Journal of contaminant hydrology最新文献

{"title":"Adsorption behavior of triclosan by different microplastics and the impact of water chemistry","authors":"Yandan Li ,&nbsp;Tianxiang Xia ,&nbsp;Dan Zhang ,&nbsp;Danyang Zhang ,&nbsp;Miao Li","doi":"10.1016/j.jconhyd.2025.104815","DOIUrl":"10.1016/j.jconhyd.2025.104815","url":null,"abstract":"<div><div>The mechanisms of triclosan (TCS) adsorption onto polyamide (PA), polystyrene (PS), polyvinylchloride (PVC) and low-density polyethylene (LDPE) microplastics (MPs) were investigated, along with the effects of solution pH, ionic strength, and dissolved organic matter (DOM). The Linear model better described TCS adsorption isotherms suggesting that hydrophobic partitioning was the primary mechanism for TCS adsorption, while the Freundlich and Langmuir model fittings showed that TCS adsorption onto MPs was favorable. Following normalization by the specific surface area (SSA) of MPs, adsorption distribution coefficient (K_d) values of 105.70, 0.56, 0.20, and 0.08 L/m² were determined for PA, PS, PVC, and LDPE MPs, respectively. Hydrophobic interaction was the main adsorption mechanism, although other mechanisms, governed by the specific structure and functional groups of the MPs, also contributed. These included the formation of hydrogen bonds between the –OH on TCS (H-bond-donating) and the amide groups on PA (H-bond-accepting), and the π-π interactions between the benzene rings of PS and TCS, and hydrogen bonds between -OH on TCS and –COO^-/–COOH on PVC MPs. TCS adsorption by MPs was found to be pH-dependent, indicating that TCS⁰ was the main species involved in adsorption. The effects of ionic strength on TCS adsorption were not significant and therefore could be ignored. Humic acid (HA) impeded the adsorption of TCS by PA, PS, and LDPE MPs, potentially due to the hydrophobic interactions of HA with the three MPs, the hydrogen bonds with PA MPs, and the π-π interactions with PS MPs, all of which competed with TCS for adsorption sites. Fulvic acid (FA) inhibited TCS adsorption onto PS MPs, as FA could be sorbed by PS MPs through π-π interactions, competing with TCS for adsorption sites. These findings improve the accuracy of risk evaluations for organic pollutants such as TCS when co-occurring with MPs, furthering our understanding of the impacts of complex pollutant mixtures on both human and environmental health.</div></div>","PeriodicalId":15530,"journal":{"name":"Journal of contaminant hydrology","volume":"277 ","pages":"Article 104815"},"PeriodicalIF":4.4,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145819491","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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":"Spatiotemporal dynamics of microplastics in urban stormwater runoff: Functional area effects and transport pathways (Shanghai, China)","authors":"Junhao Li ,&nbsp;Bowen Yu ,&nbsp;Chengjin Cao ,&nbsp;Liuxing Wu ,&nbsp;Yaping Zhao ,&nbsp;Ruiyun Zhu ,&nbsp;Yangyang Hu ,&nbsp;Minsheng Huang ,&nbsp;Lei Wang ,&nbsp;Xinlin Yan","doi":"10.1016/j.jconhyd.2026.104880","DOIUrl":"10.1016/j.jconhyd.2026.104880","url":null,"abstract":"<div><div>Urban stormwater runoff is a critical pathway for microplastics pollution, yet its detailed transport dynamics remain poorly characterized. This study employed intra-event time-series sampling (at intervals of 0, 5, 15, 30, 60, 120, and 240 min after runoff initiation) during a heavy rainfall event in Shanghai (China) to investigate microplastics concentrations and characteristics across three urban functional areas. Our results revealed that microplastic pollution levels were strongly land-use-dependent: the dining area was a severe hotspot, with a time-weighted average concentration of 689.7 ± 214.1 items/L, which was significantly higher than the residential area (215.6 ± 38.9 items/L) and the parking area (172.8 ± 18.8 items/L), and all concentrations far exceeded local aquatic background values. A pronounced first flush effect was observed, particularly in the dining area, where the peak concentration was reached within just 5 min. The runoff was dominated by small-sized (&lt;1.0 mm) and fibrous microplastics composed of PET and PP. These small fibers were preferentially exported in the early phase of runoff (within the first 30 min), whereas granules and larger-sized microplastics accumulated in the later phase. By elucidating the land-use-dependent transport dynamics and fate of microplastics, this study provides a scientific basis for targeted source control, including prioritizing initial flush interception, and stormwater management in global megacities.</div></div>","PeriodicalId":15530,"journal":{"name":"Journal of contaminant hydrology","volume":"277 ","pages":"Article 104880"},"PeriodicalIF":4.4,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146125122","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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":"Deciphering the roles of alkaline pretreatment combined with bentonite addition treatment on “extracellular hydrolysis - membrane transport - intracellular metabolism” of carbohydrate in anaerobic digestion of kitchen waste","authors":"Yuying Hu ,&nbsp;Qun Wei ,&nbsp;Ningxin Fu ,&nbsp;Xin Wang ,&nbsp;Xiaofan Wang ,&nbsp;Susu Liu","doi":"10.1016/j.jconhyd.2025.104804","DOIUrl":"10.1016/j.jconhyd.2025.104804","url":null,"abstract":"<div><div>High solid anaerobic digestion (HSAD) showed excellent potential for extracting energy from kitchen waste (KW), but it usually failed due to acidification during actual engineering. The low rate of hydrolysis was the important reason for the failure of HSAD. In this study, the HSAD systems of KW under different organic loading rates (OLR) was enhanced by alkaline pretreatment combined with bentonite addition (AP/Be) treatment. The research results revealed that as OLR increased from 3.11 g VS/L∙d to 4.04 g VS/L∙d, the methane production rate of AP/Be group was increased by 162.12 % compared to control group. Mechanistically, AP/Be treatment enriched functional microorganisms including <em>Chloroflexi</em>, <em>Thermotogae</em>, and hydrogenotrophic methanogens (<em>Methanolinea</em> and <em>Methanoculleus</em>). Furthermore, AP/Be treatment also upregulated the gene abundance of certain membrane transport enzymes (e.g. saccharides and phosphate) and enzymes related to intracellular carbohydrate metabolism and methanogenesis, which collectively facilitated substrate utilization and methane production. This study revealed the promotion mechanism of AP/Be treatment on the HSAD systems and provided theoretical support for KW reduction and methane production.</div></div>","PeriodicalId":15530,"journal":{"name":"Journal of contaminant hydrology","volume":"277 ","pages":"Article 104804"},"PeriodicalIF":4.4,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145768364","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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":"Unseen pollutants: Microplastics in deep-sea invertebrates","authors":"Camilla Mossotto ,&nbsp;Paolo Pastorino ,&nbsp;Alice Gabetti ,&nbsp;Alessandra Maganza ,&nbsp;Monia Renzi ,&nbsp;Tecla Bentivoglio ,&nbsp;Serena Anselmi ,&nbsp;Antonia Concetta Elia ,&nbsp;Damià Barceló ,&nbsp;Matteo Riccardo Di Nicola ,&nbsp;Caterina Faggio ,&nbsp;Marino Prearo ,&nbsp;Giuseppe Esposito","doi":"10.1016/j.jconhyd.2025.104794","DOIUrl":"10.1016/j.jconhyd.2025.104794","url":null,"abstract":"<div><div>Microplastics (MPs) are a growing concern in marine ecosystems, but data on their presence in deep-sea environments remain limited. This study investigates MP contamination in nine deep-sea invertebrate species collected from the Gulf of Orosei (Central eastern Sardinia, Italy) at depths of 250–450 m. A total of 105 MP particles were identified in 89 % of specimens from three phyla (Arthropoda, Echinodermata, and Mollusca). Filaments and fragments were the dominant shapes, while polyethylene (PE), polypropylene (PP), and polyethylene terephthalate (PET) were the most common polymers. Cluster analysis indicated that MP contamination patterns were driven more by ecological traits than by taxonomy. These findings provide the first evidence of MP presence among different species of deep-sea invertebrates from the Gulf of Orosei and highlight the importance of species-specific ecological characteristics in understanding MP distribution and accumulation in deep-sea ecosystems.</div></div>","PeriodicalId":15530,"journal":{"name":"Journal of contaminant hydrology","volume":"277 ","pages":"Article 104794"},"PeriodicalIF":4.4,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145735358","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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":"Quantitative profile, sources and health implications of polychlorinated biphenyls (PCBs) in the strategic Otin River water, Nigeria","authors":"Adebanjo Jacob Anifowose,&nbsp;Mariam Abolore Muritala,&nbsp;Aaliyah Omotayo Bello,&nbsp;Abosede Susannah Oguntolu,&nbsp;Kazeem Abiodun Ibrahim,&nbsp;Shola Hezekiah Awojide","doi":"10.1016/j.jconhyd.2025.104826","DOIUrl":"10.1016/j.jconhyd.2025.104826","url":null,"abstract":"<div><div>Otin River is one of the longest strategic rivers in Osun State (Nigeria) with diverse economic values: commercial fishing, community water supply, farming and domestic activities. Nineteen toxic polychlorinated biphenyls (PCBs) were studied in the river water to understand their contamination levels, sources and potential health threats to humans. The river water samples were collected from six locations. The PCBs were extracted by liquid-liquid extraction and quantified using a gas chromatograph-mass spectrometer (GC–MS). All the PCBs were detected in the river water, ranging from 0.002 μg/L (PCB206) to 0.96 μg/L (PCB180). Using the average concentration of the individual PCB measured, their total concentration was 2.96 μg/L, which exceeded the standard permissible limit of 0.5 μg/L for drinking water. This indicated a high level of contamination. The six dominant congeners in the river water were in the following order: PCB180 &gt; PCB170 &gt; PCB44 &gt; PCB5 &gt; PCB187 &gt; PCB18 (0.12 μg/L). The total PCB concentration at the river midstream housing the Eko-Ende Dam was significantly higher (<em>P</em> &lt; 0.05) than that measured at the upstream and downstream. Using principal component analysis, the PCB sources were profiled as the dam's hydraulic system, plastics, paints and farm's agrochemical runoffs. Of the 19 PCBs, PCB5, PCB44, PCB170 and PCB180 posed both non-carcinogenic and carcinogenic risks to human health. PCB170 and PCB180 posed the highest risks via ingestion. Some residents/farmers usually consume the water. Thus, the PCB concentrations could cause unimaginable health risks to the people and aquatic life, necessitating effective management strategies.</div></div>","PeriodicalId":15530,"journal":{"name":"Journal of contaminant hydrology","volume":"277 ","pages":"Article 104826"},"PeriodicalIF":4.4,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145863093","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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":"Removal of polystyrene nanosphere and fragment from aqueous solutions by magnetic biochar derived from crab shell","authors":"Yu Wang ,&nbsp;Hao Wang ,&nbsp;Yirui Xing ,&nbsp;Yufei Ren ,&nbsp;Zhiyu Liu ,&nbsp;Tongyu Zhang ,&nbsp;Jingjing Kang ,&nbsp;Xiaohui Li","doi":"10.1016/j.jconhyd.2025.104810","DOIUrl":"10.1016/j.jconhyd.2025.104810","url":null,"abstract":"<div><div>Adsorption by biochar is widely recognized as a promising strategy for micro/nanoplastics removal from aqueous systems. Magnetic biochar derived from crab shell (M-CSBC) was successfully prepared by pyrolysis and subsequent ball milling with magnetic modification, and it was pioneeringly applied for the effective removal of spherical polystyrene nanoplastics (PSNPs) and fragmental polystyrene microplastics (PSMPs) from aquatic environment. M-CSBC exhibited excellent removal for PSNPs/PSMPs with different shape and size. The adsorption process fitted Langmuir model well, and the maximum removal capacities of PSNPs (100 nm) and PSMPs (0.35–0.45 mm) were 90.090 mg/g and 14.472 g/g, respectively. The removal of PSNPs/PSMPs was significantly influenced by variations in pH and salinity, with a more pronounced effect observed for PSNPs compared to PSMPs. M-CSBC was generally more suitable for the neutral acidic, saline aquatic systems. 500 nm NPs were easier to be removed compared with 100 nm NPs, while the removal efficiency of 0.35–0.45 mm PS fragments was larger than that of 0.45–0.60 mm fragments. The removal of PSNPs/PSMPs by M-CSBC were controlled through a combination of physical trapping, chemical adsorption (electrostatic interactions, chemical bonding, complexation, cation-bridging) as well as the magnetization separation. Especially, the real-time observations revealed that both the dispersed M-CSBC and the mixture of M-CSBC and plastic particles behaved akin to a “magnetic mop”, efficiently sweeping up and removing the other plastic particles without enough M-CSBC adsorption. The present findings demonstrate the immense potential of M-CSBC as a highly promising candidate for the efficient microplastics and nanoplastics remediation.</div></div>","PeriodicalId":15530,"journal":{"name":"Journal of contaminant hydrology","volume":"277 ","pages":"Article 104810"},"PeriodicalIF":4.4,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145837534","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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":"Deciphering runoff-sediment-nutrient dynamics in agricultural watersheds supplied by large feeder Rivers: A multi-scale analysis","authors":"Xihua Wang ,&nbsp;Xuming Ji ,&nbsp;Y. Jun Xu ,&nbsp;Boyang Mao ,&nbsp;Shunqing Jia ,&nbsp;Zejun Liu ,&nbsp;Qinya Lv ,&nbsp;Chengming Luo ,&nbsp;Yan Dai ,&nbsp;Yanxin Rong","doi":"10.1016/j.jconhyd.2025.104796","DOIUrl":"10.1016/j.jconhyd.2025.104796","url":null,"abstract":"<div><div>The runoff-sediment-nutrient continuum served as a pivotal hydrological-ecological indicator system underpinning agricultural sustainability and the integrity of water resources in river watersheds. However, the spatiotemporal dynamics and intrinsic mechanisms governing these coupled processes remained incompletely characterized in intensively managed agricultural catchments drained by major tributaries. This study employed multi-source daily monitoring data (2007–2022) from an agricultural watershed, integrating change-pattern analysis, change-point detection and scale-sensitive correlation analysis to decipher the coupling mechanisms and hysteretic responses of the runoff-sediment-nutrient continuum under anthropogenic perturbations. Our results showed that runoff displayed no significant long-term trend, driven by the offsetting effects of reservoir regulation and precipitation homogenization. In contrast, sediment load at Waizhou Station underwent a marked 74 % reduction, accompanied by a sustained downward trajectory. A 5-year lag was observed between runoff-sediment dynamics and regional precipitation changes, which maybe related to reservoir storage saturation and delayed anthropogenic land-water interaction effects. Along the river course, runoff showed a gradual increase while sediment underwent non-linear changes. Spatial nutrient analysis showed the short-term spatial differences of nitrogen and phosphorus observed from 2021 to 2022, with higher concentrations in the northern and southern regions and lower concentrations in the central region.</div><div>Based on two years of observational data from this study, downstream total nitrogen (TN) may exhibit significant fluctuations due to the intensive interactions between urban and agricultural activities, with extreme values reaching a ratio of 200. Scale-dependent reversals characterized the relationships between precipitation, runoff, sediment and nutrients. Runoff closely followed precipitation, whereas sediment became decoupled owing to reservoir buffering. TP was strongly correlated with runoff at the daily scale, whereas TN dynamics might driven by dilution-biological interaction processes. This study qualitatively demonstrated how agricultural and hydraulic infrastructure reconfigured source-sink dynamics of material translocation. The findings provided preliminary directional guidance for adaptive water-nutrient management and sediment control in agricultural watersheds sustained by regulated tributaries.</div></div>","PeriodicalId":15530,"journal":{"name":"Journal of contaminant hydrology","volume":"277 ","pages":"Article 104796"},"PeriodicalIF":4.4,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145665427","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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":"Effective bioremoval of Cu (II) and Sulfate from acid mine drainage via biomineralization with an extreme acidophile bacterium V. pantothenticus WL","authors":"Chao Han ,&nbsp;Xiangwei Cheng ,&nbsp;Zuozhen Han ,&nbsp;Shourui Dai ,&nbsp;Qingyuan Chen ,&nbsp;Wen Nie ,&nbsp;Yu Han ,&nbsp;Haibo Zhu ,&nbsp;Xiao Gao ,&nbsp;Yanyang Zhao ,&nbsp;Fang Liu ,&nbsp;Maurice E. Tucker ,&nbsp;Ruirui Meng","doi":"10.1016/j.jconhyd.2025.104822","DOIUrl":"10.1016/j.jconhyd.2025.104822","url":null,"abstract":"<div><div>The management of acid mine drainage (AMD), characterized by high acidity and toxic heavy metals, remains a persistent and costly global environmental challenge. Conventional active treatments are chemical-intensive and economically unsustainable, while passive biological systems often lack resilience under extreme conditions. Here we show a novel bio-strategy for effective AMD management using an extreme acidophilic bacterium, <em>Virgibacillus pantothenticus</em> WL, isolated directly from AMD. This strain demonstrated exceptional inherent tolerance, thriving at pH 3.0 and Cu(II) concentrations up to 200 mg/L. <em>V. pantothenticu</em>s WL achieved high Cu(II) removal efficiencies of 85 % and 80 % from 100 mg/L and 200 mg/L Cu(II) solutions through a self-sustaining process. The removal was mediated by a synergistic mechanism where bacterial sulfate reduction precipitated Cu(II) as stable sulfide minerals (chalcocite and covellite), while concurrent metabolic activity elevated the system pH, activating the metal-binding capacity of extracellular polymeric substances for enhanced biosorption. This integrated microbial process simultaneously addresses multiple AMD pollutants—neutralizing acidity, removing sulfate, and immobilizing heavy metals—without continuous chemical inputs. The findings demonstrate a nature-based solution that can be integrated into treatment systems, offering a sustainable and manageable alternative for long-term AMD remediation. This study provides a critical foundation for advancing the practical application of specialized microbes in environmental managements.</div></div>","PeriodicalId":15530,"journal":{"name":"Journal of contaminant hydrology","volume":"277 ","pages":"Article 104822"},"PeriodicalIF":4.4,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145819443","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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 enhanced air sparging approach for remediation of VOCs-contaminated low-permeability soils through pore pressure regulation","authors":"Long Xu ,&nbsp;Yaokun Hu ,&nbsp;Fusheng Zha ,&nbsp;Jingjing Liu ,&nbsp;Qiong Wang ,&nbsp;Feng Zhang ,&nbsp;Qiao Wang","doi":"10.1016/j.jconhyd.2025.104797","DOIUrl":"10.1016/j.jconhyd.2025.104797","url":null,"abstract":"<div><div>Remediating VOCs-contaminated low-permeability soils remains challenging due to restricted air flow and inefficient contaminant mass transfer. This study proposes an enhanced sparging approach that integrates sparging with pressure-relief pipes. By jointly regulating the sparging pressure and backpressure to elevate pore pressure, a more stable and continuous airflow network is established, thereby improving the overall remediation performance. Laboratory model tests reveal that emitted gaseous contaminants at the soil surface show irregular and random distributions under both conventional and proposed sparging approaches, yet the proposed approach yields significantly higher emission concentrations at identical seepage pressures, with average values nearly twice those of conventional sparging. In low-permeability soils, residual contaminants remain randomly dispersed after sparging, but conventional sparging leaves higher concentrations with localized accumulation, reflecting poor removal efficiency. In contrast, proposed sparging, through pore pressure regulation, markedly reduces residual levels, and the effect becomes more pronounced as pore pressure increases, achieving a total removal rate of 80 % compared with 60 % for conventional sparging. Analysis of pore pressure distribution and air saturation reveals that proposed sparging significantly expands high-pressure zones and increases air saturation. Correlation among total removal rates, average pore pressure, and air saturation confirm their strong interdependence, validating the mechanism by which pore-pressure regulation promotes the development of a more stable and continuous airflow network, resulting in improved contaminant removal.</div></div>","PeriodicalId":15530,"journal":{"name":"Journal of contaminant hydrology","volume":"277 ","pages":"Article 104797"},"PeriodicalIF":4.4,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145683832","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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":"Integrating random forest and isotopic tracers to optimize PMF-based source apportionment of watershed pollution","authors":"Bo Zhou ,&nbsp;Xiangqin Xu ,&nbsp;Xinyan Wang ,&nbsp;Weijun Tian ,&nbsp;Jiayu Peng ,&nbsp;Kun Lei","doi":"10.1016/j.jconhyd.2025.104838","DOIUrl":"10.1016/j.jconhyd.2025.104838","url":null,"abstract":"<div><div>Based on historical data (2020–2024) and intensified sampling in 2024 from the Qujiang River Basin, this study systematically analyzed the variations in water quality parameters across different hydrological periods. By integrating the Random Forest (RF) model, Positive Matrix Factorization (PMF), stable isotope techniques, and phosphorus speciation analysis, an optimized water quality assessment framework was constructed to accurately identify pollution sources. The results indicate that water temperature (T), pH, and permanganate index (COD_Mn) were significantly higher during the wet season, whereas dissolved oxygen (DO), ammonia nitrogen (NH₄⁺-N), total nitrogen (TN), fluoride (F^-), and organic carbon exhibited higher concentrations during the dry season. The RF model successfully reduced the number of key parameters required for Water Quality Index (WQI) evaluation from 10 to 5 (TP, TN, COD, DO, and BOD₅), maintaining high predictive accuracy (R² = 0.9245) while significantly lowering monitoring costs. Stable isotope tracing provided critical validation for the PMF model in identifying pollution sources and accurately constraining their contribution ratios. The results showed that TN primarily originated from sewage (70.7% in the wet season and 40.0% in the dry season) and soil/fertilizer sources. The PMF model identified four major pollution sources: industrial wastewater, agricultural fertilizers, domestic sewage, and seasonal climatic factors. Innovatively, the Random Forest algorithm was applied to weight and optimize the PMF outcomes. To bridge the gap between mathematical solutions and practical management, this study introduces a Random Forest-based weighting calibration for PMF-derived source apportionment, shifting the focus from numerical optimum to environmental accountability. After correction, industrial wastewater was identified as the dominant contributor (39.74% in the wet season and 36.68% in the dry season), a source that had been underestimated in conventional PMF results. Phosphorus speciation analysis further confirmed the influence of land use on pollutant composition. Dissolved organic phosphorus (DOP) dominated in urban areas, dissolved inorganic phosphorus (DIP) was prevalent in agricultural regions, and particulate organic phosphorus (POP) constituted the highest proportion in forested areas. This study reveals the dominant role of anthropogenic drivers in shaping water quality dynamics in rapidly urbanizing river basins and provides a scientific basis for targeted water pollution control strategies.</div></div>","PeriodicalId":15530,"journal":{"name":"Journal of contaminant hydrology","volume":"277 ","pages":"Article 104838"},"PeriodicalIF":4.4,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145880912","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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}