Water Research最新文献

{"title":"Water temperature exhibits an overwhelming effect on the spatial allocation of sediment phosphorus fractions in the permanent backwater area of the Three Gorges Reservoir, China","authors":"Daoxi Zhang ,&nbsp;Zhiyong Zhang ,&nbsp;Jan-Peter Muller ,&nbsp;Liming Zhu ,&nbsp;Sanfeng Zhang ,&nbsp;Ji Wan ,&nbsp;Fang Shi ,&nbsp;Xi Zou ,&nbsp;Yulong Shi","doi":"10.1016/j.watres.2025.123177","DOIUrl":"10.1016/j.watres.2025.123177","url":null,"abstract":"<div><div>The upstream cascade reservoirs and the implementation of soil and water conservation practices have effectively mitigated sediment inflow to the Three Gorges Reservoir (TGR) since it was fully operational in 2010. However, total deposited sediments and algal blooms in its tributaries have increased during the post-TGR period. To investigate the spatial distribution characteristics of deposited fractional phosphorus in sediments and its influencing factors, column sediment and overlying water datasets collected from field campaigns were analysed using the multivariate statistical approaches by Partial Triadic Analysis (PTA) and Redundancy Analysis (RDA). The results revealed that fractional phosphorus within the top 20 cm of the column sediment exhibited a distinct vertical structure, and the mean contents of total phosphorus (TP), inorganic phosphorus (Inorg-P) and calcium-bound phosphorus (Ca-P) contents were significantly higher than those measured in the deeper layer. Additionally, fractional phosphorus in the mainstream and estuary sections showed longitudinal distribution patterns. Inorg-P and Ca-P were prevalent in the upstream reaches, while the organic phosphorus (Org-P) and iron-aluminium-bound phosphorus (Fe/Al-P) were enriched in the lower mainstream and estuary regions. Sediment TP reached the highest level in the middle river reach. Multivariate regression via the RDA and variance partitioning indicated that environmental factors of the overlying water were significantly correlated with surface sediment phosphorus levels (<span><math><mrow><msubsup><mrow><mi>R</mi></mrow><mrow><mi>a</mi><mi>d</mi><mi>j</mi></mrow><mrow><mn>2</mn></mrow></msubsup><mo>=</mo><mn>0</mn><mo>.</mo><mn>33</mn></mrow></math></span>, <span><math><mrow><mi>p</mi><mo>&lt;</mo><mn>0</mn><mo>.</mo><mn>05</mn></mrow></math></span>). Physicochemical variables, particularly water temperature, exerted a stronger influence on the spatial allocation of sediment phosphorus fractions compared to water phosphorus content during the flood season. These findings highlight the need to address nutrients introduced from the mainstream to tributaries via backwater intrusion before implementing flood operation approaches for algal bloom mitigation. Furthermore, biomanipulation-based schemes may represent a promising strategy for improving water quality in TGR tributaries.</div></div>","PeriodicalId":443,"journal":{"name":"Water Research","volume":"276 ","pages":"Article 123177"},"PeriodicalIF":11.4,"publicationDate":"2025-01-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143050225","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Landsat monitoring reveals the history of river organic pollution across China during 1984–2023","authors":"Nuoxiao Yan ,&nbsp;Zhiqiang Qiu ,&nbsp;Chenxue Zhang ,&nbsp;Yao Yan ,&nbsp;Dong Liu","doi":"10.1016/j.watres.2025.123210","DOIUrl":"10.1016/j.watres.2025.123210","url":null,"abstract":"<div><div>River organic pollution exhibits pronounced spatiotemporal dynamics in response to environmental changes. However, the traditional method of tracking chemical oxygen demand (COD) and/or other organic pollution indicators at fixed locations over expansive regions is labor-intensive, time-consuming, and inadequate for achieving full spatial coverage. To address this limitation, here we developed a Random Forest algorithm using Landsat satellite data in conjunction with sub-daily (every 4 h) COD data at 1,997 sites across China. The proposed model achieved high accuracy, with a root mean square error of 0.52 mg/L and a mean absolute percent difference of 13.01 %. Additionally, the model was robust across clear, algae-laden, turbid, and black-smelling waters. Then, the algorithm was applied to investigate the spatiotemporal variations of COD concentration in Chinese rivers during 1984–2023. Across China, high river COD concentrations were observed in the eastern Songliao (3.56 ± 1.11 mg/L), Haihe (3.00 ± 0.89 mg/L), and Huaihe (3.57 ± 0.67 mg/L) basins. Anthropogenic activities could explain 79.39 % of the spatial variability in COD concentrations, and the cropland distribution had a significant impact. During 1984–2023, 73.58 % of China's rivers exhibited significant changes in COD concentrations (<em>p</em> &lt; 0.05). With respect to the 800 mm isoprecipitation line, 56.62 % of the southeastern rivers showed decreasing trends; in contrast, 84.25 % of the northwestern rivers displayed increasing trends in COD concentrations. The temporal variations in COD concentrations were driven by the combined effects of factors including rainfall, vegetation coverage, and human activities; their relative contributions were 0.02 – 42.45 %, 0.07 – 68.76 %, and 0.06 – 90.31 % for COD changes in different provinces. This study underscores the feasibilities of using long-term Landsat data to efficiently and dynamically monitor organic pollution in rivers on a large scale, providing crucial implications for spatiotemporal monitoring of other water quality indicators.</div></div>","PeriodicalId":443,"journal":{"name":"Water Research","volume":"275 ","pages":"Article 123210"},"PeriodicalIF":11.4,"publicationDate":"2025-01-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143044377","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A machine learning approach to estimate domestic use of public and private water sources in the United States","authors":"Andrew Murray ,&nbsp;Alexander Hall ,&nbsp;Diego Riveros-Iregui","doi":"10.1016/j.watres.2025.123171","DOIUrl":"10.1016/j.watres.2025.123171","url":null,"abstract":"<div><div>In the United States, people obtain water for household use from one of two sources. Public water systems, which are subject to rules and regulations under the Safe Drinking Water Act, or private sources such as domestic wells, which are not subject to federal regulation and are generally the responsibility of the homeowner or occupant. Public water systems are required to treat their drinking water and conduct regular testing to ensure the delivery of safe water to consumers. From a public health perspective, it is essential to know who is drinking what water to determine risk and impacts from water-borne disease and contamination. We present a new machine-learning approach to estimating water supply source (public or private) at the census block level for the year 2020. While previous studies have largely focused on spatially delineating either public or private water supply, our method incorporates data from both universes, resulting in more accurate modeling results. The utilization of machine learning and additional explanatory data that have not been considered in prior studies results in the most accurate and up-to-date estimate of the count and location of users supplying household water from either a private source or a public water supply. We estimate that 14.1 % of US housing units are supplied by private wells and 84.9 % of housing units are served by a public water system as of 2020.</div></div>","PeriodicalId":443,"journal":{"name":"Water Research","volume":"276 ","pages":"Article 123171"},"PeriodicalIF":11.4,"publicationDate":"2025-01-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143044825","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Calcium scaling on the quartz sleeve of ultraviolet reactor: On-line measurement and model prediction","authors":"Mengkai Li ,&nbsp;Yihao Zheng ,&nbsp;Yanyan Huang ,&nbsp;Jiaying Li ,&nbsp;Zhe Sun ,&nbsp;Ernest R. Blatchley III ,&nbsp;Zhimin Qiang","doi":"10.1016/j.watres.2025.123203","DOIUrl":"10.1016/j.watres.2025.123203","url":null,"abstract":"<div><div>Quartz sleeve scaling significantly affects the efficacy of ultraviolet (UV) processes for water treatment. Investigating the scaling process and developing prediction methods are important for selecting and optimizing scaling control measures. However, these have been limited by the lack of an appropriate experimental system. Therefore, this study investigated the kinetics, mechanisms, and prediction methods of calcium scaling (a predominant scale compound encountered in drinking water treatment) on quartz sleeves. An on-line experimental system for sleeve scale UV transmittance (UVT_SS) was developed based on previously developed micro-fluorescent silica detectors. The scaling process was accelerated by increases in [Ca²⁺] (100–400 mg L^–1), alkalinity (100–400 mg L^–1), and pH (6.5–8.5). Furthermore, water temperature (20.0–30.0 °C), sleeve temperature (24.9–31.7 °C), and flow velocity (2.5–10.0 cm s^–1) exhibited diverse effects on calcium scaling. By delving into scaling mechanisms such as mass transfer, surface crystallization, and scale stripping processes, we proposed a prediction model. The extinction coefficient and stripping rate of calcium scale were estimated to be 0.80 μm^–1 and 0.155 h^–1, respectively. Model predictions were validated through both laboratory and field tests. This study provides important methods for ensuring sufficient dose delivery by a UV reactor, enhancing energy efficiency, and improving reliability in UV processes for water treatment.</div></div>","PeriodicalId":443,"journal":{"name":"Water Research","volume":"275 ","pages":"Article 123203"},"PeriodicalIF":11.4,"publicationDate":"2025-01-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143044611","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Insights into the start-up of acidic nitritation using conventional activated sludge: Process dynamics, nitrifiers succession, and pilot-scale demonstration","authors":"Zheng Kong ,&nbsp;Zhiyao Wang ,&nbsp;Zhetai Hu ,&nbsp;Yunqian Song ,&nbsp;Dongdong Xu ,&nbsp;Guanbin Li ,&nbsp;Jason Dwyer ,&nbsp;Shihu Hu","doi":"10.1016/j.watres.2025.123208","DOIUrl":"10.1016/j.watres.2025.123208","url":null,"abstract":"<div><div>Acidic nitritation driven by acid-tolerant ammonia-oxidizing bacteria (AOB) has gained wide attention due to its potential in sustainable wastewater and sludge treatment. However, limited knowledge of initiating acidic nitration using conventional activated sludge hindered the wider studies and application of this technology at lab- and field-scale. This study evaluates three strategies for initiating acidic nitritation: a constant low hydraulic retention time (HRT); an extended initial HRT followed by manual HRT reduction; and pH-controlled HRT. All strategies successfully started acidic nitritation using seed sludge from a local wastewater treatment plant (WWTP) containing undetectable acid-tolerant AOB. Among the three strategies, pH-controlled HRT was the most efficient, with a smoother (minimal fluctuations) and faster (around 30 days) start-up process than the other two strategies. This was attributed to an initial redundancy in ammonia oxidation capacity (i.e. making the proton generation rate caused by ammonium oxidation exceed the alkalinity supply rate by influent), allowing AOB to overcome the activity valley during the transition from neutral to acid pH Level. Using pH as a real-time proxy of AOB activity also leveraged the unique low buffer capacity at acidic pH. Based on these findings, a pilot-scale acidic nitritation reactor treating diluted sidestream wastewater was initiated for the first time using the pH-controlled strategy. The pilot reactor immediately achieved nitrite accumulation and reached the target hydraulic loading rate quicker than the lab reactor, indicating higher influent nitrogen concentration may facilitate NOB suppression and a higher growth rate of acid-tolerant AOB. Based on those results, the versatile start-up strategies using both mainstream or sidestream wastewater were further discussed. Overall, this work greatly expands potential applications of acidic nitritation and paves the way for future field-scale applications.</div></div>","PeriodicalId":443,"journal":{"name":"Water Research","volume":"275 ","pages":"Article 123208"},"PeriodicalIF":11.4,"publicationDate":"2025-01-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143044378","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Quantifying, predicting, and mitigating nitrous oxide emissions in a full-scale partial nitritation/anammox reactor treating reject water.","authors":"Xavier Flores-Alsina, Anna Katrine Vangsgaard, Nerea Uri Carreno, Per H. Nielsen, Krist V. Gernaey","doi":"10.1016/j.watres.2025.123200","DOIUrl":"https://doi.org/10.1016/j.watres.2025.123200","url":null,"abstract":"In this paper, a set of mathematical tools are developed and assembled to quantify, predict and virtually assess N₂O emission migration strategies in partial nitritation (PN) / anammox (ANX) granular based reactors. The proposed approach is constructed upon a set of data pre-treatment methods, process simulation models, control tools (and algorithms) and key performance indicators to analyze, reproduce, and forecast the behavior of multiple operational variables within aerobic granular sludge systems. All these elements are tested on two full-scale data sets (#D1, #D2) collected over a period of four months (Sept-Dec 2023). Results show that data pretreatment is essential for noise reduction, filling data gaps, and ensuring smooth process simulations. The model accurately predicts (normalized RMSE&lt; 1) multiple N oxidation states (NH_x, NO₂^-, NO₃^-, N₂O) and dissolved oxygen (DO), demonstrating its capability to describe bacterial behavior within the studied system. Special emphasis is placed on weak acid-base chemistry where pH is reliably reproduced, and it can be used for control purposes. Both biological and physico-chemical aspects are predicted at different time scales (months, days, minutes). While nitritation mainly occurred in the bulk, biofilm distribution showed inactive inner granule parts and increasing biomass (mostly ANX) towards the surface, with distinct organic concentrations. Gradients for multiple soluble compounds could also be reflected. The model revealed that the system was suffering from low ANX activity leading to NO₂^- accumulation. This in combination with low DO levels, resulted in nitrifier denitrification (ND) as the main identified N₂O production pathway and an unusually high emission factor (EF) as a result. The validation data set also yielded satisfactory results (normalized RMSE&lt; 1). The scenario analysis revealed that modification of the aeration patterns and operational volatile suspended solids (VSS) concentration could improve the ANX activity and lead to N₂O emission rates that are in line with what is normally expected from similar systems. The study includes a discussion on transitioning from process models to digital shadows/ twins for real-time process monitoring. Additionally, it emphasizes the necessity of evaluating reject water technologies from a plant-wide perspective.","PeriodicalId":443,"journal":{"name":"Water Research","volume":"3 1","pages":""},"PeriodicalIF":12.8,"publicationDate":"2025-01-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143031158","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"An innovative application of osmotic microbial fuel cell (OsMFC) for enhanced activated sludge thickening and stabilization with bioelectricity generation","authors":"Wenchao Xue ,&nbsp;Aye Pyae Pyae Aung ,&nbsp;Simon Guerrero-Cruz ,&nbsp;Kang Xiao ,&nbsp;Yifan He ,&nbsp;Anil Kumar Anal ,&nbsp;Allan Sriratana Tabucanon","doi":"10.1016/j.watres.2025.123199","DOIUrl":"10.1016/j.watres.2025.123199","url":null,"abstract":"<div><div>Waste activated sludge (WAS) management presents significant challenges due to its complex composition and the high cost associated with conventional treatment methods. This study investigates the potential of osmotic microbial fuel cell (OsMFC) technology for WAS thickening, stabilization, and bioelectricity generation. Compared to conventional microbial fuel cells (MFCs), OsMFCs offer several advantages, including enhanced sludge thickening performance, improved organic matter degradation efficiency, and increased bioelectricity generation. The OsMFC achieved substantial sludge thickening, with the total suspended solids (TSS) increasing from 1,753, 11,650, and 3,565 mg/L in the OsMFC to 28,550, 28,500, and 20,340 mg/L, respectively, over three consecutive operating cycles with a sludge retention time of 16 days. The total chemical oxygen demand (tCOD) mass reduction in the OsMFC averaged 90.7 %, outperforming the MFC, which achieved 61.3 %. This indicates the superior performance of the OsMFC in organic sludge digestion. Further supporting this, the VSS/TSS ratio of treated WAS was effectively reduced from 0.64 to 0.37, with an average VSS mass reduction of 65.0 % obtained in the OsMFC. Additionally, OsMFC treatment modified the physicochemical properties of the WAS, resulting in smaller floc particle size, and reduced zeta potential, potentially enhancing sludge dewaterability. Furthermore, OsMFC exhibited superior bioelectricity generation compared to MFC, with maximum power densities averaging 1,704.6 mW/m³, outperforming that of 762.3 mW/m³ observed in comparing MFC. Despite its promising potential, further research is needed to optimize OsMFC operation and fully understand its mechanisms. Overall, this study highlights the potential of OsMFC technology for sustainable and efficient management of WAS within the circular economy framework.</div></div>","PeriodicalId":443,"journal":{"name":"Water Research","volume":"275 ","pages":"Article 123199"},"PeriodicalIF":11.4,"publicationDate":"2025-01-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143031157","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Synergistic effects of quaternary ammonium compounds and antibiotics on the evolution of antibiotic resistance","authors":"Peiliang Wang ,&nbsp;Hanqing Wang ,&nbsp;Shengchun Qi ,&nbsp;Wei Wang ,&nbsp;Huijie Lu","doi":"10.1016/j.watres.2025.123206","DOIUrl":"10.1016/j.watres.2025.123206","url":null,"abstract":"<div><div>The usage of quaternary ammonium compounds (QACs) as disinfectants has surged dramatically during the COVID-19 pandemic and thereafter. QACs can promote antimicrobial resistance, but the combined effects of QACs and antibiotics in driving resistance evolution were yet revealed. This study aimed to evaluate antibiotic resistance of wastewater microorganisms under coexposure to typical antibiotics and the most widely used QAC, dodecyl dimethyl benzyl ammonium chloride (DDBAC). DDBAC exhibited synergistic effects with multiple antibiotics (ampicillin, azithromycin, ciprofloxacin, kanamycin, polymyxin B) in enhancing activated sludge resistance by 1.53–6.67 folds, compared with antibiotics exposure alone. DDBAC-ampicillin coexposure enriched multidrug and aminoglycoside ARGs with relatively high horizontal gene transfer potential. The synergistic mechanism was further explored using sludge-isolated pathogenic <em>E. coli</em>. DDBAC at 1–10 mg/L alone did not induce notable resistance, but synergized with ampicillin on enhancing resistance by 6.56–22.90 folds. Based on mutation analysis and transcriptomics, DDBAC-enhanced resistance evolution was attributable to efflux pump upregulation, target modification, and inhibition of ATP synthesis (a less reported mechanism). Five DDBAC-induced, resistance-conferring mutant genes were highly enriched in globally collected <em>E. coli</em> strains from wastewater outflow (<em>n</em> = 537) than soil/sediments (<em>n</em> = 714, <em>p</em> &lt; 0.05). Considering the strong adsorption and persistence of QACs, their coexistence with antibiotics poses elevated antimicrobial resistance risks, particularly in wastewater treatment systems with long solid retention time and sewage sludge applied farmland.</div></div>","PeriodicalId":443,"journal":{"name":"Water Research","volume":"275 ","pages":"Article 123206"},"PeriodicalIF":11.4,"publicationDate":"2025-01-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143035161","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Biological VFAs production from proteinaceous wastewater varied with protein type: The role of protein exposed enzyme cleavage sites and hydrolysates biotransformation capacity","authors":"Jing Zhou ,&nbsp;Dapeng Li ,&nbsp;Xu Duan ,&nbsp;Xuemeng Zhang ,&nbsp;Chuang Chen ,&nbsp;Yinguang Chen","doi":"10.1016/j.watres.2025.123201","DOIUrl":"10.1016/j.watres.2025.123201","url":null,"abstract":"<div><div>Proteinaceous wastewater contains various proteins, which can be valorized to biobased volatile fatty acids (VFAs), important substrates for the synthesis of biodegradable plastics, biodiesel, bioelectricity, etc., but the influence of protein type on VFAs has never been documented. It was found that among the five proteinaceous wastewater proteins investigated, ovalbumin and casein produced the most and the least VFAs, respectively. The mechanism investigation shows that proteins with higher VFAs production had higher functional microorganism abundance and key enzyme activity in the reaction system due to their more enzyme cleavage sites and looser secondary structure, which made it easier for more hydrolase to bind, causing more protein hydrolysis. Also, metaproteomics and amino acid composition analyses revealed that the hydrolysates of proteins with higher VFAs had more isoleucine and proline, which were needed for the synthesis of recognizing and binding proteins (oligopeptide permease subunit A (OppA) and dipeptide permease (Dpp)) of acidogens and beneficial for transporters (Dpp subunit F/Opp subunit F), more hydrolysates (amino acids) were therefore transported into the cell. Further investigation indicates that more electron acceptor and electron donor paired amino acids were in the hydrolysates, facilitating the Stickland reaction and promoting intracellular amino acids bio-transformation to VFAs.</div></div>","PeriodicalId":443,"journal":{"name":"Water Research","volume":"275 ","pages":"Article 123201"},"PeriodicalIF":11.4,"publicationDate":"2025-01-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143035037","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Sources and risk factors for nitrate, pathogens, and fecal contamination of private wells in rural southwestern Wisconsin, USA","authors":"Joel Stokdyk ,&nbsp;Aaron Firnstahl ,&nbsp;Kenneth Bradbury ,&nbsp;Maureen Muldoon ,&nbsp;Burney Kieke Jr ,&nbsp;Mark A. Borchardt","doi":"10.1016/j.watres.2025.123202","DOIUrl":"10.1016/j.watres.2025.123202","url":null,"abstract":"<div><div>Household well water can be degraded by contaminants from the land's surface, but private well owners lack means to protect the source water from neighboring disturbances. Rural residents of southwestern Wisconsin, USA, rely on private well water, and the combination of land use and fractured carbonate bedrock makes groundwater vulnerable to contamination. To identify the extent, sources, and risk factors of private well contamination, randomly selected wells sampled during two-day periods in fall (n = 301) and spring (n = 529) were analyzed for nitrate and indicator bacteria, and a subset (n = 138) was sampled across four seasonal events for analysis of pathogens and microbial source tracking markers by quantitative polymerase chain reaction. Risk factors representing land use, hydrology, geology, and well construction were analyzed for associations with contamination in multivariable models. The importance of risk factors varied by contaminant, illustrating the multifaceted nature of rural groundwater quality. Nitrate contamination was associated with agricultural land use, and wells with casings that extended below a shale aquitard accessed less contaminated water than those drawing water from above it. Human fecal microbes were detected in 64 wells (46%), and rainfall was the key risk factor for contamination, indicating that wastewater from septic systems was available to contaminate wells when transport conditions were favorable. Manure microbes from cattle/ruminants and pigs were detected in 33 and 13 wells, respectively, and concentrations increased with the hectarage of cultivated land near wells. Pathogen genes for viruses, bacteria, and protozoa were detected in 66 wells (48%), including more detections of zoonotic than human-specific pathogens, and human <em>Bacteroides</em>, an indicator of wastewater, was an equivocal predictor of pathogen presence in private wells. Characterizing important elements of the setting, like geology, and identifying sources and risk factors for contaminants can inform landscape-level policies to protect groundwater quality.</div></div>","PeriodicalId":443,"journal":{"name":"Water Research","volume":"275 ","pages":"Article 123202"},"PeriodicalIF":11.4,"publicationDate":"2025-01-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143031156","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}