its effectiveness in removing organic matter and potential for disinfection by-products in treated wastewater compare with resin only.METHODS: The bulk parameters, including total organic carbon, aromatic organic carbon as ultraviolet at 254 nm wavelength and specific ultraviolet absorbance value, and disinfection by-products formation potential, including trihalomethanes and haloacetic acids concentration was measured.FINDINGS: The results present that all materials could remove organic carbon in the range 58.18% - 93.45%, aromatic organic carbon removal 48.77% - 76.51%, and specific ultraviolet absorbance value decreased into less than 2 L/mg-m after longer contact time. Disinfection by-products formation potential concentration removal decreased and indicated the consistency results with bulk parameters removal. Resin immobilized photocatalyzed zinc oxide performed a higher efficiency removal than resin immobilized photocatalyzed titanium dioxide and resin only.CONCLUSION: This study exhibited the performance of resin immobilized photocatalyst with titanium dioxide and zinc oxide in removing dissolved organic matter and to control the formation of disinfection by-products. A combination between bulk parameters and disinfection by-products formation potential removal concluded that the aromatic structure, was mainly haloacetic acids precursors, while the non-aromatic organic fraction was probably trihalomethanes precursors.
Environmental Engineering
M. D. Enriquez; R. M. Tanhueco
Abstract
BACKGROUND AND OBJECTIVES: Safeguarding water resources became a major concern in many parts of the world as it aims to provide safe and healthy water for humans. Water quality monitoring is a popular tool in ensuring water quality is safe and within the allowable limits and standards for the health ...
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BACKGROUND AND OBJECTIVES: Safeguarding water resources became a major concern in many parts of the world as it aims to provide safe and healthy water for humans. Water quality monitoring is a popular tool in ensuring water quality is safe and within the allowable limits and standards for the health of the community. To provide interventions and strategies for the rehabilitation, a water quality monitoring plan was conducted to describe the water quality and the classification of the river.METHODS: This study conducted an environmental analysis to determine existing conditions and processes in the surrounding environment such as the land use, drainage pattern, reconnaissance survey of the river, and a key interview to describe the barangay profile and the community's water use and practices. The water quality monitoring covers the evaluation of ten water quality parameters: temperature, pH, dissolved oxygen, total dissolved solids, total suspended solids, phosphate, nitrate, oil and grease, chloride, and E. coli.FINDINGS: Results of the study presents the water quality against the ten water quality criteria. Phosphate measured on four stations ranges between 2.40-4.50 mg/L exceeding the allowable 0.50mg/L; the oil and grease exceeds the standards 2 mg/L with measured values of 2.40-4.60 mg/L in stations 2, 3, and 4; while measured chloride in all stations prove that the water is salty with values exceeding the freshwater requirement of 250mg/L; and the measured TSS in stations 2, 3 and 4 ranges from 32.30 to 49.3 mg/L exceeds the standards of 30mg/L. E. coli was also detected in water samples collected in all sampling stations. The computed water quality index of 39.02 described water as poor, always impaired, and threatened by the surrounding environment. CONCLUSION: The measured concentrations for phosphate, oil/ grease, chloride, and TSS exceeds the water quality requirement suggesting that the water is contaminated. The E. coli detected in all water samples, further recommends prohibition of recreational activities to avoid accidental intakes and skin contact on the polluted water. The existing activities in the surrounding residential, commercial and agricultural areas contributed to water contamination as aggravated by the unreliable drainage system, absence of proper sanitation facilities, and collection and disposal behavior of the community. From this, a scientific basis can be drawn on how the river can be rehabilitated and protected and serve as guide for policymakers and water managers on implementing strategies to achieve sustainable water resources.
Environmental Engineering
N. Robinah; A. Safiki; O. Thomas; B. Annette
Abstract
BACKGROUND AND OBJECTIVES: The effect of infrastructure equipment is taking a toll on the health and economic well-being of residents all around the world. This is mainly because it contributes to ambient air pollution, noise, and vibration in the surroundings. The study aimed at analyzing the ...
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BACKGROUND AND OBJECTIVES: The effect of infrastructure equipment is taking a toll on the health and economic well-being of residents all around the world. This is mainly because it contributes to ambient air pollution, noise, and vibration in the surroundings. The study aimed at analyzing the effects of the road infrastructure equipment on the surroundings in Uganda. The emissions of carbon dioxide, carbon monoxide, nitrogen dioxide, hydrocarbons, and particulate matter were analyzed.METHODS: Six road infrastructure equipment were sampled consisting of an excavator, roller, grader, concrete mixer, tamper, and wheel loader, obtained from a case study project in Kampala city, Uganda. The diesel exhaust air emissions were computed and analyzed using the emissions rate equation model for non-road equipment, developed by Environmental Protection Agency. This was based on the horsepower and power rating of the equipment. Noise and vibrations levels were obtained using a sound level meter, seismometers, and accelerators, while following the National Environment Regulations.FINDINGS: The greenhouse gas of carbon dioxide was the most predominant accounting for 84.1 percent of the total emissions. The grader was the highest emitter of this greenhouse gas, at 1,531.5 g/h, representing 37.1%. The lowest air pollutant emission was nitrogen dioxide at 1.43 g/h for the concrete mixer, representing 1.4%. Overall, the equipment emitted more greenhouse gases than air criteria pollutants at 88.8% and 11.2% respectively. The highest criteria air pollutant was particulate matter at 100.5 g/h, emitted by the grader. Most of the emissions met the standards stipulated by Environmental Protection Agency, for reducing emissions back to the environment, except particulate matter. However, the concentrations of some pollutants like carbon monoxide and nitrogen dioxide did not satisfy the limits required for ambient air quality that is safe for workers. All the equipment had noise levels way above the recommended 70.00 decibel, except for the wheel loader. Only the excavator produced vibrations higher than permissible vibration limit by 4%.CONCLUSION: The criteria air pollutants of carbon monoxide, nitrogen dioxide, and particulate matter emitted by the equipment were all not safe to the workers. They exceeded the permissible limits of 50 ppm, 5 ppm, and 0.02 g/kW/h respectively. This partly shows why ambient air pollution had been reported in urban centers in Uganda. The study shows the need for strengthening the regulations and monitoring of the construction equipment being used, in order to protect the surroundings.
Environmental Engineering
Y. Zehtab Yazdi; N. Mansouri; F. Atabi; H. Aghamohammadi
Abstract
BACKGROUND AND OBJECTIVES: Sand and gravel product plants are among the significant sources of dust pollutants. This study was conducted to estimate dust concentrations released from these plants in a mineral complex in the southwest of Tehran.METHODS: Initially, the amount of silt and moisture content ...
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BACKGROUND AND OBJECTIVES: Sand and gravel product plants are among the significant sources of dust pollutants. This study was conducted to estimate dust concentrations released from these plants in a mineral complex in the southwest of Tehran.METHODS: Initially, the amount of silt and moisture content of the samples taken from these plants were determined according to the American Society for Testing and Materials C136 and D2216 methods, respectively. Accordingly, the rates of particulate matter emissions from these plants were determined by the AP-42 dust emission estimation methods published by the United States Environmental Protection Agency. Next, a Gaussian model was used to estimate the particulate matter concentrations in the surrounding residential areas. Finally, the simulated concentrations were compared with the United States Environmental Protect Agency and World Health Organization standards.FINDINGS: Results showed that hauling operations, with producing 70%, 86%, and 90% of total PM2.5, PM10 and total suspended particulates, respectively, were the major sources of dust emission in the sand and gravel product plants. The lowest dust emission was related to stockpiling handling, producing 0.24%, 0.33%, and 0.16% of the total PM2.5, PM10 and total suspended particulates. The results of the presented model indicated that 24-hour average concentrations of PM2.5, PM10, and total suspended particulates produced by mining activities were about 36, 183, and 690 µg/m3 in the working zone and less than 30, 100, and 400 µg/m3 beyond the mineral complex boundary, respectively. Thus, annual average dust concentrations were negligible. The concentrations of PM2.5 and PM10 produced by these plants in the mineral complex ambient air were higher than the standard average values recommended by the United States Environmental Protect Agency and World Health Organization. However, the concentrations of PM2.5 and PM10 from these plants in the residential areas around the complex, were below the standard limits proposed by the Environmental Protection Agency.CONCLUSION: Sand and gravel mining activities increased the concentrations of particulate matter in the air of the surrounding areas and, to some extent, farther cities. PM2.5 and PM10 resulting from the sand and gravel mining activities could damage the workers in the mineral complex. They exceeded the 24-hour average permissible limits proposed by the United States Environmental Protection Agency about 1 and 33 µg/m3, respectively. This study showed the necessity of changing the industrial policies adopted to decrease dust emission rates. The results of this study can help the air pollution experts develop proper strategies for improving the air quality in the vicinity of surface mines.
Environmental Management
J. Nouri
Abstract
Global Journal of Environmental Science and Management (GJESM) is an open access quarterly Publication. The title welcomes original, review, novel and high-impact contributions from the related Environmental science, engineering and management issues. The GJESM Journal ...
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Global Journal of Environmental Science and Management (GJESM) is an open access quarterly Publication. The title welcomes original, review, novel and high-impact contributions from the related Environmental science, engineering and management issues. The GJESM Journal has been indexed in the well-known world databases mainly; Scopus (CiteScore = 3.9), Scimago Journal Rank (Q2), Web of Science (ESCI), JCI = 0.39. The title is also a member of the Committee on Publication Ethics (COPE). All submitted manuscripts are checked for similarity through a trustworthy software named iThenticate to be assured about its originality and then rigorously peer-reviewed by the international reviewers.
Environmental Engineering
D. Fadhiliani; M. Ikhwan; M. Ramli; S. Rizal; M. Syafwan
Abstract
BACKGROUND AND OBJECTIVES: The hydrodynamic uncertainty of the ocean is the reason for testing marine structures as an initial consideration. This uncertainty has an impact on the natural structure of the topography as well as marine habitats. In the hydrodynamics laboratory, ships and offshore structures ...
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BACKGROUND AND OBJECTIVES: The hydrodynamic uncertainty of the ocean is the reason for testing marine structures as an initial consideration. This uncertainty has an impact on the natural structure of the topography as well as marine habitats. In the hydrodynamics laboratory, ships and offshore structures are tested using mathematical models as input to the wave marker. For large wavenumbers, Benjamin Bona Mahony's equation has a stable direction and position in the wave tank. During their propagation, the generated waves exhibit modulation instability and phase singularity phenomena. These two factors refer to Benjamin Bona Mahony as a promising candidate for generating extreme waves in the laboratory. The aim of this research is to investigate the distribution of energy in each modulation frequency change. The Hamiltonian formula that describes the phenomenon of phase singularity is used to observe energy. This data is critical in determining the parameters used to generate extreme waves.METHODS: The envelope of the Benjamin Bona Mahony wave group can be used to study the Benjamin Bona Mahony wave. The Benjamin Bona Mahony wave group is known to evolve according to the Nonlinear Schrodinger equation. The Hamiltonian governs the dynamics of the phase amplitude and proves the Nonlinear Schrodinger equation's singularity for finite time. The Hamiltonian is derived from the appropriate Lagrangian for Nonlinear Schrodinger and then transformed into the Hamiltonian with the displaced phase-amplitude variable.FINDINGS: Potential energy is related to wave amplitude and kinetic energy is related to wave steepness in the study of surface water waves. When , the maximum wave amplitude and steepness are obtained. When , extreme waves cannot be formed due to steepness. This is due to the possibility of breaking waves into smaller waves on the shore. In terms of position, the energy curve is symmetrical.CONCLUSION: According to Hamiltonian's description of the energy distribution, the smaller the modulation frequency, the greater the potential and kinetic energy involved in wave propagation, and vice versa. While the wave's amplitude and steepness will be greatest for a low modulation frequency, and vice versa. The modulation frequency considered as an extreme wave generator is , because the resulting amplitude is quite high and the energy in the envelope is also quite large.
Environmental Engineering
M.I. Rumaling; F.P. Chee; H.W.J. Chang; C.M. Payus; S.K. Kong; J. Dayou; J. Sentian
Abstract
BACKGROUND AND OBJECTIVES: Air quality in some developing countries is dominated by particulate matter, especially those with size 10 micrometers and smaller or PM10. They can be inhaled and sometimes can get deep into lungs; some may even get into bloodstream and cause serious health problems. Therefore, ...
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BACKGROUND AND OBJECTIVES: Air quality in some developing countries is dominated by particulate matter, especially those with size 10 micrometers and smaller or PM10. They can be inhaled and sometimes can get deep into lungs; some may even get into bloodstream and cause serious health problems. Therefore, future PM10 concentration forecasting is important for early prevention and in urban development planning, which is crucial for developing cities. This paper presents the development of PM10 forecasting model using nonlinear autoregressive with exogenous input model.METHODS: To improve performance of nonlinear autoregressive with exogenous input model, principal component analysis is used prior to the model for variable selection. The first stage of principal component analysis involves Scree plot, which determines the number of principal components based on explained variance. This is then followed by selecting variables using a rotated component matrix, based on their strength of contribution towards variation of PM10 concentration. To test the model, PM10 data in Kota Kinabalu from 2003 – 2010 was used. Neural network models are developed using this data by varying number of input variables with the inclusion of temporal variables. The developed forecasting models are evaluated using data PM10 in the city from 2011 to 2012. Four performance indicators, namely root mean square error, mean absolute error, index of agreement and fractional bias are reported.FINDINGS: Results from principal component analysis show that five variables including wind direction index, relative humidity, ambient temperature, concentration of nitrogen dioxide and concentration of ozone strongly contribute to the variation of PM10 concentration. By using these variables together with temporal variables as input in the nonlinear autoregressive with exogenous input models, the resultant model shows good forecasting performance, with root mean square error of 7.086±0.873 µg/m3. The selection of significant variables helps in reducing input variables inside the forecast model without degrading its forecast performance.CONCLUSION: This model shows very promising performance in forecasting PM10 concentration in Kota Kinabalu as it requires fewer input variables and does not require variable transformation.
Environmental Engineering
N. Wibowo; R. Nurcahyo; D.S. Gabriel
Abstract
BACKGROUND AND OBJECTIVES: Electronic equipment production is one of the major industrial sectors in Indonesia, as it also contributes to Indonesia’s export commodities, which increase because of rapid technological developments. Cell phones, which have considerable potential to become electronic ...
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BACKGROUND AND OBJECTIVES: Electronic equipment production is one of the major industrial sectors in Indonesia, as it also contributes to Indonesia’s export commodities, which increase because of rapid technological developments. Cell phones, which have considerable potential to become electronic waste, recorded the enormous escalation in electronic production. This research aimed to increase community involvement and the collection of used cell phones from households in e-waste management in Indonesia. A survey was conducted to explore a household’s environmental awareness and willingness to recycle based on sociodemographics, environmental hazard awareness, and used cell phone usage in Jabodetabek, Indonesia.METHODS: In this research, a peer questionnaire was used and organized into five sections: The first section contained the sociodemographic details of the respondents. The second section comprised multiple concerns that relate to recycling and environmental awareness. The third section contained the family cell phone information. The fourth section determined the cell phone consumer behavior. The fifth section consisted of willingness to recycle. Statistical correlations between variables were assessed, and the chi-square independence test was used to evaluate the statistical correlations. FINDINGS: Mostly the households will replace their used cell phone if there is damage (66.84%) and keep the used cell phone at home (59.5%), thus becoming an obstacle in applying the appropriate recycling system and a circular economy. The average cell phone ownership in Jabodetabek is 1.28 units, and the average cell phone life span of people in Jabodetabek is 2.6 years. The Environmental Hazard Awareness variable has significant differences with occupation and income level (p-value = 0.028 and 0.046), Used Cellphone Usage variable has significant differences with the income level variable (p-value = 0.024). The others, a statistically significant difference between sociodemographic variable and Willingness to Recycle was observed; p-value = 0.003 for age and p-value = 0.034 for occupation. CONCLUSION: This paper showed that Environmental Hazard Awareness and Willingness to Recycle have an important role in increasing the collection of used cell phones from households. . This study assessed community-based factors located in urban areas. The factors could encourage their participation in collection activities, obtain information on the preferred collection channels of residents, and provide a perspective for managing cell phones through an analysis of the improvements and influences of Indonesia’s current e-waste recycling program. Therefore, to develop a new strategy, the findings of this study can provide insights into the e-waste problem and citizen’s awareness of e-waste management.
Environmental Engineering
S. Nimesha; C. Hewawasam; D. J. Jayasanka; Y. Murakami; N. Araki; N. Maharjan
Abstract
Natural waterways are contaminated due to industrialization, urbanization, population growth etc., degrading their quality. Contaminated waterways cause numerous health and environmental hazards. Therefore, it is imperative to remove contaminants. Coagulation is one of the efficient primary chemical ...
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Natural waterways are contaminated due to industrialization, urbanization, population growth etc., degrading their quality. Contaminated waterways cause numerous health and environmental hazards. Therefore, it is imperative to remove contaminants. Coagulation is one of the efficient primary chemical treatment methods that could be used to treat such contaminants. Natural coagulants have gained popularity in the water and wastewater treatment industry due to their advantage over chemical coagulants. Natural coagulants are derived from either plants, animals, or microorganisms. This study has elaborated on the nature and mechanisms, and types of natural coagulants. In this review work, many studies have proposed several types of natural coagulants. However, plant-based natural coagulants extracted from different plant components have been extensively discussed and compared based on their application and efficiency in water and waste treatment. The primary purpose of this review is to refine the knowledge on the potential use and optimization of the effectiveness of eco-friendly and sustainable natural coagulants. Besides, the development efforts and the barriers reported by recent findings for the commercialization of natural coagulants are also discussed. Further, few modified natural coagulants have also been presented for exploring the other possible approaches to promote their usage in water and wastewater treatment in the future studies.
Environmental Engineering
M. Hazbehiean; N. Mokhtarian; A. Hallajisani
Abstract
More than 5.5 trillion cigarettes are manufactured, and approximately 4.5 trillion cigarette butts are being scattered across the globe per year. These cigarette butts are considered as one of the most hazardous wastes and environmental threats in the world. Thermochemical techniques can be used to turn ...
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More than 5.5 trillion cigarettes are manufactured, and approximately 4.5 trillion cigarette butts are being scattered across the globe per year. These cigarette butts are considered as one of the most hazardous wastes and environmental threats in the world. Thermochemical techniques can be used to turn biomass and solid wastes into valuable final products. Pyrolysis is a comfortable thermochemical technique for turning biomass into biochars, biofuels, briquette solid fuels, and further valuable products such as activated carbons, carbon black, and printing ink. In this study, it was attempted to review the available researches about pyrolysis of cigarette butts with an emphasis on transforming them into carbonated solid and liquid products. It was found that, in addition to the process variables, the type of cigarette butts treatment has a significant effect on the yield and quality of the finished goods. Further studies on the pyrolysis of cigarette butts, especially microwave-assisted pyrolysis and hybrid waste pyrolysis, seemed to be necessary. Solving the technical issues associated with the pyrolysis of cigarette butts to produce the value-added goods would contribute to their application in waste disposal and recycling of other resources. Future studies should focus on the separation methods with the help of gas products to provide the heat required in the reactor. Moreover, mixing the sewage sludge material, as a feed, with cigarette butts and application of appropriate models and experiments to attain the products with specific properties are recommended. The results of this study can be used to eliminate the hazards of the cigarette butts scattered in the environment and create the added value for the pyrolysis process.
Environmental Engineering
A. Nuryadin; T. Imai
Abstract
BACKGROUND AND OBJECTIVES: Fixed-bed column has been considered an industrially feasible technique for phosphate removal from water. Besides the adsorption capacity, the effectiveness of an adsorbent is also determined by its reusability efficiency. In this study, phosphate removal by a synthesized amorphous ...
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BACKGROUND AND OBJECTIVES: Fixed-bed column has been considered an industrially feasible technique for phosphate removal from water. Besides the adsorption capacity, the effectiveness of an adsorbent is also determined by its reusability efficiency. In this study, phosphate removal by a synthesized amorphous zirconium (hydr)oxide/MgFe layered double hydroxides composite in a fixed-bed column system was examined. METHODS: The effects of flow rate, bed height, phosphate concentration, solution pH, and adsorbent particle size on the phosphate adsorption ability were examined through a series of continuous adsorption experiments. The appropriate breakthrough curve models, phosphate adsorption from real anaerobic sludge and synthetic seawater, column regeneration and reusability, and adsorption mechanism were also investigated for practical application feasibility. FINDINGS: The results showed that the increased bed height and phosphate concentration, and reduced flow rate, pH, and adsorbent particle size were found to increase the column adsorption capacity. The optimum adsorption capacity of 25.15 mg-P/g was obtained at pH 4. The coexistence of seawater ions had a positive effect on the phosphate adsorption capacity of the composite. Nearly complete phosphate desorption, with a desorption efficiency of 91.7%, could be effectively achieved by 0.1 N NaOH for an hour. Moreover, the initial adsorption capacity was maintained at approximately 83% even after eight adsorption-desorption cycles, indicating that the composite is economically feasible. The high phosphate adsorption capacity of the composite involves three main adsorption mechanisms, which are electrostatic attraction, inner-sphere complexation, and anion exchange, where the amorphous zirconium hydr(oxide) on the surface of the layered double hydroxides likely increased the number of active binding sites and surface area for adsorption. CONCLUSION: The amorphous zirconium (hydr)oxide/MgFe layered double hydroxides composite, with its high adsorption capacity and superior reusability, has the potential to be utilized as an adsorbent for phosphorus removal in practical wastewater treatment. This study provides insights into the design of amorphous zirconium (hydr)oxide/MgFe layered double hydroxides composite for phosphorus removal and recovery in a practical system.
Environmental Engineering
J. O. Castillo-Miranda; F. J. Rodríguez-Gómez; J. Genescá-Llongueras; L. G. Ruiz-Suárez; J. A. García-Reynoso
Abstract
BACKGROUND AND OBJECTIVES: Atmospheric zinc corrosion in the Mexico City Metropolitan area has long been attributed mainly to the effect of pollutants such as sulfur dipxide. There are changes in the urban atmosphere's chemical composition due to the implementation of air quality policies focused on ...
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BACKGROUND AND OBJECTIVES: Atmospheric zinc corrosion in the Mexico City Metropolitan area has long been attributed mainly to the effect of pollutants such as sulfur dipxide. There are changes in the urban atmosphere's chemical composition due to the implementation of air quality policies focused on reducing the emission of sulfur dipxide and other pollutants. This study's objectives were to estimate and map the contribution of nitric acid on zinc's atmospheric corrosion processMETHODS: The impact of nitric acid on zinc is feasible to estimate using a function for a multi-pollutant situation. This function contemplates the sum of two contributions: one of nitric acid and another that includes sulfuric acid and climatic parameters. The multi-pollutant function is suitable to apply in areas without the strong influence of chlorides and tropical and subtropical climates, comparable to the Mexico City Metropolitan area.FINDINGS: The results showed that spatial and temporal estimation of corrosion rates in grams per square meter of zinc was made for 2015-2019, using data modeling in a geographic information system. The maps of corrosion rates allowed us to visualize that, in general, the "southwest" zone has the most significant effects and that the lowest corrosion rates were presented in 2019 as an outcome of the implementation of air quality programs. Furthermore, a contribution of nitric acid up to 32% to the zinc corrosion rate was estimated.CONCLUSION: The construction of corrosion rate maps provides a spatial and temporal estimate that allows visualizing areas where zinc materials are at risk corrosion due to the dispersion of atmospheric pollutants and climatic parameters. Likewise, it can represent a decision-making tool for the implementation of atmospheric corrosion studies of materials.
