Environmental Science: Processes & Impacts最新文献

{"title":"Spatial distribution and soil-to-plant transfer factors of radionuclides in agricultural soil around the Barapukuria coal mining site, Bangladesh.","authors":"Tonima Parvin, Saiful Islam, Jannatul Ferdous, Saurav Dey Shuvo, Pradip K Bakshi","doi":"10.1039/d4em00653d","DOIUrl":"https://doi.org/10.1039/d4em00653d","url":null,"abstract":"<p><p>In order to investigate the level of radioactivity and translocation of radionuclides from soil to plants, fifteen agricultural soil and fifteen edible plant samples grown in soils were collected from Barapukuria coal mining area, Bangladesh. The physicochemical properties (pH, EC, %OC, %OM, %N, %P, and N/P) were evaluated and the XRD patterns of soil samples were obtained. The gamma activity of ²³⁸U, ²³²Th, and ⁴⁰K in soil and plant samples was analyzed by gamma-ray spectroscopy with an HPGe detector. The activity concentrations in soil samples varied in the order of ⁴⁰K > ²³⁸U > ²³²Th. The gross alpha and gross beta activity were also measured by using a ZnS(Ag) scintillation counter. The average gross alpha and gross beta activity in soil and plant samples were found to be 119 ± 4 Bq kg^-1 and 384 ± 17 Bq kg^-1, and 35.49 ± 1.94 Bq kg^-1 and 249 ± 10 Bq kg^-1, respectively. The calculated mean transfer factors (TFs) for ²³⁸U, ²³²Th, and ⁴⁰K were 0.21, 0.20 and 0.32, respectively. Spinach (<i>Amaranthus lividus</i>) had the highest uptake of ²³⁸U (TF value of 0.30), while cauliflower (<i>Brassica oleracea</i>) showed the greatest (TF value of 0.08). Nonetheless, in the cases of ²³²Th and ⁴⁰K, the highest TFs were observed for malabar spinach (<i>Basella alba</i>) (TF value of 0.31) and green pea leaf (<i>Pisum sativum</i>) (TF value of 0.45). According to the radiation hazard assessment, the levels were often lower than the UNSCEAR world-average values. The contamination factor (CF) indicates that the soil samples were moderately contaminated by ²³⁸U. Correlation analysis revealed that ²³²Th was mostly responsible for radiation health hazards, whereas for plant samples, ⁴⁰K was responsible for the internal hazard index.</p>","PeriodicalId":74,"journal":{"name":"Environmental Science: Processes & Impacts","volume":" ","pages":""},"PeriodicalIF":4.3,"publicationDate":"2025-05-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144109139","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":"Evaluation of emissions and spatial distribution of methane from offshore oil and gas platforms in the Liaodong Bay of China based on shipboard measurement.","authors":"Yue Yu, Zongcai He, Qing Su, Xuemei Xu, Jiayi Cheng, Yue Ming, Xiaomeng Wang, Hong Chen, Jianbo Han","doi":"10.1039/d4em00758a","DOIUrl":"https://doi.org/10.1039/d4em00758a","url":null,"abstract":"<p><p>Offshore oil and gas platforms are a notable source of methane (CH₄) in the marine environment, yet there remains a lack of comprehensive understanding regarding their impact along the coastal areas of China. Besides, relevant emissions are generally derived from systematic inventory and rarely quantified by top-down methods. To this end, a ship-based measurement of CH₄ emissions from three offshore oil and gas platforms with different oil and gas production levels was conducted over the Liaodong Bay of China in August 2023. The results demonstrated that there were differences in CH₄ background concentrations around the three platforms (2291 ± 15 ppb, 2468 ± 32 ppb and 2100 ± 12 ppb). At moderate wind speeds, CH₄ levels showed a gradual increase as the ship approached the target upwind, with peak concentrations typically observed within a range of 2-3 km from the platform. Along with meteorological data and the Gaussian plume model, CH₄ emission rates were determined corresponding to the average values of 229 ± 48 kg h^-1, 59 ± 16 kg h^-1 and 13 ± 8 kg h^-1 for the three platforms. By analyzing the concurrent changes in carbon dioxide concentration, it was hypothesized that gas flaring was the primary source of CH₄ emissions from one of the platforms. Additionally, when considering the revised emission factors for the oil and gas industry from the IPCC and combining them with the production data from the three platforms, the results clearly demonstrated a substantial contrast between top-down emissions and inventory emissions. Diverse platforms and continuous monitoring are necessary to validate the aforementioned perspective and ultimately enhance the precision of CH₄ emission data provided to regulators and the general public.</p>","PeriodicalId":74,"journal":{"name":"Environmental Science: Processes & Impacts","volume":" ","pages":""},"PeriodicalIF":4.3,"publicationDate":"2025-05-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144109084","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":"Role of sediment particle size in cypermethrin toxicity to <i>Chironomus dilutus</i> and <i>Hyalella azteca</i>: insights from bioavailability and exposure pathways.","authors":"Hang Su, Jie Zhang, Huizhen Li, Jing You","doi":"10.1039/d5em00100e","DOIUrl":"https://doi.org/10.1039/d5em00100e","url":null,"abstract":"<p><p>Variation in sediment particle properties gives rise to diverse settling velocities and distances, leading to distinct distributions of particle sizes in field sediments, while the impact of particle size on sediment toxicity is scarcely known. We investigated the variations in spiked-sediment toxicity across different particle sizes (<20 μm, 63-180 μm, 180-500 μm, and original) with cypermethrin, one of the main toxicity contributors in sediment from South China, as the target compound and two invertebrates <i>Chironomus dilutus</i> and <i>Hyalella azteca</i> as the testing species. Cypermethrin in fine sediments was more toxic than in coarse sediments, as evidenced by lower LC50 values, even though the desorption rate from fine sediments was slower than that from coarse sediments. The LC50 and LC25 (μg per g OC) values of cypermethrin for <i>C</i>. <i>dilutus</i> and <i>H</i>. <i>azteca</i> differed by 5- and 4-fold, respectively, across sediments. The variation in toxicity was only partially reduced when the LC50 values were based on bioavailable concentrations derived from biomimetic extraction methods, implying that bioavailability was not responsible for the enhanced toxicity of fine particle sizes. The ingestion of fine sediment particles bound with cypermethrin may significantly contribute to sediment toxicity to benthic and epibenthic invertebrates, underscoring the importance of evaluating multiple exposure pathways in sediment toxicity assessments.</p>","PeriodicalId":74,"journal":{"name":"Environmental Science: Processes & Impacts","volume":" ","pages":""},"PeriodicalIF":4.3,"publicationDate":"2025-05-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144092211","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":"Spatiotemporal changes in chlorophyll-a concentration in China's lakes and its driving factors.","authors":"Liwei Gao, Xin Huang, Xueqiang Lu, Yindong Tong, Jianfeng Feng, Yingying Xu, Yan Lin","doi":"10.1039/d4em00731j","DOIUrl":"https://doi.org/10.1039/d4em00731j","url":null,"abstract":"<p><p>This study provides a comprehensive analysis of the temporal and spatial variations in chlorophyll-a (Chl-a) concentrations across 524 lakes in China from 2007 to 2016, leveraging extensive water quality monitoring data to identify the key drivers of these changes. Our results indicate a general decline in Chl-a concentrations, suggesting a mitigation of eutrophication. However, significant regional and seasonal disparities persist, reflecting varying ecological conditions and anthropogenic influences. Elevated Chl-a concentrations were predominantly observed in regions with intensive agricultural and urban areas, such as the middle and lower reaches of the Yangtze River, the Pearl River Delta, and the North China Plain. In contrast, lower concentrations were recorded in areas with extensive forest and grassland cover, such as the northeast and southwest. Multiple linear regression analysis revealed that ammonia nitrogen (NH₃-N) and chemical oxygen demand (COD_Mn) were the primary factors influencing Chl-a levels during the growing season, while water temperature (W-T), COD_Mn, and pH had greater impacts in the non-growing season. Categorized according to the key factors influencing Chl-a concentration, 52 lakes were divided into 7 categories, and future Chl-a concentrations were projected using data from the China National Environmental Monitoring Centre and the China Environmental Status Bulletin. Specifically, we estimate a 3.060% annual decrease in COD_Mn and a 2.748% annual decrease in NH₃-N, total nitrogen (TN), and total phosphorus (TP), alongside a 0.350% annual increase in water temperature. These projections suggest that while most lakes are expected to see reductions in Chl-a concentrations, some COD_Mn-sensitive and water temperature-sensitive lakes may still experience increases, underscoring the complexity of interactions between multiple environmental factors. To address these dynamics, we recommend targeted management strategies, including reducing nutrient and organic matter inputs, enhancing ecological protection measures, and closely monitoring temperature fluctuations to mitigate the risk of algal blooms and maintain lake health.</p>","PeriodicalId":74,"journal":{"name":"Environmental Science: Processes & Impacts","volume":" ","pages":""},"PeriodicalIF":4.3,"publicationDate":"2025-05-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144074983","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":"Neonicotinoid pesticide residues in bottled water: a worldwide assessment of distribution and human exposure risks.","authors":"Yuanchen Chen, Ruirui Meng, Gege Liu, Wenfei Yu, Hangbiao Jin","doi":"10.1039/d4em00813h","DOIUrl":"https://doi.org/10.1039/d4em00813h","url":null,"abstract":"<p><p>Neonicotinoid pesticides, recognized for their broad-spectrum efficacy, are extensively applied in agriculture, leading to widespread contamination of soil and surface waters and posing significant risks to non-target organisms, wildlife, and human health. While many studies have reported neonicotinoid residues in surface and tap water, the potential risk of human exposure through bottled water remains unknown. This study analyzed 84 natural mineral water samples and 13 purified bottled water samples collected across five continents to determine the residual concentrations of nine neonicotinoid pesticides. At least one neonicotinoid pesticide was detected in all samples. The highest concentrations of total neonicotinoids were found in bottled water from Asia (62.56 ± 39.56 ng L^-1), followed by similar levels in Oceania (21.66 ± 7.21 ng L^-1) and South America (21.21 ± 15.68 ng L^-1), while lower concentrations were observed in Europe (15.84 ± 11.56 ng L^-1) and North America (8.77 ± 3.07 ng L^-1). Residual concentrations were significantly higher in purified bottled water (70.71 ± 42.29 ng L^-1) than in natural mineral water (19.15 ± 14.75 ng L^-1). Seasonal variations were observed, with concentrations higher during the dry season. Additionally, a significant positive correlation was found between pesticide usage and neonicotinoid residues in natural mineral water. Based on the Monte Carlo simulation, the average daily intake of neonicotinoids from bottled water was estimated at 0.64 ± 0.50 ng per kg per day, with a range of 0.12-2.88 ng per kg per day, and the highest exposure was observed in the infant group (4.28 ± 1.14 ng per kg per day), all of which were below the reference dose of 0.057 mg per kg per day. The results provide new insights into personal exposure to neonicotinoids through drinking water.</p>","PeriodicalId":74,"journal":{"name":"Environmental Science: Processes & Impacts","volume":" ","pages":""},"PeriodicalIF":4.3,"publicationDate":"2025-05-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143957635","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 optimized TCN-LSTM model for predicting PM_2.5 in metro systems.","authors":"Canyun Yang, Zhang Kai, Xinyuan Wang, Tong Hu, Hongbin Liu","doi":"10.1039/d5em00249d","DOIUrl":"https://doi.org/10.1039/d5em00249d","url":null,"abstract":"<p><p>Metro has become one of the main transportation modes for people's daily travel, and a good indoor air environment helps ensure people's health. This study aims to develop a data-driven, soft-measurement-based model for predicting and optimizing key metrics of metro air quality. In order to capture the key features in the indoor air quality data, a new model combining a temporal convolutional network (TCN) and long short-term memory (LSTM) is introduced in this study. As an example, subway air quality data from Seoul City Hall Station in South Korea are unified to reduce the complexity of the subsequent process. The TCN and LSTM, which perform better as single models, are chosen to build a hybrid model to capture more detailed features in it, and an attention mechanism is introduced to predict PM_2.5, which is the most important metric in indoor air quality data. In addition, experiments are conducted to compare the size of the residual modules and convolution kernels, which are critical parameters in the TCN model. Finally, the proposed TCN-LSTM model achieves a coefficient of determination of 0.88 on the test set, demonstrating superior prediction performance relative to other baseline models.</p>","PeriodicalId":74,"journal":{"name":"Environmental Science: Processes & Impacts","volume":" ","pages":""},"PeriodicalIF":4.3,"publicationDate":"2025-05-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143951487","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":"Spontaneous aqueous defluorination of trifluoromethylphenols: substituent effects and revisiting the mechanism.","authors":"Zhefei Guo, Geneviève W Tremblay, Jingdan Chen, Shira Joudan","doi":"10.1039/d4em00739e","DOIUrl":"https://doi.org/10.1039/d4em00739e","url":null,"abstract":"<p><p>Trifluoromethylphenols (TFMPs) are environmental contaminants that exist as transformation products of aryl-CF₃ pharmaceuticals and agrochemicals. Their -CF₃ moiety raises concerns as it may form problematic fluorinated transformation products such as the persistent pollutant trifluoroacetic acid (TFA). This study investigates the hydrolysis and spontaneous defluorination mechanisms of 2-TFMP, 3-TFMP, 4-TFMP, and 2-Cl-4-TFMP under environmentally relevant aqueous conditions, and under alkaline pH to investigate the mechanism of defluorination. 3-TFMP did not undergo hydrolysis. The other TFMPs reacted to primarily form the corresponding hydroxybenzoic acids and fluoride. High-resolution mass spectrometry identified a benzoyl fluoride intermediate in the hydrolysis of 4-TFMP and other dimer-like transformation products of the 4- and 2-Cl-4-TFMP. Density functional theory calculations revealed that the key defluorination step likely proceeds <i>via</i> an E1cb mechanism, driven by β-elimination. Experimental and computational results demonstrated substituent-dependent differences in reactivity, and the importance of the deprotonation of TFMPs for the hydrolysis reaction to proceed. These findings provide mechanistic insights into the complete defluorination of TFMPs and broader implications for the environmental defluorination of other PFAS.</p>","PeriodicalId":74,"journal":{"name":"Environmental Science: Processes & Impacts","volume":" ","pages":""},"PeriodicalIF":4.3,"publicationDate":"2025-05-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143955033","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":"PFAS drinking water treatment trade-offs: comparing the health burden of GAC treatment to the health benefits of reduced PFAS exposure.","authors":"Sanne J Smith, Émile Sylvestre, Anne Marieke Motelica-Wagenaar, Beatrice Cantoni, Parvathi Suresh Nair, Mar Palmeros Parada","doi":"10.1039/d5em00238a","DOIUrl":"https://doi.org/10.1039/d5em00238a","url":null,"abstract":"<p><p>To protect human health, limits for the concentrations of per- and polyfluoroalkyl substances (PFAS) in drinking water are decreasing in many countries. However, the required treatment to achieve these lower concentrations is more resource and energy intensive than conventional drinking water treatment. Consequently, this intensified water treatment has an indirect negative impact on human health. For example, treatment with granular activated carbon (GAC), commonly used for PFAS removal, can lead to particulate matter emissions and additional global warming. These negative impacts partly off-set the health benefit achieved by lower PFAS exposure <i>via</i> drinking water. In this study, we quantified health impacts of both the increased treatment and the reduced PFAS exposure in disability-adjusted life years (DALYs), to assess whether PFAS removal from drinking water to specified targets with GAC results in a net health benefit. We selected the prospective Dutch drinking water guideline for PFAS of 4.4 ng PFOA-equivalent (PEQ) L^-1, as this guideline is amongst the more conservative concentration targets globally. We first conducted a Life Cycle Assessment (LCA) to quantify the health cost associated with the increased reactivation frequency of an existing GAC system in the Netherlands, required to achieve PFAS concentrations below 4.4 ng PEQ L^-1. Then, we quantified the health benefit obtained by the corresponding lower PFAS exposure, using pharmacokinetic modelling combined with published dose-response relationships. For the treatment plant investigated in the current study, which uses reactivated wood-based GAC, increasing the reactivation frequency to remove more PFAS was found to result in a net health benefit of 6.9-300 DALYs per 10⁶ persons per year. However, when single-use rather than reactivated GAC would be used for PFAS treatment, the health losses from the GAC production were in the same range as the health benefits from lower PFAS exposure. Overall, the negative health impacts associated with more intensive water treatment should be considered when developing strategies to reduce PFAS exposure.</p>","PeriodicalId":74,"journal":{"name":"Environmental Science: Processes & Impacts","volume":" ","pages":""},"PeriodicalIF":4.3,"publicationDate":"2025-05-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143956411","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":"Quaternary ammonium compounds in wastewater during the COVID-19 pandemic: occurrence, exposure evaluation and risk assessment.","authors":"Jingjing Li, Yongfeng Lin, Lihua Yu, Wei Gao, Bing Wang, Yuxin Zheng","doi":"10.1039/d5em00040h","DOIUrl":"https://doi.org/10.1039/d5em00040h","url":null,"abstract":"<p><p>Quaternary ammonium compounds (QACs) are widely used as active ingredients in cleaning products and personal care products, which could enter domestic wastewater through various daily human activities. During the COVID-19 pandemic, elevated usage of QACs was reported; however, whether the increase could pose potential risks to the environment and human health is still unknown. To evaluate the population exposure and risks of QACs, influent and effluent wastewater samples were collected from December 15, 2022, to January 31, 2023, in a wastewater treatment plant. QACs were detected at mean ΣQAC concentrations of 711 ng L^-1 in influent and 50.4 ng L^-1 in effluent. Dialkyldimethyl ammonium compounds (DADMACs) and benzylalkyldimethyl ammonium compounds (BACs) accounted for the largest mean proportion of 48.5% and 66.1% in influent and effluent, respectively. The evaluated daily ΣQAC exposure ranged from 0.309 to 2114 mg per 1000 residents during the sampling period. Most QACs could be removed, with mean removal efficiency in the range of 62.6-100%. DADMAC-14:14, DADMAC-16:16 and BAC-C12 in effluent displayed higher risks to aquatic organisms based on risk quotient calculation. The estimated daily intakes of QACs were below the reference dose, suggesting negligible health concerns. The environmental occurrence and physico-chemical properties were further integrated in the toxicological priority index approach to rank the monitored QACs. DADMAC-16:16 exhibited the highest score, indicating its priority in further environmental and toxicological research.</p>","PeriodicalId":74,"journal":{"name":"Environmental Science: Processes & Impacts","volume":" ","pages":""},"PeriodicalIF":4.3,"publicationDate":"2025-05-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143951371","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":"Study on the mechanism of Phoslock's impact on nitrogen migration at the sediment–water interface†","authors":"Penglong Wang, Jiehua Wang, Songwei Zhang, Jinyue Fan, Xiuling Bai, Pingping Zhang, Zhiqiang Jiao, Bing Zhao and Xiubo Ren","doi":"10.1039/D5EM00062A","DOIUrl":"10.1039/D5EM00062A","url":null,"abstract":"<p >Phoslock has a wide range of applications in regulating the release of endogenous phosphorus. Nevertheless, the knowledge regarding its influence on the nitrogen migration process at the sediment–water interface (SWI) remains rather limited. Therefore, this study explores Phoslock's impact on NO<small>₃</small><small>⁻</small>–N and NH<small>₄</small><small>⁺</small>–N migration at the SWI in Lake Xuanwu and Lake Li using DGT and Rhizon samplers. The results revealed that at 30 °C, Phoslock increased bioavailable NO<small>₃</small><small>⁻</small>–N concentrations in the overlying water compared to the control group in both lakes. However, there were no significant differences in bioavailable NH<small>₄</small><small>⁺</small>–N concentrations between experimental and control groups in the overlying water at different temperatures. At 30 °C, the downward diffusion intensity of bioavailable NO<small>₃</small><small>⁻</small>–N in the overlying waters of Lake Xuanwu was about 41.59% and 45.76% higher under aerobic and anaerobic conditions (<em>p</em> &lt; 0.05), respectively, and 10.64% and 184.33% higher in Lake Li, compared to the control group. At 15 °C, compared to the control groups, the overall diffusion intensity in the experimental groups of both lakes showed an increasing trend, but the differences were not significant. Phoslock reduced the upward diffusion flux of bioavailable NH<small>₄</small><small>⁺</small>–N at the SWI of Lake Xuanwu and Lake Li. The inhibitory effect on the release flux of bioavailable NH<small>₄</small><small>⁺</small>–N increased as the temperature decreased, but the impact on dissolved oxygen (DO) was minimal. For example, at 30 °C, the addition of Phoslock in Lake Xuanwu reduced the upward diffusion flux of bioavailable NH<small>₄</small><small>⁺</small>–N by approximately 23.4% and 22.01% under aerobic and anaerobic conditions, respectively. At 15 °C, the reduction was approximately 33.52% and 36.25%, respectively. Phoslock also decreased the abundance of sediment nitrification functional genes (AOA and AOB) and enhanced the ability of sediments to replenish bioavailable NO<small>₃</small><small>⁻</small>–N into interstitial water, while the ability to replenish bioavailable NH<small>₄</small><small>⁺</small>–N decreased. According to the diffusion direction and intensity of bioavailable NO<small>₃</small><small>⁻</small>–N and NH<small>₄</small><small>⁺</small>–N at the SWI, the addition of Phoslock makes more bioavailable nitrogen in the overlying water accumulate in the sediments.</p>","PeriodicalId":74,"journal":{"name":"Environmental Science: Processes & Impacts","volume":" 5","pages":" 1253-1265"},"PeriodicalIF":4.3,"publicationDate":"2025-04-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143952417","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}