Journal of contaminant hydrology最新文献

{"title":"Assessment of microplastics and heavy metal contamination in surficial sediments of Pasig River, Philippines during wet season","authors":"Clarissa Ileana L. Ilao ,&nbsp;Joan Cecilia C. Casila ,&nbsp;Tonni Agustiono Kurniawan ,&nbsp;Ronnie S. Sampang ,&nbsp;Lars Lerry T. Panganiban ,&nbsp;Liza B. Patacsil ,&nbsp;Jomel S. Limbago","doi":"10.1016/j.jconhyd.2025.104527","DOIUrl":"10.1016/j.jconhyd.2025.104527","url":null,"abstract":"<div><div>This study investigates the contamination of microplastics (MPs) and heavy metals in surficial sediments of the Pasig River, Philippines, during the wet season. This season, marked by heightened rainfall, runoff, and stormwater flow, potentially enhances the dispersion and accumulation of pollutants, leading to elevated pollution levels. MPs and heavy metals pose significant threats to aquatic ecosystems and human health, and their accumulation in river sediments warrants urgent attention. Samples were collected from multiple sites along the river, focusing on sediment composition, to analyze MP abundance and heavy metal concentrations. Results revealed high concentrations of MPs, predominantly polyester, polyethylene and acrylonitrile-butadiene copolymer, and heavy metals which were significantly higher in urbanized areas. MPs were found at all sampling locations, ranging from 2700 to 28,250 particles per kilogram of sediments. Heavy metals in the sediments varied, with concentrations of Cd (&lt;0.003 mg/kg), Pb (3.09–50.48 mg/kg), Zn (53.37–175.74 mg/kg), and Fe (11,629–25,687 mg/kg), in the order Fe &gt; Zn &gt; Pb &gt; Cd. According to the Hong Kong-Interim Sediment Quality Values criteria, the sediments were not contaminated by Cd, Pb, and Zn. Correlations between MP abundance and metals were found to be moderate for Pb and Zn but low for Fe, suggesting complex pollution dynamics. These findings emphasize the need for comprehensive monitoring and targeted waste management strategies to address MPs and heavy metal pollution, particularly during the wet season. Identifying MPs polymer types and their possible pollution sources provides valuable data to mitigate sediment contamination and protect aquatic ecosystems and human health.</div></div>","PeriodicalId":15530,"journal":{"name":"Journal of contaminant hydrology","volume":"270 ","pages":"Article 104527"},"PeriodicalIF":3.5,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143510683","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":"Pesticide fate under varying cropping systems and soil depths: A study using leaching experiments and inverse modelling.","authors":"Clémence Pirlot ,&nbsp;Alodie Blondel ,&nbsp;Boris Krings ,&nbsp;Bastien Durenne ,&nbsp;Olivier Pigeon ,&nbsp;Aurore Degré","doi":"10.1016/j.jconhyd.2025.104526","DOIUrl":"10.1016/j.jconhyd.2025.104526","url":null,"abstract":"<div><div>Current pesticide leaching risk assessments overlook critical site-specific factors such as soil depth and agricultural practices. Relying on transport parameters from databases or manufacturer studies, often based on limited soil types, can lead to inaccurate contamination risk estimates and ineffective protection of groundwater resources. In this study, the fate of eight pesticides of concern for groundwater was investigated under three cropping systems and three soil depths. Leaching experiments were carried out in undisturbed columns from a loamy agricultural soil and mass balances were realized. Inverse dual-porosity modelling using Hydrus 1-D was then performed to adjust mobility parameters. The results reveal that different soil properties and structure between soil depths have a more substantial impact on pesticide leaching behaviour than the cropping systems. Significant differences in pesticide transport and retention are observed between soil horizons, illustrating the inadequacy of using surface parameters for the entire soil profile, which can lead to underestimation of groundwater contamination. Our analysis indicates that root architecture, soil properties and surface tillage can affect pesticide leaching dynamics. While short-term differences between cropping systems were limited, these factors could be important for long-term effects. The experimental transport parameters showed discrepancies with established databases, where higher adsorption and degradation could underestimate pesticide leaching and metabolites production. This study highlights the need to adapt transport parameter values for all pesticides of concern to site-specific conditions. In addition, accurate risk assessment requires advanced modelling techniques that take into account soil depth variability and local conditions to improve water protection decision-making. Future research should focus on long-term monitoring of the effects of sustainable agricultural practices on pesticide behaviour over several seasons and for a range of soil types. Special emphasis should be placed on the role of metabolites in environmental contamination.</div></div>","PeriodicalId":15530,"journal":{"name":"Journal of contaminant hydrology","volume":"270 ","pages":"Article 104526"},"PeriodicalIF":3.5,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143552654","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":"A land use regression model to explain the spatial variation of nitrate concentration – A regional scale case study in the north-west of Ireland","authors":"Arghadyuti Banerjee,&nbsp;Aonghus Ó'Domhnaill,&nbsp;Leo Creedon,&nbsp;Noelle Jones,&nbsp;Salem Gharbia","doi":"10.1016/j.jconhyd.2025.104528","DOIUrl":"10.1016/j.jconhyd.2025.104528","url":null,"abstract":"<div><div>Regional-scale groundwater contamination estimation is crucial for sustainable water management. The primary obstacles in evaluating groundwater include limited data availability, small sample sizes, and difficulties in linking concentration levels to land use patterns. Linear regression identifies the relationship between measured concentrations and both natural and human-influenced factors. However, the primary difficulty with this method lies in choosing a group of regressors that meet all necessary criteria for the model when multiple potential regressors exist. This study introduces a buffer-based land-use linear regression method to develop a catchment-scale model for predicting nitrate concentrations in groundwater. The model successfully captures 85 % of the spatial variability in nitrate across the study area, as indicated by the validation results from 32 training sites. The model's prediction capability and ability to capture the spatial variability of nitrate concentration were found to be good in the model development (R² = 0.89) and validation (R² = 0.80) steps. The model performed well in the accuracy assessment and error estimation processes (RMSE = 0.025 and MAE = 0.020). In future, this LUR model can be reparameterised with the latest available time series datasets to capture climate change scenarios. While this study focused on a small sub-catchment of the Bonet River, the methodology has the potential to be applied in a border study area. Future studies with a more robust methodology and more accurate predictor variables to explain the influence of the contamination sources, transport and attenuation processes can improve the buffer-based LUR technique for better model adaptation and applicability to other study areas.</div></div>","PeriodicalId":15530,"journal":{"name":"Journal of contaminant hydrology","volume":"270 ","pages":"Article 104528"},"PeriodicalIF":3.5,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143552656","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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":"Effects of stratification on hydrodynamics and mixing process at a large asymmetric confluence in northern China","authors":"Cheng Dong,&nbsp;Minquan Feng,&nbsp;Haixiao Jing,&nbsp;Xiaoge Dang","doi":"10.1016/j.jconhyd.2025.104531","DOIUrl":"10.1016/j.jconhyd.2025.104531","url":null,"abstract":"<div><div>The hydrodynamics in the confluence area of rivers are typically governed by the geometrical configuration of the surrounding landforms, the momentum and discharge ratios of the converging watercourses, and the morphological features of the riverbed. Recently, it has been discovered that stratification effects resulting from disparities in temperature, salinity, sediment concentration can also have significant impact on the downstream hydrodynamics of the confluence area. In this study, the impact of stratification induced by sediment concentration on fluid dynamics and pollutant mixing in the Yellow - Fen River confluence area is studied by using a 3D numerical model. The distribution of the depth-averaged field and secondary flow are analyzed. The findings revealed that the alterations in density caused by sediment concentration had effect on the flow dynamics across both horizontal and vertical dimensions of the confluence area. These alterations encompassed flow magnitude, shear layer, low velocity zone, cross-section vortex, and secondary flow. When the sediment concentration in the main stream was high, a noticeable stratification phenomenon emerged, whereby the tributary pollutants rode above the main stream during transport and mixing. Under these conditions, the pollutant mixing process accelerated, resulting in a shortened mixing distance. This acceleration can be attributed to the intensified secondary flow in the cross-section, brought about by the stratification effect. The findings from this study enhance our understanding of pollutant mixing patterns in river confluence areas.</div></div>","PeriodicalId":15530,"journal":{"name":"Journal of contaminant hydrology","volume":"270 ","pages":"Article 104531"},"PeriodicalIF":3.5,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143510785","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":"Uranium dynamics at an iron ore mine site in Northern Sweden: Sources and mobility along the mine value chain","authors":"Vimbainashe L. Dzimbanhete ,&nbsp;Lena Alakangas ,&nbsp;Torbjörn Karlsson ,&nbsp;Elsa Peinerud ,&nbsp;Oscar Paulsson ,&nbsp;Olof Martinsson ,&nbsp;Thomas Aiglsperger","doi":"10.1016/j.jconhyd.2025.104530","DOIUrl":"10.1016/j.jconhyd.2025.104530","url":null,"abstract":"<div><div>Uranium (U) release from mining has been typically associated with former U mine sites, but trace U levels in iron or base metal ores can also lead to U mobilization into ground and surface water posing potential risks due to U's chemical toxicity and radioactivity. This study investigates U sources and mobility at an iron ore mine site in Northern Sweden, where U concentrations (median 1.8 μg/l) exceeding the Swedish annual guideline value of 0.17 μg/l have been detected in a river receiving excess process water from the mine site. Drill core samples were characterized to identify the minerals hosting U in the iron ore and sequential extraction tests were conducted on solid samples from the processing plant to assess U mobility potential. Results indicate that, given its low U content, iron ore is not a significant source of the elevated U levels detected in the process water. Thorite, the main U-bearing mineral remains stable under the neutral to alkaline pH conditions in the processing plant. U speciation calculations on process water monitoring data, performed in PHREEQC with the PRODATA thermodynamic database, revealed dominant calcium uranyl carbonate complexes, specifically Ca₂UO₂(CO₃)₃ and CaUO₂(CO₃)₃²⁻. Mine water from Leveäniemi and Gruvberget open pits, particularly Leveäniemi, was identified as the main source of U to the process water in the recirculation system. The U in mine water originates from groundwater infiltration into the open pits and leaching of U from the open pit wall rocks. Further investigation of these sources and U's geochemical behavior in mine water before it mixes with process water in the processing plant is crucial for understanding the processes driving elevated downstream U concentrations.</div></div>","PeriodicalId":15530,"journal":{"name":"Journal of contaminant hydrology","volume":"270 ","pages":"Article 104530"},"PeriodicalIF":3.5,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143552657","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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":"Formation mechanisms of hydraulic circulation and its effects on the nitrobenzene migration in homogeneous aquifers with different medium sizes during air sparging remediation","authors":"Xuyang Chen ,&nbsp;Meng Yao ,&nbsp;Liming Ren ,&nbsp;Wei Du ,&nbsp;Linchao Hu ,&nbsp;Bowen Li ,&nbsp;Mingxin Wang","doi":"10.1016/j.jconhyd.2025.104529","DOIUrl":"10.1016/j.jconhyd.2025.104529","url":null,"abstract":"<div><div>Porewater flow is known to introduce uncertainty in the effectiveness and extent of remediation in aquifers during air sparging (AS). In this study, the hydraulic circulation migration behavior, influencing factors, and its effects on nitrobenzene transport in AS process were investigated using light transmission visualization technology. Experimental results showed that when the air injection rate (Q) exceeded a critical threshold (Qc), porewater flow induced hydraulic circulation in homogeneous aquifers with different medium sizes. The values of Qc were found to be approximately 300 L/h for medium sand, 100 L/h for coarse sand, and 0.5 L/h for gravel aquifers. It was observed that the flow velocity of hydraulic circulation was linearly positively correlated with Q, while the zone of influence (ZOI) area was logarithmically correlated with Q. In aquifers with coarse sand, continuous channelized flow was seen to impede contaminant migration from the left to the right hydraulic circulation zone. In contrast, in gravel aquifers, discontinuous bubbly flow allowed contaminants to migrate between zones, which increased the risk of expanding the contaminant plume's range. Moreover, in aquifers with medium and coarse sand, hydraulic circulation was mainly caused by the chimney effect, whereas in gravel aquifers, oscillating bubble effects were notably observed. This observation explained why the hydraulic circulation effect in gravel aquifers was superior compared to that in medium and coarse sand aquifers. These findings are expected to contribute to expanding the remediation mechanisms, achieving precise remediation, and improving contaminant removal in AS technology.</div></div>","PeriodicalId":15530,"journal":{"name":"Journal of contaminant hydrology","volume":"270 ","pages":"Article 104529"},"PeriodicalIF":3.5,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143552655","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":"Spatio-temporal characteristics and influencing factors of water quality in Xiangxi Bay under the operation of the three gorges reservoir","authors":"Aiping Jiang ,&nbsp;Dongsheng Wang ,&nbsp;Zhen Ning ,&nbsp;Peng Li ,&nbsp;Tao Xu ,&nbsp;Boran Zhu ,&nbsp;Qidong Peng ,&nbsp;Tiantian Jin ,&nbsp;Junqiang Lin ,&nbsp;Di Zhang","doi":"10.1016/j.jconhyd.2025.104518","DOIUrl":"10.1016/j.jconhyd.2025.104518","url":null,"abstract":"<div><div>As the largest hydropower project in the world, the Three Gorges Reservoir (TGR) exerts significant backwater effects, leading to various water quality issues. The Xiangxi River, the largest tributary near the dam, has experienced algal bloom phenomena for several years. However, the characteristics and influencing factors of water quality during different operational periods of the reservoir remain unclear. This study analyzes 12 physical and chemical parameters of the Xiangxi Bay (XXB) from 2019 to 2023, employing a data-driven approach to explore the temporal and spatial characteristics of water quality under varying operational conditions of the TGR. It discusses the influencing factors and proposes countermeasures to address water quality challenges. The results indicate that: (1) Water quality parameters in XXB exhibit significant spatial and temporal variability, peaking in summer, with higher values observed in the middle and upper reaches. The Water Quality Index (WQI) indicates overall good water quality, while the Trophic Level Index (TLI) suggests medium eutrophication, particularly evident in spring and summer. (2) The backwater effects of the TGR have altered hydrodynamic conditions and mixing processes in XXB, significantly impacting water quality and promoting eutrophication. (3) Water quality is influenced by nutrient, organic matter, algae, and temperature, especially during low water levels in summer, with the middle and upper reaches being most affected. Key factors driving algal growth during this period include Total Nitrogen (TN), Transparency (SD), and Water Temperature (WT). (4) Effective control of eutrophication and algal blooms in XXB should focus on long-term upstream source management, close monitoring and prediction during spring and summer, and ecological operation of reservoir. This study enhances our understanding of the temporal and spatial characteristics of water quality in XXB under the operational dynamics of the TGR, providing guidance for eutrophication management and bloom prevention.</div></div>","PeriodicalId":15530,"journal":{"name":"Journal of contaminant hydrology","volume":"270 ","pages":"Article 104518"},"PeriodicalIF":3.5,"publicationDate":"2025-02-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143437746","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":"Black tea waste/iron slag reactive filter media-electrokinetic for mixed heavy metals treatment from contaminated site","authors":"Faris M. Hamdi ,&nbsp;Ali Altaee ,&nbsp;Yahia Aedan ,&nbsp;John Zhou ,&nbsp;Syed Javaid Zaidi ,&nbsp;Lilyan Alsaka ,&nbsp;Raed Almalki ,&nbsp;Abdulmajeed Al-Askar ,&nbsp;Akshaya K. Samal","doi":"10.1016/j.jconhyd.2025.104517","DOIUrl":"10.1016/j.jconhyd.2025.104517","url":null,"abstract":"<div><div>Electrokinetic (EK) remediation is a cutting-edge technique used for extracting heavy metals from soils by applying an electric field. This study explores the integration of EK remediation with reactive filtration media (RFM) composed of recycled waste materials of powder iron slag/black tea waste (PIS/BTW) and granular iron slag/black tea waste (GIS/BTW) to improve the removal efficiency of single and mixed heavy metals from kaolinite and natural soils. Results demonstrated that PIS/BTW significantly outperformed GIS/BTW in heavy metal extraction, achieving 98.75 % copper removal compared to 90.06 % with GIS/BTW. Recycled RFMs achieved excellent copper removal, reaching 91.28 % for PIS/BTW and 84.90 % for GIS/BTW over 3 weeks. Specific energy consumption (SEC) increased with treatment durations, ranging from 0.055 to 0.254 kWh kg⁻¹ in kaolin soil, while 0.344 kWh kg⁻¹ increased in natural soil. For a heavy metals mixture in kaolinite soil, the removal of copper, nickel, and zinc achieved 97.15 %, 98.30 %, and 96.68 %, respectively, after 4 weeks, while in natural soil, the removal rates for copper, nickel, and zinc were 16.39 %, 89.22 %, and 84.38 % after 5 weeks. The alkaline pH of the RFMs facilitated the adsorption and precipitation of metal ions, contributing to their immobilization. The research study demonstrated the effectiveness of using recyclable and eco-friendly RFMs to optimize EK remediation, providing a sustainable and efficient solution for addressing heavy metal contamination in soils.</div></div>","PeriodicalId":15530,"journal":{"name":"Journal of contaminant hydrology","volume":"270 ","pages":"Article 104517"},"PeriodicalIF":3.5,"publicationDate":"2025-02-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143437744","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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":"Comparative study of standard and modified groundwater vulnerability methods in the gold and iron mining regions of Western Quadrilátero Ferrífero, Brazil","authors":"Alice Zupo ,&nbsp;Rodrigo S. de Paula ,&nbsp;Jarbas L.D. Sampaio ,&nbsp;Jorge G.R. Júnior ,&nbsp;Marília C. Melo","doi":"10.1016/j.jconhyd.2025.104516","DOIUrl":"10.1016/j.jconhyd.2025.104516","url":null,"abstract":"<div><div>This study aims to evaluate the intrinsic vulnerability of the Moeda Syncline, located in the western portion of the Quadrilátero Ferrífero in the State of Minas Gerais, Brazil. This region stands out for hosting important gold and iron ore mines and is the target of geological studies due to its structural complexity and economic importance. The Moeda Syncline is responsible for feeding springs and important tributaries in the hydrographic basins of the Velhas and Paraopeba rivers, thus contributing with a great part of the water consumed by the population of the Metropolitan Region of Belo Horizonte (RMBH). The main threats to the sustainable use of water in the Moeda Syncline are urban expansion and mining enterprises. From the mapping of vulnerability to contamination it is possible to identify the areas that need to receive priority treatment. To assess the vulnerability of aquifers, four methods were selected according to the types of aquifers, namely: DRASTIC, SINTACS, GOD and EPIK. The DRASTIC method was developed to be used in any type of aquifer, the SINTACS method was developed for fissural aquifers, the GOD method for porous aquifers and the EPIK method for karst aquifers. In addition to the application of the proposed methods, modifications were made in order to adapt the method to the physical characteristics of the region, considering the less efficient parameters. From the results obtained, it was found that the most appropriate method to assess the vulnerability of the study area are those specific to each type of aquifer, considering that the proposed adaptations proved to be more efficient than the original methods. In addition, it was observed that the DRASTIC method, developed for all types of aquifers, demonstrates efficacy by indicating that the main aquifers susceptible to contamination are those of the cover layers, Cauê and Gandarela.</div></div>","PeriodicalId":15530,"journal":{"name":"Journal of contaminant hydrology","volume":"270 ","pages":"Article 104516"},"PeriodicalIF":3.5,"publicationDate":"2025-02-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143395581","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":"Escherichia coli transport in two acidic soils: Effect of microbially induced calcite precipitation technology","authors":"Zahra Ramezani,&nbsp;Mohammad Bagher Farhangi,&nbsp;Nasrin Ghorbanzadeh,&nbsp;Mahmoud Shabanpour","doi":"10.1016/j.jconhyd.2024.104493","DOIUrl":"10.1016/j.jconhyd.2024.104493","url":null,"abstract":"<div><div>Microbially induced calcite precipitation (MICP) while neutralizing soil pH, can lead to pore clogging which in turn may reduce bacteria transport. This study aimed to evaluate the effectiveness of the MICP process for <em>E. coli</em> filtration in two acidic soils. Two soil samples from Amlash (Am) and Lahijan (La) areas with pH values of 5.88 and 3.93, repectively, were collected and poured into plastic columns (14.92 × 2.4 cm). For the MICP reaction, the soil columns were saturated with a solidification solution (1:1 urea: CaCl₂, 1.5 M) and <em>Sporosarcina pasteurii</em> (∼10⁸ cell mL⁻¹), and incubated at 30 °C for 72 h. Leaching experiments were conducted on both MICP-treated and control soil columns at steady-state, saturated flow condition. A pulse of influent (0.1 PV) containing <em>Escherichia coli</em> (ciprofloxacin-resistant) (∼10⁸ cell mL⁻¹) and bromide tracer (1000 mg L⁻¹ KBr) was added at the top of the soil columns, followed by sterile water to collect the effluent. Recovered <em>E. coli</em>, and Br⁻, HCO₃⁻, NH₄⁺, Ca²⁺ ions were measured in the leachate. The profile of residual <em>E. coli</em> count, urease activity, and bioprecipitated CaCO₃ content were also assessed in the soil. Correlated with bioprecipitated CaCO₃, the hydraulic conductivity coefficients (<em>K</em>_s) was reduced by 4.4 and 5.8 times after MICP treatment in Am and La soils, respectively, thus bacteria leaching was significantly reduced. A higher filtration coefficient (<em>λ</em>_<em>f</em>) and recovery rate of <em>E. coli</em> were calculated in the La soil column, likely due to the lower pH and higher anion exchange capacity, which induced greater bacterial mortality and electrostatic attraction, respectively. MICP treatment reduced the average and cumulative count of <em>E. coli</em> by ∼3.4 times compared to the control column. In conclusion, the application of MICP in acidic soil increased soil pH and reduced the risk of <em>E. coli</em> transport to deeper layers by reducing soil hydraulic conductivity.</div></div>","PeriodicalId":15530,"journal":{"name":"Journal of contaminant hydrology","volume":"269 ","pages":"Article 104493"},"PeriodicalIF":3.5,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142927310","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}