Water Research最新文献

{"title":"Fast and Eco-friendly Sulfidation of Zero-Valent Iron Using Elemental Sulfur and Geobacter Sulfurreducens for Groundwater Remediation","authors":"Runze Li, Liang Zhang, Yanduo Yang, Weiqi Zhang, Yuming Zhen, Jianliang Sun, Feng Jiang","doi":"10.1016/j.watres.2025.124706","DOIUrl":"https://doi.org/10.1016/j.watres.2025.124706","url":null,"abstract":"Sulfidated zero-valent iron (S-ZVI) with high electron selectivity and reactivity toward contaminants is a promising reagent for groundwater remediation. However, the widely-used chemical and mechanical sulfidation methods to prepare S-ZVI are often chemical- or energy-intensive. Biogenic sulfidation method relying on sulfate-reducing bacteria (SRB) are considered as green methods, yet are time-consuming and may release toxic and odorous hydrogen sulfide gas. Instead, elemental sulfur (S⁰) as sulfur precursor may avoid prolonged preparation time and hydrogen sulfide emission. However, elemental sulfur is difficult to be utilized by SRB so as to hinder the production rate of S-ZVI. In this study, therefore, we proposed a novel biogenic sulfidation method using <em>Geobacter sulfurreducens</em> (PCA) to achieve fast, low-cost and eco-friendly S-ZVI preparation with insoluble S⁰ and Fe⁰ powders. The results showed that the successful sulfidation of ZVI using PCA strains and S⁰ without the addition of organic carbon was achieved within 2 hours, 13 times faster than SRB mediated sulfidation. The rate of hexavalent chromium removal by the PCA<em>-</em>synthesized S-ZVI was 68% higher than that by SRB-synthesized S-ZVI. The fast sulfidation proceeded via the reductive dissolution of iron oxide passivation layer on ZVI by PCA and the enhanced electron transfer between ZVI and S⁰ mediated by conductive PCA cells. The PCA-mediated sulfidation minimized the potential secondary pollution associated hydrogen sulfide and chemical consumption for the S-ZVI preparation. This study demonstrated a fast, chemical-saving and eco-friendly approach for S-ZVI preparation, which could be an ideal solution for groundwater remediation.","PeriodicalId":443,"journal":{"name":"Water Research","volume":"1 1","pages":""},"PeriodicalIF":12.8,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145203123","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":"Electrochemical ammonia recovery from wastewater: the critical roles of electrode engineering toward scale-up","authors":"Dejia Liu, Jixin Yuan, Panyu Ren, Le Shi, Zhiping Zhu, Changyong Zhang, Hongmin Dong, Dezhao Liu","doi":"10.1016/j.watres.2025.124708","DOIUrl":"https://doi.org/10.1016/j.watres.2025.124708","url":null,"abstract":"Ammonia is indispensable for producing fertilizers that sustain the global population, yet its agricultural application contributes significantly to water pollution. Electrochemical technologies offer a renewable-energy-driven and chemical-free pathway for recovering ammonia directly from wastewater, representing a critical step toward a circular nitrogen economy and net-zero emissions in the wastewater sector. Nevertheless, translating lab-scale advances to industrialization remains constrained by technological hurdles. Emerging electrode-engineering strategies promise scalable, membrane-less electrochemical systems, yet a systematic and comparative assessment is lacking. In this review, we first present the electrochemical ammonia recovery pathway and elucidate the mechanisms of various electrode materials in this process. Secondly, we critically evaluate state-of-the-art scalable electrode systems for electrochemical ammonia recovery. Thirdly, we comparatively analyze the ammonia recovery performance at both the electrode-material and electrode-system levels, comprehensively discussing the current challenges and future research opportunities toward technological scale-up. Finally, we outline key research targets toward next-generation electrochemical engineering for sustainable ammonia recovery and wastewater treatment.","PeriodicalId":443,"journal":{"name":"Water Research","volume":"114 1","pages":""},"PeriodicalIF":12.8,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145203178","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":"Reactive transport and retention of Cd, Pb, and Zn under coexisting multimetal-xanthate conditions in porous media","authors":"Bowen Luo ,&nbsp;Kouping Chen ,&nbsp;Xianwu Zheng ,&nbsp;Jichun Wu ,&nbsp;Ping Li ,&nbsp;Huali Chen","doi":"10.1016/j.watres.2025.124713","DOIUrl":"10.1016/j.watres.2025.124713","url":null,"abstract":"<div><div>The geochemical fate of heavy metals in mining regions is significantly complicated by the coupled effects of residual flotation reagents and the co-existence of multiple metals. Combining column transport experiments and spectroscopic characterization, this study developed a Multisurface Speciation Model (MSM) to describe the reaction processes between cadmium (Cd), lead (Pb), and zinc (Zn) and key retention components including iron oxides, organic matter, clay minerals, and ethyl xanthate (EX), to quantitatively elucidate the impact of system complexity and EX-loaded concentration on their transport and retention behaviors in actual porous media. First, increasing the EX-loaded concentration from 0 to 1 mmol/L enhanced overall retention and inhibited the transport of all the three metals. Conversely, increasing system complexity from single-metal to multimetal systems diminished overall retention and enhanced transport. EX loading established EX as a dominant component for metal retention and concurrently suppressed the retention contribution of other soil components. However, the transition from single metal systems to ternary metal systems led to the intensified competition between metals and EX, thereby reducing the adsorption of EX onto the porous media and consequently weakening its overall capacity to retain the heavy metals, with the EX-retained concentrations of Cd, Pb, and Zn decreasing by 78.62 %, 52.44 %, and 80.46 %, respectively. The characterization results demonstrated that while the introduction of EX enhanced heavy metal retention through introducing new sulfur-containing functional groups, increasing the net negative surface charge, and promoting metal-immobilizing sulfidation reactions, the enhancement was significantly offset in multimetal systems by the intensified inter-metal competition and by a concurrent weakening of electrostatic attraction. This study successfully deconvolved the dual effects of EX loading and multimetal competition on the transport and retention of Cd, Pb, and Zn, offering a new perspective on the fate of heavy metals in xanthate-affected systems.</div></div>","PeriodicalId":443,"journal":{"name":"Water Research","volume":"288 ","pages":"Article 124713"},"PeriodicalIF":12.4,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145203177","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":"Environmental co-exposure to roxarsone and heavy metals drives bacterial antibiotic multidrug resistance via genetic and phenotypic adaptations","authors":"Qian-He Liu, Li Yuan, Zheng-Hao Li, Kenneth Mei Yee Leung, Guo-Ping Sheng","doi":"10.1016/j.watres.2025.124682","DOIUrl":"https://doi.org/10.1016/j.watres.2025.124682","url":null,"abstract":"Agricultural wastewater, a significant component of the anthropogenic water cycle, often contains complex mixtures of contaminants, including non-antibiotic feed additives, posing largely uncharacterized risks for antimicrobial resistance (AMR) evolution. This study addresses the critical knowledge gap regarding the combined impact of commonly co-occurring roxarsone (ROX) and heavy metals (Zn, Cu) at environmentally relevant concentrations on the <em>de novo</em> evolution and persistence of multidrug resistance in aquatic environments. Using a 90-day laboratory evolution experiment with <em>Escherichia coli</em>, we demonstrate that while ROX alone induced moderate resistance (e.g., 6.2-fold increase in minimum inhibitory concentration (MIC) for chloramphenicol), co-exposure with Zn and Cu synergistically drove multidrug tolerance to nine antibiotics and selected for stable, heritable resistance to chloramphenicol, tetracycline, and kanamycin (up to 8.2-fold MIC increase). This robust resistance persisted even after pollutant removal, highlighting a significant long-term threat to water quality and public health via the dissemination of resilient AMR bacteria from agricultural sources. Co-exposure intensified oxidative stress-induced mutagenesis and selected for key adaptive strategies enhancing bacterial survival and AMR persistence in contaminated water. These include upregulated efflux pumps, increased secretion of extracellular polymeric substances (1.1-3.2-fold), enhanced motility (1.1-1.5-fold), and cell filamentation (lengths 2.4-8.2-fold greater). These findings illuminate a potent, previously underestimated environmental pathway where mixtures of common agricultural pollutants in wastewater synergistically select for persistent multidrug resistance. This research underscores the urgent need to revise water quality criteria and wastewater treatment paradigms to address the co-selection pressures exerted by non-antibiotic chemical mixtures in aquatic ecosystems.","PeriodicalId":443,"journal":{"name":"Water Research","volume":"54 1","pages":""},"PeriodicalIF":12.8,"publicationDate":"2025-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145183129","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":"Bioinspired polyethylene/boron nitride woven mesh integrating heterogeneous wettability and radiation cooling for water recycling of cooling tower","authors":"Feicong Fan ,&nbsp;Kang Zhou ,&nbsp;Yu Du ,&nbsp;Weilong Zhou ,&nbsp;Jiabao Lu ,&nbsp;Heng Xie ,&nbsp;Ting Wu","doi":"10.1016/j.watres.2025.124699","DOIUrl":"10.1016/j.watres.2025.124699","url":null,"abstract":"<div><div>Industrial cooling towers, consuming ∼50 % of global industrial water, incur significant losses via evaporation, drift, and blowdown. To address this challenge, we developed a melting blending and extrusion-drawing method to fabricate spider-web inspired woven mesh based on polyethylene/boron nitride composites. The bioinspired mesh integrates heterogeneous wettability with radiative cooling to efficiently harvest water from the cooling tower. The bioinspired woven mesh exhibited a strong mid-infrared emissivity of 96.46 % and a temperature reduction of 6.68 °C is achieved. The micro/nanostructure-induced heterogeneous wettability synergized with radiative cooling to enhance droplet nucleation and growth, boosting water recycling efficiency by 54.67 % compared to conventional meshes. When applied to the water recycling of the cooling tower, the bioinspired woven mesh achieved a water recycling rate of 13.58 kg m⁻² h⁻¹ with a recovery efficiency of 71.46 %. Furthermore, the water recycling efficiency and material properties of the bioinspired woven mesh remained stable after 30 days of outdoor testing and 72 h of continuous UV irradiation of 0.5 W cm⁻², ensuring long-term durability for sustainable water recovery in industrial applications. Critically, global implementation of this spider-web-inspired woven mesh in industrial cooling towers could conserve ∼149.0 billion m³ of water annually. This rapid, efficient strategy addresses key challenges in cooling tower water recycling through synergistic heterogeneous wettability and radiative cooling.</div></div>","PeriodicalId":443,"journal":{"name":"Water Research","volume":"288 ","pages":"Article 124699"},"PeriodicalIF":12.4,"publicationDate":"2025-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145188918","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":"Double filament feed spacers for enhanced performance in reverse osmosis modules","authors":"Najat A. Amin ,&nbsp;Adnan Qamar ,&nbsp;Henry J. Tanudjaja ,&nbsp;Sarah Kerdi ,&nbsp;Ho Kyong Shon ,&nbsp;Noreddine Ghaffour","doi":"10.1016/j.watres.2025.124696","DOIUrl":"10.1016/j.watres.2025.124696","url":null,"abstract":"<div><div>Optimizing feed spacer geometry can significantly improve the efficiency of reverse osmosis (RO) modules through enhanced hydrodynamics. In this study, a novel symmetrical spacer is developed to mitigate concentration polarization and enhance RO performance. The proposed double filament spacer design features double elliptical or circular filaments separated by a slit along their length, connected by column-type nodes. Flow simulations, a type of computational fluid dynamics simulation in which the Navier-Stokes equations are numerically solved without relying on turbulence models, provided a fundamental analysis of double filament spacer performance. These reveal an even velocity distribution and increased flow mixing induced by the double filament, regardless of the cross-section type. Moreover, additional vortices were promoted downstream of the double filament spacer nodes, producing a jetting effect. This phenomenon helped to reduce the polarization region on the membrane surface and improve the permeation potential, as confirmed by salt concentration and permeation velocity computations. Although both double filament spacers outperformed the commercial design, the circular double filament spacer exhibited higher permeation and lower salt deposition capabilities than the elliptical-shaped filaments. Furthermore, the practical effectiveness of a double filament spacer was experimentally assessed in the RO system. Both spacers showed the potential to enhance flux production and specific flux relative to commercial design, with an enhancement reaching 68 % in the case of the circular double filament spacer. Utilizing this spacer also demonstrated a substantial reduction in pressure drop by 35 %. Therefore, the novel double filament spacer design, particularly the circular filament type, appears well-suited for achieving highly efficient and low-energy performance in RO module elements.</div></div>","PeriodicalId":443,"journal":{"name":"Water Research","volume":"288 ","pages":"Article 124696"},"PeriodicalIF":12.4,"publicationDate":"2025-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145183125","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":"Carbonate radicals in environmental systems: mechanistic insights and engineering applications","authors":"Zhantao Cai, Gancheng Zuo, Liping Huang, Xiaoyu Lou, Guoyang Zhang, Huan He, Shujuan Zhang","doi":"10.1016/j.watres.2025.124703","DOIUrl":"https://doi.org/10.1016/j.watres.2025.124703","url":null,"abstract":"Carbonate radical (CO₃^•−) is prevalent in both natural environments and engineered water treatment systems, originating from reactions between carbonate species (CO₃²⁻/HCO₃⁻) and free radicals or triplet states of dissolved organic matter (³DOM*). Its significant roles in environmental oxidation, advanced oxidative water treatment, and cellular oxidative damage are increasingly recognized. Despite extensive research on CO₃^•−, a gap remains in comprehensive reviews addressing its kinetics and mechanisms in pollutant removal and environmental impact. This review synthesizes previous studies, tracing the historical recognition of CO₃^•− in environmental sciences and comparing various detection methods. The reaction rate constants of CO₃^•− with organic contaminants (<em>k</em>_CO3•−) are summarized, and the relationship between pollutant structure and reactivity is explored. Reaction mechanisms and the selectivity of CO₃^•− are critically evaluated in comparison to other common radicals, such as hydroxyl (HO^•) and sulfate (SO₄^•−). Furthermore, the dual roles of CO₃^•− as both primary and secondary radicals in advanced oxidation processes (AOPs), along with its impact on degradation pathways and byproduct toxicity, are assessed. Finally, the environmental implications of CO₃^•−, including its contributions to self-purification, metal transport, and biological oxidative damage, are discussed. This review aims to offer a comprehensive framework for understanding CO₃^•− in environmental contexts, enhancing its application in AOP systems and natural remediation.","PeriodicalId":443,"journal":{"name":"Water Research","volume":"54 1","pages":""},"PeriodicalIF":12.8,"publicationDate":"2025-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145183126","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":"Phototransformation of benzodiazepines in water mediated by dissolved black carbon: Mechanisms and the structure-reactivity relationship","authors":"Zhi-Cheng Zhou ,&nbsp;Bin Yang ,&nbsp;He-Yun Fu ,&nbsp;Xiao-Lei Qu ,&nbsp;Pei-Zhe Sun ,&nbsp;Yong Feng ,&nbsp;Guang-Guo Ying","doi":"10.1016/j.watres.2025.124701","DOIUrl":"10.1016/j.watres.2025.124701","url":null,"abstract":"<div><div>Dissolved black carbon (DBC) within aquatic dissolved organic matters demonstrates potent photochemical activity, yet its effects on emerging contaminant transformation and structure-reactivity relationships remain inadequately characterized. In this study, benzodiazepines were employed as model emerging contaminants to investigate the photoactivity, mediation effect, and structural-activity relationships of five DBC samples and four well-studied dissolved humic substances (DHSs) under simulated sunlight irradiation. DBC efficiently generated superoxide anions (O₂^·-), singlet oxygen (¹O₂), and triplet excited states, thereby facilitating the phototransformation of benzodiazepines. Under DBC mediation, midazolam and flurazepam achieved transformation rates of 61.1-99.5% and 19.0-84.6%, respectively, within 8 h, exceeding direct phototransformation efficiencies (1.3-13.3%). Triplet excited states were identified as the dominant reactive intermediates, contributing more than 46.7% to the photoreactions. At equivalent total organic carbon levels, DBCs averagely exhibited 1.3-, 2.7-, and 3.3-fold higher photoactivity (O₂^·-, ¹O₂, and triplet excited states) alongside 2.5- and 4.7-fold enhanced benzodiazepine (midazolam and flurazepam) transformation compared to DHSs based on quantum yield measurements. Phototransformation pathways of benzodiazepines via DBC-mediation included ¹O₂ oxidation and charge transfer with triplet excited states, generating charge-separated intermediates that subsequently induce ring cleavage and coupling reactions. The molecular structures of DBC and DHS were characterized using UV-visible spectroscopy and Fourier transform-ion cyclotron resonance mass spectrometry. To elucidate the structure-reactivity relationship, Spearman rank correlation analysis, structural equation modeling, and orthogonal partial least squares regression were employed. The results identify molecular weight, aromaticity, and oxidation degree as key structural determinants of photoactivity. Low-molecular-weight compounds containing condensed aromatic structures and lignins demonstrate superior photoactivity in DBC/DHS structures, driving triplet excited-state and ¹O₂ formation, while O₂^·- might be generated from different structures. This study elucidated DBC mediation mechanisms and structure-reactivity relationships in benzodiazepine phototransformation, identifying low-molecular-weight fractions containing condensed aromatic and lignin moieties as dominant photoactive drivers in aquatic environment.</div></div>","PeriodicalId":443,"journal":{"name":"Water Research","volume":"288 ","pages":"Article 124701"},"PeriodicalIF":12.4,"publicationDate":"2025-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145183127","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":"Fine-scale Evaluation on Phosphorus Dynamics in Sediments of Hongjian Nur, the Largest Desert Lake in China","authors":"Xinyue Guo, Wenquan Liu, Chao Han, Odsuren Batdelger, Narangerel Serdyanjiv, Hongbin Yin","doi":"10.1016/j.watres.2025.124702","DOIUrl":"https://doi.org/10.1016/j.watres.2025.124702","url":null,"abstract":"Very few reports on the fine-scale behavior of phosphorus (P) in desert lakes largely restricts our comprehensive comprehension of their eutrophication processes and the evolution of effective lake management strategies. This study presented the novel application of two advanced high-resolution imaging technologies, <em>i.e.</em>, diffusive gradients in thin films (DGT) and planar optode (PO), to investigate the micro-distribution and kinetic mobility of P in sediments of a typical desert lake (Hongjian Nur) for the first time. The obtained high-resolution profiles of labile P and microenvironments (<em>e.g</em>., pH, DO, sulfide (S^2-), iron (Fe²⁺)) in all sediments underscored the intricate biogeochemical complexity and pronounced heterogeneity inherent in the sediments. Specifically, labile P concentrations ranged from 0.10 to 0.61 mg/L with an average value of 0.33 ± 0.16 mg/L. It is noteworthy that the mosaic distribution of labile P hotspots was observed predominantly at depths between -100 mm and -130 mm, which was probably corresponding to the active layer of labile P under the sediment-water interface (SWI). Moreover, the co-distributions of labile S and P in most sediments revealed significant correlations (<em>p</em> &lt; 0.01), thereby highlighting that P mobility is intrinsically linked to the S cycle. Sediment adsorption simulation experiments revealed a gradually increasing risk of P release from Hongjian Nur sediments as the desert lake’s progressive salinization accelerates under a warming, drying climate. Collectively, these findings firstly offer valuable insights into distribution and mobility mechanisms of P in desert lakes at a fine-scale, which are essential to understand the complex biogeochemical processes that regulate nutrient cycling in these fragile ecosystems.","PeriodicalId":443,"journal":{"name":"Water Research","volume":"70 1","pages":""},"PeriodicalIF":12.8,"publicationDate":"2025-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145188919","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":"Storm-driven overflow disinfection highlights toxicity risk of chlorophenylacetonitriles: Unveiling indole in sewer sediments as a key precursor","authors":"Tianyi Dong ,&nbsp;Cheng Ye ,&nbsp;Wenyuan Yang ,&nbsp;Yayun Zhang ,&nbsp;Feifei Wang ,&nbsp;Zuxin Xu ,&nbsp;Zoran Kapelan ,&nbsp;Wenhai Chu","doi":"10.1016/j.watres.2025.124700","DOIUrl":"10.1016/j.watres.2025.124700","url":null,"abstract":"<div><div>Storm-driven runoff scours accumulated sediments within stormwater drainage systems, transporting multi-source pollutants (including pathogens) into surface water through stormwater overflows, thereby elevating contamination risks in the recipient. Chlorine-based disinfection of overflowed stormwater applied in related storage tanks mitigates these risks before release. This study reveals that chlorophenylacetonitriles (CPANs), which are formed during the disinfection process, exhibit toxicity levels higher than conventional trihalomethanes and haloacetonitriles. Laboratory analyses conducted in this work demonstrated that sewer sediments — not runoff or stormwater — are the dominant precursor source for CPAN formation during overflow disinfection. Source apportionment further identified a robust linear correlation (R² = 0.95) between sediment indole concentrations (0.093–0.91 μg/g) and CPAN formation, experimentally confirming for the first time that indole is a critical precursor. Laboratory experiments also uncovered the presence of monochloroindoles in indole chlorination, a novel class of aromatic nitrogenous disinfection byproducts (DBPs). In addition, density functional theory calculations demonstrated that monochloroindole formation has lower activation energy barriers compared to CPAN pathways, resulting in new molecular-level insights into their preferential transformation. Given that indole serves as a shared precursor for both highly toxic CPANs and even more ecotoxic monochloroindoles, this study emphasizes the urgent need for sewer sediment management to mitigate the ecological and human health risks associated with these highly toxic nitrogenous DBPs.</div></div>","PeriodicalId":443,"journal":{"name":"Water Research","volume":"288 ","pages":"Article 124700"},"PeriodicalIF":12.4,"publicationDate":"2025-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145188920","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}