Journal of contaminant hydrology最新文献

{"title":"Competitive ligand control of Cu bioavailability: Decoupling anion (Cl−/SO42−/PO43−) versus fulvic acid regulation in speciation-phytotoxicity coupling","authors":"Xiaoqing Zhang ,&nbsp;Yujia Jiao ,&nbsp;Jiaxue Si ,&nbsp;Dajun Ren ,&nbsp;Shuqin Zhang","doi":"10.1016/j.jconhyd.2025.104806","DOIUrl":"10.1016/j.jconhyd.2025.104806","url":null,"abstract":"<div><div>The interactions between anions and dissolved organic matter play a crucial role in determining copper (Cu) bioavailability in soil environment. This study examined the impact of chloride (Cl⁻), sulfate (SO₄²⁻), phosphate (PO₄³⁻), and fulvic acid (FA) on soluble Cu speciation distribution, and phytotoxicity in barley root elongation. FA had a superior Cu²⁺-complexing ability, reducing the free Cu²⁺ content to 0.042 %–2.36 % through organic complexation (FA-Cu), which accounted for &gt;97.4 % of the total Cu. In contrast, anion treatments without FA primarily maintained soluble Cu as free ions with limited formation of inorganic complexes, with FA having the most significant effect, followed by PO₄³⁻, SO₄²⁻, and Cl⁻. The coexistence of FA and anions led to the emergence of competitive ligand interactions, with particularly pronounced variations in Cu speciation and complexation patterns observed. At low Cu, FA-Cu was the dominant soluble species, with free Cu²⁺ ≤ 31.50 %. Elevated Cu levels shifted speciation toward free Cu²⁺ and FA-Cu, except in systems with high PO₄³⁻-FA concentrations where PO₄³⁻ precipitates dominated. Furthermore, the single FA and co-coexistence of FA and anions of FA all increased the toxicity threshold (50 % inhibition, EC50) within a range of 2.8–12.4 folds, generally in the order of FA + Cl⁻ &lt; FA + SO₄²⁻ &lt; FA + PO₄³⁻, FA. It indicated that the protective effect of FA against Cu phytotoxicity was gradually weakened with the increasing addition of Cl⁻ and SO₄²⁻. This study provides important insights into the role of both organic and inorganic ligands in assessing Cu speciation and phytotoxicity in Cu-contaminated agroecosystems.</div></div>","PeriodicalId":15530,"journal":{"name":"Journal of contaminant hydrology","volume":"277 ","pages":"Article 104806"},"PeriodicalIF":4.4,"publicationDate":"2025-12-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145735360","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":"2025-12-05","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":"Metagenomic insights into rhizosphere microbiome dynamics of Oenanthe javanica in ecological floating beds under different hydrodynamic regimes","authors":"Xuming Xu ,&nbsp;Jiawei Wang ,&nbsp;Chunfang Deng ,&nbsp;Xiao Yu ,&nbsp;Rui Nie ,&nbsp;Siya Wang ,&nbsp;Wei Huang","doi":"10.1016/j.jconhyd.2025.104795","DOIUrl":"10.1016/j.jconhyd.2025.104795","url":null,"abstract":"<div><div>Ecological floating beds (EFBs) are a cost-effective and sustainable technology that utilizes macrophyte to remove nutrients from aquatic ecosystems, where rhizosphere bacterial degradation and assimilation play a key role in nutrient removal. However, the current knowledge about how hydrodynamic regimes impact the rhizosphere bacterial community on EFB systems remains limited. Here, we investigated the effects of different hydrodynamic regimes (<em>i.e.</em>, stagnant water, pulsed water, and flowing water conditions) on the rhizosphere bacterial community structure and function of <em>Oenanthe javanica</em> in an experimental EFB system based on metagenomic sequencing. We observed that bacterial community compositions on the roots of <em>O. javanica</em> were significantly differed across the three hydrodynamic regimes, with the highest bacterial biodiversity captured from the flowing water condition. Moreover, a total of 65 nitrogen functional genes (NFGs) were identified in the rhizosphere bacterial community, with nitrate reduction pathways dominating the nitrogen cycling processes. In contrast, totally 139 phosphorus functional genes (PFGs) were detected, primarily involved in purine metabolism, which drove the phosphorus cycling dynamics. We found the distinct nitrogen and phosphorus metabolic strategies of rhizosphere bacterial communities in response to hydrodynamic regime changes. Specifically, the relative abundances of NFGs like <em>nasB</em>, <em>narl</em>, and <em>ansB</em> were significantly increased under the pulsed water condition, whereas <em>gdh_K00262</em> were relative abundant under the flowing condition. Moreover, pulsed water condition promoted the relative abundances of PFGs such asas <em>phnC</em>, <em>phoD</em>, and <em>pgtP</em> in rhizosphere bacterial communities, in contrast to the stagnant condition, which favored genes like <em>ugpC</em>, <em>purK</em>, <em>phoH</em>, and <em>purA</em>. Our study offers technical support for regulating plant degradation of pollutants to improve EFB's performance in engineering applications.</div></div>","PeriodicalId":15530,"journal":{"name":"Journal of contaminant hydrology","volume":"277 ","pages":"Article 104795"},"PeriodicalIF":4.4,"publicationDate":"2025-12-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145735289","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":"2025-12-03","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":"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":"2025-12-03","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":"An efficient strategy of Bayesian optimized attention-enhanced LSTM surrogate model and its application in groundwater pump-and-treat remediation: A case study of a chromium-contaminated site in southern China","authors":"Yanhong Zou ,&nbsp;Fuqiang Yang ,&nbsp;Hao Deng ,&nbsp;Xiancheng Mao ,&nbsp;Yong He","doi":"10.1016/j.jconhyd.2025.104790","DOIUrl":"10.1016/j.jconhyd.2025.104790","url":null,"abstract":"<div><div>The simulation-optimization of pump-and-treat (PAT) systems for groundwater remediation often encounters significant computational demands due to the reliance on high-fidelity numerical models. Surrogate modeling has emerged as an effective strategy to mitigate this burden. However, a common limitation in existing studies is the oversimplification of temporal pumping dynamics through the assumption of uniform pumping durations, potentially leading to suboptimal and excessive pumping. To address this, we propose a novel surrogate modeling approach based on a Bayesian Optimization-enhanced Long Short-Term Memory network with an Attention mechanism (BO-LSTM-Attention). This methodology is applied to systematically optimize the PAT remediation strategy for a hexavalent chromium (Cr(VI)) contaminated site in southern China, treating the pumping rate, start time, and end time of each well as independent decision variables. By integrating attention-based temporal feature weighting and Bayesian hyperparameter optimization, the BO-LSTM-Attention surrogate model significantly enhances the predictive accuracy of Cr(VI) concentration on the test set, achieving a RMSE below 0.08, a MAE below 0.065, and a R² exceeding 0.99. Subsequently, the trained surrogate model was embedded into the multi-objective optimization framework to improve the existing uniform pumping scheme (680 m³/d) by simultaneously minimizing total pumping volume and maximizing restoration efficiency. The resulting optimized strategy yielded a 10 % reduction in the area exhibiting Cr(VI) concentrations above 80 mg/L and an average daily pumping reduction of 182.37 m³ over a one-year operational period, alongside a 96 % improvement in simulation-optimization computational efficiency. A two-year projection of the optimized strategy indicates the potential to reduce the maximum Cr(VI) concentration below 50 mg/L, with a substantial 62.5 % reduction in total extraction volume. These findings demonstrate that the BO-LSTM-Attention surrogate model concurrently enhances predictive accuracy and optimization efficiency, enabling coordinated control of high-concentration contaminant plumes and precise regulation of pumping operations. This approach offers an efficient and practical solution for groundwater remediation under complex hydrogeological conditions.</div></div>","PeriodicalId":15530,"journal":{"name":"Journal of contaminant hydrology","volume":"277 ","pages":"Article 104790"},"PeriodicalIF":4.4,"publicationDate":"2025-12-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145735290","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":"2025-12-02","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":"Mechanism of direct-push injection impact on porous media structure and contaminant removal performance","authors":"Mingxiu Ji ,&nbsp;Ruipeng Dong ,&nbsp;Liu Yang ,&nbsp;Shupei Wu ,&nbsp;Yan Zhao","doi":"10.1016/j.jconhyd.2025.104792","DOIUrl":"10.1016/j.jconhyd.2025.104792","url":null,"abstract":"<div><div>This study focused on the mass transfer limitations in the remediation of organic contaminants in porous media with low hydraulic conductivity. It investigated how direct-push injection (DPI) technology enhances the degradation of phenol (C₆H₅OH) by potassium permanganate (KMnO₄). Three representative aquifer media with low-to-medium hydraulic conductivity were selected, and experiments were conducted under both ambient pressure control (APC) and DPI conditions. Nuclear magnetic resonance (NMR) was employed to monitor the degradation process in real time, while the pore structure evolution was comparatively analyzed. The results showed that under DPI conditions of 0.3 MPa and 0.6 MPa, the overall C₆H₅OH degradation efficiency was enhanced by up to 13.60 % and 32.63 %, respectively. This improvement originated from two synergistic mechanisms. On one hand, DPI reinforced the dominance of convective transport as the primary transport mechanism of KMnO₄ and enhanced its mechanical dispersion, thereby improving the overall mass transfer efficiency. On the other hand, the external pressure applied by DPI effectively modified the pore structure, improved inter-pore connectivity, and enlarged the contact area between KMnO₄ and C₆H₅OH. Together, these effects accelerated the oxidation process, reduced intermediate product accumulation, and ultimately enhanced the overall degradation efficiency. Moreover, DPI promoted the penetration of KMnO₄ into small pores, which is particularly beneficial for low hydraulic conductivity media dominated by fine pores. This study elucidates the mechanism by which DPI enhances oxidant transport and reaction efficiency, and clarified the dual influence of pore structure and injection pressure on the effectiveness of DPI.</div></div>","PeriodicalId":15530,"journal":{"name":"Journal of contaminant hydrology","volume":"276 ","pages":"Article 104792"},"PeriodicalIF":4.4,"publicationDate":"2025-11-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145661314","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":"Transport, retention and degradation of the urban biocides terbutryn, diuron and octylisothiazolinone and the herbicide acetochlor in urban surface-soil interfaces","authors":"Tobias Junginger ,&nbsp;Sylvain Payraudeau ,&nbsp;Felicia Linke ,&nbsp;Jens Lange ,&nbsp;Gwenaël Imfeld","doi":"10.1016/j.jconhyd.2025.104788","DOIUrl":"10.1016/j.jconhyd.2025.104788","url":null,"abstract":"<div><div>Urban biocides, including terbutryn, diuron, and octylisothiazolinone (OIT), commonly leached from facade coatings during rainfall-runoff events, can infiltrate subsurface environments through permeable urban surfaces, posing a risk to groundwater quality. Despite frequent detection of biocides in urban groundwater, the transport and transformation processes occurring at the surface-soil interface remain insufficiently characterized. This study combines outdoor lysimeter experiments with reactive transport modeling and compound-specific isotope analysis (CSIA) to assess biocide leaching, retention, and degradation across three typical urban interfaces: gravel strips, permeable pavements, and vegetated soils. Leaching of biocides differed among lysimeters, with 10–17 % of terbutryn, 40–47 % of acetochlor, and 5–40 % of diuron released from the gravel and pavement systems, whereas leaching from vegetated soil was minimal (&lt;0.5 %). OIT was not detected in any leachates, likely due to rapid degradation. Eight-year modeling further indicated limited retention in gravel and pavement, with up to 36 % and 22 % of the applied terbutryn mass, respectively, migrating to depths greater than 30 cm. In contrast, vegetated soils retained over 99 % of terbutryn mass, primarily through sorption and biodegradation. CSIA indicated higher biodegradation rates in pavements than in gravel. Measurements and modeling showed substantial transformation of terbutryn into transformation products. These results underscore the critical role of biogeochemical processes at surface–soil interfaces in regulating biocide transport to groundwater. Permeable, non-vegetated surfaces receiving facade runoff were identified as significant contributors to subsurface contamination. The study highlights the limited and variable retention capacity of different urban surfaces and stresses the need to integrate biocide control into sustainable stormwater management practices.</div></div>","PeriodicalId":15530,"journal":{"name":"Journal of contaminant hydrology","volume":"277 ","pages":"Article 104788"},"PeriodicalIF":4.4,"publicationDate":"2025-11-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145665428","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":"Protonated epichlorohydrin-crosslinked chitosan beads for ibuprofen removal from water: Insights into adsorption mechanisms, isotherms, kinetics, and reusability","authors":"Amir Hossein Behroozi ,&nbsp;Arghavan Mirahsani ,&nbsp;Pascale Champagne ,&nbsp;Ehssan Koupaie","doi":"10.1016/j.jconhyd.2025.104786","DOIUrl":"10.1016/j.jconhyd.2025.104786","url":null,"abstract":"<div><div>Ibuprofen (IBP) is a pharmaceutical commonly released into water, where it poses environmental risks. Effective treatments must be developed to remove IBP from water. In this study, protonated epichlorohydrin-crosslinked chitosan beads (PECBs) were synthesized and characterized for the adsorption of IBP from aqueous solutions. Chitosan, a non-toxic and biodegradable biopolymer, was crosslinked with epichlorohydrin to improve acid stability (mass retention of 98 %), which also reduced the equilibrium water content (20 %) and created a mesoporous structure (2–12 nm) favorable for adsorption. Optimal adsorption conditions were achieved at neutral pH and 1.00 g IBP/L concentration, with a maximum adsorption capacity of 232 mg IBP/g PECB and followed by the Langmuir model (sum of squared error (<em>SSE)</em> = 104, coefficient of determination (<em>R</em>^<em>2</em><em>)</em> = 0.998). Adsorption kinetics data showed a rapid initial adsorption phase (&lt;60 min) followed by a slower approach to equilibrium at 12 h. Adsorption kinetics were best fitted by the Avrami model (<em>SSE</em> = 1.90, <em>R</em>^<em>2</em> = 0.999), indicating a mixed adsorption process involving both physical and chemical interactions. The strong fit of this kinetic model suggests that chemisorption contributes considerably to the overall rate of adsorption, whereas electrostatic attraction governs the extent of adsorption under specific pH conditions. At pH &gt; <em>pK</em>_<em>a</em> (4.9), the negatively charged IBP molecules interact electrostatically with the protonated amino groups on PECBs, whereas at pH &lt; <em>pK</em>_<em>a</em>, hydrogen bonding becomes more prominent due to the neutral form of IBP. PECBs retained ∼85 % of their adsorption capacity after four reuse cycles, indicating a potential for reusability. Leaching tests revealed no detectable release of potentially toxic epichlorohydrin into the water. These findings suggest that PECBs are effective adsorbents for removing anionic contaminants, such as IBP, from aqueous environments.</div></div>","PeriodicalId":15530,"journal":{"name":"Journal of contaminant hydrology","volume":"276 ","pages":"Article 104786"},"PeriodicalIF":4.4,"publicationDate":"2025-11-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145661386","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}