Journal of contaminant hydrology最新文献

{"title":"Magnetic biochar prepared by co-pyrolysis of sludge and organic medical solid waste for pH-universal removal of ciprofloxacin","authors":"Junping Meng ,&nbsp;Binbin Yao ,&nbsp;Jinsheng Liang ,&nbsp;Xinhui Duan ,&nbsp;Xiangying Wei","doi":"10.1016/j.jconhyd.2026.104862","DOIUrl":"10.1016/j.jconhyd.2026.104862","url":null,"abstract":"<div><div>In this study, sludge biochar was prepared via the co-pyrolysis method using the compatibility of sewage sludge (SS) in different seasons with organic medical solid waste (OMSW) and activated by alkali conditions for the removal of ciprofloxacin (CIP) in water with different pH values. The maximum adsorption capacity of the two biochars (KS1MBC and KS2MBC) reached 83.49 mg/g and 86.19 mg/g, respectively. The structure of the biochars was characterized via XRD, BET and SEM, and the adsorption mechanism of the biochars was investigated by FTIR, Raman, and XPS. The adsorption processes of the modified biochar followed pseudo-second-order kinetics and the Langmuir isothermal adsorption model, were dominated by chemical adsorption and monolayer adsorption, and were controlled by both liquid film diffusion and intraparticle diffusion. The adsorption mechanisms included pore adsorption, electrostatic attraction, π-π interactions, hydrogen bonding, and surface complexation. After hydrothermal activation by KOH, the surface of the biochar was etched by alkali to produce a nanothin lamellar structure, which increased the specific surface area to more than 200 m²/g in both cases, thus greatly enhancing the adsorption performance of the biochar. Moreover, due to the iron-containing properties of the sludge, it can be recycled through magnetic separation, thereby reducing treatment costs and enhancing the material's overall sustainability. The alkali-modified biochar demonstrates significant potential for application in antibiotic contamination remediation and provides a theoretical foundation for advancing waste treatment and promoting green environmental protection.</div></div>","PeriodicalId":15530,"journal":{"name":"Journal of contaminant hydrology","volume":"277 ","pages":"Article 104862"},"PeriodicalIF":4.4,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146022904","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":"Heavy metals in unsaturated urban soils: Experimental insights and stochastic forecasting","authors":"Aronne Dell'Oca ,&nbsp;Davide Abu El Khair ,&nbsp;Chiara Ferré ,&nbsp;Roberto Comolli ,&nbsp;Monica Riva","doi":"10.1016/j.jconhyd.2026.104855","DOIUrl":"10.1016/j.jconhyd.2026.104855","url":null,"abstract":"<div><div>The toxicity and long-term persistence of heavy metals pose a major threat across environmental compartments. Heavy metal contamination of soils poses long-term risks to groundwater resources, particularly in urban environments where rainfall-driven infiltration under unsaturated conditions can promote contaminant migration toward underlying aquifers. The aim of this study is to assess how uncertainty in soil hydraulic and sorption properties affects predictions of heavy metals migration from urban soils to groundwater. To this aim, we cast our work in a stochastic framework that integrates column scale drainage experiments and batch sorption tests to estimate key parameters governing water flow and heavy metal sorption dynamic, along with their associated uncertainty. Monte Carlo simulations are then performed to mimic the rainfall-induced drainage of heavy metals from metal-enriched soils through sewage sludge application. We consider two representative urban soil types and five heavy metals commonly detected in urban environments, i.e. lead (Pb), copper (Cu), chromium (Cr), nickel (Ni) and zinc (Zn). Our results indicate that Cr is highly mobile, while Ni, Zn, Cu exhibit consistently low mobility across both soils. Lead displays a strong soil-dependent behavior, transitioning from high to low mobility depending on the substrate. Outputs of a rigorous global sensitivity analysis reveal that, for highly mobile metals, flow and transport parameters have significant influence on metals migrations, reflecting the strong interplay of unsaturated flow and reactive transport processes. On the other hand, for low mobile heavy metals, parameters defining the initial contamination conditions and soil water content dominate the temporal evolution of metals retention in the soil. These findings indicate that parameter uncertainty and flow-transport processes in the vadose zone should be explicitly considered in groundwater contamination risk assessment protocols for urban environments.</div></div>","PeriodicalId":15530,"journal":{"name":"Journal of contaminant hydrology","volume":"277 ","pages":"Article 104855"},"PeriodicalIF":4.4,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146073939","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":"Effects of transient air-water interfacial area on PFOA transport in unsaturated soil","authors":"Craig Klevan ,&nbsp;Uriel Garza-Rubalcava ,&nbsp;Linda M. Abriola,&nbsp;Kurt D. Pennell","doi":"10.1016/j.jconhyd.2026.104859","DOIUrl":"10.1016/j.jconhyd.2026.104859","url":null,"abstract":"<div><div><em>Per</em>- and polyfluoroalkyl substances (PFAS) may be retained in the vadose zone for extended periods due to adsorption on soil and at the air-water interface (AWI). While adsorption to the AWI has been shown to slow PFAS leaching, the magnitude of interfacial area can fluctuate with precipitation events, leading to its reduction or collapse. The objective of this study was to investigate PFAS mass transfer from the AWI into mobile pore water in response to changes in water saturation, and to determine the corresponding effects on PFAS transport through the soil profile. To quantify these processes, a combination of batch experiments and water-saturated and unsaturated column studies were performed with perfluorooctanoic acid (PFOA) and Appling soil. At 56% water saturation, the effluent PFOA breakthrough curve exhibited greater spreading than expected under equilibrium conditions, indicating rate-limited adsorption-desorption at the AWI. Under transient conditions, where the average water saturation increased from approximately 60% to 82%, the corresponding decrease in the AWI area led to a spike in effluent PFOA concentrations. These observations were accurately reproduced by a mathematical model that incorporated (1) symmetric rate-limited adsorption/desorption to/from the AWI, (2) regions of immobile water, as determined from non-reactive tracer data, and (3) a dynamic AWI area, as estimated using the Leverett model with a scaling factor. This work demonstrates the potential for precipitation events to temporarily increase PFAS leaching due to a reduction or collapse of the AWI and shows that these fluctuations can be predicted using an existing multiphase reactive transport simulator.</div></div>","PeriodicalId":15530,"journal":{"name":"Journal of contaminant hydrology","volume":"277 ","pages":"Article 104859"},"PeriodicalIF":4.4,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146018665","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":"Identification and assessment of urban groundwater pollution based on Monte Carlo health risk modeling and self-organizing map (SOM)","authors":"Di Kang ,&nbsp;Qizhi Hu ,&nbsp;Hailong Qin ,&nbsp;Hao Chen ,&nbsp;Xiaoyu Xu ,&nbsp;Xianming Xie ,&nbsp;Xiang Ren ,&nbsp;Xinyuan Zhang ,&nbsp;Bingbing Cao ,&nbsp;Chih-Huang Weng ,&nbsp;Kai Liu ,&nbsp;Na Liu","doi":"10.1016/j.jconhyd.2025.104807","DOIUrl":"10.1016/j.jconhyd.2025.104807","url":null,"abstract":"<div><div>With the acceleration of urbanization, groundwater quality is severely threatened, posing health risks to public health and the environment. In reality, the highly heterogeneous geological background and hydrochemical relationships not only increase the difficulty in identifying pollution, but also pose significant challenges in groundwater risk prevention and control. Taking Guangzhou, a megacity in the bustling Pearl River Delta, as the research object, this study leverages the ability of machine learning to mine complex data and the advantage of Monte Carlo simulation in quantifying random uncertainties to deeply analyze the driving factors, pollution sources, and potential health risks of urban groundwater chemistry. Through the SOM model, a cluster analysis was conducted on 107 groundwater samples, resulting in the classification of 5 distinct water chemical groups with significant characteristics (Clusters I - V). Among them, human activities (domestic pollution) have a significant impact on groundwater chemistry mainly in Cluster I (a total contribution of 52.9 %). Manganese (Mn) and nitrate (NO₃⁻) pose non-carcinogenic risks, with the highest risks observed for Mn in Cluster II and NO₃⁻ in Cluster III. Monte Carlo simulation indicates that the overall health risk in the region is low, with only 1.3 % of children potentially exposed to high HI conditions. This study provides valuable insights for the precision prevention, control, and risk management of complex groundwater pollution in cities such as those in the Pearl River Delta.</div></div>","PeriodicalId":15530,"journal":{"name":"Journal of contaminant hydrology","volume":"277 ","pages":"Article 104807"},"PeriodicalIF":4.4,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145735357","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":"Groundwater sustainability challenges in urban deltas: A DRASTIC-GIS and hydrogeophysical approach for assessing the Nile Delta aquifer for sustainable management","authors":"Ahmed M. Nosair ,&nbsp;Rahma El-Sayed Samra ,&nbsp;Rehab Hassan ,&nbsp;Khaled Gemail","doi":"10.1016/j.jconhyd.2025.104823","DOIUrl":"10.1016/j.jconhyd.2025.104823","url":null,"abstract":"<div><div>Groundwater sustainability in densely populated deltas, such as Egypt's Nile Delta, faces growing threats from wastewater contamination, climate change, and unregulated urban development. This study employs a multidisciplinary approach, combining hydrochemical analysis, GIS-based DRASTIC modeling, and 1D/2D hydrogeophysical resistivity surveys to evaluate aquifer vulnerability in the southeastern Nile Delta. A significant innovation in this research is the integration of DC resistivity measurements with the DRASTIC index, which improves the identification of high-risk zones. Furthermore, anthropogenic impacts were incorporated as an additional layer in the vulnerability modeling, guided by a sensitivity analysis of the controlling parameters.</div><div>The results indicate two major threats to the Quaternary aquifer. First, the southern and eastern regions are highly vulnerable due to the lack of protective clay layers and detrimental land-use practices, such as wastewater irrigation and urban growth. Second, hydraulic connectivity between the freshwater Quaternary and brackish Miocene aquifer exacerbates salinization and pollutant migration from intensive pumping. Validation using hydrogeophysical data reveals a strong correlation with the DRASTIC model, highlighting areas with significant groundwater degradation, including high total dissolved solids (TDS) levels (&gt;6470 ppm) and nitrate concentrations (&gt;102 mg/L). In contrast, northwestern areas with thick clay caps (exceeding 9 m) exhibit greater resilience.</div><div>These findings highlight the critical role of land-use practices and aquifer connectivity in urban groundwater management. The study recommends strategies such as optimal extraction zone mapping, IoT monitoring, and drainage lining to minimize contamination, offering a scalable model for sustainable groundwater management in water-stressed deltaic regions.</div></div>","PeriodicalId":15530,"journal":{"name":"Journal of contaminant hydrology","volume":"277 ","pages":"Article 104823"},"PeriodicalIF":4.4,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145837532","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":"Enhancing urban river water quality in Indonesia using mineral wool: Long-term field performance, seasonal dynamics, and multi-index assessment","authors":"Wisnu Prayogo ,&nbsp;Prayatni Soewondo ,&nbsp;Gerry Andhikaputra ,&nbsp;Sarra Rahmadani ,&nbsp;Laili Fitria ,&nbsp;Zhilli Izzadati Khairuni ,&nbsp;I. Made Wahyu Widyarsana ,&nbsp;Muammar Qadafi ,&nbsp;Novi Fitria ,&nbsp;Januar Parlaungan Siregar ,&nbsp;Aristya Ardhitama","doi":"10.1016/j.jconhyd.2025.104819","DOIUrl":"10.1016/j.jconhyd.2025.104819","url":null,"abstract":"<div><div>Urban rivers in rapidly growing tropical cities face persistent pollution pressures and limited wastewater infrastructure, demanding scalable in-stream restoration approaches. This study presents the first long-duration, field-scale deployment of mineral wool (MW) in a tropical monsoon river system, evaluating pollutant attenuation and seasonal treatment dynamics in the Cikapayang River, Bandung, Indonesia. Two MW configurations were installed in cascade channels without pumping, chemical inputs, or hydraulic control, and monitored across wet and dry seasons. Water quality was assessed using 11 physical and chemical parameters and interpreted through four Water Quality Indices (PI, STORET, CCME-WQI, NSF-WQI) to benchmark regulatory and international assessment frameworks. MW achieved mean pollutant removal of 43.51 %, improving river status from heavily polluted to moderate/lightly polluted. Dry-season performance intensified due to longer hydraulic retention and mature biofilms, yielding up to 61.52 % COD and 50.28 % TN removal, while wet-season turbulence reduced residence time but retained stable performance. Microstructural imaging confirmed a transition from mineral-mediated filtration and cation exchange to biofilm-driven nitrification–denitrification. Among WQIs, CCME-WQI exhibited the highest sensitivity, improving from “very poor” to “poor–fair (44.24)”, while PI offered more optimistic classifications. Findings demonstrate MW as an effective, low-energy, circular-material solution for decentralized urban river treatment under monsoon hydrology. This work bridges the gap between controlled experiments and real-river implementation, providing performance and assessment benchmarks for scalable nature-based interventions in developing regions. Future studies should address media longevity, regeneration, and hydrodynamic optimization.</div></div>","PeriodicalId":15530,"journal":{"name":"Journal of contaminant hydrology","volume":"277 ","pages":"Article 104819"},"PeriodicalIF":4.4,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145788160","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":"Key factors controlling transport of biochar colloids in porous media and the mutual effects with coexisting contaminants","authors":"Wei Wei ,&nbsp;Xinyu Huan ,&nbsp;Ziyi Chen ,&nbsp;Yuanyi Li","doi":"10.1016/j.jconhyd.2026.104851","DOIUrl":"10.1016/j.jconhyd.2026.104851","url":null,"abstract":"<div><div>Large-scale application of biochar (BC) has been considered as an effective strategy for carbon sequestration, soil quality improvement, and water/soil remediation. Once introduced into soils, BC can disintegrate or fragment through physical, chemical and biological processes, resulting in the formation of BC colloids (BCCs) with particle size ranging from 1 to 1000 nm. Due to the small size, large surface area, and high surface activity, BCCs exhibit stronger colloidal stability in aquatic environments and higher mobility in porous media than the bulk BC particles. In particular, BCCs have much higher adsorption affinity for various contaminants, and thus may serve as vehicles for facilitating contaminants transport, posing potential risks to the environment and human health. In this review, we summarize the current state of knowledge on the transport of BCCs influenced by (1) the intrinsic physicochemical properties of BCCs (i.e. pyrolysis temperature, size, aging effect), (2) solution chemistry (i.e. pH, ionic strength, ionic composition), (3) inorganic/organic colloids (i.e., minerals, humic/fulvic acid), (4) flow conditions (i.e. flow velocity), and (5) properties of porous media (i.e. grain size, media type and surface properties, moisture and mineral content). In addition, differing from previous works, this review provides a systematic analysis of BCCs transport through an integrated lens of governing mechanisms and mathematical models, with a dedicated focus on the mutual effects between BCCs and contaminants—a critical yet underexplored area determining their combined environmental fate. Finally, this work concluded with remarks on the importance of BCCs transport in porous media and directions for future research.</div></div>","PeriodicalId":15530,"journal":{"name":"Journal of contaminant hydrology","volume":"277 ","pages":"Article 104851"},"PeriodicalIF":4.4,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146003307","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":"Enhancing water quality assessment in Skikda, Algeria using the PCA-based weighted index (WQI_P) and its predictive performance: a comparison with traditional WA_WQI approaches","authors":"Benacherine Mostefa ,&nbsp;Hafid Hinda ,&nbsp;Alejandro Martínez ,&nbsp;Allaoua Noua ,&nbsp;Satour Abdelatif ,&nbsp;Fertas Fadila ,&nbsp;Mir Talas Mahammad Diganta ,&nbsp;Lyazid Mohamed Nadjib ,&nbsp;Bouchra Debassi ,&nbsp;Md Galal Uddin","doi":"10.1016/j.jconhyd.2026.104875","DOIUrl":"10.1016/j.jconhyd.2026.104875","url":null,"abstract":"<div><div>Ensuring reliable river-water quality assessment is increasingly important in North Africa, where pollution pressures and data limitations complicate monitoring. Therefore, the research developed a principal-component-analysis–based water quality index (WQI_P) that is designed to address eclipsing, multicollinearity, and subjectively assigned weights that affect traditional indices such as the weighted-arithmetic WQI (WA_WQI). The objective of the research is to evaluate whether PCA-derived weights and objective parameter selection improve reliability, uncertainty, and classification stability. A dataset of 159 river-water samples from the Skikda region (Algeria) was analyzed. After screening correlated variables and extracting PCA contributions, WQI_P was constructed from the retained components. Eight machine-learning algorithms and a stacked ensemble were used under 10-fold cross-validation to compare the prediction performance and uncertainty of WQI_P and WA_WQI. Agreement metrics, PREI scores, confidence intervals, and class-transition analysis were used to assess the differences between the two indices, Predictive uncertainty was quantified using a Gaussian Monte Carlo simulation, which propagates variability by repeatedly perturbing model residuals to generate distributions of index predictions. The WQI_P consistently produced lower prediction errors (stacked RMSE = 2.74; MAE = 1.75) than the WA_WQI (RMSE = 3.16; MAE = 2.21), together with narrower 95% confidence intervals and reduced predictive uncertainty. The classification outcomes shifted toward a stricter and more balanced assessment: the proportion of samples classified as “Excellent” decreased (30 to 7), “Good” increased (55 to 88), and “Unsuitable” declined (40 to 12). These results indicated that grounding weights in the multivariate structure enhances stability and reduces dependence on a small set of dominant parameters. The findings demonstrated that the WQI_P can improve transparency, objectivity, and monitoring efficiency by focusing on the most informative variables. The index is applicable to data-scarce regions where objective weighting and uncertainty control are essential. Future work should test WQI_P across larger and more heterogeneous basins, extend validation using spatial–temporal blocking, and explore its integration into operational monitoring frameworks.</div></div>","PeriodicalId":15530,"journal":{"name":"Journal of contaminant hydrology","volume":"277 ","pages":"Article 104875"},"PeriodicalIF":4.4,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146124979","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":"Anthropogenically-induced saline wetland recharge drives denitrification: Implications for nitrate attenuation in semi-arid aquifer–wetland systems","authors":"D. Sanz ,&nbsp;D. Salcedo ,&nbsp;B. Toledo ,&nbsp;I. Dountcheva ,&nbsp;R. Margalef-Martí ,&nbsp;N. Otero ,&nbsp;A. Soler ,&nbsp;J.J. Gómez-Alday","doi":"10.1016/j.jconhyd.2026.104840","DOIUrl":"10.1016/j.jconhyd.2026.104840","url":null,"abstract":"<div><div>Saline wetlands are highly sensitive to anthropogenic pressures, particularly in semi-arid regions where groundwater abstraction, land use changes, and climate variability modify their hydrogeological functioning. This study focuses on the Tirez and Peñahueca hypersaline wetlands (Central Spain), which have undergone a shift from natural groundwater discharge zones to induced recharge areas due to intensive irrigation. Declining piezometric levels have reversed the hydraulic gradient between the aquifer and the wetlands, resulting in recharge conditions. A multidisciplinary approach combining hydrochemistry, (including historical monitoring data), multi-isotopic characterization (N, O, C, S), and geophysical (ERT) techniques was applied to assess groundwater quality evolution and nitrate attenuation processes. Results show a significant increase in groundwater salinity and nitrate concentrations over the past five decades, with NO₃⁻ levels reaching up to 245 mg/L. Average nitrate concentrations increased from ∼25 mg/L in the 1990s to over 200 mg/L in 2019–2021. Isotopic signatures indicate multiple nitrate sources, including manure, organic soil nitrogen, and synthetic fertilizers. A coupled increase of δ¹⁵N–NO₃⁻ values ranging from +5.1 ‰ to +44 ‰ and δ¹⁸O–NO₃⁻ from +3 ‰ to +23 ‰, along with δ³⁴S–SO₄²⁻ values between +16 ‰ and + 18 ‰ and δ¹³C–DIC from −12 ‰ to −4 ‰, suggest that heterotrophic denitrification is the main attenuation process. Electrical resistivity profiles reveal density-driven flow from the saline wetland water into the underlying aquifer, facilitating the transport of dissolved organic carbon and creating redox gradients favorable for denitrification. Maximum denitrification rates of up to 73% were estimated using literature isotopic fractionation values. Understanding the coupled hydrological and biogeochemical dynamics of saline wetland–aquifer systems is essential for developing sustainable groundwater management strategies in vulnerable arid and semi-arid regions.</div></div>","PeriodicalId":15530,"journal":{"name":"Journal of contaminant hydrology","volume":"277 ","pages":"Article 104840"},"PeriodicalIF":4.4,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145966315","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":"Bioconversion of heavy metals in river sediments: Seasonal dynamics, driving mechanisms, and BSAF-based assessment in the Liujiang River basin","authors":"Yupei Hao ,&nbsp;Xueqin Wei ,&nbsp;Tianyao Yang ,&nbsp;Xiongyi Miao ,&nbsp;Gaohai Xu ,&nbsp;Sheping Yang ,&nbsp;Xiaohua Zhou","doi":"10.1016/j.jconhyd.2025.104821","DOIUrl":"10.1016/j.jconhyd.2025.104821","url":null,"abstract":"<div><div>The bioconversion of heavy metals (HMs) in sediments has received limited research attention, despite its critical importance for ecological risk assessment. The Liujiang River Basin, a typical karst catchment in Southwest China, provides an ideal context for investigating HM bioconversion due to the generally high bioavailability of HMs in its sediments. This study employed the Biotic Sediment Accumulation Factor (BSAF) to analyze spatio-temporal variations in the bioconversion of seven priority metals between sediments and wild fish. Results demonstrated that BSAF values for most HMs were significantly higher in the wet season than in the dry season. Zinc demonstrated the highest bioaccumulation potential, with its BSAF frequently exceeding 1 and reaching up to 1.99, unlike the other studied HMs. A clear correspondence was observed between BSAF values and oxidizable fractions, suggesting the crucial role of oxidizable forms in driving HM bioconversion. Multivariate correlation analysis further revealed that combined proportions of oxidizable and carbonate-bound fractions shaped three distinct bioconversion patterns: inhibited bioconversion under dual low fractions (resulting in low BSAFs), promoted bioconversion with a single high fraction, and significantly promoted bioconversion under dual high fractions (producing high BSAFs). Notably, seasonal variations in BSAF values between <em>Pseudohemiculter dispar</em> and <em>Cyprinus carpio</em> indicated that pelagic feeding amplifies the impact of exogenous HMs, while benthic feeding intensifies the influence of sediment-destabilized HMs. Given the dominant roles of carbonate-bound and oxidizable fractions, we recommend implementing strict wastewater emission controls coupled with enhanced dissolved oxygen levels in water bodies to effectively mitigate HM bioconversion in sediments.</div></div>","PeriodicalId":15530,"journal":{"name":"Journal of contaminant hydrology","volume":"277 ","pages":"Article 104821"},"PeriodicalIF":4.4,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145837531","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}