Pub Date : 2025-12-01Epub Date: 2025-08-30DOI: 10.1016/j.clwat.2025.100120
Vasudha V. Patil , Manisha Singh , Balasubramanian Kandasubramanian
The potential of the Spirulina algae powder as a biosorbent for the adsorption of lubricating oil from freshwater was investigated. The impact of various contact times between the biosorbent and oil–water mixture was studied through different experiments. Under optimum conditions, a maximum removal efficiency of 32.69 % was achieved within 180 min, highlighting the gradual yet effective adsorption behavior of Spirulina algae powder over time. A high regression coefficient (R² = 0.9981) indicates that the experimental result closely matched pseudo-second order kinetics, suggesting a strong model fit and suggesting that the dominant mechanism was chemisorption, which is defined by strong interactions between oil molecules and mobile sites on the algae surface. FTIR analysis confirmed that oil adsorption onto Spirulina algae powder involves hydroxyl, carbonyl, amide, and polysaccharide groups through hydrogen bonding and van der Waals interactions, accompanied by surface chemical modifications. SEM images showed a transition from a porous to a smoother, compact structure with reduced pore population, indicating effective oil deposition. Contact angle measurements revealed a shift from 63.2° to 20.3°, reflecting increased surface polarity and enhanced hydrophilicity after adsorption. These results show that Spirulina algae powder effectively adsorbs lubricating oil from water through multiple interaction mechanisms, making it a promising bio-sorbent for oil removal.
{"title":"Utilization of Spirulina algae powder for efficient removal of lubricating oil from aqueous media","authors":"Vasudha V. Patil , Manisha Singh , Balasubramanian Kandasubramanian","doi":"10.1016/j.clwat.2025.100120","DOIUrl":"10.1016/j.clwat.2025.100120","url":null,"abstract":"<div><div>The potential of the <em>Spirulina</em> algae powder as a biosorbent for the adsorption of lubricating oil from freshwater was investigated. The impact of various contact times between the biosorbent and oil–water mixture was studied through different experiments. Under optimum conditions, a maximum removal efficiency of 32.69 % was achieved within 180 min, highlighting the gradual yet effective adsorption behavior of <em>Spirulina</em> algae powder over time. A high regression coefficient (R² = 0.9981) indicates that the experimental result closely matched pseudo-second order kinetics, suggesting a strong model fit and suggesting that the dominant mechanism was chemisorption, which is defined by strong interactions between oil molecules and mobile sites on the algae surface. FTIR analysis confirmed that oil adsorption onto <em>Spirulina</em> algae powder involves hydroxyl, carbonyl, amide, and polysaccharide groups through hydrogen bonding and van der Waals interactions, accompanied by surface chemical modifications. SEM images showed a transition from a porous to a smoother, compact structure with reduced pore population, indicating effective oil deposition. Contact angle measurements revealed a shift from 63.2° to 20.3°, reflecting increased surface polarity and enhanced hydrophilicity after adsorption. These results show that <em>Spirulina</em> algae powder effectively adsorbs lubricating oil from water through multiple interaction mechanisms, making it a promising bio-sorbent for oil removal.</div></div>","PeriodicalId":100257,"journal":{"name":"Cleaner Water","volume":"4 ","pages":"Article 100120"},"PeriodicalIF":0.0,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144925653","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}
Pub Date : 2025-12-01Epub Date: 2025-08-07DOI: 10.1016/j.clwat.2025.100108
Aditya Gaur , Nishchay Saurabh , Akash Kankane , S. Janakiraman , Satyanarayan Patel
Piezocatalysis and tribocatalysis have been widely used for wastewater treatment and disinfection using poly (vinylidene fluoride) (PVDF) and composites. However, the pyrocatalytic potential of these materials remains largely unexplored. The present study synthesized PVDF and PVDF-ZnO composite fiber films using the electrospinning technique for wastewater treatment applications. The fabricated compositions were characterized using various measurements to confirm their phase structure and surface morphology. The PVDF/PVDF-ZnO fiber film is analyzed for pyrocatalytic-driven dye degradation using methylene blue (MB) dye as a pollutant. The highest MB dye degradation is 91.84 % after 60 heating/cooling cycles. The effect of the electric field applied during the fabrication is also analyzed, and it was found that the PVDF-ZnO film electrospun under 18 kV provides maximum dye degradation. The confirmation of active species during dye degradation is done using a scavenger test. The repeatability and reusability of the fabricated composite are also studied.
{"title":"Electrospun polyvinylidene fluoride-ZnO composite fibers for pyrocatalytic wastewater treatment","authors":"Aditya Gaur , Nishchay Saurabh , Akash Kankane , S. Janakiraman , Satyanarayan Patel","doi":"10.1016/j.clwat.2025.100108","DOIUrl":"10.1016/j.clwat.2025.100108","url":null,"abstract":"<div><div>Piezocatalysis and tribocatalysis have been widely used for wastewater treatment and disinfection using poly (vinylidene fluoride) (PVDF) and composites. However, the pyrocatalytic potential of these materials remains largely unexplored. The present study synthesized PVDF and PVDF-ZnO composite fiber films using the electrospinning technique for wastewater treatment applications. The fabricated compositions were characterized using various measurements to confirm their phase structure and surface morphology. The PVDF/PVDF-ZnO fiber film is analyzed for pyrocatalytic-driven dye degradation using methylene blue (MB) dye as a pollutant. The highest MB dye degradation is 91.84 % after 60 heating/cooling cycles. The effect of the electric field applied during the fabrication is also analyzed, and it was found that the PVDF-ZnO film electrospun under 18 kV provides maximum dye degradation. The confirmation of active species during dye degradation is done using a scavenger test. The repeatability and reusability of the fabricated composite are also studied.</div></div>","PeriodicalId":100257,"journal":{"name":"Cleaner Water","volume":"4 ","pages":"Article 100108"},"PeriodicalIF":0.0,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144810381","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}
Pub Date : 2025-12-01Epub Date: 2025-10-15DOI: 10.1016/j.clwat.2025.100154
Farha Bente Rahim , Sadhon Chandra Swarnokar , Sajib Roy , Mohammad Mahfuzur Rahman , Tusar Kumar Das
Ensuring access to safe and affordable drinking water remains a core target of the Sustainable Development Goals (SDGs), yet this remains a critical challenge in many developing regions due to inadequate sanitation infrastructure. In Bangladesh, where over 90 % of the population relies on groundwater, shallow aquifers are increasingly at risk of contamination from on-site sanitation systems. This study investigates the impacts of pit latrines and septic tank latrines on groundwater quality in Khulna, a coastal city in southwestern Bangladesh. A total of 40 groundwater samples were collected from 20 tube wells located within 0–6 m from pit latrines and septic tank latrines, during monsoon and dry seasons. Fifteen physicochemical and microbiological parameters were assessed, including pH, EC, TDS, major ions, total coliforms (TC), fecal coliforms (FC), and Escherichia coli (E. coli). The results indicate widespread contamination across both sanitation types, with more severe impacts observed near pit latrines. Approximately 50–70 % of samples exceeded WHO limits for EC, TDS, Na⁺, Cl⁻, and HCO₃⁻, with elevated concentrations more pronounced during the monsoon season. Microbial contamination was found in 80 % of tubewells located near pit latrines and in 50 % of those near septic tank latrines. The temporal analysis revealed that TC, FC, and E. coli contamination were more prevalent during the monsoon season compared to the dry season. The spatial and temporal analysis revealed that chemical parameters dominate during the dry season, whereas microbial contaminants are more prevalent in the monsoon. The correlation matrix and PCA suggest that microbial contamination likely originates from a common source, with its occurrence in shallow aquifers largely influenced by stormwater infiltration and tubewell depth. Water Quality Index (WQI) assessments classified over 50 % of the samples as very poor or unsuitable for drinking, with pit latrine-adjacent wells consistently exhibiting higher health risks. The study concludes that shallow aquifer groundwater in Khulna is unsafe for consumption without treatment and recommends urgent measures, including improved sanitation design, regular water quality monitoring, and the development of alternative safe water sources. These findings offer critical baseline data for policymakers aiming to reduce waterborne health risks in coastal Bangladesh.
{"title":"The quality of groundwater in shallow aquifers impacted by inadequately managed sanitation facilities in coastal Bangladesh","authors":"Farha Bente Rahim , Sadhon Chandra Swarnokar , Sajib Roy , Mohammad Mahfuzur Rahman , Tusar Kumar Das","doi":"10.1016/j.clwat.2025.100154","DOIUrl":"10.1016/j.clwat.2025.100154","url":null,"abstract":"<div><div>Ensuring access to safe and affordable drinking water remains a core target of the Sustainable Development Goals (SDGs), yet this remains a critical challenge in many developing regions due to inadequate sanitation infrastructure. In Bangladesh, where over 90 % of the population relies on groundwater, shallow aquifers are increasingly at risk of contamination from on-site sanitation systems. This study investigates the impacts of pit latrines and septic tank latrines on groundwater quality in Khulna, a coastal city in southwestern Bangladesh. A total of 40 groundwater samples were collected from 20 tube wells located within 0–6 m from pit latrines and septic tank latrines, during monsoon and dry seasons. Fifteen physicochemical and microbiological parameters were assessed, including pH, EC, TDS, major ions, total coliforms (TC), fecal coliforms (FC), and Escherichia coli (E. coli). The results indicate widespread contamination across both sanitation types, with more severe impacts observed near pit latrines. Approximately 50–70 % of samples exceeded WHO limits for EC, TDS, Na⁺, Cl⁻, and HCO₃⁻, with elevated concentrations more pronounced during the monsoon season. Microbial contamination was found in 80 % of tubewells located near pit latrines and in 50 % of those near septic tank latrines. The temporal analysis revealed that TC, FC, and E. coli contamination were more prevalent during the monsoon season compared to the dry season. The spatial and temporal analysis revealed that chemical parameters dominate during the dry season, whereas microbial contaminants are more prevalent in the monsoon. The correlation matrix and PCA suggest that microbial contamination likely originates from a common source, with its occurrence in shallow aquifers largely influenced by stormwater infiltration and tubewell depth. Water Quality Index (WQI) assessments classified over 50 % of the samples as very poor or unsuitable for drinking, with pit latrine-adjacent wells consistently exhibiting higher health risks. The study concludes that shallow aquifer groundwater in Khulna is unsafe for consumption without treatment and recommends urgent measures, including improved sanitation design, regular water quality monitoring, and the development of alternative safe water sources. These findings offer critical baseline data for policymakers aiming to reduce waterborne health risks in coastal Bangladesh.</div></div>","PeriodicalId":100257,"journal":{"name":"Cleaner Water","volume":"4 ","pages":"Article 100154"},"PeriodicalIF":0.0,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145332842","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}
Pub Date : 2025-12-01Epub Date: 2025-10-30DOI: 10.1016/j.clwat.2025.100167
Arefa Ferdous Ruma , Yeasmin Nahar Jolly , Md. Abdus Samad , A.S.M. Mohiuddin
The rivers encircling Dhaka are experiencing severe pollution due to unregulated industrial discharge and inefficient waste management systems. This study assesses heavy metal contamination and associated ecological and human health risks in these urban rivers. Seventeen stations were sampled during winter and rainy seasons. Water samples were analyzed for physicochemical properties and heavy metals (Cr, Ni, Cu, As, Cd, Pb) using Energy Dispersive X-ray Florescence (EDXRF). Water Quality Index (WQI), Heavy Metal Pollution Index (HPI), Ecological Risk Index (ERI), and health risk assessments were conducted as per American Public Health Association (APHA) and United States Environmental Protection Agency (USEPA) guidelines. Heavy metal concentrations exceeded World Health Organization (WHO)/Department of Public Health Engineering (DPHE) limits: As (0.33 mg/L), Cd (0.019 mg/L), Cr (0.22 mg/L), and Cu (1.98 mg/L). WQI ranged from 105.36 to 268.62 in winter with 68.18 % of samples classified as “Very Poor.” HPI peaked at 379.2, while ERI reached 245.86 in Buriganga. Children exhibited the highest non-carcinogenic hazard index (HI = 0.15842), however remains below the threshold of 1, but the total carcinogenic risk (TCR = 1.34E-04) exceeded the acceptable safety limit 1.00E-04. Among the rivers, the pollution severity ranking as Buriganga>Turag>Dhaleshwari>Shitalakshya>Balu. The persistent presence of heavy metals poses severe ecological and public health threats, especially during the dry season. Urgent policy actions including mandatory Effluent Treatment Plant (ETP) implementation, improved wastewater infrastructure, and continuous real-time monitoring are essential to restore river health and protect public welfare.
{"title":"Integrated analysis of heavy metal pollution and physicochemical parameters in Dhaka’s industrial-affected rivers highlighting ecological and human health risks","authors":"Arefa Ferdous Ruma , Yeasmin Nahar Jolly , Md. Abdus Samad , A.S.M. Mohiuddin","doi":"10.1016/j.clwat.2025.100167","DOIUrl":"10.1016/j.clwat.2025.100167","url":null,"abstract":"<div><div>The rivers encircling Dhaka are experiencing severe pollution due to unregulated industrial discharge and inefficient waste management systems. This study assesses heavy metal contamination and associated ecological and human health risks in these urban rivers. Seventeen stations were sampled during winter and rainy seasons. Water samples were analyzed for physicochemical properties and heavy metals (Cr, Ni, Cu, As, Cd, Pb) using Energy Dispersive X-ray Florescence (EDXRF). Water Quality Index (WQI), Heavy Metal Pollution Index (HPI), Ecological Risk Index (ERI), and health risk assessments were conducted as per American Public Health Association (APHA) and United States Environmental Protection Agency (USEPA) guidelines. Heavy metal concentrations exceeded World Health Organization (WHO)/Department of Public Health Engineering (DPHE) limits: As (0.33 mg/L), Cd (0.019 mg/L), Cr (0.22 mg/L), and Cu (1.98 mg/L). WQI ranged from 105.36 to 268.62 in winter with 68.18 % of samples classified as “Very Poor.” HPI peaked at 379.2, while ERI reached 245.86 in Buriganga. Children exhibited the highest non-carcinogenic hazard index (HI = 0.15842), however remains below the threshold of 1, but the total carcinogenic risk (TCR = 1.34E-04) exceeded the acceptable safety limit 1.00E-04. Among the rivers, the pollution severity ranking as Buriganga>Turag>Dhaleshwari>Shitalakshya>Balu. The persistent presence of heavy metals poses severe ecological and public health threats, especially during the dry season. Urgent policy actions including mandatory Effluent Treatment Plant (ETP) implementation, improved wastewater infrastructure, and continuous real-time monitoring are essential to restore river health and protect public welfare.</div></div>","PeriodicalId":100257,"journal":{"name":"Cleaner Water","volume":"4 ","pages":"Article 100167"},"PeriodicalIF":0.0,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145578714","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}
Pub Date : 2025-12-01Epub Date: 2025-10-27DOI: 10.1016/j.clwat.2025.100164
Antoine Tamsa Arfao , Awawou Njoya Manouore , Siméon Tchakonté , Fils Mamert Onana , Annette Ngo Hei , Yves Yogne Poutoum , Paul Alain Nana , Moise Nola
Antibiotic resistance in Staphylococcus is a major public health issue. Wastewater treatment plants and waterways added to urban, hospital and even agricultural discharges are potential reservoirs of resistant bacteria, enabling them to spread into the environment. The aim of this study was to assess the prevalence of antibiotic resistance in Staphylococcus species (Staphylococcus aureus and Staphylococcus epidermidis) isolated from a number of wastewater treatment plants and waterways in the city of Yaoundé, as well as the impact of abiotic factors. Water samples were taken at the discharge points of the Wastewater Treatment Plants (WWTP) and in the waterways receiving the WWTP discharges. Staphylococcus strains were isolated on Chapman-mannitol medium and then identified using standard biochemical techniques. Antibiotic susceptibility testing of Staphylococcal isolates was done using the antibiotic disc diffusion method on Müller-Hinton agar. Physicochemical parameters were analysed using appropriate techniques. The results showed that the water was slightly alkaline (pH > 7.5), contained organic matter (nitrates > 8 mg/L, orthophosphates > 4 mg/L) and inorganic salts (electrical conductivity > 380 µS/cm and TDS > 200 mg/L), and harboured species of S. aureus and S. epidermidis that ranged respectively from 1.42 to 1.96 Log10 CFU/100 µL, and from 1.24 to 2.87 Log10 CFU/100 µL. The prevalence of antibiotic resistance varied from species to species in the different sampling points and was higher in Staphylococcus strains isolated upstream of waterways receiving wastewater treatment plant discharges. Overall, the Staphylococcus strains were resistant to β-lactam antibiotics (methicillin), glycopeptides (vancomycin) and quinolones (ofloxacin), thus demonstrating the multi-resistant nature of these strains, particularly S. aureus, for which the prevalence rate was 100 % with methicillin and ofloxacin, and 99.1 % with vancomycin. Significant positive and negative correlations (P < 0.05) were noted between the physicochemical parameters and the inhibition diameters of the various antibiotics. WWTPs and waterways could be hotspots for the dissemination of resistant Staphylococci, requiring optimisation of purification processes and increased monitoring to limit environmental contamination.
{"title":"Wastewater and urban waterways as hotspots for multidrug-resistant Staphylococcus aureus and Staphylococcus epidermidis in Yaoundé, Cameroon","authors":"Antoine Tamsa Arfao , Awawou Njoya Manouore , Siméon Tchakonté , Fils Mamert Onana , Annette Ngo Hei , Yves Yogne Poutoum , Paul Alain Nana , Moise Nola","doi":"10.1016/j.clwat.2025.100164","DOIUrl":"10.1016/j.clwat.2025.100164","url":null,"abstract":"<div><div>Antibiotic resistance in <em>Staphylococcus</em> is a major public health issue. Wastewater treatment plants and waterways added to urban, hospital and even agricultural discharges are potential reservoirs of resistant bacteria, enabling them to spread into the environment. The aim of this study was to assess the prevalence of antibiotic resistance in <em>Staphylococcus</em> species (<em>Staphylococcus aureus</em> and <em>Staphylococcus epidermidis</em>) isolated from a number of wastewater treatment plants and waterways in the city of Yaoundé, as well as the impact of abiotic factors. Water samples were taken at the discharge points of the Wastewater Treatment Plants (WWTP) and in the waterways receiving the WWTP discharges. <em>Staphylococcus</em> strains were isolated on Chapman-mannitol medium and then identified using standard biochemical techniques. Antibiotic susceptibility testing of Staphylococcal isolates was done using the antibiotic disc diffusion method on Müller-Hinton agar. Physicochemical parameters were analysed using appropriate techniques. The results showed that the water was slightly alkaline (pH > 7.5), contained organic matter (nitrates > 8 mg/L, orthophosphates > 4 mg/L) and inorganic salts (electrical conductivity > 380 µS/cm and TDS > 200 mg/L), and harboured species of <em>S. aureus</em> and <em>S. epidermidis</em> that ranged respectively from 1.42 to 1.96 Log<sub>10</sub> CFU/100 µL, and from 1.24 to 2.87 Log<sub>10</sub> CFU/100 µL. The prevalence of antibiotic resistance varied from species to species in the different sampling points and was higher in <em>Staphylococcus</em> strains isolated upstream of waterways receiving wastewater treatment plant discharges. Overall, the <em>Staphylococcus</em> strains were resistant to β-lactam antibiotics (methicillin), glycopeptides (vancomycin) and quinolones (ofloxacin), thus demonstrating the multi-resistant nature of these strains, particularly <em>S. aureus</em>, for which the prevalence rate was 100 % with methicillin and ofloxacin, and 99.1 % with vancomycin. Significant positive and negative correlations (P < 0.05) were noted between the physicochemical parameters and the inhibition diameters of the various antibiotics. WWTPs and waterways could be hotspots for the dissemination of resistant Staphylococci, requiring optimisation of purification processes and increased monitoring to limit environmental contamination.</div></div>","PeriodicalId":100257,"journal":{"name":"Cleaner Water","volume":"4 ","pages":"Article 100164"},"PeriodicalIF":0.0,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145416177","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}
Pub Date : 2025-12-01Epub Date: 2025-07-29DOI: 10.1016/j.clwat.2025.100103
Sk Saruk Islam , Sudip Narayan Dhara , Sujoy Midya
Since rivers provide freshwater to all rural and urban communities, it is necessary but difficult to monitor the river water quality. The goal of this study was to assess how water-quality parameters relate to zooplankton communities. Water samples were collected from five different locations along the main streams of the Kangsabati River, West Medinipur. Analysed twelve common water quality indicators, including pH, temperature (temp.), dissolve oxygen (DO), secchi depth (SD), salinity (Sal), biological oxygen demand (BOD), electrical conductivity (EC), total dissolve solid (TDS), hardness (Hard), Alkalinity (Alk), total nitrogen (TN), total phosphorous (TP) and plankton density (PD) to assess the water quality index (WQI). The WQI model was employed to determine water quality (WQ) status, while two-tailed Pearson’s correlation and multivariate PCA analysis assessed relationship between the PD and WQ. 57 zooplankton species were found, including copepods (49.12 %), cladocera (17.54 %), and rotifers (33.33 %). The WQI value ranged from 87.68–125.88, indicating very poor to unfit for consumption water quality. Strong correlation among PD, BOD, and DO, was observed by multivariate analysis. As a result, the zooplankton index should only be used with expertise to indicate water quality. In order to promote sustainable community growth, findings of present investigation may be useful in preserving the complex aquatic ecosystem.
{"title":"Water quality assessment using WQI and zooplankton indicators in aquatic ecosystems: Insights from a correlation-based study","authors":"Sk Saruk Islam , Sudip Narayan Dhara , Sujoy Midya","doi":"10.1016/j.clwat.2025.100103","DOIUrl":"10.1016/j.clwat.2025.100103","url":null,"abstract":"<div><div>Since rivers provide freshwater to all rural and urban communities, it is necessary but difficult to monitor the river water quality. The goal of this study was to assess how water-quality parameters relate to zooplankton communities. Water samples were collected from five different locations along the main streams of the Kangsabati River, West Medinipur. Analysed twelve common water quality indicators, including pH, temperature (temp.), dissolve oxygen (DO), secchi depth (SD), salinity (Sal), biological oxygen demand (BOD), electrical conductivity (EC), total dissolve solid (TDS), hardness (Hard), Alkalinity (Alk), total nitrogen (TN), total phosphorous (TP) and plankton density (PD) to assess the water quality index (WQI). The WQI model was employed to determine water quality (WQ) status, while two-tailed Pearson’s correlation and multivariate PCA analysis assessed relationship between the PD and WQ. 57 zooplankton species were found, including copepods (49.12 %), cladocera (17.54 %), and rotifers (33.33 %). The WQI value ranged from 87.68–125.88, indicating very poor to unfit for consumption water quality. Strong correlation among PD, BOD, and DO, was observed by multivariate analysis. As a result, the zooplankton index should only be used with expertise to indicate water quality. In order to promote sustainable community growth, findings of present investigation may be useful in preserving the complex aquatic ecosystem.</div></div>","PeriodicalId":100257,"journal":{"name":"Cleaner Water","volume":"4 ","pages":"Article 100103"},"PeriodicalIF":0.0,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144737975","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}
Pub Date : 2025-12-01Epub Date: 2025-10-30DOI: 10.1016/j.clwat.2025.100162
Toton Pal , Sarbendu Bikash Dhar , Kamalesh Sen
Groundwater quality in Bankura District, West Bengal, is strongly influenced by a combination of geogenic processes and anthropogenic activities. This study integrates hydrogeochemical characterization with Water Quality Index (WQI) assessment, Human Health Hazard Index (HHHI) estimation, and Monte Carlo Simulation (10,000 iterations) to comprehensively evaluate drinking water safety and human health risks. The major cation dominance follows the order Na⁺ > Ca²⁺ > Mg²⁺ > K⁺ > Fe³ ⁺, while anions are distributed as HCO₃⁻ > Cl⁻ > SO₄²⁻ > PO₄³ ⁻ > F⁻. Post-monsoon analysis revealed that approximately 30 % of groundwater samples exceeded permissible limits for drinking water. The southern blocks (Simlapal, Raipur, Khatra, Taldangra) exhibited the highest contamination potential, largely attributed to permeable lateritic soils, recharge-induced mobilization, and intensive agricultural practices. Probabilistic health risk modeling using Monte Carlo Simulation highlighted fluoride as the dominant contributor to HHHI (69 %), followed by nitrate (HQ-NO₃) (25 %) and iron (6 %). Sensitivity analysis confirmed that contaminant concentration is the primary driver of health risk variance. These findings emphasize the critical need for integrated groundwater management strategies—such as artificial recharge, defluoridation units, and regulated irrigation practices—to mitigate exposure risks and align with Sustainable Development Goals (SDG 6: Clean Water and Sanitation). The outcomes provide a decision-making framework for policymakers to prioritize vulnerable zones and implement targeted interventions for long-term groundwater sustainability.
{"title":"Geochemical insights into water quality index and health risk assessment using Monte Carlo simulation in water-scarce regions of India","authors":"Toton Pal , Sarbendu Bikash Dhar , Kamalesh Sen","doi":"10.1016/j.clwat.2025.100162","DOIUrl":"10.1016/j.clwat.2025.100162","url":null,"abstract":"<div><div>Groundwater quality in Bankura District, West Bengal, is strongly influenced by a combination of geogenic processes and anthropogenic activities. This study integrates hydrogeochemical characterization with Water Quality Index (WQI) assessment, Human Health Hazard Index (HHHI) estimation, and Monte Carlo Simulation (10,000 iterations) to comprehensively evaluate drinking water safety and human health risks. The major cation dominance follows the order Na⁺ > Ca²⁺ > Mg²⁺ > K⁺ > Fe³ ⁺, while anions are distributed as HCO₃⁻ > Cl⁻ > SO₄²⁻ > PO₄³ ⁻ > F⁻. Post-monsoon analysis revealed that approximately 30 % of groundwater samples exceeded permissible limits for drinking water. The southern blocks (Simlapal, Raipur, Khatra, Taldangra) exhibited the highest contamination potential, largely attributed to permeable lateritic soils, recharge-induced mobilization, and intensive agricultural practices. Probabilistic health risk modeling using Monte Carlo Simulation highlighted fluoride as the dominant contributor to HHHI (69 %), followed by nitrate (HQ-NO₃) (25 %) and iron (6 %). Sensitivity analysis confirmed that contaminant concentration is the primary driver of health risk variance. These findings emphasize the critical need for integrated groundwater management strategies—such as artificial recharge, defluoridation units, and regulated irrigation practices—to mitigate exposure risks and align with Sustainable Development Goals (SDG 6: Clean Water and Sanitation). The outcomes provide a decision-making framework for policymakers to prioritize vulnerable zones and implement targeted interventions for long-term groundwater sustainability.</div></div>","PeriodicalId":100257,"journal":{"name":"Cleaner Water","volume":"4 ","pages":"Article 100162"},"PeriodicalIF":0.0,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145473930","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}
Pub Date : 2025-12-01Epub Date: 2025-09-06DOI: 10.1016/j.clwat.2025.100127
Chioma Perpetua Okafor , John Kanayochukwu Nduka , Peter Olisaemeka Okafor , Chideraa Courage Offor
Lakes in South-East Nigeria are vital for domestic and agricultural water use, yet increasing anthropogenic pressures raise concerns about trace metal contaminations and associated health risks. A total of 100 water samples were collected from ten stations of Agulu Lake during dry and rainy seasons. Fifteen water quality parameters, including trace metals, were analyzed. Multivariate indices; heavy metal pollution index (HPI), toxicity load, and hazard index (HI); were applied to evaluate contamination levels and potential human health risks. The dominant trace metals were Cr (range: 0.11–1.20 mg/L) and Pb (range: 0.33–1.08 mg/L) during the dry season, whereas in the rainy season Cr (range: 0.51–1.43 mg/L) and Pb (range: 0.29–0.51 mg/L) remained the most prevalent. NO3- and NO2- peaked at the IEN and OYT stations in the dry season. HPI indicated Cd and Pb as the major contributors to water quality deterioration. Toxicity loads of Cr, Mn, and Cu reached 589,536.5, 141,405.6, and 196,262.4 in the dry season, with notable seasonal shifts. The HI values for all sampling locations were greater than 1, designating the lake as a high-risk zone. Agulu Lake water is unsafe for human consumption due to trace metal contamination, primarily from Cd, Cr, and Pb. Identification and control of point sources of pollution are urgently required to protect public health.
{"title":"Behavioural dynamics of water quality parameters and human exposure assessment of trace metals in Agulu Lake Water, South-East Nigeria","authors":"Chioma Perpetua Okafor , John Kanayochukwu Nduka , Peter Olisaemeka Okafor , Chideraa Courage Offor","doi":"10.1016/j.clwat.2025.100127","DOIUrl":"10.1016/j.clwat.2025.100127","url":null,"abstract":"<div><div>Lakes in South-East Nigeria are vital for domestic and agricultural water use, yet increasing anthropogenic pressures raise concerns about trace metal contaminations and associated health risks. A total of 100 water samples were collected from ten stations of Agulu Lake during dry and rainy seasons. Fifteen water quality parameters, including trace metals, were analyzed. Multivariate indices; heavy metal pollution index (HPI), toxicity load, and hazard index (HI); were applied to evaluate contamination levels and potential human health risks. The dominant trace metals were Cr (range: 0.11–1.20 mg/L) and Pb (range: 0.33–1.08 mg/L) during the dry season, whereas in the rainy season Cr (range: 0.51–1.43 mg/L) and Pb (range: 0.29–0.51 mg/L) remained the most prevalent. NO<sub>3</sub><sup>-</sup> and NO<sub>2</sub><sup>-</sup> peaked at the IEN and OYT stations in the dry season. HPI indicated Cd and Pb as the major contributors to water quality deterioration. Toxicity loads of Cr, Mn, and Cu reached 589,536.5, 141,405.6, and 196,262.4 in the dry season, with notable seasonal shifts. The HI values for all sampling locations were greater than 1, designating the lake as a high-risk zone. Agulu Lake water is unsafe for human consumption due to trace metal contamination, primarily from Cd, Cr, and Pb. Identification and control of point sources of pollution are urgently required to protect public health.</div></div>","PeriodicalId":100257,"journal":{"name":"Cleaner Water","volume":"4 ","pages":"Article 100127"},"PeriodicalIF":0.0,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145026359","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}
Pub Date : 2025-12-01Epub Date: 2025-05-12DOI: 10.1016/j.clwat.2025.100082
Saleh Abuzir , Lisa Gren , Marta Domini , Giorgio Bertanza , Åsa Davidsson , Hamse Kjerstadius
The growing global population has increased the demand for circular sanitation solutions that enhance energy and nutrient recovery. Anaerobic digestion (AD) of blackwater (BW) offers a promising solution, but its application in full-scale UASB reactors remains unexplored. This study evaluated the performance of a full-scale UASB (50 m3) treating BW collected from a new city district (Oceanhamnen) located in Helsingborg, Sweden, over 130 weeks, applying two different organic loading rates (OLRs), focusing on COD removal, biogas production, and mass balances for COD, nitrogen, and phosphorus, and compared its performance with previous lab-scale studies. The full-scale UASB achieved its highest COD removal efficiency (88 %) and degree of methanisation (0.77 kgCOD-CH4 kg⁻¹ CODin) during the low organic loading rate (OLR) phase. In the higher OLR phase, COD removal dropped to 72 % due to sludge washout, although the degree of methanisation remained high (0.71 kg COD-CH4 kg⁻¹ CODin). Mass balance results showed 69 % of influent COD was converted into methane, while 28 % remained in the effluent, likely due to sludge washout. The decanted effluent contained 92 % of N and 82 % of P reflecting the low sludge production. Compared with lab-scale studies, the full-scale UASB achieved comparable COD removal and biogas yields despite challenges like sludge washout during the higher OLR. The results confirm that the full-scale application of blackwater treatment is suitable for circular sanitation solutions. Further research is needed to optimize solids retention and reduce effluent COD for sustainable full-scale operations, as well as optimizing the energy balance calculations.
{"title":"Performance of a full-scale anaerobic UASB digester treating blackwater from an urban city district in Helsingborg, Sweden","authors":"Saleh Abuzir , Lisa Gren , Marta Domini , Giorgio Bertanza , Åsa Davidsson , Hamse Kjerstadius","doi":"10.1016/j.clwat.2025.100082","DOIUrl":"10.1016/j.clwat.2025.100082","url":null,"abstract":"<div><div>The growing global population has increased the demand for circular sanitation solutions that enhance energy and nutrient recovery. Anaerobic digestion (AD) of blackwater (BW) offers a promising solution, but its application in full-scale UASB reactors remains unexplored. This study evaluated the performance of a full-scale UASB (50 m<sup>3</sup>) treating BW collected from a new city district (Oceanhamnen) located in Helsingborg, Sweden, over 130 weeks, applying two different organic loading rates (OLRs), focusing on COD removal, biogas production, and mass balances for COD, nitrogen, and phosphorus, and compared its performance with previous lab-scale studies. The full-scale UASB achieved its highest COD removal efficiency (88 %) and degree of methanisation (0.77 kgCOD-CH<sub>4</sub> kg⁻¹ COD<sub>in</sub>) during the low organic loading rate (OLR) phase. In the higher OLR phase, COD removal dropped to 72 % due to sludge washout, although the degree of methanisation remained high (0.71 kg COD-CH<sub>4</sub> kg⁻¹ COD<sub>in</sub>). Mass balance results showed 69 % of influent COD was converted into methane, while 28 % remained in the effluent, likely due to sludge washout. The decanted effluent contained 92 % of N and 82 % of P reflecting the low sludge production. Compared with lab-scale studies, the full-scale UASB achieved comparable COD removal and biogas yields despite challenges like sludge washout during the higher OLR. The results confirm that the full-scale application of blackwater treatment is suitable for circular sanitation solutions. Further research is needed to optimize solids retention and reduce effluent COD for sustainable full-scale operations, as well as optimizing the energy balance calculations.</div></div>","PeriodicalId":100257,"journal":{"name":"Cleaner Water","volume":"4 ","pages":"Article 100082"},"PeriodicalIF":0.0,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144471311","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}
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