Journal of contaminant hydrology最新文献

{"title":"Occurrence and transport of per- and polyfluoroalkyl substances (PFAS) within a coastal groundwater aquifer","authors":"Oliver A.H. Jones ,&nbsp;Alexander Brindle ,&nbsp;Mikaela Sterjovski ,&nbsp;Shadha Al-Mashari ,&nbsp;Pacian Netherway ,&nbsp;Phoebe Lewis ,&nbsp;Jennifer Martin ,&nbsp;Matthew Currell","doi":"10.1016/j.jconhyd.2026.104861","DOIUrl":"10.1016/j.jconhyd.2026.104861","url":null,"abstract":"<div><div>Understanding the sources, fate, and transport of per- and polyfluoroalkyl substances (PFAS) in coastal aquifers is essential for assessing the risk to these systems. We investigated PFAS concentrations within the Quaternary Aquifer of the Mornington Peninsula, Australia. The goals were to identify the sources of any observed contamination and assess the risk to ecological receptors associated with surface water bodies that interact with the aquifer. Fifteen bores were sampled at various depths. Multiple PFAS were detected in eight bores at ng/L concentrations (maximum ∑₈PFAS = 78.8 ng/L), while seven bores contained no detectable PFAS. Notable compounds included legacy perfluoroalkyl acids, such as PFOA, PFOS, and PFHxS, as well as the fluorotelomers 6:2 FTS and 6:2 diPAP. Several potential sources were identified, including two local landfills, a wastewater treatment plant, and the use of recycled water for irrigation in local agriculture. The bores with the highest total PFAS concentrations were located near the identified sources, particularly the landfills. No clear source was apparent for several PFOS-contaminated bores. Concentrations of PFOS at six bores were just above the current ecological guideline values for 99% species protection (0.00023 μg/L) but below the value for 95% species protection (0.13 μg/L). The risk to aquatic ecological receptors from contaminant discharge from groundwater into local watercourses is considered low, due to relatively low PFAS concentrations and moderate groundwater velocities; however, the combined total risk from seasonal fluxes and surface water runoff, and other discharges could be higher. Further monitoring and risk assessment are therefore recommended.</div></div>","PeriodicalId":15530,"journal":{"name":"Journal of contaminant hydrology","volume":"277 ","pages":"Article 104861"},"PeriodicalIF":4.4,"publicationDate":"2026-01-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146022905","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":"Experimental and numerical investigation of colloid-facilitated strontium transport in fractured granite under different hydrogeochemical conditions","authors":"Funing Ma ,&nbsp;Fangfei Cai ,&nbsp;Lihong Zhang ,&nbsp;Sida Jia","doi":"10.1016/j.jconhyd.2026.104858","DOIUrl":"10.1016/j.jconhyd.2026.104858","url":null,"abstract":"<div><div>Accurate prediction of radionuclide transport in fractured crystalline rock is vital for the long-term safety of high-level radioactive waste (HLW) geological disposal. However, the specific threshold conditions determining whether bentonite colloids (BC) facilitate or inhibit radionuclide transport in realistic fracture geometries remain quantitatively undefined. This study systematically investigates the transport of strontium (Sr) in fractured granite with and without BC, employing both column experiments and numerical simulations. The effects of varying hydrogeochemical conditions, including flow velocity (1.8–7.2 mL/h), pH (6.5–8.5), and ionic strength (0.001–0.1 M), were quantitatively evaluated. The results revealed that in the absence of colloids, Sr migration was primarily governed by non-equilibrium sorption interactions with the rock matrix. Lower flow velocities enhanced the solute residence time and interaction with the rock surface, promoting retention, while acidic conditions increased Sr mobility by reducing surface complexation. Crucially, the study reveals a complex dual role of BC dictated by hydrogeochemical thresholds. Under high flow velocity and low ionic strength, BC acted as effective carriers, facilitating Sr migration. In contrast, a distinct transition to transport inhibition was observed under low flow velocities or high ionic strength. Under these conditions, the stability of BC was compromised, leading to aggregation and straining within the fracture. This induced a site-shielding effect, where deposited colloids physically blocked sorption sites on the rock matrix, effectively retarding Sr transport. These findings challenge the generalized assumption of unconditional colloid-facilitated transport, underscoring the importance of incorporating specific hydrogeochemical thresholds in the safety assessment of HLW geological disposal systems.</div></div>","PeriodicalId":15530,"journal":{"name":"Journal of contaminant hydrology","volume":"277 ","pages":"Article 104858"},"PeriodicalIF":4.4,"publicationDate":"2026-01-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146010584","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":"2026-01-16","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":"Nitrate source apportionments in the South Han River basin and its main tributaries using multi-isotopes and Bayesian approaches","authors":"Hyeongseok Song ,&nbsp;Kwang-Sik Lee ,&nbsp;Nohsung Jeong ,&nbsp;Sunghyen Cho ,&nbsp;Dongguen Lee ,&nbsp;Cheolho Yoon ,&nbsp;Woo-Jin Shin","doi":"10.1016/j.jconhyd.2026.104856","DOIUrl":"10.1016/j.jconhyd.2026.104856","url":null,"abstract":"<div><div>The nitrate apportionment approach provides valuable insights into efficient water quality management. Water samples were collected from the South Han River (SHR), and the three tributaries of the SHR showed relatively high nutrient levels. Water samples were collected from the North Han River (NHR), another contaminated stream (Gyeongan Stream, GA), and wastewater treatment plants (WWTP). The objectives of this study were to identify the sources impacting water chemistry in the SHR and its tributaries, especially nitrate contaminants, and to estimate the apportionment of nitrate sources. Plots of SO₄/Cl and NO₃/Cl showed relatively low ratios for the tributary, GA, and WWTPs samples compared to those of the SHR and NHR. Interestingly, samples from the lowest reaches of a tributary showed considerably high SO₄/Cl and low NO₃/Cl, with distinct δ³⁴S values, indicating a specific contaminant source in its watershed and subsequently influencing SHR water chemistry. The contributions of each source to nitrate in SHR and tributaries were estimated to be 58.9% to 93.3% and 0.2% to 95.7% for soil N and 15.9% to 40.3% and 4.1% to 99.4% for manure/domestic sewage, respectively, using a Bayesian isotope mixing model. These source contributions were not clearly consistent with the land-use patterns. δ¹¹B related to δ¹⁵N-NO₃ values for SHR samples indicate that domestic wastewater exerts a greater influence on water chemistry than agricultural inputs. We suggest a comprehensive approach for identifying nitrate contaminants in water using multiple isotopes, including nitrate isotopes, with a Bayesian isotope mixing model.</div></div>","PeriodicalId":15530,"journal":{"name":"Journal of contaminant hydrology","volume":"277 ","pages":"Article 104856"},"PeriodicalIF":4.4,"publicationDate":"2026-01-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146010543","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":"Toward closed-loop remediation: A dynamic optimization approach for hydraulic conductivity estimation and pump-and-treat design","authors":"JunZe Wei ,&nbsp;Simin Jiang ,&nbsp;Qi Liu ,&nbsp;Xun Zhang ,&nbsp;Na Zheng ,&nbsp;Jingwen Xing","doi":"10.1016/j.jconhyd.2026.104852","DOIUrl":"10.1016/j.jconhyd.2026.104852","url":null,"abstract":"<div><div>In the remediation of contaminated sites, the accuracy of the hydraulic conductivity field (K-field) is a critical factor affecting remediation efficiency. Traditional methods, which rely on sparse historical data, short-term pumping tests, and static interpolation methods, often fail to capture heterogeneity of K-fields due to limited monitoring data. This inaccuracy leads to suboptimal remediation designs, resulting in increased costs and reduced efficiency. To address these limitations, this study proposes a dynamic iterative optimization framework that integrates parameter inversion with remediation plan design into a closed-loop system of simulation-observation-update-optimization. The framework iteratively updates the K-field using pilot point parameterization and simulation-optimization techniques, while dynamically adjusting the remediation strategy based on real-time monitoring data. Numerical experiments conducted on a virtual contaminated site demonstrate that the proposed framework significantly improves the accuracy of K-field characterization, as evidenced by decreasing logarithmic root mean square error (LRMSE) and increasing spatial correlation coefficient (SCC) over iterations. Critically, when compared with a conventional static remediation plan that is designed once and executed without updates, the dynamic framework achieves a substantially higher contaminant removal rate while simultaneously reducing the total pumping volume. These results highlight the framework’ s potential to enhance remediation effectiveness and reduce operational costs in heterogeneous aquifers, offering a practical and adaptive solution for complex contaminated site management.</div></div>","PeriodicalId":15530,"journal":{"name":"Journal of contaminant hydrology","volume":"277 ","pages":"Article 104852"},"PeriodicalIF":4.4,"publicationDate":"2026-01-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145977452","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":"2026-01-14","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":"The influence of sediment content and salinity in estuarine areas on the settling velocity of microplastics","authors":"Yefeng Ji,&nbsp;Lu Cao,&nbsp;Yun Gao,&nbsp;Zhongyan Huo,&nbsp;Zhequan Leng,&nbsp;Qi Chen,&nbsp;Zhutao Ding,&nbsp;Ying Xiong","doi":"10.1016/j.jconhyd.2026.104854","DOIUrl":"10.1016/j.jconhyd.2026.104854","url":null,"abstract":"<div><div>Since their emergence in the 20th century, plastics have been extensively utilized worldwide. Owing to their pronounced hydrophobicity, chemical inertness, and resistance to microbial degradation, plastics persist in the environment and are difficult to eliminate. Rivers serve as an important pathway for microplastics (MPs) to flow into the ocean. The mechanisms that affect the migration, transportation and fate of MPs in rivers are not yet clear. This poses obstacles to understanding the dynamics of MPs in the ocean, determining their main aggregation areas, and conducting sampling in the ocean. Through a comprehensive series of settling experiments, this study demonstrates that the settling dynamics of MPs are significantly modulated by suspended solid concentration (SSC) and salinity gradients—factors that are particularly characteristic of estuarine transition zones at the river–ocean interface. The results indicate that SSC significantly enhance the settling velocity of MPs, with a maximum increase of 15.6%. However, this promoting effect diminishes as sediment concentration increases, and an inhibitory effect emerges under high concentrations. Conversely, elevated salinity markedly suppresses settling velocity, with a maximum reduction of 33.96%, though the magnitude of this influence gradually decreases with further increases in salinity. Based on the experimental results, a modified settling velocity model that integrates the effects of SSC and salinity was developed. Validation indicates that the model reliably predicts MPs settling velocity under a wide range of environmental conditions. This study provides a theoretical framework for advancing the understanding of MPs transport processes in estuarine and coastal environments and offers valuable insights for marine environmental management and remediation.</div></div>","PeriodicalId":15530,"journal":{"name":"Journal of contaminant hydrology","volume":"277 ","pages":"Article 104854"},"PeriodicalIF":4.4,"publicationDate":"2026-01-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146010585","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":"Response of microplastic color to photoaging and its influence on the release characteristics of derived dissolved organic matters","authors":"Maocai Shen ,&nbsp;Shiwei Liu ,&nbsp;Haokai Li ,&nbsp;Ruixin Jin","doi":"10.1016/j.jconhyd.2026.104849","DOIUrl":"10.1016/j.jconhyd.2026.104849","url":null,"abstract":"<div><div>This study systematically investigated the regulatory mechanisms of color parameters on the photoaging behavior and ecological effects of polypropylene (PP) and polymethylmethacrylate (PMMA). We revealed the evolution of the physicochemical properties of various colored microplastics. These results indicate that red and yellow microplastics significantly accelerated surface oxidation and chain breakage due to their strong ultraviolet absorption properties (long wavelength of 380–420 nm). This led to an increase in specific surface area, exemplified by a 10.8% increase in the crystallinity of red PP, an enhancement in surface roughness characterized by dense cracks on the surface of red PMMA, and a greater release of dissolved organic matter (MPs-DOM). DOM components exhibited color dependence, with the red group displaying the highest peak fluorescence intensity. PMMA was primarily composed of humic acids (Ex/Im = 240–250/420–425 nm), while PP released polycyclic aromatic hydrocarbons (Ex/Im = 220–225/305–310 nm). Biological toxicity experiments demonstrated that PMMA-DOM aged for 30 days significantly inhibited the germination rate of Chinese cabbage seeds, averaging 92%. Red PP-DOM promoted a 22.7% increase in seed wet weight during the early stage (10 d). However, long-term exposure (90 days) inhibited the activities of superoxide dismutase (SOD) and catalase (CAT) due to the accumulation of free radicals. Further research has shown that green microplastics exhibit weaker light absorption capabilities and lower toxicity effects related to DOM. This study elucidates the mechanism by which color influences the environmental fate of microplastics through their photoresponsive properties, providing a theoretical foundation for microplastic control strategies based on pigment photosensitivity.</div></div>","PeriodicalId":15530,"journal":{"name":"Journal of contaminant hydrology","volume":"277 ","pages":"Article 104849"},"PeriodicalIF":4.4,"publicationDate":"2026-01-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145952063","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":"Unraveling the adsorption mechanisms of greenhouse gases on microporous MAF-4 nanoparticles using a statistical physics approach","authors":"E.A. Elghmaz ,&nbsp;Ghada M. Alnafesah ,&nbsp;Mohammed Alissa ,&nbsp;Khalil ur Rehman ,&nbsp;Abdullah Alghamdi ,&nbsp;Suad A. Alghamdi ,&nbsp;Abdulkarim S. Binshaya ,&nbsp;Ghfren S. Aloraini ,&nbsp;Amira K. Hajri ,&nbsp;Adil Abalkhail","doi":"10.1016/j.jconhyd.2026.104850","DOIUrl":"10.1016/j.jconhyd.2026.104850","url":null,"abstract":"<div><div>The continuing struggle to reduce greenhouse gas emissions continues to be one of the most crucial obstacles in achieving both energy efficiency and sustainable, long-term environmental practices. Microporous metal azolate framework-4 nanoparticles (MAF-4 NPs) have emerged as attractive adsorbent materials with their large surface area, adjustable pore architecture, and high chemical stability. Herein we present a green and rapid synthesis of ultramicroporous MAF-4 nanoparticles via the production of no organic solvents through the use of minimal external heating. The resulting MAF-4 NPs (particle size ≥70 nm) have been characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and nitrogen physisorption analysis and demonstrate a high BET surface area of 1796 m³/g, a total pore volume of 0.75 cm³/g, and ultramicropores predominantly occurring at an average pore diameter of 0.62 nm. A number of gas adsorption behaviors have been experimentally evaluated for four different gases (CO₂, SF₆, CH₄, and N₂) and are subsequently explained using a multilayer adsorption model based on statistical physics that has recently been developed for porous metal-organic frameworks. This combination of theoretical and experimental information provides a greater understanding of how adsorption occurs within porous metal-organic frameworks. The results indicate that gas molecules (at low temperatures) are unaligned, but at higher temperatures they have primarily parallel arrangements and are able to form many layers (multilayer arrangements). The average number of adsorbed gas molecules on an active site range from 0.51 to 1.92 for each different type of gas and temperature combination, and the total number of layers varies from 1.2 to 8.0. Energy of adsorption indicates strong attractive forces for the initial layer of adsorbing molecules and a decrease in attraction for subsequent layers of adsorbing molecules, with values between 2.64 and 8.42 kJ/mol indicating the adsorptive forces are due to physisorption with significant contributions from van der Waals and London dispersion forces. Using thermodynamic evaluations of internal energy and Gibbs' free energy to estimate the spontaneity and exothermicity of the adsorption process shows that at low temperatures there is more disorder among the molecules (higher entropy) than at higher temperatures when the number of adsorbate molecules reaches saturation. This indicates that MAF-4 nanoparticles will be energy-efficient, selective, and regenerable when used for CO₂ and SF₆ capture and have significant capability for scale-up and increased capacity of these adsorbates.</div></div>","PeriodicalId":15530,"journal":{"name":"Journal of contaminant hydrology","volume":"277 ","pages":"Article 104850"},"PeriodicalIF":4.4,"publicationDate":"2026-01-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146010544","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":"Long term rebound and transport of perfluorinated sulfonic acids (PFSAs) in the vadose zone following flushing","authors":"Charles E. Schaefer ,&nbsp;Graig M. Lavorgna ,&nbsp;David R. Lippincott ,&nbsp;Shilai Hao ,&nbsp;J. Conrad Pritchard ,&nbsp;Christopher P. Higgins","doi":"10.1016/j.jconhyd.2026.104848","DOIUrl":"10.1016/j.jconhyd.2026.104848","url":null,"abstract":"<div><div>Increases in perfluorinated sulfonic acid (PFSA) porewater concentrations over a 35 month duration following in situ flushing were monitored at an aqueous film-forming foam (AFFF) site using porous cup suction lysimeters within a highly instrumented test cell. Results provided evidence that perfluorooctane sulfonate (PFOS) slow desorption kinetics contributed to slow contaminant rebound in measured porewater concentrations. PFSAs in the shallow (0.23 m depth) highly PFSA-impacted soils migrated downward during the monitored post-flushing period, with short-chained PFSAs migrating more rapidly in porewater than long-chained PFSAs. Following flushing, apparent equilibrium porewater concentrations at a depth of 0.61 m below ground surface were attained within two months for perfluoropentane sulfonate (PFPeS), between 2 and 20 months for perfluorohexane sulfonate (PFHxS), and 25 months for PFOS. For PFPeS and PFHxS, apparent steady-state rebound concentrations (to 38% of their pre-flushing baseline levels, with no increasing or decreasing trend over time subsequently observed) were reasonably predicted based on an equilibrium model. PFOS rebound and ultimately vertical migration were highly impacted by non-equilibrium soil desorption. Excavation of elevated PFSAs in surface soils had no impact on PFSA porewater concentrations 0.38 m below the excavation over a 1.2 year post-excavation monitoring period. Together, these long-term rebound data highlight the potential importance of mass transfer-controlled processes for PFOS leaching, and suggest that removal of elevated PFSAs in surface soils may take years until PFSA discharges to groundwater are diminished.</div></div>","PeriodicalId":15530,"journal":{"name":"Journal of contaminant hydrology","volume":"277 ","pages":"Article 104848"},"PeriodicalIF":4.4,"publicationDate":"2026-01-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145966331","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}