Pub Date : 2025-10-01DOI: 10.1016/j.clwat.2025.100143
Azuka N. Amitaye , Elias E. Elemike , Esther Amitaye , Khairia M. Al-Ahmary , Saedah R. Al-Mhyawi , Ismail Hossain
<div><div>Magnetite nanoparticles (Fe<sub>3</sub>O<sub>4</sub>NPs) was phytosynthesized using aqueous extract of unripe plantain peel and salts of iron. The technique is simple, cost-effective and eco-friendly. Synthesized nanomagnetite was characterized by Fourier-transform Infrared (FTIR) Spectroscopy, X-ray diffraction (XRD), Scanning Electron Microscopy with Energy Dispersive X-ray (SEM/EDX), Transmission Electron Microscopy (TEM), Sear’s surface area and Isoelectric point. The magnetite nanoparticles are well dispersed with spherical surface morphology and mean particle size of 10.2 nm. The nanomagnetite is crystalline in nature with inverse spinel cubic structure and mean crystallite size of 12.4 nm. The specific surface area and isoelectric point of the nanomagnetite are 243.8 m<sup>2</sup>/g and 7.2 respectively, which make it a potential adsorbent material. Arsenite’s adsorption unto Fe<sub>3</sub>O<sub>4</sub>NPs was evaluated by batch equilibrium method. The empirical equilibrium data were fitted into Langmuir, Freundlich and Dubinin-Radushkevich (D-R) isotherm models to give insight into the pattern of adsorption of arsenite unto Fe<sub>3</sub>O<sub>4</sub>NPs. The best fit of isotherm model to empirical equilibrium data was obtained using error validity function and regression correlation coefficient value. Based on values of R<sup>2</sup>, the Langmuir model is a better fit between empirical and simulated equilibrium data but D-R model best explains the adsorption process due to its least error validity function (<span><math><msup><mrow><mi>χ</mi></mrow><mrow><mn>2</mn></mrow></msup></math></span> = 41.907). The kinetic data obtained at different contact time were analyzed using pseudo-first-order, pseudo-second-order, Elovic, intraparticles diffusion and Boyd diffusion models. The empirical rate data obey the pseudo-second-order model based on high R<sup>2</sup> which indicate possibility of two reaction centres on the adsorbent. However, least <span><math><msup><mrow><mi>χ</mi></mrow><mrow><mn>2</mn></mrow></msup></math></span> value of 3.151 for Elovic kinetic model shows the adsorption process occurred on heterogenous surface by chemisorption. Although the rate-controlling step in arsenite’s adsorption unto Fe<sub>3</sub>O<sub>4</sub>NPs is multi-stepped but the rate of adsorption is controlled slightly by film diffusion (Boyd diffusion model). Adsorption of arsenite unto Fe<sub>3</sub>O<sub>4</sub>NPs was optimized and was found to be affected by initial concentration, magnetite dosage, solution pH, and contact time. Maximum adsorption capacity of 483.513 mg/g was achieved at pH 8 over contact time of 60 min at 28 ˚C. The negative value of Gibbs free energy (-17.346 J/mol) indicates the adsorption of As(III) unto Fe<sub>3</sub>O<sub>4</sub>NPs is spontaneous and occurred by physisorption due to the low value of energy of adsorption (E = 22.3607 J/mol). The effect of co-existing anions on adsorption of arsenite was investigated
{"title":"Phytosynthesis of magnetite (Fe3O4) nanoparticles for arsenite removal from waste water: Characterization, isotherm and kinetic studies","authors":"Azuka N. Amitaye , Elias E. Elemike , Esther Amitaye , Khairia M. Al-Ahmary , Saedah R. Al-Mhyawi , Ismail Hossain","doi":"10.1016/j.clwat.2025.100143","DOIUrl":"10.1016/j.clwat.2025.100143","url":null,"abstract":"<div><div>Magnetite nanoparticles (Fe<sub>3</sub>O<sub>4</sub>NPs) was phytosynthesized using aqueous extract of unripe plantain peel and salts of iron. The technique is simple, cost-effective and eco-friendly. Synthesized nanomagnetite was characterized by Fourier-transform Infrared (FTIR) Spectroscopy, X-ray diffraction (XRD), Scanning Electron Microscopy with Energy Dispersive X-ray (SEM/EDX), Transmission Electron Microscopy (TEM), Sear’s surface area and Isoelectric point. The magnetite nanoparticles are well dispersed with spherical surface morphology and mean particle size of 10.2 nm. The nanomagnetite is crystalline in nature with inverse spinel cubic structure and mean crystallite size of 12.4 nm. The specific surface area and isoelectric point of the nanomagnetite are 243.8 m<sup>2</sup>/g and 7.2 respectively, which make it a potential adsorbent material. Arsenite’s adsorption unto Fe<sub>3</sub>O<sub>4</sub>NPs was evaluated by batch equilibrium method. The empirical equilibrium data were fitted into Langmuir, Freundlich and Dubinin-Radushkevich (D-R) isotherm models to give insight into the pattern of adsorption of arsenite unto Fe<sub>3</sub>O<sub>4</sub>NPs. The best fit of isotherm model to empirical equilibrium data was obtained using error validity function and regression correlation coefficient value. Based on values of R<sup>2</sup>, the Langmuir model is a better fit between empirical and simulated equilibrium data but D-R model best explains the adsorption process due to its least error validity function (<span><math><msup><mrow><mi>χ</mi></mrow><mrow><mn>2</mn></mrow></msup></math></span> = 41.907). The kinetic data obtained at different contact time were analyzed using pseudo-first-order, pseudo-second-order, Elovic, intraparticles diffusion and Boyd diffusion models. The empirical rate data obey the pseudo-second-order model based on high R<sup>2</sup> which indicate possibility of two reaction centres on the adsorbent. However, least <span><math><msup><mrow><mi>χ</mi></mrow><mrow><mn>2</mn></mrow></msup></math></span> value of 3.151 for Elovic kinetic model shows the adsorption process occurred on heterogenous surface by chemisorption. Although the rate-controlling step in arsenite’s adsorption unto Fe<sub>3</sub>O<sub>4</sub>NPs is multi-stepped but the rate of adsorption is controlled slightly by film diffusion (Boyd diffusion model). Adsorption of arsenite unto Fe<sub>3</sub>O<sub>4</sub>NPs was optimized and was found to be affected by initial concentration, magnetite dosage, solution pH, and contact time. Maximum adsorption capacity of 483.513 mg/g was achieved at pH 8 over contact time of 60 min at 28 ˚C. The negative value of Gibbs free energy (-17.346 J/mol) indicates the adsorption of As(III) unto Fe<sub>3</sub>O<sub>4</sub>NPs is spontaneous and occurred by physisorption due to the low value of energy of adsorption (E = 22.3607 J/mol). The effect of co-existing anions on adsorption of arsenite was investigated ","PeriodicalId":100257,"journal":{"name":"Cleaner Water","volume":"4 ","pages":"Article 100143"},"PeriodicalIF":0.0,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145219106","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 : 2025-10-01DOI: 10.1016/j.clwat.2025.100144
Nidhi Sahu, Atul Maldhure
Ensuring water quality requires continuous monitoring and assessment. Traditional approaches, based on manual sampling and laboratory analysis, are time-consuming, labour-intensive, and costly. Sensor-based technologies offer real-time water quality monitoring with high sensitivity, selectivity, cost-effectiveness, and operational efficiency. However, before field deployment, sensors must undergo rigorous validation to ensure accuracy, reliability, and long-term performance. Implementing validation protocols is essential to achieve consistency, reproducibility, and comparability of sensor performance across diverse monitoring locations and environmental conditions. This study proposes a structured validation framework, providing a systematic methodology to evaluate water quality sensors. To demonstrate its applicability, a commercially procured pH sensor was validated under controlled laboratory conditions using standard buffer solutions. The results indicate that the sensor showed the accuracy of 97.58 % in the acidic range (pH 1–6), 98.84 % at neutral pH (pH 7), and 94.38 % in the basic range (pH 8–14). Precision analysis showed intraday variability between 0.89–1.75 % RSD and interday variability between 0.71–2.85 % RSD, with strong linearity (R² = 0.9988), confirming consistent and reproducible performance. These results confirm that standards-based validation offers assurance of the sensor’s operational reliability and accuracy. While validation with standards is a critical first step, comprehensive assessment requires testing across different water matrices, where complex ionic composition, organic matter, and interfering species may influence sensor performance. To ensure sustained performance, it is also recommended that the sensor undergo field validation following installation and be periodically reassessed, typically every six months. This study establishes the foundation for a robust validation framework that can be extended to diverse sensors and water matrices, thereby ensuring reliable real-world applications. Moreover, the framework serves as a benchmark for future sensor validation studies, enhancing comparability, reproducibility, and standardization in water quality monitoring research.
{"title":"Framework for evaluating the performance of water quality sensors","authors":"Nidhi Sahu, Atul Maldhure","doi":"10.1016/j.clwat.2025.100144","DOIUrl":"10.1016/j.clwat.2025.100144","url":null,"abstract":"<div><div>Ensuring water quality requires continuous monitoring and assessment. Traditional approaches, based on manual sampling and laboratory analysis, are time-consuming, labour-intensive, and costly. Sensor-based technologies offer real-time water quality monitoring with high sensitivity, selectivity, cost-effectiveness, and operational efficiency. However, before field deployment, sensors must undergo rigorous validation to ensure accuracy, reliability, and long-term performance. Implementing validation protocols is essential to achieve consistency, reproducibility, and comparability of sensor performance across diverse monitoring locations and environmental conditions. This study proposes a structured validation framework, providing a systematic methodology to evaluate water quality sensors. To demonstrate its applicability, a commercially procured pH sensor was validated under controlled laboratory conditions using standard buffer solutions. The results indicate that the sensor showed the accuracy of 97.58 % in the acidic range (pH 1–6), 98.84 % at neutral pH (pH 7), and 94.38 % in the basic range (pH 8–14). Precision analysis showed intraday variability between 0.89–1.75 % RSD and interday variability between 0.71–2.85 % RSD, with strong linearity (R² = 0.9988), confirming consistent and reproducible performance. These results confirm that standards-based validation offers assurance of the sensor’s operational reliability and accuracy. While validation with standards is a critical first step, comprehensive assessment requires testing across different water matrices, where complex ionic composition, organic matter, and interfering species may influence sensor performance. To ensure sustained performance, it is also recommended that the sensor undergo field validation following installation and be periodically reassessed, typically every six months. This study establishes the foundation for a robust validation framework that can be extended to diverse sensors and water matrices, thereby ensuring reliable real-world applications. Moreover, the framework serves as a benchmark for future sensor validation studies, enhancing comparability, reproducibility, and standardization in water quality monitoring research.</div></div>","PeriodicalId":100257,"journal":{"name":"Cleaner Water","volume":"4 ","pages":"Article 100144"},"PeriodicalIF":0.0,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145219105","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 : 2025-09-30DOI: 10.1016/j.clwat.2025.100141
Jianqiao Song , Arash Pashazadeh , Shenghua Wu , Victoria Rose Greene , Katherine Olivia Hallee , Amber Mai Tannehill , Tyler Matthew Saxon , Madeline Potter , Zach Beneke
Uncontrolled increase in the global plastics production has ushered in an environmental disaster that destroys human well-being and ecosystems. Most waste plastics are dumped in landfills or the environment, i.e., soil, waters, and air, where biodiversity loss, ecosystem service, and human well-being are jeopardized by air and ingestion exposure through microplastics (MPs). This review investigates current technologies for identifying and detecting MPs across a variety of environmental matrices, evaluates innovative interception strategies, and identifies research gaps to guide future mitigation efforts. It focuses on spectroscopic, microscopic, thermal, and AI-driven detection techniques, alongside innovative interception strategies encompassing physical, biological, and policy-based approaches, while identifying key research gaps to inform future mitigation. Addressing the complex challenge of MPs pollution demands integrated advancements in standardized detection protocols, cost-effective interception technologies, AI-driven automation, and interdisciplinary research, harmonized with robust global policies and increased investment to minimize the pervasive impacts of MPs across ecosystems.
{"title":"Advances in microplastic detection and interception: A state-of-the-art review","authors":"Jianqiao Song , Arash Pashazadeh , Shenghua Wu , Victoria Rose Greene , Katherine Olivia Hallee , Amber Mai Tannehill , Tyler Matthew Saxon , Madeline Potter , Zach Beneke","doi":"10.1016/j.clwat.2025.100141","DOIUrl":"10.1016/j.clwat.2025.100141","url":null,"abstract":"<div><div>Uncontrolled increase in the global plastics production has ushered in an environmental disaster that destroys human well-being and ecosystems. Most waste plastics are dumped in landfills or the environment, i.e., soil, waters, and air, where biodiversity loss, ecosystem service, and human well-being are jeopardized by air and ingestion exposure through microplastics (MPs). This review investigates current technologies for identifying and detecting MPs across a variety of environmental matrices, evaluates innovative interception strategies, and identifies research gaps to guide future mitigation efforts. It focuses on spectroscopic, microscopic, thermal, and AI-driven detection techniques, alongside innovative interception strategies encompassing physical, biological, and policy-based approaches, while identifying key research gaps to inform future mitigation. Addressing the complex challenge of MPs pollution demands integrated advancements in standardized detection protocols, cost-effective interception technologies, AI-driven automation, and interdisciplinary research, harmonized with robust global policies and increased investment to minimize the pervasive impacts of MPs across ecosystems.</div></div>","PeriodicalId":100257,"journal":{"name":"Cleaner Water","volume":"4 ","pages":"Article 100141"},"PeriodicalIF":0.0,"publicationDate":"2025-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145219136","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 : 2025-09-27DOI: 10.1016/j.clwat.2025.100139
Vitalice O. Ouma , Dickens O. Agumba , Peter M. Weramwanja , Dickens O. Okello , Purity Nakami , Bernard O. Alunda
Invasive plant species like water hyacinth (WH) are often problematic due to their rapid growth, forming dense colonies that deplete nutrients and reduce oxygen levels in water bodies. However, the green valorization of this aquatic weed and its transformation into valuable products could help address the interconnected challenges of pollution, climate change, and biodiversity loss. In this study, we utilized WH - a sustainable, low-cost, and abundant biomass-to develop eco-friendly biopolymers as sustainable alternatives to synthetic plastics. Unlike kraft pulping, our approach uses a highly adaptable and recyclable green deep eutectic solvent (DES) to break down WH into a viscous lignocellulose slurry. By casting this slurry, we created bioplastics with excellent physical and mechanical properties. The resulting biopolymer displays a high tensile strength of 101.8 MPa, outperforming kraft paper and surpassing common bioplastics like PLA and PHA, demonstrating superior structural performance. These biopolymers can be easily recycled at the end of their life by mechanical disintegration in water, allowing the lignocellulose slurry to be reused. Unlike non-biodegradable synthetic plastics, our bioplastics can naturally biodegrade in the soil, exemplifying a desirable closed-loop cycle. The biopolymer also retained high antioxidant activity of 90.2 %, making it suitable for applications requiring oxidative stability. This work advances eco-friendly material science by promoting resource recovery, reducing plastic pollution, and offering a method to control the spread of WH. In the future, WH biopolymers could replace commonly used petrochemical plastics in sustainable, multifunctional applications such as agricultural mulching films, food packaging, and foams.
{"title":"Sustainable valorization of water hyacinth-derived lignocellulose towards functional applications","authors":"Vitalice O. Ouma , Dickens O. Agumba , Peter M. Weramwanja , Dickens O. Okello , Purity Nakami , Bernard O. Alunda","doi":"10.1016/j.clwat.2025.100139","DOIUrl":"10.1016/j.clwat.2025.100139","url":null,"abstract":"<div><div>Invasive plant species like water hyacinth (WH) are often problematic due to their rapid growth, forming dense colonies that deplete nutrients and reduce oxygen levels in water bodies. However, the green valorization of this aquatic weed and its transformation into valuable products could help address the interconnected challenges of pollution, climate change, and biodiversity loss. In this study, we utilized WH - a sustainable, low-cost, and abundant biomass-to develop eco-friendly biopolymers as sustainable alternatives to synthetic plastics. Unlike kraft pulping, our approach uses a highly adaptable and recyclable green deep eutectic solvent (DES) to break down WH into a viscous lignocellulose slurry. By casting this slurry, we created bioplastics with excellent physical and mechanical properties. The resulting biopolymer displays a high tensile strength of 101.8 MPa, outperforming kraft paper and surpassing common bioplastics like PLA and PHA, demonstrating superior structural performance. These biopolymers can be easily recycled at the end of their life by mechanical disintegration in water, allowing the lignocellulose slurry to be reused. Unlike non-biodegradable synthetic plastics, our bioplastics can naturally biodegrade in the soil, exemplifying a desirable closed-loop cycle. The biopolymer also retained high antioxidant activity of 90.2 %, making it suitable for applications requiring oxidative stability. This work advances eco-friendly material science by promoting resource recovery, reducing plastic pollution, and offering a method to control the spread of WH. In the future, WH biopolymers could replace commonly used petrochemical plastics in sustainable, multifunctional applications such as agricultural mulching films, food packaging, and foams.</div></div>","PeriodicalId":100257,"journal":{"name":"Cleaner Water","volume":"4 ","pages":"Article 100139"},"PeriodicalIF":0.0,"publicationDate":"2025-09-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145264933","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 : 2025-09-27DOI: 10.1016/j.clwat.2025.100138
Daniela Duran-Romero , Karina Barquet
Access to safe and sustainable drinking water services remains a significant challenge, particularly in rapidly urbanizing and climate-impacted urban and peri-urban areas. Traditional utilities, often operating under public-private partnerships, are frequently constrained by underinvestment, fragmented governance, and weak accountability, resulting in service gaps. Decentralized Drinking Water Services (DWS) offer adaptable, user-centered alternatives through locally tailored technologies and alternative water sources. However, their adoption is constrained by financial barriers, regulatory uncertainty, and limited community engagement. While previous studies have emphasized the technical and operational aspects of DWS, this study addresses a gap by examining how business model innovation can enable long-term adoption and scalability. Using a mixed-methods approach, combining a systematic literature review with interviews of private-sector providers, this research identifies Product-Service Systems, Social Enterprises, and Community-Based Management as key business models. Findings reveal that hybrid approaches, which bridge formal/informal, centralized/decentralized, and public/private boundaries, are central to navigating heterogeneous infrastructure configurations in diverse contexts. Providers must balance financial viability with equitable access, adapt to varying institutional capacities, and respond to evolving policy landscapes. The analysis shows that regions with advanced water infrastructure industries often shape service models in markets with more constrained resources, underscoring the need to adapt these transfers to local socio-political and cultural contexts. Scalable DWS delivery depends not only on technological innovation but also on coherent regulatory frameworks, inclusive governance, and financing strategies aligned with community affordability. Finally, the study calls for future policy efforts that prioritize coherent regulatory frameworks, including clear quality standards, permitting procedures for alternative water sources, mechanisms for public oversight, and community engagement to ensure long-term functionality and local ownership.
{"title":"Business models for decentralized water services in urban and peri-urban areas","authors":"Daniela Duran-Romero , Karina Barquet","doi":"10.1016/j.clwat.2025.100138","DOIUrl":"10.1016/j.clwat.2025.100138","url":null,"abstract":"<div><div>Access to safe and sustainable drinking water services remains a significant challenge, particularly in rapidly urbanizing and climate-impacted urban and peri-urban areas. Traditional utilities, often operating under public-private partnerships, are frequently constrained by underinvestment, fragmented governance, and weak accountability, resulting in service gaps. Decentralized Drinking Water Services (DWS) offer adaptable, user-centered alternatives through locally tailored technologies and alternative water sources. However, their adoption is constrained by financial barriers, regulatory uncertainty, and limited community engagement. While previous studies have emphasized the technical and operational aspects of DWS, this study addresses a gap by examining how business model innovation can enable long-term adoption and scalability. Using a mixed-methods approach, combining a systematic literature review with interviews of private-sector providers, this research identifies Product-Service Systems, Social Enterprises, and Community-Based Management as key business models. Findings reveal that hybrid approaches, which bridge formal/informal, centralized/decentralized, and public/private boundaries, are central to navigating heterogeneous infrastructure configurations in diverse contexts. Providers must balance financial viability with equitable access, adapt to varying institutional capacities, and respond to evolving policy landscapes. The analysis shows that regions with advanced water infrastructure industries often shape service models in markets with more constrained resources, underscoring the need to adapt these transfers to local socio-political and cultural contexts. Scalable DWS delivery depends not only on technological innovation but also on coherent regulatory frameworks, inclusive governance, and financing strategies aligned with community affordability. Finally, the study calls for future policy efforts that prioritize coherent regulatory frameworks, including clear quality standards, permitting procedures for alternative water sources, mechanisms for public oversight, and community engagement to ensure long-term functionality and local ownership.</div></div>","PeriodicalId":100257,"journal":{"name":"Cleaner Water","volume":"4 ","pages":"Article 100138"},"PeriodicalIF":0.0,"publicationDate":"2025-09-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145219134","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 : 2025-09-27DOI: 10.1016/j.clwat.2025.100140
Saiful Islam , Saif Ahmad Khan , Izrar Ahmad
NO3⁻ has become a major contaminant in groundwater within Central Ganga Plains seeing a significant rise in NO3⁻and heavy metal contaminants, particularly Mn, which often acts as its intermediary. This study investigates the hydrochemical characteristics by analyzing major ions, trace metals, and spatial distribution of δ¹ ⁸O and δ²D isotopes while collaborating with hydrographic features and water level dynamics. Gibbs plot and principal component analysis identify rock-water interaction as the primary process governing hydrochemistry. Various bivariate scatter plots infer silicate weathering, carbonate dissolution, and ion-exchange reactions and anthropogenic pollutions. The Chadha diagram confirms Ca-HCO₃ as the dominant species, though localized variations towards Na-Cl are linked to anthropogenic influences. Specifically, NO3⁻ and Mn concentrations are closely tied (attributed) to anthropogenic sources like fertilizer use, livestock waste, manure, and sewage. However, their concentration is shaped by seasonal recharge dynamics and fluctuating redox conditions. Seasonal variation in natural background levels (NBL) of NO3⁻ and Mn also reflects recharge dynamics, with concentrations varying from 7.81 to 21.87 mg/L and from 15.7 to 10.88 µg/L from dry to wet season, respectively. Isotopic data shows shallow groundwater with a wide range of δ¹ ⁸O values (-10.1 ‰ to −6.5 ‰), indicating mixed recharge and evaporation, while deep groundwater aligns more tightly with the local meteoric water line (LMWL) δ¹ ⁸O values (-9.2 ‰ to −5.1 ‰), suggesting consistent paleo-recharge. The study emphasizes how anthropogenic pollutants are enhanced in groundwater due to the combined influence of geogenic and hydro-dynamic factors in the aquifer. The study recommends controlled fertilizer use, adequate waste management and improved sewerage systems for safe and sustainable groundwater management.
{"title":"Integrating hydrochemical evolution, contamination sources and stable isotopes (δ¹⁸O and δ²D) behaviour in a river-fed alluvial aquifer, Saharanpur, India","authors":"Saiful Islam , Saif Ahmad Khan , Izrar Ahmad","doi":"10.1016/j.clwat.2025.100140","DOIUrl":"10.1016/j.clwat.2025.100140","url":null,"abstract":"<div><div>NO<sub>3</sub>⁻ has become a major contaminant in groundwater within Central Ganga Plains seeing a significant rise in NO<sub>3</sub>⁻and heavy metal contaminants, particularly Mn, which often acts as its intermediary. This study investigates the hydrochemical characteristics by analyzing major ions, trace metals, and spatial distribution of δ¹ ⁸O and δ²D isotopes while collaborating with hydrographic features and water level dynamics. Gibbs plot and principal component analysis identify rock-water interaction as the primary process governing hydrochemistry. Various bivariate scatter plots infer silicate weathering, carbonate dissolution, and ion-exchange reactions and anthropogenic pollutions. The Chadha diagram confirms Ca-HCO₃ as the dominant species, though localized variations towards Na-Cl are linked to anthropogenic influences. Specifically, NO<sub>3</sub>⁻ and Mn concentrations are closely tied (attributed) to anthropogenic sources like fertilizer use, livestock waste, manure, and sewage. However, their concentration is shaped by seasonal recharge dynamics and fluctuating redox conditions. Seasonal variation in natural background levels (NBL) of NO<sub>3</sub>⁻ and Mn also reflects recharge dynamics, with concentrations varying from 7.81 to 21.87 mg/L and from 15.7 to 10.88 µg/L from dry to wet season, respectively. Isotopic data shows shallow groundwater with a wide range of δ¹ ⁸O values (-10.1 ‰ to −6.5 ‰), indicating mixed recharge and evaporation, while deep groundwater aligns more tightly with the local meteoric water line (LMWL) δ¹ ⁸O values (-9.2 ‰ to −5.1 ‰), suggesting consistent paleo-recharge. The study emphasizes how anthropogenic pollutants are enhanced in groundwater due to the combined influence of geogenic and hydro-dynamic factors in the aquifer. The study recommends controlled fertilizer use, adequate waste management and improved sewerage systems for safe and sustainable groundwater management.</div></div>","PeriodicalId":100257,"journal":{"name":"Cleaner Water","volume":"4 ","pages":"Article 100140"},"PeriodicalIF":0.0,"publicationDate":"2025-09-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145219137","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 : 2025-09-24DOI: 10.1016/j.clwat.2025.100137
Aysha Akter , Ramisa Tanjum Rain
Rapid urban growth, poor drainage, and climate-induced heavy rainfall have led to frequent urban flooding. Green roofs, as a form of Low Impact Development (LID), provide a sustainable option to mitigate surface runoff and enhance urban resilience. This study evaluates the potential of green roofs in Chattogram City using the Storm Water Management Model (SWMM) with ten years of rainfall data (2013–2022) and geospatial inputs processed through Google Earth Engine (GEE) and Geographic Information System (GIS). Rooftop areas of 6584 buildings were classified following Bangladesh National Building Code (BNBC) 2020 to simulate four types of green roof configurations, supported by 2D and 3D visualization for spatial planning. Model calibration and validation ensured reliability, with runoff coefficients aligned with earlier studies. Results indicate that green roofs can significantly reduce surface runoff, with an annual reduction of 752,800 m³ , while also delaying peak flows. A sensitivity analysis further confirmed that storage-related parameters, particularly soil thickness and field capacity, exert the greatest influence on runoff reduction outcomes. In addition to flood mitigation, green roofs demonstrate co-benefits including urban cooling, biodiversity enhancement, and water reuse potential. The findings highlight the scope of integrating green infrastructure into urban planning and emphasize the importance of enabling policies, particularly the incorporation of green roofs into the BNBC, to promote climate-resilient development in rapidly urbanizing cities.
{"title":"A study on harvesting rainwater by applying green roof","authors":"Aysha Akter , Ramisa Tanjum Rain","doi":"10.1016/j.clwat.2025.100137","DOIUrl":"10.1016/j.clwat.2025.100137","url":null,"abstract":"<div><div>Rapid urban growth, poor drainage, and climate-induced heavy rainfall have led to frequent urban flooding. Green roofs, as a form of Low Impact Development (LID), provide a sustainable option to mitigate surface runoff and enhance urban resilience. This study evaluates the potential of green roofs in Chattogram City using the Storm Water Management Model (SWMM) with ten years of rainfall data (2013–2022) and geospatial inputs processed through Google Earth Engine (GEE) and Geographic Information System (GIS). Rooftop areas of 6584 buildings were classified following Bangladesh National Building Code (BNBC) 2020 to simulate four types of green roof configurations, supported by 2D and 3D visualization for spatial planning. Model calibration and validation ensured reliability, with runoff coefficients aligned with earlier studies. Results indicate that green roofs can significantly reduce surface runoff, with an annual reduction of 752,800 m³ , while also delaying peak flows. A sensitivity analysis further confirmed that storage-related parameters, particularly soil thickness and field capacity, exert the greatest influence on runoff reduction outcomes. In addition to flood mitigation, green roofs demonstrate co-benefits including urban cooling, biodiversity enhancement, and water reuse potential. The findings highlight the scope of integrating green infrastructure into urban planning and emphasize the importance of enabling policies, particularly the incorporation of green roofs into the BNBC, to promote climate-resilient development in rapidly urbanizing cities.</div></div>","PeriodicalId":100257,"journal":{"name":"Cleaner Water","volume":"4 ","pages":"Article 100137"},"PeriodicalIF":0.0,"publicationDate":"2025-09-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145219135","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}
Nitrogenous wastewater causes significant environmental challenges, including eutrophication, biodiversity loss, and ecosystem degradation. Achieving desired nitrogen discharge standards remains a critical task for conventional wastewater treatment processes. The Downflow Hanging Sponge (DHS) reactor, an advanced iteration of the trickling filter (TF) concept, has emerged as a promising technology for biological wastewater treatment. Its low energy consumption, high efficiency, and operational simplicity make it suitable for both developed and developing nations. This review critically evaluates the nitrogen removal performance of DHS reactors, focusing on the underlying mechanisms, operational parameters, and microbial ecology. Key influencing factors, including hydraulic retention time (HRT), organic loading rate (OLR), sludge retention time (SRT), external carbon supplementation, and recirculation strategies, are analyzed to elucidate their impact on nitrogen removal efficiency. A comparative analysis of previous studies highlights performance trends, revealing the DHS reactor’s strength in achieving high nitrogen removal rates under optimized conditions. However, technological gaps, such as inconsistent performance under varying environmental conditions and limited scalability, pose challenges. By synthesizing current knowledge, this study aims to guide future developments in DHS technology, fostering its broader application for sustainable nitrogen removal from wastewater and mitigating environmental impacts.
{"title":"Nitrogen removal performances of Downflow Hanging Sponge (DHS) reactors for wastewater treatment: A critical review","authors":"Nadeeka P. Darshani , Choolaka Hewawasam , D.J. Jayasanka , P.M. Manage , Masashi Hatamoto","doi":"10.1016/j.clwat.2025.100136","DOIUrl":"10.1016/j.clwat.2025.100136","url":null,"abstract":"<div><div>Nitrogenous wastewater causes significant environmental challenges, including eutrophication, biodiversity loss, and ecosystem degradation. Achieving desired nitrogen discharge standards remains a critical task for conventional wastewater treatment processes. The Downflow Hanging Sponge (DHS) reactor, an advanced iteration of the trickling filter (TF) concept, has emerged as a promising technology for biological wastewater treatment. Its low energy consumption, high efficiency, and operational simplicity make it suitable for both developed and developing nations. This review critically evaluates the nitrogen removal performance of DHS reactors, focusing on the underlying mechanisms, operational parameters, and microbial ecology. Key influencing factors, including hydraulic retention time (HRT), organic loading rate (OLR), sludge retention time (SRT), external carbon supplementation, and recirculation strategies, are analyzed to elucidate their impact on nitrogen removal efficiency. A comparative analysis of previous studies highlights performance trends, revealing the DHS reactor’s strength in achieving high nitrogen removal rates under optimized conditions. However, technological gaps, such as inconsistent performance under varying environmental conditions and limited scalability, pose challenges. By synthesizing current knowledge, this study aims to guide future developments in DHS technology, fostering its broader application for sustainable nitrogen removal from wastewater and mitigating environmental impacts.</div></div>","PeriodicalId":100257,"journal":{"name":"Cleaner Water","volume":"4 ","pages":"Article 100136"},"PeriodicalIF":0.0,"publicationDate":"2025-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145158051","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 : 2025-09-22DOI: 10.1016/j.clwat.2025.100135
E. Festus Omozeje , F. Oluwatoyin Ijasan , O. Marvellous Omorogieva
The study employed the Natural Audio Frequency Telluric Method (NAFTM) to investigate subsurface geophysical properties in Ikpere-Ekiti, southwestern Nigeria. Profile maps and resistivity curves revealed predominantly H, KH, HK, and A-type curves, indicating variations in lithology, fluid content, and boundary interfaces. Results show topsoil thicknesses of 0.3–0.6 m, overburden depths of 3.36–31.88 m, and weathered layers extending up to 56.65 m, with higher weathering observed at Igbede, Ilesemon, and GRA. These conditions favor groundwater accumulation, supported by static water levels of 2.9–9.2 m and evidence of a phreatic unconfined aquifer at approximately 120 m depth. The data demonstrate strong correlation with existing borehole logs, indicating groundwater occurrence at depths up to 120 m, with some boreholes reaching 100 m. The findings suggest significant potential for sustainable groundwater exploitation to support socio-economic development in the area.
{"title":"Geophysical assessment of groundwater resources in Ikpere – Ekiti, South Western Nigeria","authors":"E. Festus Omozeje , F. Oluwatoyin Ijasan , O. Marvellous Omorogieva","doi":"10.1016/j.clwat.2025.100135","DOIUrl":"10.1016/j.clwat.2025.100135","url":null,"abstract":"<div><div>The study employed the Natural Audio Frequency Telluric Method (NAFTM) to investigate subsurface geophysical properties in Ikpere-Ekiti, southwestern Nigeria. Profile maps and resistivity curves revealed predominantly H, KH, HK, and A-type curves, indicating variations in lithology, fluid content, and boundary interfaces. Results show topsoil thicknesses of 0.3–0.6 m, overburden depths of 3.36–31.88 m, and weathered layers extending up to 56.65 m, with higher weathering observed at Igbede, Ilesemon, and GRA. These conditions favor groundwater accumulation, supported by static water levels of 2.9–9.2 m and evidence of a phreatic unconfined aquifer at approximately 120 m depth. The data demonstrate strong correlation with existing borehole logs, indicating groundwater occurrence at depths up to 120 m, with some boreholes reaching 100 m. The findings suggest significant potential for sustainable groundwater exploitation to support socio-economic development in the area.</div></div>","PeriodicalId":100257,"journal":{"name":"Cleaner Water","volume":"4 ","pages":"Article 100135"},"PeriodicalIF":0.0,"publicationDate":"2025-09-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145219099","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}
Groundwater (GW) quality is a critical concern for safe drinking water in Bangladesh. This study aimed to evaluate the GW quality in Kashiani Upazila (KaU) and Kotalipara Upazila (KoU) of Bangladesh. A total of 35 GW samples were collected from hand tube wells at the depths of 30 m - 370 m and analyzed using Water Quality Index (WQI), Synthetic Pollution Index (SPI), Geospatial Techniques (GST), and Multivariate Statistical Techniques (MST). Key parameters, including turbidity, pH, and nitrate (NO₃⁻), met Bangladesh standards, while electrical conductivity (EC), total dissolved solids (TDS), sodium (Na), potassium (K), ammonia (NH₃), iron (Fe), and arsenic (As) exceeded recommended limits in 5.72–80.0 % of the samples. Manganese (Mn), copper (Cu), and zinc (Zn) were not detected in any sample of the two Upazila. Pearson Correlation (PC) and Principal Component Analysis (PCA) indicated that both anthropogenic and natural factors influenced GW quality. The WQI classified 2.85 % of samples as “excellent”, 57.14 % as “good”, 28.57 % as “poor”, and 11.43 % as “very poor”, whereas SPI categorized 14.28 % as “very pure”, 42.85 % as “slightly polluted”, 5.72 % as “moderately polluted”, 8.57 % as “highly polluted”, and 28.57 % as “unfit for drinking”. The results revealed that GW in KaU was largely unsafe for drinking and domestic uses, while KoU samples were generally suitable. This study emphasizes the need for proper GW management to protect public health.
{"title":"Evaluation of pollution intensity in groundwater of Kashiani and Kotalipara upazila (Bangladesh) by using different indices and multivariate statistical techniques","authors":"Molla Rahman Shaibur , Masum Howlader , M. Moklesur Rahman , Mobin Hossain Shohan , Md. Habibur Rahman , Ashik Md Mamun","doi":"10.1016/j.clwat.2025.100134","DOIUrl":"10.1016/j.clwat.2025.100134","url":null,"abstract":"<div><div>Groundwater (GW) quality is a critical concern for safe drinking water in Bangladesh. This study aimed to evaluate the GW quality in Kashiani Upazila (KaU) and Kotalipara Upazila (KoU) of Bangladesh. A total of 35 GW samples were collected from hand tube wells at the depths of 30 m - 370 m and analyzed using Water Quality Index (WQI), Synthetic Pollution Index (SPI), Geospatial Techniques (GST), and Multivariate Statistical Techniques (MST). Key parameters, including turbidity, pH, and nitrate (NO₃⁻), met Bangladesh standards, while electrical conductivity (EC), total dissolved solids (TDS), sodium (Na), potassium (K), ammonia (NH₃), iron (Fe), and arsenic (As) exceeded recommended limits in 5.72–80.0 % of the samples. Manganese (Mn), copper (Cu), and zinc (Zn) were not detected in any sample of the two Upazila. Pearson Correlation (PC) and Principal Component Analysis (PCA) indicated that both anthropogenic and natural factors influenced GW quality. The WQI classified 2.85 % of samples as “excellent”, 57.14 % as “good”, 28.57 % as “poor”, and 11.43 % as “very poor”, whereas SPI categorized 14.28 % as “very pure”, 42.85 % as “slightly polluted”, 5.72 % as “moderately polluted”, 8.57 % as “highly polluted”, and 28.57 % as “unfit for drinking”. The results revealed that GW in KaU was largely unsafe for drinking and domestic uses, while KoU samples were generally suitable. This study emphasizes the need for proper GW management to protect public health.</div></div>","PeriodicalId":100257,"journal":{"name":"Cleaner Water","volume":"4 ","pages":"Article 100134"},"PeriodicalIF":0.0,"publicationDate":"2025-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145219098","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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