Environmental Research最新文献

{"title":"Comammox-based simultaneous nitrification and denitrification in mainstream membrane-aerated biofilm reactor – A modeling study","authors":"Shukang Cui ,&nbsp;Runan Yang ,&nbsp;Ying Zhu ,&nbsp;Jiaying Hou ,&nbsp;Yuanji Shi ,&nbsp;Meiying Xu ,&nbsp;Linyan Yang ,&nbsp;Xueming Chen","doi":"10.1016/j.envres.2025.122423","DOIUrl":"10.1016/j.envres.2025.122423","url":null,"abstract":"<div><div>This study applied a novel complete ammonium oxidation (comammox)-inclusive biological nitrogen removal (BNR) model to simulate total nitrogen (TN) removal and nitrous oxide (N₂O) production in mainstream membrane-aerated biofilm reactor (MABR) performing simultaneous nitrification and denitrification (SND). The results were compared with those from a conventional comammox-exclusive BNR model under the same operational conditions. The findings revealed that the MABR involving the functionality of comammox bacteria capable of two-step nitrification demonstrated superior TN removal performance compared to the MABR performing the conventional ammonium-oxidizing bacteria (AOB)-based SND. Although comammox bacteria cannot produce N₂O directly, the unexpected functional shift of heterotrophic denitrifying bacteria from an N₂O sink in the MABR with AOB-based SND to an N₂O source in the MABR with comammox-based SND resulted in even higher N₂O production factors in the latter driven by the abundant nitrite/nitrate supply provided by comammox bacteria performing two-step nitrification under specific conditions (e.g., O₂ surface loading ≥ 3.53 g-O₂/m²/d and hydraulic retention time (HRT) ≥ 0.7 d). By precisely regulating operational conditions (e.g., O₂ surface loading = 3.16 g-O₂/m²/d, influent C/N ratio = 6, HRT = 0.60 d, and steady-state biofilm thickness = 300 μm), the MABR performing comammox-based SND could achieve efficient TN removal (e.g., 81.3 %) with minimal N₂O production/emissions (e.g., 0.06 %). This study demonstrated the feasibility of establishing comammox-based SND in MABR and provided critical insights for advancing further research and design/control of sustainable BNR systems.</div></div>","PeriodicalId":312,"journal":{"name":"Environmental Research","volume":"285 ","pages":"Article 122423"},"PeriodicalIF":7.7,"publicationDate":"2025-07-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144702547","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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":"Composite dust suppression material of fish scale based chitosan intercalated MMT: Synthesis process, performance parameters, and mechanism of action","authors":"Gang Zhou ,&nbsp;Shu Li ,&nbsp;Shuo Lu ,&nbsp;Xi Chen ,&nbsp;Jingxu Chen ,&nbsp;Gang Li ,&nbsp;Mengrou Zhao ,&nbsp;Hongrui Qu ,&nbsp;Shuailong Li","doi":"10.1016/j.envres.2025.122405","DOIUrl":"10.1016/j.envres.2025.122405","url":null,"abstract":"<div><div>The exposure of petroleum coke to wind in open-air petroleum coke stockpiles results in dust pollution, adversely impacting the local ecosystem and public health. To address the inadequate wetting properties of water spray dust suppression technology for petroleum coke, which is prone to volatilization and secondary dust generation, a new durable dust suppression material with enhanced wetting capabilities and the capacity to create a solidified shell, CTS-CN/MMT, has been developed. This dust suppression material is synthesized by extracting chitosan (CTS) from discarded fish scales, reacting it with cinnamaldehyde to create a Schiff base (CTS-CN), and subsequently polymerizing it with montmorillonite (MMT). Through establishing a response surface model, the optimum process conditions were determined with the dust suppression rate of 91.17 %. Performance testing indicated that the contact angle on petroleum coke powder cake was 36.52°, demonstrating successful wetting of the dust, while the compressive strength of the solidified shell generated with petroleum coke dust after drying was 81.62 KPa. Characterization results showed that CTS-CN/MMT can establish a three-dimensional network structure, enhancing water retention and prolonging efficacy duration. The weathering test confirmed that the wind erosion rate of CTS-CN/MMT was 13.23 % at a wind speed of 17 m/s, exhibiting robust erosion resistance in both freezing and heat conditions. Material Studios software was used to research the dust suppression mechanism. The findings declared that the \"spider-like\" multicomponent synergistic effect of CTS-CN/MMT positively influenced the dust control of petroleum coke, contributing to environmental sustainability and the reutilization of biological resources.</div></div>","PeriodicalId":312,"journal":{"name":"Environmental Research","volume":"285 ","pages":"Article 122405"},"PeriodicalIF":7.7,"publicationDate":"2025-07-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144705926","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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":"Source identification and partition behavior of organophosphate esters in surface water bodies of a megacity in northwest China based on self-organizing map and fugacity fraction","authors":"Qian Zhang,&nbsp;Lijun Wang","doi":"10.1016/j.envres.2025.122422","DOIUrl":"10.1016/j.envres.2025.122422","url":null,"abstract":"<div><div>A total of 111 surface water, suspended particulate matter (SPM), and sediment samples were collected from the megacity of Xi'an in Northwest China to study the source, partitioning behavior, and ecological risk of 13 organophosphate esters (OPEs) by self-organizing map, fugacity fraction (<em>ff</em>), and risk quotient (RQ). The total concentration of 13 OPEs (Ʃ₁₃OPEs) in surface water, SPM, and sediment averaged 68.0 ± 26.8 ng/L, 6.27 ± 2.04 ng/L, and 26.2 ± 13.4 ng/g (dw), respectively, dominated by chlorinated and alkyl OPEs. The Ʃ₁₃OPEs demonstrated an increasing trend from upstream to downstream in urban river water, while this distribution pattern was not apparent in sediment. OPEs originated from wastewater treatment plant discharges, traffic emissions, and atmospheric depositions in urban river water as well as its SPM and sediment, while OPEs-containing product release/abrasion, traffic emissions, and atmospheric depositions in urban artificial lake water and its SPM. Alkyl OPEs tended to diffuse from water to sediment with <em>ff</em> &lt; 0.5, while chlorinated OPEs inclined to diffuse from sediment to water with <em>ff</em> &gt; 0.50. OPEs posed a negligible ecological risk to algae and fish (RQ &lt; 0.01), while a low to medium ecological risk to crustaceans, especially for 2-ethylhexyl diphenyl phosphate with RQ of 0.01–0.50.</div></div>","PeriodicalId":312,"journal":{"name":"Environmental Research","volume":"285 ","pages":"Article 122422"},"PeriodicalIF":7.7,"publicationDate":"2025-07-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144705930","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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":"Refined bifunctional deep eutectic solvent for one-step selective indium and tin recovery from spent LCDs","authors":"Yadi Wang,&nbsp;Runchang Su,&nbsp;Shujie Tang,&nbsp;Mei Zhang,&nbsp;Min Guo","doi":"10.1016/j.envres.2025.122400","DOIUrl":"10.1016/j.envres.2025.122400","url":null,"abstract":"<div><div>In this study, a bifunctional deep eutectic solvent (DES), consisting of choline chloride (ChCl) and oxalic acid dihydrate (OAD), is introduced for the efficient and eco-friendly recovery of indium (In) from indium tin oxide (ITO) - coated glass extracted from discarded liquid crystal displays (LCDs). An innovative one - step in - situ separation process is demonstrated, which exhibits high efficiency and selectivity. A comprehensive investigation was conducted into the leaching conditions affecting In recovery, including temperature, duration, solvent ratio, and solid - to - liquid ratio. Response Surface Methodology (RSM) was employed to optimize these parameters, determining the optimal conditions to be an 80 °C treatment for 8 h, a 2.6:1 M ratio of ChCl to OAD, and a solid-to-liquid ratio of 10 g/L. Under these conditions, a remarkable 95.6 % In recovery efficiency was achieved, with tin (Sn) retained as tin oxide (SnO₂). Notably, the DES (2.6ChCl:1OAD) maintained a recovery efficiency of approximately 75 % even after six cycles, highlighting its excellent cyclic stability. In addition, a thorough analysis of the reaction pathway and mechanism underlying this separation process is provided. This study not only underscores the superior selectivity and efficiency of DES in In recovery but also establishes its suitability for real - world applications, presenting a novel approach to the valorization of waste LCDs.</div></div>","PeriodicalId":312,"journal":{"name":"Environmental Research","volume":"285 ","pages":"Article 122400"},"PeriodicalIF":7.7,"publicationDate":"2025-07-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144705929","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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":"Millennial-scale depth-resolved ancient microbial diversity and pathogenic potential in Styx Glacier, Antarctica","authors":"Minkyung Kim ,&nbsp;Hanbyul Lee ,&nbsp;Subin Lee ,&nbsp;Yeongcheol Han ,&nbsp;Ok-Sun Kim","doi":"10.1016/j.envres.2025.122421","DOIUrl":"10.1016/j.envres.2025.122421","url":null,"abstract":"<div><div>The cryosphere offers crucial insights into historical ecosystems and biomes on our planet, preserving ancient microorganisms and other biological materials. The recent discovery of pathogens released from permafrost and Arctic regions has emphasized potential threats to human health. However, the ancient microbial diversity in Antarctic glaciers remains largely unexplored. To address this gap, we investigated the microbial diversity and the presence of potential pathogens in the Styx ice core (Northern Victoria Land, Antarctica) with millennial-scale dated between 525 and 1978 CE. A total of 656 isolates, representing 27 species, were obtained by incubation on four different media at 10 °C and 25 °C. Among the cultured isolates, the Alphaproteobacteria was the predominant class, with <em>Sphingomonas echinoides</em> (70 % at 10 °C) and <em>Bradyrhizobium elkanii</em> (76.2 % at 25 °C) being the most prevalent species across all depths. Genomic analysis of four isolates (<em>Roseomonas mucosa</em>, <em>Gordonia hongkongensis</em>, <em>Paenibacillus glucanolyticus</em>, and <em>Dermacoccus nishinomiyaensis</em>) among nine species suspected to be potential pathogens was performed to identify the presence of antibiotic resistance and virulence genes. Amino acid sequences of HbhA, a mycobacterial surface antigen, in <em>G. hongkongensis</em> strains exhibit AKKA repeat motifs, similar to those found in pathogenic <em>Mycobacterium tuberculosis</em> and <em>Nocardia cyriacigeorgica</em>. Furthermore, the hemolysin produced by <em>R. mucosa</em> and <em>P. glucanolyticus</em> showed no activity at 25 °C but exhibited activity at 37 °C. This study demonstrated that glacial ice contains core microbiomes and also highlighted the presence of potential opportunistic pathogens, resonating between ancient microbiology and contemporary environmental health concerns.</div></div>","PeriodicalId":312,"journal":{"name":"Environmental Research","volume":"285 ","pages":"Article 122421"},"PeriodicalIF":7.7,"publicationDate":"2025-07-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144705928","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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":"Recent developments in halide perovskite based Z-scheme heterostructures for solar CO2 reduction","authors":"Fan Xue ,&nbsp;Rameshwari Verma ,&nbsp;Sahana Raju ,&nbsp;Santosh Kumar Verma ,&nbsp;Haijun Yan ,&nbsp;K. Pramoda ,&nbsp;Kothanahally S. Sharath Kumar","doi":"10.1016/j.envres.2025.122416","DOIUrl":"10.1016/j.envres.2025.122416","url":null,"abstract":"<div><div>Z-scheme charge transfer mechanism is thought as one of the promising concepts for photocatalyst design, to eventually commercialize photocatalytic CO₂ reduction. However, the photocatalytic CO₂ reduction using Z-scheme photocatalyst systems did not give the expected performance. As a case study, the halide perovskites based photocatalyst with Z-scheme configuration is reviewed here. Approaches to stabilize halide perovskites are also reviewed. Finally, it has been uniquely visualized why Z-scheme photocatalytic systems do not exhibit the expected photocatalytic activity. It will be clarified what the real hurdles are, and what practical solutions can be proposed.</div></div>","PeriodicalId":312,"journal":{"name":"Environmental Research","volume":"285 ","pages":"Article 122416"},"PeriodicalIF":7.7,"publicationDate":"2025-07-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144702439","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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 potential mechanism of triclosan-induced neurotoxicity in zebrafish at environmental Concentrations: Splicing disruption of tecra mediates the circRNA266/miR-214/dapk2-gad2 axis","authors":"Zejun Wang ,&nbsp;Zhuoya Dai ,&nbsp;Xiaowen Han ,&nbsp;Xincong Su ,&nbsp;Xiao Yang ,&nbsp;Xuedong Wang ,&nbsp;Jin Yan ,&nbsp;Qiuhui Qian ,&nbsp;Huili Wang ,&nbsp;Randy A. Dahlgren","doi":"10.1016/j.envres.2025.122398","DOIUrl":"10.1016/j.envres.2025.122398","url":null,"abstract":"<div><div>Many environmental pollutants are known to exhibit neurotoxic effects; however, the initiating molecular events and their associated adverse outcome pathways (AOPs) remain largely unclear. This study investigated the role of circRNA266 and its target miRNA in Triclosan (TCS)-induced neurodevelopmental toxicity in zebrafish (<em>Danio rerio</em>) based on candidates circRNAs identified via high-throughput sequencing. Toxicological effects were characterized at multiple levels, including phenotype alterations, motor behavior, neural damage, and the expression of marker genes. TCS exposure was found to upregulate circRNA266, thereby reducing the availability of free miR-214. As a crucial neuroprotective factor, miR-214 downregulation was associated with increased expression of <em>dapk2</em> and <em>gad2</em>, resulting in elevated inhibitory neurotransmitter levels and neuronal apoptosis. Furthermore, molecular docking analysis suggests that the upregulation of circRNA266 by TCS may occur via its interaction with U2AF1, thereby disrupting the splicing of the <em>tecra</em> gene. While high concentrations of TCS caused marked neurotoxic phenotypes and behavioral impairments, environmentally relevant concentrations did not elicit overt symptoms. Nonetheless, the activation of key molecular events within the AOP framework suggests a potential neurotoxic risk even at low exposure levels. This study is the first to confirm that TCS induces neurotoxicity in zebrafish by interfering with the splicing of the <em>tecra</em> gene and mediating the regulatory role of the circRNA266/miR-214/<em>dapk2</em>-<em>gad2</em> signaling axis. These findings provide novel insights into the molecular mechanisms of TCS-induced neurotoxicity and propose a potential new AOP model for environmental risk assessment.</div></div>","PeriodicalId":312,"journal":{"name":"Environmental Research","volume":"285 ","pages":"Article 122398"},"PeriodicalIF":7.7,"publicationDate":"2025-07-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144697241","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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":"Contamination and risk assessment of Thallium in the alluvial paddy rice soil system of Pakistan","authors":"Waqar Ali ,&nbsp;Kang Mao ,&nbsp;Muhammad Shafeeque ,&nbsp;Muhammad Wajahat Aslam ,&nbsp;Hua Zhang ,&nbsp;Wei Li","doi":"10.1016/j.envres.2025.122388","DOIUrl":"10.1016/j.envres.2025.122388","url":null,"abstract":"<div><div>Thallium (Tl) is considered a highly toxic trace metal. This study not only examines Tl contamination in paddy soil and its accumulation in rice tissues within the Alluvial Indus Basin of Pakistan, but also evaluates its potential risk associated with the food chain. Tl concentrations in paddy soil ranged from 0.01 to 5.89 mg/kg, averaging 0.89 mg/kg, which exceeded the typical background level of 0.58 mg/kg in Chinese soils. Tl levels in rice grains ranged from 0.11 to 1.78 mg/kg, averaging 0.33 mg/kg, with 15.5 % of samples exceeding the Food Safety and Standards Authority of India's (FSSAI) limit of 0.2 mg/kg, confirming Tl accumulation and raising health concerns. Geographically weighted regression (GWR) modelling revealed spatially varying correlations between rice Tl and soil (pH, SOM, TOC, TIC, TC, and Tl) and plant tissue (shoot and root Tl) variables, with differential impacts on Tl accumulation. The GWR model determined the Critical Tl Threshold (CTT) for Tl concentrations in paddy soil, confirming significant Tl risk in areas exceeding the CTT. The GWR model also assessed Tl Loading Capacity (TLC), defined as the difference between the CTT and the actual Tl concentration in paddy soil. This analysis identified areas at risk for Tl contamination in rice, classified as low-risk (10 %), high-risk (59.2 %), and very high-risk (30.8 %). The study highlights that children face a significantly higher health risk from Tl exposure, with a Hazard Index (HI) of 29.6 %, exceeding the safety threshold. In comparison, adults and lifetime exposure have lower HI values of 19.6 % and 19 %, respectively. These findings underscore the need for effective soil management strategies to mitigate Tl contamination and associated health risks.</div></div>","PeriodicalId":312,"journal":{"name":"Environmental Research","volume":"285 ","pages":"Article 122388"},"PeriodicalIF":7.7,"publicationDate":"2025-07-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144697244","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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":"Concurrent associations of glyphosate, dithiocarbamate fungicides, and PFAS with body fat composition and BMI in adolescents from agricultural communities","authors":"Alexis Elliott ,&nbsp;Rajendra Prasad Parajuli ,&nbsp;Matthew Mazzella ,&nbsp;Kun Yang ,&nbsp;Briana N.C. Chronister ,&nbsp;Carin A. Huset ,&nbsp;Lisa A. Peterson ,&nbsp;Danilo Martinez ,&nbsp;Dana Boyd Barr ,&nbsp;Parita Ratnani ,&nbsp;Chris Gennings ,&nbsp;Franklin de la Cruz ,&nbsp;Jose Suarez-Torres ,&nbsp;Jose R. Suarez-Lopez","doi":"10.1016/j.envres.2025.122378","DOIUrl":"10.1016/j.envres.2025.122378","url":null,"abstract":"<div><h3>Background</h3><div>Dithiocarbamate fungicides, glyphosate, and per- and polyfluoroalkyl substances (PFAS) are chemicals found in agricultural settings. These chemicals have been linked to anthropometric indicators, but findings are contradictory. This study evaluated associations of PFAS, glyphosate, and dithiocarbamate metabolites (ethylene thiourea [ETU] and propylene thiourea [PTU]) with anthropometric indicators among adolescents in agricultural settings.</div></div><div><h3>Methods</h3><div>We examined 535 adolescents in agricultural communities in Ecuador (ESPINA study) in 2016. Concentrations of urinary pesticides, 6 serum PFAS, and all co-variates of interest were measured in 507 participants. Associations between chemicals and anthropometric measures were calculated using linear regression, and chemical mixtures were assessed using weighted quantile sum regression (WQS). Models adjusted for sex, race, parental education, and number of smokers at home.</div></div><div><h3>Results</h3><div>Glyphosate had a significant negative association with body mass index (BMI)-for-age z score (difference per a 2-fold increase of chemical concentration (β) = −0.06 SD [95 % CI: −0.12, −0.02]) and % body fat (β = −0.31 % [95 % CI: −0.58, −0.04]). ETU also had a significant negative association with BMI-for-age z score (β = −0.07 SD [-0.12, −0.01]). The mixture of chemicals was also negatively associated with BMI-for-age z scores (difference per a decile increase in the mixture (β_WQS): −0.10 SD [-0.14, −0.05]) and % body fat (β_WQS: −0.44 % [-0.72, −0.17]).</div></div><div><h3>Conclusions</h3><div>Glyphosate, and to an extent ETU, had negative associations with BMI and % body fat in adolescents in these cross-sectional analyses. The mixture of all 4 chemicals had stronger associations with these outcomes compared to any individual chemical. Longitudinal analyses are warranted. These exploratory findings may inform future hypothesis-driven research on pesticide exposures and adolescent body composition.</div></div>","PeriodicalId":312,"journal":{"name":"Environmental Research","volume":"285 ","pages":"Article 122378"},"PeriodicalIF":7.7,"publicationDate":"2025-07-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144697243","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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":"Changes in sedimentary organic carbon sources from rivers to bays and their responses to human activities","authors":"Rijun Hu ,&nbsp;Donghan Li ,&nbsp;Jiandong Qiu ,&nbsp;Jixuan Lyu ,&nbsp;Yang Wang ,&nbsp;Yongchen Xu ,&nbsp;Xiaodong Zhang ,&nbsp;Longhai Zhu ,&nbsp;Jingrui Li","doi":"10.1016/j.envres.2025.122353","DOIUrl":"10.1016/j.envres.2025.122353","url":null,"abstract":"<div><div>Human activities have significantly altered the sources and concentrations of organic carbon (OC) in sediments of rivers and bays, and small-to medium-sized rivers are particularly sensitive to these changes. This study investigates the sources and sequestration of OC in sediments across Laizhou Bay and its riverine inflows under varying human influences. Analyses of total organic carbon (TOC), total nitrogen (TN), δ¹³C, δ¹⁵N, and C/N ratios indicate that rivers along the southern coast deliver substantial OC fluxes to the ocean. Bayesian stable isotope mixing model analysis reveals that organic matter (OM) in the lower Yellow and Xiaoqing Rivers is mainly derived from soil OM, with minor contributions from sewage. In contrast, OM in the Bailang, Wei, and Jiaolai Rivers predominantly originates from sewage and phytoplankton, reflecting the significant impact of human activities. In Laizhou Bay, terrestrial and marine contributions to OC are 57 % and 43 %, respectively, with shellfish biodeposition playing a crucial role. Overall, human activities such as sewage discharge and shellfish farming have markedly reshaped the sources and contributions of OC across the river-to-bay continuum. Industrial, agricultural, and marine aquaculture activities play critical roles in shaping the river-bay OC system and should not be overlooked.</div></div>","PeriodicalId":312,"journal":{"name":"Environmental Research","volume":"285 ","pages":"Article 122353"},"PeriodicalIF":7.7,"publicationDate":"2025-07-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144670883","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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}