M. Camara; N.R.B. Jamil; F.B. Abdullah
Abstract
Rapid development and population growth have resulted in an ever-increasing level of water pollution in Malaysia. Therefore, this study was conducted to assess water quality of Selangor River in Malaysia. The data collected under the river water quality monitoring program by the Department of environment ...
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Rapid development and population growth have resulted in an ever-increasing level of water pollution in Malaysia. Therefore, this study was conducted to assess water quality of Selangor River in Malaysia. The data collected under the river water quality monitoring program by the Department of environment from 2005 to 2015 were used for statistical analyses. The local water quality indices were computed and a trend detection technique and cluster analysis were applied, respectively, to detect changes and spatial disparity in water quality trends. The results showed that the river water is of good quality at all stations, with the exception of 1SR01 and 1SR09 located upstream, which recorded moderate water quality indices of 68 and 71, respectively. The results of trend analysis showed downward trends in dissolved oxygen, biochemical oxygen demand and ammonia nitrogen, for most water quality stations, as well as increasing trends in chemical oxygen, suspended solids, pH and temperature for most stations. In addition, the results of cluster and time series analyses showed that the trend variation in dissolved oxygen, pH, and temperature between the station clusters is relatively low as compared to chemical oxygen demand, biochemical oxygen demand, suspended solids, and ammonia nitrogen. With the peak concentration of 13 mg/L for dissolved oxygen observed in cluster 2 in 2014, and the highest decrease in suspended solids (8 mg/L) observed in cluster 1 for 2015. This finding demonstrates that these combined statistical analyses can be a useful approach for assessing water quality for adequate management of water resources.
F.M. Muvea; G.M. Ogendi; S.O. Omondi
Abstract
The use of constructed wetlands for purifying pre-treated wastewater is a cost effective technology that has been found to be more appropriate for many developing countries. The technology is also environmentally friendly with the wetlands being habitats for many water birds and other aquatic organisms. ...
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The use of constructed wetlands for purifying pre-treated wastewater is a cost effective technology that has been found to be more appropriate for many developing countries. The technology is also environmentally friendly with the wetlands being habitats for many water birds and other aquatic organisms. This study assessed nutrient removal efficiency of two floating macrophytes (Lemna minor and Azolla pinnata). The data generated was analyzed using both descriptive and inferential statistics. The significance level was maintained at 0.05. The results showed that the wastewater physicochemical parameters did not vary during the study period. The concentrations of nitrites and nitrates increased over the experimental period in all the treatments (Azolla pinnata, Lemna minor and control), and the increase between the sampling occasions was statistically significant for the two nutrients (Nitrates: F=24.78, P= 0.00; Nitrates: F=198.26, P= 0.00). To the contrary, in all the treatments the concentrations of ammonia, total phosphorous, soluble reactive phosphorous and total nitrogen, decreased over the experimental period. The decrease in concentration for these nutrients between the sampling occasions was statistically significant (ammonia: F=195.57, p= 0.00; total phosphorous: F= 56.50, p= 0.00; soluble reactive phosphorous: F= 37.11, p= 0.00; total phosphorous: F= 104.025, p= 0.00). Azolla pinnata proved to be better than Lemna minor in the uptake of the nutrients particularly for the soluble reactive phosphorous (F= 35.18, P= 0.044). We conclude that the two macrophytes are good for wastewater treatment. It is recommended introduction and/or multiplication of Azolla pinnata in the constructed wetlands meant for wastewater treatment especially within the tropics.
A. Tahir; P. Taba; M.F. Samawi; S. Werorilangi
Abstract
Plastic pollution has universally known accumulated in all environment compartments and accelerating threat to the sustainability of earth. Field survey to examine the occurrence of microplastics in ancient sea water evaporation technology of ponds at Pallengu-Jeneponto, was conducted. From this sea ...
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Plastic pollution has universally known accumulated in all environment compartments and accelerating threat to the sustainability of earth. Field survey to examine the occurrence of microplastics in ancient sea water evaporation technology of ponds at Pallengu-Jeneponto, was conducted. From this sea salt producing ponds, samples of water, sediment and freshly harvested salts were collected. Sixteen samples each of water and sediments and 12 salts were collected. From 16 water and sediment samples there are 31 microplastics item discovered in 11 water samples (68.75% of total contamination) and 41 microplastics item observed in 10 sediment samples (62.5% total contamination), respectively. Interestingly, sampling points at sedimentation/heating pools were found to be the locations with highest occurrence of microplastics in both water and sediment. There are 7 salt samples positively contaminated with 29 microplastics or 58.3% of total contamination, which predominated by line and fragment forms. Fourier transform infra-red spectroscopy analysis has revealed polymers of polyvinyl acetate (41.7%), polyethylene (33.3%) and polystyrene (25%). There was no significant difference found on microplasticss occurrence from 3 kinds of samples collected, although there was a decreasing trend of total microplastics found from water, sediment and salt. Microplasticss abundance were ranged 7-55 items/L water, 14.6-50 items/kg sediments and 6.7-53.3 items/kg salt. With microplastics abundance reached over 53 microplastics items/kg salt, it is believed that continuous consumption by people will end up with possible accumulation of potentially absorbed of various toxic chemical pollutants which present in sea water as salt raw materials. The need for robust and practical strategy in water quality management for reduction of microplasticss contamination in consumed salts is a must.
J. Samaniego; M.A.N. Tanchuling
Abstract
The use of amalgamation process to recover gold from mined ores by the small-scale gold miners in the Philippines and other developing countries produces and dispose of untreated wastewater to the receiving water bodies. In this study, a field-scale filter bed system was constructed to treat heavy metal ...
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The use of amalgamation process to recover gold from mined ores by the small-scale gold miners in the Philippines and other developing countries produces and dispose of untreated wastewater to the receiving water bodies. In this study, a field-scale filter bed system was constructed to treat heavy metal metal-laden wastewater collected from small-scale gold mining site in Paracale, Camarines Norte, Philippines. The filter bed system was consists of sedimentation tank and filter bed with Cocopeat, a by-product of coconut husk, as adsorbent. Physico-chemical parameters (temperature, pH, oxidation-reduction potential, electrical conductivity, turbidity, dissolved oxygen, total dissolved solids, salinity, total suspended solids, color) and heavy metal (As, Ba, Cd, Hg, Pb) concentrations were monitored during the 50 days experiment at a flow rate of 40 Liter per hour for 3 hours daily wastewater application. Significant reduction was achieved on heavy metals; As (97.11%), Ba (39.75%), Cd (74.24%), Hg (97.02%), Pb (98.82%) from small-scale gold mining (SSGM)wastewater in sedimentation phase and further reductions on As (1.39%), Ba (28.00%), Cd (4.95%), Hg (2.91%), Pb (0.97%) were achieved by adsorption in the Cocopeat filter bed. Measured effluent physico-chemical parameters and heavy metal concentrations were within the respective regulatory limits. Other effluent parameters with strong correlation with total suspended solids such as turbidity and color, though not regulated, were reduced significantly. All adsorbed heavy metals accumulated in the upper 25 cm of the Cocopeat column in the filter bed. Measured heavy metal concentrations in Cocopeat suggest that the adsorbent was not saturated and further application of small-scale gold mining wastewater is recommended to determine its useful life.
V. Anand; B. Oinam
Abstract
Hydrological components in a river basin can get adversely affected by climate change in coming future. Manipur River basin lies in the extreme northeast region of India nestled in the lesser Himalayan ranges and it is under severe pressure from anthropogenic and natural factors. Basin is un-gauged as ...
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Hydrological components in a river basin can get adversely affected by climate change in coming future. Manipur River basin lies in the extreme northeast region of India nestled in the lesser Himalayan ranges and it is under severe pressure from anthropogenic and natural factors. Basin is un-gauged as it lies in remote location and suffering from large data scarcity. This paper explores the impact of climate change towards understanding the inter-relationships between various complex hydrological factors in the river basin. An integrated approach is applied by coupling Soil and Water Assessment Hydrological Model and Hadley Center Coupled Model based on temperature, rainfall and geospatial data. Future representative concentration pathways 2.6, 4.5 and 8.5 scenarios for 2050s and 2090s decades were used to evaluate the effects of climatic changes on hydrological parameters. Both annual mean temperature and annual precipitation is predicted to be increased by 2.07oC and 62% under RCP 8.5 by the end of 21st century. This study highlights that change in meteorological parameters will lead to significant change in the hydrological regime of the basin. Runoff, actual evapotranspiration and water yield are expected to be increased by 40.96 m3/s, 52.2% and 86.8% respectively under RCP 8.5. This study shows that water yield and evapotranspiration will be most affected by increase in precipitation and temperature in the upper and middle sub-basins. Different region within the basin is likely to be affected by frequent landslides and flood in coming decades.
Environmental Engineering
A. Włodarczyk
Abstract
The tightening of the European Union climate and energy policy, directed to raising the resilience and effectiveness of the European Union Emissions Trading System, may influence on companies' economic performance. Polish energy companies, which mainly use coal in the energy production process, are particularly ...
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The tightening of the European Union climate and energy policy, directed to raising the resilience and effectiveness of the European Union Emissions Trading System, may influence on companies' economic performance. Polish energy companies, which mainly use coal in the energy production process, are particularly worried about the potential negative consequences associated with the implementation of new CO2 emission reduction targets and their participation in the European Union Emissions Trading System. This paper analyzes the link between economic performance and environmental performance of Polish energy companies, covered by the European Union Emissions Trading System in the years 2013-2017. This analysis may focus the attention of the European Union’s and Polish institutions responsible for developing the climate and energy policies on positive and negative consequences concerning the low-carbon transformation of the Polish energy sector. Two indicators of environmental performance: carbon intensity and the ratio of carbon dioxide emissions over the allowances, as well as chosen financial ratios: return on assets, return on investment, return on sales, asset turnover ratio are calculated for these companies. A Spearman’s rank correlation coefficient is used in order to analyze the relationship between these environmental and financial variables. Presented empirical results highlight that the situation of Polish enterprises worsened in the 3rd trading period, as the number of allocated allowances in case of all energy companies was insufficient to cover their own CO2 emission. A negative direction of the correlation dependency can be observed in the years 2013-2017 only between asset turnover ratio and return on assets, and the CO2 emission intensity.
Environmental Engineering
O.А. Mykoliuk; V.М. Bobrovnyk
Abstract
The study highlights the importance to develop the national economy through assuring energy security. The study aims to analyze how to develop renewable energy sources, determine the main priorities of Ukraine’s national security policy and discover novel ways of assuring energy security due to ...
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The study highlights the importance to develop the national economy through assuring energy security. The study aims to analyze how to develop renewable energy sources, determine the main priorities of Ukraine’s national security policy and discover novel ways of assuring energy security due to developing the industry of renewable energy in the light of environmental safety, energy conservation, and efficiency. The following scientific methods were employed: synthesis and analysis – to determine the essence and significance of RES in order to assure energy security; theoretical generalization – to single out the main stages of renewable energy development; classification – to classify the main advantages of introduction of RES, as well as the obstacles to their implementation; logical generalization – to justify the relevance, aim and objectives of the study; the method of rising from the abstract to the concrete – to develop and justify the ways of assuring energy security provided that renewable production is developed. The following results are obtained: the main conditions for developing RE are determined; some relevant issues of energy efficiency and assurance of Ukraine’s energy security are justified; significant potential of Ukraine’s renewable energy industry is discovered and analyzed; target values Ukraine seeks to achieve with the help of the energy generated from RES in final energy consumption are analyzed; the main criteria for developing Ukraine’s fuel and energy complex are revealed and the key branch ratio values of the state’s energy balance are determined.
Environmental Engineering
V. Babenko; V. Sidorov; Y. Koniaieva; L. Kysliuk
Abstract
This article discusses the prospects for the development of the implementation of scientific and technical cooperation. On the example of international cooperation between Ukraine and Chile, there are approaches to improving the procedure for developing cooperation priorities. The current state of these ...
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This article discusses the prospects for the development of the implementation of scientific and technical cooperation. On the example of international cooperation between Ukraine and Chile, there are approaches to improving the procedure for developing cooperation priorities. The current state of these relations does not reflect real trends in the development of international economic relations in the vector of strengthening the scientific and technical component. Based on the analysis of analytical materials, one of the priority areas of the joint development of scientific and technical issues may be the use of non-traditional renewable energy technologies. Both in Ukraine and in Chile there are objective factors (natural, resource, socio-economic, environmental-technological) for their development. For Ukraine, it is interesting the experience of the scientific and production implementation of these technologies and the organizational and economic support of these priorities in the context of state and regional policy. All these aspects, including through the exchange of intellectual products, will make it possible to increase the effectiveness of support policies, the innovative susceptibility of subjects of production and business activities of Ukraine and the corresponding development of producers and consumers' motivation to non-conventional renewable energy technology.
G.R. Puno; R.C.C. Puno
Abstract
Geomorphometric features and land use/land cover are essential in the context of watershed prioritization for resources conservation and protection. Watersheds in tropical regions like the Philippines are under threat of degradation due to the combined effects of uncontrolled agricultural activities ...
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Geomorphometric features and land use/land cover are essential in the context of watershed prioritization for resources conservation and protection. Watersheds in tropical regions like the Philippines are under threat of degradation due to the combined effects of uncontrolled agricultural activities in the uplands and frequently increasing erosive precipitations brought about by climate change. Watershed managers are challenged with these pressing issues and concerns because most watersheds have no sufficient data as a basis for decision making. This paper presents the method of analyzing the different geomorphometric features and the existing land use or land cover to assess the propensity of the watershed against erosion so that areas needing immediate treatment can be prioritized. Arbitrarily, fourteen subwatersheds coded as SW1 to SW14 were delineated using a digital elevation model and geographic information system tool. Geomorphometric features categorized as areal aspect, relief features, and channel morphology parameters were generated and analyzed. Parameters having direct and inverse effect to erosion risk was used as the criteria in the ranking process. Land use/land cover was added to geomorphometric parameters to come up with compound values for final prioritization. Results showed that SW13, SW14, and SW4 were classified under very high priority implying focus for appropriate management actions while SW10, SW6, and SW7 were classified under very low priority suggesting favorable environmental condition in these areas. The study provides significant information helpful to watershed managers and planners especially in crafting a plan for integrated watershed management wherein programs and projects implementation have to be prioritized.
A. Masih
Abstract
In view of pollution prediction modeling, the study adopts homogenous (random forest, bagging, and additive regression) and heterogeneous (voting) ensemble classifiers to predict the atmospheric concentration of Sulphur dioxide. For model validation, results were compared against widely known single ...
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In view of pollution prediction modeling, the study adopts homogenous (random forest, bagging, and additive regression) and heterogeneous (voting) ensemble classifiers to predict the atmospheric concentration of Sulphur dioxide. For model validation, results were compared against widely known single base classifiers such as support vector machine, multilayer perceptron, linear regression and regression tree using M5 algorithm. The prediction of Sulphur dioxide was based on atmospheric pollutants and meteorological parameters. While, the model performance was assessed by using four evaluation measures namely Correlation coefficient, mean absolute error, root mean squared error and relative absolute error. The results obtained suggest that 1) homogenous ensemble classifier random forest performs better than single base statistical and machine learning algorithms; 2) employing single base classifiers within bagging as base classifier improves their prediction accuracy; and 3) heterogeneous ensemble algorithm voting have the capability to match or perform better than homogenous classifiers (random forest and bagging). In general, it demonstrates that the performance of ensemble classifiers random forest, bagging and voting can outperform single base traditional statistical and machine learning algorithms such as linear regression, support vector machine for regression and multilayer perceptron to model the atmospheric concentration of sulphur dioxide.
I. Fayaji; M.H. Sayadi; H. Mousazadeh
Abstract
In the current study, the qualitative status of potable well water was assessed using the groundwater quality index during a course of 4 years (2014-2017). This study was carried out with an aim to monitor the drinking water resources from 12 potable wells on the multivariate analysis basis and for determination ...
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In the current study, the qualitative status of potable well water was assessed using the groundwater quality index during a course of 4 years (2014-2017). This study was carried out with an aim to monitor the drinking water resources from 12 potable wells on the multivariate analysis basis and for determination of groundwater quality index, the following 13 physicochemical parameters including electrical conductivity, total dissolved solids, pH, total hardness, potassium, fluoride, bicarbonate, chloride, calcium, magnesium, sulphate, and nitrate were used. On the basis of Piper diagram, the results revealed that the type and faces of samples were chloride-sodic and bicarbonate-sodic respectively. Groundwater quality index level in the potable well water of case study area was 42.89 to 56.58 and zone water was in the good and medium range. Besides, 66.7% of the wells were in the good range and 33.3% of wells were in the medium range of water quality index. In this study, potassium and fluoride level in all the zone wells was lower than the ideal level and the electrical conductivity, total dissolved solids, sodium, magnesium and sulphate in all the wells was higher than the ideal range for drinking purposes. Based on this study results, the potable water quality of most of the study area wells generally in 2017 vis-à-vis 2014 had reduced and its main reason was the presence of geology formations, agricultural runoffs and absorbing wells in this zone.
G.C.B. Paclibar; E.R. Tadiosa
Abstract
Non-native plants that can cause adverse effects are otherwise known as invasive alien plant species which pose a major threat to plant biodiversity conservation and sustainability. This study is dedicated to determine the plant diversity and to assess the vulnerability of Quezon Protected Landscape, ...
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Non-native plants that can cause adverse effects are otherwise known as invasive alien plant species which pose a major threat to plant biodiversity conservation and sustainability. This study is dedicated to determine the plant diversity and to assess the vulnerability of Quezon Protected Landscape, Southern Luzon, the Philippines to invasive alien plant species. Data from 90 10x10 m randomly established plots using the quadrat method showed that there are 318 plant species wherein 208 are native, 100 are non-native, and 10 are invasive. Results from the association of the physicochemical factors and the presence of invasive alien plant species through Spearman rho test revealed that most of the physicochemical factors have significant association except percent slope and hill shade. Soil pH, aspect and number of non-native plants show positive association while soil moisture, leaf litter thickness, elevation, species richness, species evenness, plot species diversity index, and the number of native plants signify negative association. Differences between the plots of with and without invasive alien plant species in physicochemical factors indicate that most of the physicochemical factors have a significant difference between plots of with and without invasive alien plant species except percent slope, hill shade, and aspect. Lastly, the MaxEnt model exemplifies that the most suitable predicted conditions for invasive alien plant species are at the edges of boundary and buffer zones. This study implies that most of the physicochemical factors are linked to the presence of invasive alien plant species and Quezon Protected Landscape has a low vulnerability to invasive alien plant species invasion.
R.C.C. Puno; G.R. Puno; B.A.M. Talisay
Abstract
Predicting the impact of land cover and climate change on hydrologic responses using modeling tools are essential in understanding the movement and pattern of hydrologic processes within the watershed. The paper provided potential implications of land conversions and climate change scenarios on the hydrologic ...
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Predicting the impact of land cover and climate change on hydrologic responses using modeling tools are essential in understanding the movement and pattern of hydrologic processes within the watershed. The paper provided potential implications of land conversions and climate change scenarios on the hydrologic processes of Muleta watershed using soil and water assessment tool model. Model inputs used include interferometric synthetic aperture radar-digital elevation model, 2016 land cover map, soil map, meteorological and hydrologic data. The model was calibrated using appropriate statistical parameters (R2=0.80, NS=0.80 and RSR=0.45). Model validation using observed streamflow with the same statistical parameters (R2 = 0.79, NS = 0.67 and RSR = 0.57) showed that the result was statistically acceptable. The model provided potential implications of land conversions and climate change adversely affecting hydrologic processes of critical watersheds. Climate change projections with a 13% decrease in rainfall directly influenced the decrease in hydrologic processes. Meanwhile, urbanization had influenced the increase in surface runoff, evapotranspiration, and baseflow. The increase of forest vegetation resulted in a minimal decrease in baseflow and surface runoff. The watershed hydrologic processes were influenced by changes in land cover and climate. Results of this study are useful by the localities and policy makers in coming up with a more informed decision relative to the issues and concern on hydrological responses in the uplands.
B. Gwada; G. Ogendi; S.M. Makindi; S. Trott
Abstract
Among the emerging environmental issues within Sub-Saharan Africa is the haphazard disposal of plastic waste, some of which end up downstream in the marine environment leading to negative effects. Notably there have been cases of humpback whales getting entangled in ‘ghost’ fishing nets, ...
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Among the emerging environmental issues within Sub-Saharan Africa is the haphazard disposal of plastic waste, some of which end up downstream in the marine environment leading to negative effects. Notably there have been cases of humpback whales getting entangled in ‘ghost’ fishing nets, and endangered turtles ingesting plastic wastes in Watamu beach in Kenya. The aim of the current study was to assess the composition and management of plastic waste discarded by households in Watamu ward. Stratified random sampling was used to collect data from households in four sub-locations within Watamu ward. Data were analysed using descriptive and inferential statistics (the Freeman-Halton extension of the Fisher’s Exact test). The composition of plastics usually discarded as waste by households in order of dominance were low density polyethylene, polyethylene terephthalate, high density polyethylene and polypropylene (FH=37.959, p = 0.000). From the results, only 0.7% of respondents recycled their plastic waste. The most preferred disposal method of household plastic waste was open dumpsites (61.4%) followed by burning (12.9%) and discards (6.4%). Majority of respondents (93.6%), re-use some plastic containers for food, water, and oil storage. There was a significant difference in terms of how the respondents re-used their plastic waste in the four sub-locations (FH=36.437, p=0.005). In conclusion, the current plastic waste disposal methods at Watamu are not environmentally friendly and recycling is still at a smaller scale despite its potential to generate income and clean the environment, and promote ecosystem services and human wellbeing.
A. Cruz-Salomón; E. Ríos-Valdovinos; F. Pola-Albores; S. Lagunas-Rivera; R. Meza-Gordillo; V.M. Ruíz-Valdiviezo; K.C. Cruz-Salomón
Abstract
The expanded granular sludge bed bioreactor appears today as a cheap, robust and more popular technology because it operates using a fluidized bed, which allows increasing in organic load and in cell retention times, generating higher treatment efficiencies (up to 95 %) and renewable energy (i.e., biogas, ...
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The expanded granular sludge bed bioreactor appears today as a cheap, robust and more popular technology because it operates using a fluidized bed, which allows increasing in organic load and in cell retention times, generating higher treatment efficiencies (up to 95 %) and renewable energy (i.e., biogas, biomethane, and biohydrogen). Nevertheless, the efficiency of this bioreactor mainly depends on the operating conditions. Thus, the content presented in this review paper focuses on the analysis of the operating conditions and performance of expanded granular sludge bed bioreactor for treating different types of industrial, agro-industrial and domestic wastewaters (e.g., agro-food, beverage, alcohol distillery, tannery, slaughterhouse, chemical, pharmaceutical, municipal sewage, among others). Because of this reason, this study aimed to analyze the operating conditions and type of substrate, which has been used in these bioreactors to improve future research to wastewater treatment and renewable energy production. According to the review, it is concluded that the EGSB bioreactor is a novel sustainable alternative to treat different types of wastewaters and consequently change the paradigm of wastewater management from "treatment and disposal" to "beneficial use" as well as "profitable effort".
G. Elkiran; V. Nourani; S.I. Abba; J. Abdullahi
Abstract
ABSTRACT: In this study, adaptive neuro-fuzzy inference system, and feed forward neural network as two artificial intelligence-based models along with conventional multiple linear regression model were used to predict the multi-station modelling of dissolve oxygen concentration at the downstream of Mathura ...
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ABSTRACT: In this study, adaptive neuro-fuzzy inference system, and feed forward neural network as two artificial intelligence-based models along with conventional multiple linear regression model were used to predict the multi-station modelling of dissolve oxygen concentration at the downstream of Mathura City in India. The data used are dissolved oxygen, pH, biological oxygen demand and water temperature at upper, middle and downstream of the river. To predict outlet of dissolved oxygen of the river in each station, considering different input combinations as i) 11 inputs parameters for all three locations except, dissolved oxygen at the downstream ii) 7 inputs for middle and downstream except dissolved oxygen, at the target location and lastly iii) 3 inputs for downstream location. To determine the accuracy of the model, root mean square error and determination coefficient were employed. The simulated results of dissolved oxygen at three stations indicated that, multi-linear regression is found not to be efficient for predicting dissolved oxygen. In addition, both artificial intelligence models were found to be more capable and satisfactory for the prediction. Adaptive neuro fuzzy inference system model demonstrated high prediction ability as compared to feed forward neural network model. The results indicated that adaptive neuro fuzzy inference system model has a slight increment in performance than feed forward neural network model in validation step. Adaptive neuro fuzzy inference system proved high improvement in efficiency performance over multi-linear regression modeling up to 18% in calibration phase and 27% in validation phase for the best models.
S.S. Hosseini; K. Yaghmaeian; N. Yousefi; A.H. Mahvi
Abstract
Anaerobic decomposition of organic compounds in landfills is responsible for generation of greenhouse gases. The present study aimed to determine the total gas and methane emission from a landfill located in Hamedan (west of Iran) from 2011 to 2030. LandGEM 3.02 model was used to estimate the gas emission ...
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Anaerobic decomposition of organic compounds in landfills is responsible for generation of greenhouse gases. The present study aimed to determine the total gas and methane emission from a landfill located in Hamedan (west of Iran) from 2011 to 2030. LandGEM 3.02 model was used to estimate the gas emission with the volumetric methane percent of 60%, production potential of 107, and methane generation rate of 0.2. Spatial distribution of annual methane and total landfill gas emission rate in the study area at three decades were provided through ArcGIS software. The results showed that organic and food wastes had the maximum amounts in the solid waste stream (over 75%). The results showed that 4.371×108 m3 methane would be produced after 20 years, mostly (4.053×106m3) in the first year. In addition, methane production capacity in Hamedan landfill site was 107 m3/Mg. According to the results, the maximum and minimum gas generation rates are in summer (the hottest season) and winter (the coldest season) respectively. The results of the LandGEM model represented that the total gas and methane generation rates will be significant in the first 10 years. The potential of rapidly degradable organic compounds for gas emission will be higher than that of slowly degradable organic compounds. The results obtained in the present study can be beneficially used in planning for energy production and other applications in landfill sites.
S.M. Tajbakhsh; H. Memarian; K. Moradi; A.H. Aghakhani Afshar
Abstract
The change of land use/land cover has been known as an imperative force in environmental alteration, especially in arid and semi-arid areas. This research was mainly aimed to assess the validity of two major types of land change modeling techniques via a three dimensional approach in Birjand urban watershed ...
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The change of land use/land cover has been known as an imperative force in environmental alteration, especially in arid and semi-arid areas. This research was mainly aimed to assess the validity of two major types of land change modeling techniques via a three dimensional approach in Birjand urban watershed located in an arid climatic region of Iran. Thus, a Markovian approach based on two suitability and transition potential mappers, i.e. fuzzy analytic hierarchy process and artificial neural network-multi layer perceptron was used to simulate land use map. Validation metrics, quantity disagreement, allocation disagreement and figure of merit in a three-dimensional space were used to perform model validation. Utilizing the fuzzy-analytic hierarchy processsimulation of total landscape in the target point 2015, quantity error, the figure of merit and allocation error were 2%, 18.5% and 8%, respectively. However, Artificial neural network-multi layer perceptron simulation led to a marginal improvement in figure of merit, i.e. 3.25%.
D. Sivakumar; J. Nouri; T.M. Modhini; K. Deepalakshmi
Abstract
Water is prime requirement for surviving of any living beings. The existence of surface water and groundwater sources are used for domestic, agriculture and industrial purposes in all over the world. Fresh water from both the water sources is highly contaminated in recent years because of rapid ...
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Water is prime requirement for surviving of any living beings. The existence of surface water and groundwater sources are used for domestic, agriculture and industrial purposes in all over the world. Fresh water from both the water sources is highly contaminated in recent years because of rapid population growth, modern agriculture and industrial growth. Among them, contamination of water sources due to industrialization is high and it requires more attention to protect those water sources. In this study, nickel removal from electroplating industry wastewater was done with the help of bamboo activated carbon. The nickel removal from electroplating industry wastewater by bamboo activated carbon was done in this study at various adsorbent dosages (0.5, 1.0, 1.5 and 2.0 g/L), agitation speeds (25, 50, 75 and 100 rpm), particle sizes (2.36, 1.18, 0.6 and 0.3 mm), and concentration dilutions (0, 25, 50, 75 and 100%). The maximum removal percentage of nickel from electroplating industry wastewater using bamboo activated carbon was found to be 98.7 % at an optimum adsorption dosage 1.5 g/L, agitation speed 25 rpm, particle size 0.6 mm and concentration dilution 75 % with 110 min. contact time and 5.5 pH. Functional groups available in a bamboo activated carbon before and after treatment were determined by fourier-transform infrared spectroscopy analysis. Fourier-transform infrared spectroscopy analysis specified that alkanes, carboxylic acids, esters, amides, amines, aromatic compounds, alkyl halides, ethers, alcohols, carboxylic acids, aldehydes functional groups in bamboo activated carbon was contributed for removing nickel from the electroplating industry wastewater. Isotherm models were used to know the adsorption behaviour of bamboo activated carbon for removing nickel from electroplating industry wastewater. Isotherm results revealed that Langmuir model was best suited with the equilibrium data than Freundlich model. Finally, this study concluded that bamboo activated carbon was best suited for removing nickel from electroplating industry wastewater.
M. Rafiei; P.J. Sturm
Abstract
The aim of this study is to investigate the problems caused by discharge of polluted air from tunnels into the environment with a specific focus on residential areas. In city tunnels, portal or stacks, pollutant management is a big challenge. Nowadays, air quality management, particularly in urban tunnels, ...
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The aim of this study is to investigate the problems caused by discharge of polluted air from tunnels into the environment with a specific focus on residential areas. In city tunnels, portal or stacks, pollutant management is a big challenge. Nowadays, air quality management, particularly in urban tunnels, is considered as a part of the ventilation system design. The goal is to see the environmental impacts beforehand. From environmental aspects, preventive measures are required either inside or outside the tunnel in some cases. Niayesh tunnel in Tehran is taken as a case for proving the objectives presented in this study. Concentration of carbon monoxide at the vicinity of the portals is calculated using the proper dispersion simulation. The results of dispersion modeling for the assumed worst case of ventilation can help to understand the environmental impact of ventilation. The worst traffic emissions for a congested traffic scenario,are selected as an emission source for dispersion modeling. According to the traffic condition and fleet composition, the crucial emission extracted from the tunnel is carbon monoxide. Therefore, the performed simulation only focuses on carbon monoxide dispersion modeling. From the other side, carbon monoxide is taken as a demonstration pollutant, because it is inert and chemical reactions can be neglected in short-term considerations. A lagrangian model composed of Graz Lagrangian Model and Graz Mesoscale Model is used for flow-field and dispersion calculations.
B. Seng; T. Fujiwara; B. Seng
Abstract
Solid waste management is challenging in Phnom Penh city, Capital of Cambodia. The only one formal treatment taken is the final disposal of mixed waste into an open dumpsite. The current study analyses the physical and chemical characteristics of municipal solid waste disposed of in the dumpsite to assess ...
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Solid waste management is challenging in Phnom Penh city, Capital of Cambodia. The only one formal treatment taken is the final disposal of mixed waste into an open dumpsite. The current study analyses the physical and chemical characteristics of municipal solid waste disposed of in the dumpsite to assess their suitable handling methods. The current study found that the major compositions of waste are food waste (49.18%) and plastic (21.13%), and recyclable waste shares about 17.28% of the total. On average, it contains 60.92% moisture, 35.89% combustible, 3.19% ash, 58.32% carbon and 1.05% nitrogen. High calorific value is 10.03 MJ/kg when the low calorific value is 7.77 MJ/kg. The moisture content is too high to meet the technology demands, especially in the rainy season. It seems workable for incineration without energy recovery. Gasification for melting and incineration with energy recovery are only suitable for the dry season. If the solid waste is well pre-separated, material recovery could be one of the suitable handling methods. Food waste, wood and leave could be digested in the one-stage continuous wet system and co-composted, and plastic is appropriate for refuse-derived fuel generation. The current study recommends that the waste pre-separation should be requisite for any handling methods.
S.M. Tajbakhsh; H. Memarian; M. Sobhani; A.H. Aghakhani Afshar
Abstract
Hydrologic modeling of semi-arid watersheds is imperative for the development of appropriate water and soil conservation plans. In the current study, the efficiency of Kinematic Runoff and Erosion model-version 2 (K2) model was used to evaluate water discharge and sediment load simulation of Bar watershed, ...
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Hydrologic modeling of semi-arid watersheds is imperative for the development of appropriate water and soil conservation plans. In the current study, the efficiency of Kinematic Runoff and Erosion model-version 2 (K2) model was used to evaluate water discharge and sediment load simulation of Bar watershed, located in the north-eastern part of Iran. The K2 model relies on the kinematic wave approach to route surface flow. The drainage network and planes are discretized to represent the watershed. In order to evaluate the model, 3 and 2 reported rainfall incidents in various dates were selected for K2 calibration and validation, respectively. The multiplier approach was employed for model calibration. The results of sensitivity investigation revealed that the soil parameters Ks-CH, n and G had the highest impact on flow discharge. Through the calibration process, the Nash-Sutcliff Efficiency and the coefficient of determination as fitting metrics for water discharge simulation (based on event #2, dated 16 March 1992) were estimated to be 0.78 and 0.88, respectively. According to the aggregated measure, the highest K2 efficiency was obtained during the calibration process based on event #2. Other storm events were resulted in a good simulation, as well. During the validation process, K2 simulation (based on event #4, dated 07 March 1991) led to the Nash-Sutcliffe Efficiency and R2 of 0.77 and 0.71, respectively. The K2 calibration for sediment load simulation was performed through the alterations of the Pave and Rainsplash parameters. The bias percentages between simulated and observed total sediment loads based on events #2 and #4 were 5% and 16%, respectively. Conclusively, the K2 model showed an acceptable robustness in the hydrological simulation of Bar watershed as a representative semi-arid watershed in northeast of Iran.
B. Te; B. Wichitsathian; C. Yossapol; W. Wonglertarak
Abstract
Mesoporous pellet adsorbent developed from mixing at an appropriate ratio of natural clay, iron oxide, iron powder, and rice bran was used to investigate the optimization process of batch adsorption parameters for treating aqueous solution coexisting with arsenate and arsenite. Central composite design ...
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Mesoporous pellet adsorbent developed from mixing at an appropriate ratio of natural clay, iron oxide, iron powder, and rice bran was used to investigate the optimization process of batch adsorption parameters for treating aqueous solution coexisting with arsenate and arsenite. Central composite design under response surface methodology was applied for optimizing and observing both individual and interactive effects of four main influential adsorption factors such as contact time (24-72 h), initial solution pH (3-11), adsorbent dosage (0-20 g/L) and initial adsorbate concentration (0.25-4.25 mg/L). Analysis of variance suggested that experimental data were better fitted by the quadratic model with the values of regression coefficient and adjusted regression coefficient higher than 95%. The model accuracy was supported by the correlation plot of actual and predicted adsorption efficiency data and the residual plots. The Pareto analysis suggested that initial solution pH, initial adsorbate concentration, and adsorbent dosage had greater cumulative effects on the removal system by contributing the percentage effect of 47.69%, 37.07% and 14.26%, respectively. The optimum values of contact time, initial solution pH, adsorbent dosage and initial adsorbate concentration were 52 h, 7, 10 g/L and 0.5 mg/L, respectively. The adsorption efficiency of coexisting arsenate and arsenite solution onto the new developed adsorbent was over 99% under the optimized experimental condition.
F. Esfandi; A.H. Mahvi; M. Mosaferi; F. Armanfar; M. Hejazi; S. Maleki
Abstract
Eutrophication is considered as a serious problem in water reservoirs. Awareness about the eutrophic status of each reservoir could help in providing a better understanding of the problem in a global scale. The present study was conducted to assess temporal and spatial eutrophication index in a water ...
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Eutrophication is considered as a serious problem in water reservoirs. Awareness about the eutrophic status of each reservoir could help in providing a better understanding of the problem in a global scale. The present study was conducted to assess temporal and spatial eutrophication index in a water reservoir (Sahand dam) in the northwest of Iran. Physico-chemical parametres that are effective on eutrphic condition occurrence were analyzed, and trophic state index was calculated on a scale of 0-100 by measuring Secchi disk depth, chlorophyll a, total phosphorus, total nitrogen, total suspended solids, and phosphorus P/N ratio. Moreover, using the overlapping, the reservoir was mapped based on the mentioned index. Seasonal variation of dissolved solids in the reservoir was recorded due to precipitation and subsequent dilution and evaporation. Thermal stratification was observed during the summer months. The total trophic state index value was calculated as 55.5- 58.07, with minimum value belonging to P/N and maximum value belonging to suspended solids for individual parameters. There were some spatial and temporal differences for trophic state index in the reservoir. It was found that the whole area of the reservoir was in almost moderately upper-mesotrophic condition and in some target stations it was very close to eutrophic condition. The worst condition was observed in Qaranqu River as the main input to the reservoir. Due to the significant impact of suspended particles resulting from erosion of the surrounding lands on TSI value, there is an urgent need for mitigation measures to intercept eutrophication.
K.O. Demirarslan; B.Y. Çelik
Abstract
In the current study, the solid waste characterisation that belongs to Artvin city centre, which is located in East Black Sea Region of Turkey, were searched. The study has the feature of being the first study for the country of Artvin in terms of study. The field of study is composed of 7 neighborhoods ...
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In the current study, the solid waste characterisation that belongs to Artvin city centre, which is located in East Black Sea Region of Turkey, were searched. The study has the feature of being the first study for the country of Artvin in terms of study. The field of study is composed of 7 neighborhoods and those can be separated into 3 groups as low, middle and high level of income. In this study, 11 kind of waste were examined, which are organic, paper, plastic, glass, metal, ash, electronic, textile, garden waste, hazardous and others. The effect of seasons on the amount of waste was examined; also, the relationship between the amount of waste and the level of income was also examined by using the two-way ANOVA analysis. Furthermore, all ratios of wastes that are located in Artvin city centre were searched. According to that, the waste ratios, occurs in one year, of all neighborhoods in the Artvin city centre are found as 61.06% organic, 10.28% paper, 9% plastic, 3.20% glass, 2.29% metal, 3.87% ash, 0.037% electronic, 1.58% textile, 1.35% garden waste, 0.51 % hazardous and 7.23% others. Those obtained values were compared with other similar studies in the literature. Moreover, for collecting recyclable wastes for the city centre 3 different methods are proposed named as methods collection from households, collection from buildings and collection from neighborhoods. These methods have been studied economically and the collection from buildings method is the most appropriate among these three methods.
