Environmental Science: Processes & Impacts最新文献

{"title":"Environmental drivers of monomethylmercury photodegradation along the land-to-ocean aquatic continuum.","authors":"Sonja Gindorf, Johannes West, Andrew Graham, Sofi Jonsson","doi":"10.1039/d4em00636d","DOIUrl":"https://doi.org/10.1039/d4em00636d","url":null,"abstract":"<p><p>In surface waters, photodegradation is a major abiotic removal pathway of the neurotoxin monomethylmercury (MMHg), acting as a key control on the amounts of MMHg available for biological uptake. Different environmental factors can alter the rate of MMHg photodegradation. However, our understanding of how MMHg photodegradation pathways in complex matrixes along the land-to-ocean aquatic continuum respond to changes in salinity, dissolved organic carbon (DOC) concentration and dissolved organic matter (DOM) composition is incomplete. In a set of laboratory experiments combining several artificial and natural waters, we demonstrate that the interplay of DOC concentration, DOM composition, and salinity affects the photodegradation rate of MMHg. The presence of DOM was found to facilitate MMHg photodegradation, but degradation rates were not altered by varying DOC concentrations over two orders of magnitude. We found DOM composition to have a stronger effect on MMHg photodegradation rates than DOC concentration. However, at high DOC levels, where most UV radiation was lost within the first cm of the reaction vessels, lower MMHg photodegradation rates were observed. When moving from terrestrially influenced waters, characterized by a high degree of humification, towards marine conditions with a protein-rich DOM pool, MMHg photodegradation rates increased. In contrast, salinity had a stabilizing effect on MMHg. Hence, especially in systems with low salt and DOC concentrations, changes in either salinity or DOC concentration can impact the photodegradation rates of MMHg.</p>","PeriodicalId":74,"journal":{"name":"Environmental Science: Processes & Impacts","volume":" ","pages":""},"PeriodicalIF":4.3,"publicationDate":"2025-01-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142976915","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":"Mitigating matrix effects in oil and gas wastewater analysis: LC-MS/MS method for ethanolamines.","authors":"Glen Andrew D de Vera, Loredana Caldiero, Giovanni Conte, Desirée L Plata","doi":"10.1039/d4em00716f","DOIUrl":"https://doi.org/10.1039/d4em00716f","url":null,"abstract":"<p><p>The high salinity and organic content in oil and gas wastewaters can cause ion suppression during liquid chromatography mass spectrometry (LC/MS) analysis, diminishing the sensitivity and accuracy of measurements in available methods. This suppression is severe for low molecular weight organic compounds such as ethanolamines (<i>e.g.</i>, monoethanolamine (MEA), diethanolamine (DEA), triethanolamine (TEA), <i>N</i>-methyldiethanolamine (MDEA), and <i>N</i>,<i>N</i>-ethyldiethanolamine (EDEA)). Here, we deployed solid phase extraction (SPE), mixed-mode LC, triple quadrupole MS with positive electrospray ionization (ESI), and a suite of stable isotope standards (<i>i.e.</i>, one per target compound) to correct for ion suppression by salts and organic matter, SPE losses, and instrument variability. The method was evaluated in produced water samples from Italy (NaCl salinity from 8110-18 100 mg L^-1; diesel range organic compounds ranging from 5.1-7.9 mg L^-1). After correcting for matrix effects, ethanolamines in produced water samples were quantified. The first batch of samples (March 2019) had 37-646 μg L^-1 total ethanolamines. The second batch of samples (September 2019) had greater ethanolamine content of 77-3976 μg L^-1 which was attributed to a reduced water cut during oil production, enhancing the proportionate abundance of these compounds in the aqueous phase. In all samples, DEA and MEA were the dominant ethanolamine species. Possible sources (<i>e.g.</i>, corrosion inhibitor and biotransformation) and natural attenuation potential during storage (<i>e.g.</i>, at different temperatures, acidification, and addition of sodium azide) were investigated. The developed analytical method enables further investigation of the fate of low molecular weight organic additives in oil and gas development and provides an enhanced ability to evaluate risks associated with chemical release to the environment.</p>","PeriodicalId":74,"journal":{"name":"Environmental Science: Processes & Impacts","volume":" ","pages":""},"PeriodicalIF":4.3,"publicationDate":"2025-01-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142976926","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 role of persistent free radicals in soil for persulfate activation: impacts on benzo[<i>a</i>]pyrene degradation.","authors":"Yiwen Ou, Xintong Li, Shixu Feng, Hongxia Zhao","doi":"10.1039/d4em00437j","DOIUrl":"https://doi.org/10.1039/d4em00437j","url":null,"abstract":"<p><p>Environmentally persistent free radicals (EPFRs) have been widely detected in polycyclic aromatic hydrocarbon (PAH)-contaminated soils, but the activation of persulfate by inherent EPFRs in PAH-contaminated soil for the transformation of PAHs remains unclear. In the present study, benzo[<i>a</i>]pyrene (B[<i>a</i>]P) was selected as a representative PAH and its transformation in a persulfate/B[<i>a</i>]P-contaminated soil system was studied without the addition of any other activator. Results indicated that EPFRs in the soil activated persulfate to produce reactive oxygen species (ROS) and degraded B[<i>a</i>]P. It was found that the decomposition of persulfate was accompanied with the decay of EPFRs in the soil, which was quantified using electron paramagnetic resonance (EPR) technique. Correspondingly, combined with EPR and quenching experiments, it was confirmed that sulfate radicals (SO₄˙^-), hydroxyl radicals (˙OH), superoxide radicals (˙O₂^-) and singlet oxygen (¹O₂) coexist in the reaction system, and ˙O₂^- and ¹O₂ play major roles in the degradation of B[<i>a</i>]P. Primary intermediates were identified <i>via</i> gas chromatography-mass spectrometry (GC-MS), and the transformation pathway underlying B[<i>a</i>]P degradation was proposed. Furthermore, the acute and chronic toxicities of seven intermediates to aquatic organisms were predicted using Ecological Structure Activity Relationships (ECOSAR) software, and the corresponding results showed that the seven intermediates detected were very toxic to the environment. This study provides new insights into the activation of persulfate by EPFRs in the degradation of refractory pollutants.</p>","PeriodicalId":74,"journal":{"name":"Environmental Science: Processes & Impacts","volume":" ","pages":""},"PeriodicalIF":4.3,"publicationDate":"2025-01-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142968700","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":"Preliminary insight into the intracellular behaviour of rare earths and other technology-critical elements (TCEs) in northern pike liver: study of TCE-binding biomolecules via size-exclusion HPLC-ICP-MS†","authors":"Zrinka Dragun, Zoran Kiralj, Željka Fiket and Dušica Ivanković","doi":"10.1039/D4EM00674G","DOIUrl":"10.1039/D4EM00674G","url":null,"abstract":"<p >Technology-critical elements (TCEs) refer to the elements that play an important role in many emerging technologies and the production of advanced materials, and these include lanthanides, tungsten and vanadium. Actinides, Tl, and Pb, which also belong to TCEs, are abundantly used in power generation, industrial applications, and modern agricultural practices. The information on the influence of these elements on the aquatic environment and biota is still rather scarce. Thus, the distributions of the above-mentioned metals among cytosolic biomolecules of different molecular masses in the liver of the northern pike (<em>Esox lucius</em>) from the Mrežnica River (Croatia) were studied to obtain an insight into their intracellular behaviour and potential for toxicity. The applied method was a hyphenated system of size-exclusion high-performance liquid chromatography and inductively coupled plasma mass spectrometry. In the samples with lower cytosolic concentrations, the obtained distributions of several TCEs (lanthanides, W, Th, and U) and Pb, among biomolecules of a wide range of molecular masses, which covered the entire column separation range (&lt;10 to &gt;600 kDa), indicated their nonspecific binding to various intracellular components. In the sample with the highest cytosolic concentration, a shift towards the highest molecular masse (&gt;600 kDa) was observed for lanthanides and actinides, which is a sign of their possible binding to protein aggregates. In contrast, W and Pb showed a preference for medium molecular mass biomolecules (30–100 kDa). Moreover, it was hypothesized that prominent elution of U and Pb observed in the low molecular mass region (&lt;10 kDa) possibly indicated their partial detoxification. Potential Pb associations with metallothionein-like proteins were also recorded (∼6–7 kDa). The remaining two elements, V and Tl, exhibited more specific intracellular binding, as they were eluted within one/two narrow peaks in the high molecular mass region (575 kDa/100–400 kDa). The tendency of the studied TCEs and other potentially toxic elements to bind to medium and high molecular mass intracellular proteins necessitates further research of their specific targets.</p>","PeriodicalId":74,"journal":{"name":"Environmental Science: Processes & Impacts","volume":" 1","pages":" 262-276"},"PeriodicalIF":4.3,"publicationDate":"2025-01-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.rsc.org/en/content/articlepdf/2025/em/d4em00674g?page=search","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142941679","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":"A mechanistic model for determining factors that influence inorganic nitrogen fate in corn cultivation.","authors":"Patrick J Dunn, Leanne M Gilbertson","doi":"10.1039/d4em00566j","DOIUrl":"https://doi.org/10.1039/d4em00566j","url":null,"abstract":"<p><p>Conventional practices for inorganic nitrogen fertilizer are highly inefficient leading to excess nitrogen in the environment. Excess environmental nitrogen induces ecological (<i>e.g.</i>, hypoxia, eutrophication) and public health (<i>e.g.</i>, nitrate contaminated drinking water) consequences, motivating adoption of management strategies to improve fertilizer use efficiency. Yet, how to limit the environmental impacts from inorganic nitrogen fertilizer while maintaining crop yields is a persistent challenge. The lack of empirical data on the fate and transport of nitrogen in an agriculture soil-crop system and how transport changes under varying conditions limits our ability to address this challenge. To this end, we developed a mechanistic model to assess how various parameters within a soil-crop system affect where nitrogen goes and inform how we can perturb the system to improve crop nitrogen content while reducing nitrogen emissions to the environment. The model evaluates nitrogen transport and distribution in the soil-corn plant system on a conventional Iowa corn farm. Simulations determine the amount of applied nitrogen fertilizer acquired by the crop root system, leached to groundwater, lost to tile drainage, and denitrified. Through scenario modeling, it was found that reducing application rates from 200 kg ha^-1 to 160 kg ha^-1 had limited impact on plant nitrogen content, while decreasing wasted nitrogen fertilizer by 25%. Delayed application until June significantly increased the f-NUE and denitrification while reducing the amount of fertilizer leached and exported through tile drainage. The value in a model like the one presented herein, is the ability to perturb the system through manipulation of variables representative of a specific scenario of interest to inform how one can improve crop-based nitrogen management.</p>","PeriodicalId":74,"journal":{"name":"Environmental Science: Processes & Impacts","volume":" ","pages":""},"PeriodicalIF":4.3,"publicationDate":"2025-01-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142941659","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":"Accounting for <i>in situ</i> air cleaner utilization and performance to improve interpretation of patient outcomes in real-world indoor air cleaner intervention trials.","authors":"Saeed Farhoodi, Insung Kang, Yicheng Zeng, Kaveeta Jagota, Nancy Karpen, Mohammad Heidarinejad, Zane Elfessi, Israel Rubinstein, Brent Stephens","doi":"10.1039/d4em00648h","DOIUrl":"https://doi.org/10.1039/d4em00648h","url":null,"abstract":"<p><p>There is an increasing number of randomized clinical trials intended to assess the effectiveness of indoor air cleaners for improving participant outcomes in real-world settings. In this communication, we synthesize the current state of registered air cleaner intervention trials and call attention to the critical importance of conducting measurements to characterize the performance and <i>in situ</i> utilization of air cleaners in such trials to improve interpretation of exposure measurements and patient outcomes. We draw upon the existing literature and preliminary findings from our ongoing one-year, randomized, single-blind, placebo-controlled case-control trial of stand-alone air filtration in the homes of U.S. military Veterans to inform our recommendations. We demonstrate how to conduct industry-standard performance testing and how to use long-term measurements of air cleaner power draw to assess air cleaner operation. In our analysis of interim data from 53 homes to date with a mean data collection period of 275 days, we found that most air cleaners, whether active or sham, were operated predominantly at low or medium fan speeds, and most participants operated their air cleaner on predominantly one fan speed. In a few homes, air cleaners were mostly off. We estimate that air cleaner operation in these homes is providing a median additional equivalent particle loss rate of ∼0.7/h (ranging ∼0-2.8/h). Accordingly, we recommend that air cleaner intervention trials adopt the steps described herein to account for the amount of clean air delivered in real-world settings and to provide important context alongside indoor exposure measurements and analysis of patient outcomes.</p>","PeriodicalId":74,"journal":{"name":"Environmental Science: Processes & Impacts","volume":" ","pages":""},"PeriodicalIF":4.3,"publicationDate":"2025-01-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142941676","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":"Seasonal effect of PM_2.5 exposure in patients with COPD: a multicentre panel study.","authors":"Jin-Young Huh, Hajeong Kim, Shinhee Park, Seung Won Ra, Sung-Yoon Kang, Bock Hyun Jung, Mihye Kim, Sang Min Lee, Sang Pyo Lee, Dirga Kumar Lamichhane, Young-Jun Park, Seon-Jin Lee, Jae Seung Lee, Yeon-Mok Oh, Hwan-Cheol Kim, Sei Won Lee","doi":"10.1039/d4em00376d","DOIUrl":"https://doi.org/10.1039/d4em00376d","url":null,"abstract":"<p><p><i>Background</i>: Exposure to particulate matter <2.5 μm (PM_2.5) is linked to chronic obstructive pulmonary disease (COPD), but most studies lack individual PM_2.5 measurements. Seasonal variation and their impact on clinical outcomes remain understudied. <i>Objective</i>: This study investigated the impact of PM_2.5 concentrations on COPD-related clinical outcomes and their seasonal changes. <i>Methods</i>: A multicentre panel study enrolled 105 COPD patients (age range: 46-82) from July 2019 to August 2020. Their mean forced expiratory volume in 1 second after bronchodilation was 53.9%. Individual PM_2.5 levels were monitored continuously with indoor measurements at residences and outdoor data from the National Ambient Air Quality Monitoring Information System. Clinical parameters, including pulmonary function tests, symptom questionnaires (CAT and SGRQ-C), and impulse oscillometry (IOS), were assessed every three months over the course of one year. Statistical analysis was conducted using a linear mixed-effect model to account for repeated measurements and control for confounding variables, including age, sex, smoking status and socioeconomic status. <i>Results</i>: The mean indoor and outdoor PM_2.5 concentrations were 16.2 ± 8.4 μg m^-3 and 17.2 ± 5.0 μg m^-3, respectively. Winter had the highest PM_2.5 concentrations (indoor, 18.8 ± 11.7 μg m³; outdoor, 22.5 ± 5.0 μg m^-3). Higher PM_2.5 concentrations significantly correlated with poorer St. George's Respiratory Questionnaire for COPD (SGRQ-C) scores and increased acute exacerbations, particularly in winter. Patients of lower socioeconomic status were more vulnerable. Increased PM_2.5 concentrations were also associated with amplified small airway resistance (<i>R</i>5-<i>R</i>20). <i>Conclusions</i>: PM_2.5 concentration changes are positively correlated with poorer SGRQ-C scores and increased acute exacerbations in COPD patients with significant seasonal variations, especially in winter.</p>","PeriodicalId":74,"journal":{"name":"Environmental Science: Processes & Impacts","volume":" ","pages":""},"PeriodicalIF":4.3,"publicationDate":"2025-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142913256","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":"Environmental impact of an acid-forming alum shale waste rock legacy site in Norway†","authors":"Mila K. Pelkonen, Estela Reinoso-Maset, Gareth T. W. Law, Ole Christian Lind and Lindis Skipperud","doi":"10.1039/D4EM00298A","DOIUrl":"10.1039/D4EM00298A","url":null,"abstract":"<p >Alum shale formations in Scandinavia are generally enriched in uranium (U) and, when exposed to air and water, may produce acidic rock drainage (ARD), releasing potentially harmful elements into the environment. Taraldrud is a legacy site in southeast Norway where approx. 51 000 m<small>³</small> of alum shale was deposited in the 1980s–1990s. In 2006, ARD formation became obvious after high concentrations of leachable elements and low environmental pH were measured in a nearby stream. A manmade precipitation pond and liming treatments attempt to address the environmental pollution, but the site remains non-remediated. This study aimed to evaluate the extent of contamination caused by ARD and examine environmental and human health risks caused by mobilized trace elements and radionuclides. Surface water, sediment, soil, and biota samples were collected in the area and chemically and/or radiochemically analyzed to assess the prevailing concentrations within different environmental compartments. The elemental distribution and variation patterns were studied using principal component analysis. Most of the leachable elements were present in highly mobile and bioavailable forms in the pond water, out of which Cd, Mn, Ni, and U exceeded drinking water regulations. The highest enrichment in soil and sediment was for U, which was associated with the sulfide-bearing soil fraction, Fe, Cu, Mo, and As. No changes in water quality were observed between up- and downstream from the site, indicating that the Fe and S rich phases in the pond retain the leachable elements effectively under prevailing environmental conditions. This study provides valuable insights into the risks and challenges associated with ARD and where U is the main pollutant of concern.</p>","PeriodicalId":74,"journal":{"name":"Environmental Science: Processes & Impacts","volume":" 1","pages":" 225-243"},"PeriodicalIF":4.3,"publicationDate":"2025-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.rsc.org/en/content/articlepdf/2025/em/d4em00298a?page=search","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142913253","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":"Chemical characterization of polymer and chloride content in waste plastic materials using pyrolysis – direct analysis in real time – high-resolution mass spectrometry†","authors":"Emily Halpern, Lauren Heirty, Christopher West, Yitao Li, Won M. Kim, Anthony S. Mennito and Alexander Laskin","doi":"10.1039/D4EM00501E","DOIUrl":"10.1039/D4EM00501E","url":null,"abstract":"<p >The increasing global demand for plastic has raised the need for effective waste plastic management due to its long lifetime and resistance to environmental degradation. There is a need for rapid plastic identification to improve the mechanical waste plastic sorting process. This study presents a novel application of Temperature-Programmed Desorption-Direct Analysis in Real Time-High Resolution Mass Spectrometry (TPD-DART-HRMS) that enables rapid characterization of various plastics. This technique was applied on four commercially available reference polymers (polyethylene, polypropylene, polystyrene, polyvinyl chloride) as well as three “waste” plastic samples of mixed origin. These waste plastic samples were obtained as discards from various industrial processes with limited analytical characterization data. Through the application of CH<small>₂</small> Kendrick mass defect (KMD) grouping, characteristic trends in the mass spectra of each sample were identified, allowing for a simplified numerical comparison. This approach utilized a robust statistical approach using the Tanimoto coefficient, allowing for the quantitative measures of similarity between standards and unknown samples. The application of this mathematical evaluation methodology was used to identify plastic types and to distinguish structurally similar polymers. Additionally, we report that a chloride ion clustering effect with copper substrate can identify chlorinated polymer PVC (polyvinyl chloride) utilizing pyro-(−)DART-HRMS mode. PVC polymer is of particular interest in recycling due to its high chloride content, which can present technical challenges for some types of recycling. We found that chloride ion clusters are a good screening marker for the presence of chlorinated polymers in mixed waste plastic samples. This study can possibly help advance rapid and accurate analytical techniques for identifying the composition of waste plastics to advance the effectiveness of the waste plastic sorting process.</p>","PeriodicalId":74,"journal":{"name":"Environmental Science: Processes & Impacts","volume":" 1","pages":" 104-118"},"PeriodicalIF":4.3,"publicationDate":"2024-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.rsc.org/en/content/articlepdf/2025/em/d4em00501e?page=search","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142941677","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":"Reversible and irreversible retention of heavy metals in saturated porous media: association with kaolin.","authors":"Yan Liang, Erxiao Jiang, Hui Tang, Qiuyu Luo, Pengcheng Dong, Tian Xie","doi":"10.1039/d4em00372a","DOIUrl":"https://doi.org/10.1039/d4em00372a","url":null,"abstract":"<p><p>Contamination of heavy metals (HMs) has caused increasing concern due to their ecological toxicities and difficulties in degradation. The transport, retention, and release of HMs in porous media are highly related to their environmental fate and risk to groundwater. Column transport experiments and numerical simulations were conducted to investigate the retention and release behaviors of Cu²⁺, Pb²⁺, Cd²⁺, and Zn²⁺ in the presence and absence of kaolin under varying ionic strengths and cation types. The interaction between HMs and soil colloids is critical to these processes, yet it remains poorly understood. In both single and multi-metal systems, the mobility of HMs ranked as Cd²⁺ > Zn²⁺ > Cu²⁺ > Pb²⁺, is influenced by their hydrolysis ability. Multi-metal systems showed higher mobility due to competition for retention sites, and Ca²⁺ enhanced transport more than Na⁺ due to greater affinity to the sand surface. Kaolin reduced HM transport by adsorption and led to irreversible retention. Cation exchange (Na⁺ replacing Ca²⁺) followed by reduced ionic strength promoted HM release due to the remobilization of kaolin associated with HMs. Uniform, nonmonotonic, and exponential retention profiles indicated variations in the spatial distribution of HMs. The Pb²⁺ and Cu²⁺ were more retained near the column inlet than Cd²⁺ and Zn²⁺, indicating limited mobility in the deep subsurface. Numerical simulations well described HM transport, considering the adsorption and desorption of HMs and the solid-water interface. These results enhance understanding of HM fate in terrestrial environments.</p>","PeriodicalId":74,"journal":{"name":"Environmental Science: Processes & Impacts","volume":" ","pages":""},"PeriodicalIF":4.3,"publicationDate":"2024-12-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142880738","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}