Bruno Moreno Ramos da Silva, Rafael Kopschitz Xavier Bastos, Thiago José Dias Godinho
Abstract In this work, the influence of mixing conditions on aluminium recovery from alum sludge and on the recovered coagulant (RC) quality was investigated using acidic treatment. The response surface methodology with a face centred design was used to evaluate the effects of velocity gradient and mixing time on aluminium recovery efficiency, and on the chemical oxygen demand (COD), total suspended solids (TSS) and total phosphorus contents of the RC. No significant effects of both mixing intensity and mixing time on aluminium recovery efficiency were observed; however, these factors significantly affected the quality of the RC in terms of COD, TSS and total phosphorus. The higher velocity gradient increased COD and TSS and the longer mixing time increased phosphorus and TSS in the RC. The defined operational conditions (velocity gradient = 100 s−1 and mixing time = 5 min) for aluminium recovery were suggested on economic basis. At these optimal conditions, the RC presented the lowest values of TSS and total phosphorus (100 mg L−1 and 7.0 mg P L−1, respectively), and the following other characteristics: 1,001 mg Al L−1; 384 mg Fe L−1 and 1,100 mg COD L−1.
摘要采用酸性处理方法，研究了混合条件对明矾污泥回收铝的影响以及对回收混凝剂质量的影响。采用面中心设计的响应面法，考察了速度梯度和搅拌时间对RC中铝回收率、化学需氧量(COD)、总悬浮固体(TSS)和总磷含量的影响。混合强度和混合时间对铝回收率无显著影响;然而，这些因素在COD、TSS和总磷方面对RC质量有显著影响。速度梯度越大，RC中COD和TSS增加，混合时间越长，RC中磷和TSS增加。从经济的角度提出了铝回收的操作条件(速度梯度为100 s−1，混合时间为5 min)。在这些最佳条件下，RC的TSS和总磷含量最低(分别为100 mg L−1和7.0 mg P L−1)，并且具有以下特征:Al L−1为1001 mg;384 mg Fe L−1和1100 mg COD L−1。
{"title":"Influence of mixing conditions on coagulant recovery efficiency and quality","authors":"Bruno Moreno Ramos da Silva, Rafael Kopschitz Xavier Bastos, Thiago José Dias Godinho","doi":"10.2166/wpt.2023.190","DOIUrl":"https://doi.org/10.2166/wpt.2023.190","url":null,"abstract":"Abstract In this work, the influence of mixing conditions on aluminium recovery from alum sludge and on the recovered coagulant (RC) quality was investigated using acidic treatment. The response surface methodology with a face centred design was used to evaluate the effects of velocity gradient and mixing time on aluminium recovery efficiency, and on the chemical oxygen demand (COD), total suspended solids (TSS) and total phosphorus contents of the RC. No significant effects of both mixing intensity and mixing time on aluminium recovery efficiency were observed; however, these factors significantly affected the quality of the RC in terms of COD, TSS and total phosphorus. The higher velocity gradient increased COD and TSS and the longer mixing time increased phosphorus and TSS in the RC. The defined operational conditions (velocity gradient = 100 s−1 and mixing time = 5 min) for aluminium recovery were suggested on economic basis. At these optimal conditions, the RC presented the lowest values of TSS and total phosphorus (100 mg L−1 and 7.0 mg P L−1, respectively), and the following other characteristics: 1,001 mg Al L−1; 384 mg Fe L−1 and 1,100 mg COD L−1.","PeriodicalId":23794,"journal":{"name":"Water Practice and Technology","volume":"353 5","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-11-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135474882","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract Groundwater contamination is of global concern. The study area (Ikot Ekpene–Obot Akara Local Government Areas) continues to experience a swift increase in human population and associated economic activities, leading to the generation of more waste. The fundamental goal of this work is therefore to weigh up the groundwater standard through hydrogeochemical investigation of groundwater samples and the susceptibility potential of the economically exploited aquifer units in the area. The results of the electrical geo-sounding data acquired at 28 locations in the area reveal three to four lithological successions comprising fine/coarse sands and gravels amid patches of thin clay interbeddings at several places. The primary aquifer is the third layer, which is between 10.5 and 101.5 m deep with resistivity values between 359.4 and 2,472.8 Ωm. The hydrogeochemical evaluation of groundwater samples in the area shows that the measured physicochemical parameters are well within the World Health Organization's acceptable limits except for lead and nickel ions. The groundwater quality and susceptibility potential maps generated seem to correlate well and clearly demarcate the poor groundwater quality/high susceptibility potential zones. These maps are useful tools that could aid policymakers in successful groundwater management in the area to meet the needs of the populace.
{"title":"Hydrogeochemical–geophysical investigations of groundwater quality and susceptibility potential in Ikot Ekpene–Obot Akara Local Government Areas, Southern Nigeria","authors":"Aniekan Martin Ekanem, Ndifreke I. Udosen","doi":"10.2166/wpt.2023.187","DOIUrl":"https://doi.org/10.2166/wpt.2023.187","url":null,"abstract":"Abstract Groundwater contamination is of global concern. The study area (Ikot Ekpene–Obot Akara Local Government Areas) continues to experience a swift increase in human population and associated economic activities, leading to the generation of more waste. The fundamental goal of this work is therefore to weigh up the groundwater standard through hydrogeochemical investigation of groundwater samples and the susceptibility potential of the economically exploited aquifer units in the area. The results of the electrical geo-sounding data acquired at 28 locations in the area reveal three to four lithological successions comprising fine/coarse sands and gravels amid patches of thin clay interbeddings at several places. The primary aquifer is the third layer, which is between 10.5 and 101.5 m deep with resistivity values between 359.4 and 2,472.8 Ωm. The hydrogeochemical evaluation of groundwater samples in the area shows that the measured physicochemical parameters are well within the World Health Organization's acceptable limits except for lead and nickel ions. The groundwater quality and susceptibility potential maps generated seem to correlate well and clearly demarcate the poor groundwater quality/high susceptibility potential zones. These maps are useful tools that could aid policymakers in successful groundwater management in the area to meet the needs of the populace.","PeriodicalId":23794,"journal":{"name":"Water Practice and Technology","volume":"522 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-11-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135637387","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract There are several process design options for enhanced coagulation-filtration in drinking water treatment plants (DWTPs). This study compares the carbon footprint and economic impact of two common process designs based on enhanced coagulation-filtration with pH, Ca, and alkalinity adjustment for corrosion control. The process designs are direct filtration (DF) using Al coagulant with limewater (DF-Al) and contact filtration (CF) using Fe coagulant with alkaline filter layers (CF-Fe). The comparison focuses on the operational phase, which has the largest carbon footprint in the plant's life cycle. The operational data are retrieved from full-scale DWTPs. The results show that the carbon footprint from operations is five times larger for the DF-Al compared to the CF-Fe. Operational costs covering chemicals and energy are almost 30% higher for the DF-Al. Simplified material intensity estimations for the construction phase show that the carbon footprint and investment cost increase with increasing process area, which are larger for the DF-Al. Therefore, to reduce environmental impacts and costs, the design of drinking water treatment processes should be carefully considered even for very similar processes. The results should motivate both water professionals and decision-makers to include a carbon footprint evaluation as a routine step in the DWTP selection and design phases.
{"title":"Importance of process design on carbon footprint from drinking water treatment by enhanced coagulation-filtration","authors":"Paula Pellikainen, Bjørnar Eikebrokk, Riku Vahala","doi":"10.2166/wpt.2023.189","DOIUrl":"https://doi.org/10.2166/wpt.2023.189","url":null,"abstract":"Abstract There are several process design options for enhanced coagulation-filtration in drinking water treatment plants (DWTPs). This study compares the carbon footprint and economic impact of two common process designs based on enhanced coagulation-filtration with pH, Ca, and alkalinity adjustment for corrosion control. The process designs are direct filtration (DF) using Al coagulant with limewater (DF-Al) and contact filtration (CF) using Fe coagulant with alkaline filter layers (CF-Fe). The comparison focuses on the operational phase, which has the largest carbon footprint in the plant's life cycle. The operational data are retrieved from full-scale DWTPs. The results show that the carbon footprint from operations is five times larger for the DF-Al compared to the CF-Fe. Operational costs covering chemicals and energy are almost 30% higher for the DF-Al. Simplified material intensity estimations for the construction phase show that the carbon footprint and investment cost increase with increasing process area, which are larger for the DF-Al. Therefore, to reduce environmental impacts and costs, the design of drinking water treatment processes should be carefully considered even for very similar processes. The results should motivate both water professionals and decision-makers to include a carbon footprint evaluation as a routine step in the DWTP selection and design phases.","PeriodicalId":23794,"journal":{"name":"Water Practice and Technology","volume":"577 2","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-11-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135635879","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Kai Su, Zhongshan Peng, Qin Wang, Rong Cao, Yingwei Xi
Abstract In order to analyze and compare the characteristics and applicability of different water quality evaluation methods applied to lake water quality evaluation, four monitoring sections were set up in Sancha Lake in 2019, 2020, and 2021, and 20 water quality parameters were selected. The single factor index method, the comprehensive pollution index method, the Nemerow pollution index method, and the improved Nemerow pollution index method were used to comprehensively evaluate water quality. The research results showed that the single factor index evaluation method is simple to operate and can quickly determine the water quality category by identifying the worst single water quality indicator. The comprehensive pollution index method and the Nemerow pollution index method determine the degree of water pollution based on the numerical values representing the overall pollution level of the representative water body. The evaluation results showed that except for the evaluation results of the single factor evaluation method with categories II and III, the results of other evaluation methods were all category I, indicating that the water quality was good.
{"title":"Application and comparison of four assessment methods for water quality of Sancha Lake in Central Sichuan Province, China","authors":"Kai Su, Zhongshan Peng, Qin Wang, Rong Cao, Yingwei Xi","doi":"10.2166/wpt.2023.186","DOIUrl":"https://doi.org/10.2166/wpt.2023.186","url":null,"abstract":"Abstract In order to analyze and compare the characteristics and applicability of different water quality evaluation methods applied to lake water quality evaluation, four monitoring sections were set up in Sancha Lake in 2019, 2020, and 2021, and 20 water quality parameters were selected. The single factor index method, the comprehensive pollution index method, the Nemerow pollution index method, and the improved Nemerow pollution index method were used to comprehensively evaluate water quality. The research results showed that the single factor index evaluation method is simple to operate and can quickly determine the water quality category by identifying the worst single water quality indicator. The comprehensive pollution index method and the Nemerow pollution index method determine the degree of water pollution based on the numerical values representing the overall pollution level of the representative water body. The evaluation results showed that except for the evaluation results of the single factor evaluation method with categories II and III, the results of other evaluation methods were all category I, indicating that the water quality was good.","PeriodicalId":23794,"journal":{"name":"Water Practice and Technology","volume":"31 2","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-11-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135775500","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Alley Michael da Silva Procópio, Fabricio Vieira de Andrade, Flávio Soares da Silva, Sandro Andrade
Abstract This study evaluated the potential of using raw peanut shells as an adsorbent to remove the hormone 17α-ethylestradiol (EE2) from water. High-performance liquid chromatography with fluorescence detection was used in the determination of EE2. Kinetics data were tested with the pseudo-first-order, pseudo-second-order, and Elovich models, whereas isothermal data were tested with the Langmuir, Freundlich, and Sips models, and the parameters (ΔG°, ΔH° and ΔS°) were evaluated. A maximum removal rate of approximately 90% was observed in a solution with an initial EE2 concentration of 263.2 μg L−1, under the best experimental conditions (stirring speed = 500 rpm, pH = 6, and adsorbent mass = 2 g in 24 h), and showed an adsorption capacity of 17.3 μg g−1 at 306 K. The pseudo-first-order model adjusted better to the data in the studied temperature range, presenting a potential barrier of 16.69 kJ mol−1 (Ea) for adsorption kinetics. The Freundlich model and Sips model adjusted better to the data in the studied temperature range. The negative value of ΔG° (−15.87 kJ mol−1 at 306 K) confirmed the viability and spontaneity of the adsorption process. The positive value of ΔH° (168.9 kJ mol−1) characterized the chemical nature of the adsorption process.
{"title":"Removal of 17<i>α</i>-ethinylestradiol (EE2) from aqueous solutions by peanut shells (A<i>rachis hypogaea</i>): adsorption kinetic, isothermal, and thermodynamic studies","authors":"Alley Michael da Silva Procópio, Fabricio Vieira de Andrade, Flávio Soares da Silva, Sandro Andrade","doi":"10.2166/wpt.2023.183","DOIUrl":"https://doi.org/10.2166/wpt.2023.183","url":null,"abstract":"Abstract This study evaluated the potential of using raw peanut shells as an adsorbent to remove the hormone 17α-ethylestradiol (EE2) from water. High-performance liquid chromatography with fluorescence detection was used in the determination of EE2. Kinetics data were tested with the pseudo-first-order, pseudo-second-order, and Elovich models, whereas isothermal data were tested with the Langmuir, Freundlich, and Sips models, and the parameters (ΔG°, ΔH° and ΔS°) were evaluated. A maximum removal rate of approximately 90% was observed in a solution with an initial EE2 concentration of 263.2 μg L−1, under the best experimental conditions (stirring speed = 500 rpm, pH = 6, and adsorbent mass = 2 g in 24 h), and showed an adsorption capacity of 17.3 μg g−1 at 306 K. The pseudo-first-order model adjusted better to the data in the studied temperature range, presenting a potential barrier of 16.69 kJ mol−1 (Ea) for adsorption kinetics. The Freundlich model and Sips model adjusted better to the data in the studied temperature range. The negative value of ΔG° (−15.87 kJ mol−1 at 306 K) confirmed the viability and spontaneity of the adsorption process. The positive value of ΔH° (168.9 kJ mol−1) characterized the chemical nature of the adsorption process.","PeriodicalId":23794,"journal":{"name":"Water Practice and Technology","volume":"30 6","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-11-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135775502","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract Urban constructed water quality treatment (WQT) wetlands are often applied to be integrated with ecological engineered landscaping (EEL) measures for wastewater treatments. This study aims to identify the interrelationships between the hydrological factors and pollutant removal contributions of typical WQT wetlands at each WQT stage, i.e., subsurface flow wetlands (SSF), vertical flow wetlands (VF), free surface flow wetland (FSF), floating wetland island (FWI), aeration ponds (APs), and ornamental ponds (OPs) in four typical wetland parks in Hangzhou, China. Water quality indices (WQIs) of wetland parks have been monitored. Interactive comparisons and correlations between hydrological indicators and WQIs (i.e., pH, DO, NH3-N, CODCr, and TP) are developed, while the removal contribution of each WQI was explained. It is found that each stage had heterogeneous effects on wastewater treatment due to various geo-ecological factors, including hydraulic conditions, plant type, and microbial microenvironment, whereas the temperature of waterbodies affected WQT performances at full sites in all seasons. Three corresponding EEL guiding principles were derived, i.e., optimising the EEL measures, adapting planting methods, and incorporating multifunctional design and adaptive management. The findings will be helpful for improving the efficacy of WQT stages as one of the potential ecosystem services provided by wetland parks.
{"title":"Wetland water quality assessment of eco-engineered landscaping practices: a case study of constructed wetland parks in Hangzhou","authors":"Yan Huang, Tianjie Li, Yang Jin","doi":"10.2166/wpt.2023.184","DOIUrl":"https://doi.org/10.2166/wpt.2023.184","url":null,"abstract":"Abstract Urban constructed water quality treatment (WQT) wetlands are often applied to be integrated with ecological engineered landscaping (EEL) measures for wastewater treatments. This study aims to identify the interrelationships between the hydrological factors and pollutant removal contributions of typical WQT wetlands at each WQT stage, i.e., subsurface flow wetlands (SSF), vertical flow wetlands (VF), free surface flow wetland (FSF), floating wetland island (FWI), aeration ponds (APs), and ornamental ponds (OPs) in four typical wetland parks in Hangzhou, China. Water quality indices (WQIs) of wetland parks have been monitored. Interactive comparisons and correlations between hydrological indicators and WQIs (i.e., pH, DO, NH3-N, CODCr, and TP) are developed, while the removal contribution of each WQI was explained. It is found that each stage had heterogeneous effects on wastewater treatment due to various geo-ecological factors, including hydraulic conditions, plant type, and microbial microenvironment, whereas the temperature of waterbodies affected WQT performances at full sites in all seasons. Three corresponding EEL guiding principles were derived, i.e., optimising the EEL measures, adapting planting methods, and incorporating multifunctional design and adaptive management. The findings will be helpful for improving the efficacy of WQT stages as one of the potential ecosystem services provided by wetland parks.","PeriodicalId":23794,"journal":{"name":"Water Practice and Technology","volume":"66 12","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-11-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135868659","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract The outdoor rainwater drainage pollution in a large general hospital poses considerable threats to the environment and our health. A systematic analysis method was summarized in the investigation practice. Results showed that the pipe network damage caused by uneven geological settlement was the main reason for the pollution of the rainwater pipe network in the hospital. Countermeasures such as settlement repair and geological foundation reinforcement, rainwater and sewage pipeline transformation, the repair of mixed connection of rainwater and sewage pipes and polluted water sources, drainage health safety in isolated areas, and emergency storage tanks were discussed. After implementing the measures, the NH3-N measured value was within 0.82 mg/L, and the average removal rate was 97.4%. The COD concentration also decreased significantly with an average of 12 mg/L and the average removal rate was 91.8%. The results show that the reconstruction can effectively deal with the problem of outdoor rainwater drainage pollution in the hospital. The study has specific engineering reference significance for medical building drainage system's health and safety research.
{"title":"Study of outdoor rainwater drainage pollution in a hospital","authors":"Ming Fang, Chunhu Chen, Xinren Ding, Zhen Qian","doi":"10.2166/wpt.2023.185","DOIUrl":"https://doi.org/10.2166/wpt.2023.185","url":null,"abstract":"Abstract The outdoor rainwater drainage pollution in a large general hospital poses considerable threats to the environment and our health. A systematic analysis method was summarized in the investigation practice. Results showed that the pipe network damage caused by uneven geological settlement was the main reason for the pollution of the rainwater pipe network in the hospital. Countermeasures such as settlement repair and geological foundation reinforcement, rainwater and sewage pipeline transformation, the repair of mixed connection of rainwater and sewage pipes and polluted water sources, drainage health safety in isolated areas, and emergency storage tanks were discussed. After implementing the measures, the NH3-N measured value was within 0.82 mg/L, and the average removal rate was 97.4%. The COD concentration also decreased significantly with an average of 12 mg/L and the average removal rate was 91.8%. The results show that the reconstruction can effectively deal with the problem of outdoor rainwater drainage pollution in the hospital. The study has specific engineering reference significance for medical building drainage system's health and safety research.","PeriodicalId":23794,"journal":{"name":"Water Practice and Technology","volume":"42 14","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-11-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135820025","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract Satellite imagery-based spectral indices are essential for monitoring natural resource changes and urban environments. Assessing these indices is vital for natural resource management and environmental sustainability. This study adopted geospatial techniques and satellite imagery (Landsat 5 TM and Landsat 8 OLI/TIRS) to analyze changes in key spectral indices, i.e. Normalized Difference Vegetation Index (NDVI), Normalized Difference Built-Up Index (NDBI), and Normalized Difference Water Index (NDWI) over the past three decades (1991–2022) in the low land region of Far Western Nepal. The study examined the temporal trends and intricate relationships between these indices during this time frame. The substantial changes in NDVI, NDBI, and NDWI within the study area have been quantified from 1991 to 2022. The findings revealed significantly elevated NDBI values in 1991, 2001, and 2013 compared to 2022, while NDWI and NDVI values were consistently lower in 1991,2001, and 2013 compared to 2022. Notably, a negative correlation was observed between NDVI and both NDBI and NDWI, contrasting with the positive correlation found between NDBI and NDWI. The study underscores the potential of combining these spectral indices to evaluate vegetated areas, built-up areas, and water bodies, providing valuable insights for effective land management, urban planning, environmental monitoring, and sustainable water resource management.
{"title":"Mapping and analyzing temporal variability of spectral indices in lowland regions of Far western Nepal","authors":"Mahesh Prasad Awasthi","doi":"10.2166/wpt.2023.180","DOIUrl":"https://doi.org/10.2166/wpt.2023.180","url":null,"abstract":"Abstract Satellite imagery-based spectral indices are essential for monitoring natural resource changes and urban environments. Assessing these indices is vital for natural resource management and environmental sustainability. This study adopted geospatial techniques and satellite imagery (Landsat 5 TM and Landsat 8 OLI/TIRS) to analyze changes in key spectral indices, i.e. Normalized Difference Vegetation Index (NDVI), Normalized Difference Built-Up Index (NDBI), and Normalized Difference Water Index (NDWI) over the past three decades (1991–2022) in the low land region of Far Western Nepal. The study examined the temporal trends and intricate relationships between these indices during this time frame. The substantial changes in NDVI, NDBI, and NDWI within the study area have been quantified from 1991 to 2022. The findings revealed significantly elevated NDBI values in 1991, 2001, and 2013 compared to 2022, while NDWI and NDVI values were consistently lower in 1991,2001, and 2013 compared to 2022. Notably, a negative correlation was observed between NDVI and both NDBI and NDWI, contrasting with the positive correlation found between NDBI and NDWI. The study underscores the potential of combining these spectral indices to evaluate vegetated areas, built-up areas, and water bodies, providing valuable insights for effective land management, urban planning, environmental monitoring, and sustainable water resource management.","PeriodicalId":23794,"journal":{"name":"Water Practice and Technology","volume":"1 8","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135870312","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Dian Arrisujaya, Niti Sae Utami, Tia Mulyawati, Dea Rahmalisa, Siska Wati, Hidayat Hidayat
Abstract This work reports the use of Mangifera kemanga leaves (MKL) treated with ethanol and nitric acid as an adsorbent to remove Cr(VI) and Pb(II) ions at different pHs, adsorbent dosages, times, initial metal ion concentrations, and temperatures. The MKL's maximum adsorption capacity was 213 mg/g for Cr(VI) at pH 2 and 89 mg/g for Pb(II) at pH 6. Batch experiments showed that MKL follows the Langmuir isotherm model in absorbing Cr(VI) and Pb(II). The Cr(VI) and Pb(II) adsorption kinetics are best suited by the pseudo-second-order kinetics model. Thermodynamic data studies indicated that surface complexation coexisted with ion exchange as the preliminary removal means. The results implied that MKL could potentially remove Cr(VI) and Pb(II).
{"title":"Chromium (VI) and lead (II) adsorption using <i>Mangifera kemanga</i> leaves","authors":"Dian Arrisujaya, Niti Sae Utami, Tia Mulyawati, Dea Rahmalisa, Siska Wati, Hidayat Hidayat","doi":"10.2166/wpt.2023.182","DOIUrl":"https://doi.org/10.2166/wpt.2023.182","url":null,"abstract":"Abstract This work reports the use of Mangifera kemanga leaves (MKL) treated with ethanol and nitric acid as an adsorbent to remove Cr(VI) and Pb(II) ions at different pHs, adsorbent dosages, times, initial metal ion concentrations, and temperatures. The MKL's maximum adsorption capacity was 213 mg/g for Cr(VI) at pH 2 and 89 mg/g for Pb(II) at pH 6. Batch experiments showed that MKL follows the Langmuir isotherm model in absorbing Cr(VI) and Pb(II). The Cr(VI) and Pb(II) adsorption kinetics are best suited by the pseudo-second-order kinetics model. Thermodynamic data studies indicated that surface complexation coexisted with ion exchange as the preliminary removal means. The results implied that MKL could potentially remove Cr(VI) and Pb(II).","PeriodicalId":23794,"journal":{"name":"Water Practice and Technology","volume":"133 4","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136232199","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
John A. O. Oyekunle, Solomon S. Durodola, Oluwakemi O. Tovide, Allen A. Olorunkosebi, Ebunoluwa O. Olufisayo, Abolanle S. Adekunle, Aderemi O. Ogunfowokan
Abstract This study investigated the performance of different ionic solvents (NaCl, KNO3, and Na2SO4) in mediating electrolytic decontamination of pesticide-containing wastewaters and established the most suitable ionic solvent that can satisfactorily achieve decontamination of such wastewaters. These were done to find a water-purification technique suitable for the removal of recalcitrant and hazardous trace organic substances from wastewater. Organochlorine pesticide (OCP)-containing wastewaters were constituted according to prescribed modalities. It was observed that complete decontamination of the wastewater was achieved within 2 h of using Na2SO4. The study concluded that the 1.0 M of Na2SO4 solution-mediated electrolytic process was most efficient in decontaminating OCP-containing wastewater.
摘要本研究考察了不同离子溶剂(NaCl、KNO3和Na2SO4)在含农药废水电解除污中的中介作用，确定了最适合的离子溶剂，能较好地实现含农药废水的除污。这些都是为了找到一种适合去除废水中顽固和有害的微量有机物质的水净化技术。按规定的方式配制含有机氯农药废水。结果表明，在使用Na2SO4后的2 h内，废水得到了完全的净化。研究结果表明，1.0 M Na2SO4溶液介导的电解工艺对含ocp废水的净化效果最好。
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