Marine pollution bulletinPub Date : 2025-01-01Epub Date: 2024-11-27DOI: 10.1016/j.marpolbul.2024.117338
Ke Liu, Jie Fu, Li Li, Daolai Zhang, Xiaotong Xiao
{"title":"Source characteristics and quantitative estimates of organic carbon composition in the intertidal zones of Jiaozhou Bay, China.","authors":"Ke Liu, Jie Fu, Li Li, Daolai Zhang, Xiaotong Xiao","doi":"10.1016/j.marpolbul.2024.117338","DOIUrl":"10.1016/j.marpolbul.2024.117338","url":null,"abstract":"<p><p>The Jiaozhou Bay (JZB) intertidal zone is a significant carbon reservoir that plays a crucial role in transporting and accumulating organic matter; however, quantitative studies of organic matter sources are scarce. In this study, we present bulk parameters of total organic carbon (TOC), TOC/TN, δ<sup>13</sup>C, and biomarker contents in 36 surface sediment samples from the JZB intertidal zones to quantify the contribution of organic carbon (OC) derived from terrestrial/marine sources, such as C<sub>3</sub> plants, C<sub>4</sub> plants, estuarine productivity, sewage outlets, and marine productivity. The results demonstrated that a two-end-member model based on the traditional indicators of TOC/TN or δ<sup>13</sup>C is not appropriate for quantifying the OC source. The presence of C<sub>3</sub> plants, C<sub>4</sub> plants, and sewage outlets in the JZB intertidal zone could lead to errors in determining OC contribution when solely using TOC/TN or δ<sup>13</sup>C. A classical mixing diagram (three-end-member model) utilizing TOC/TN and δ<sup>13</sup>C values revealed that OC contribution was dominated by marine productivity throughout the intertidal zone. In the west, the average OC contribution from marine productivity, estuarine productivity, and C<sub>4</sub> plants was 73.8 %, 14.2 %, and 12.0 %, respectively. In the east, the average OC contribution from marine productivity, estuarine productivity, and sewage outlets was 57.6 %, 24.9 %, and 17.4 %, respectively. The higher OC contribution from marine productivity in the west was attributed to the occurrence of Spartina alterniflora, while the OC contribution from estuarine productivity in the east was primarily due to the presence of more rivers flowing into the JZB compared to the west. By combining biomarkers and OC contents, a significant positive relationship verified the suitability of the end-member values selected for the three-end-member mixing model in the west and east intertidal zones of JZB. This finding was further supported by principal component analysis (PCA) analyses of these proxies. This study demonstrated that OC sources in intertidal zones varied among contrasting coastal environmental conditions and addressed the knowledge gap regarding biogeochemical cycles and ecological protection in the JZB intertidal zones.</p>","PeriodicalId":18215,"journal":{"name":"Marine pollution bulletin","volume":"210 ","pages":"117338"},"PeriodicalIF":5.3,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142729950","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Effects of steroid hormones and their mixtures on western mosquitofish (Gambusia affinis).","authors":"Chen-Si Wang, Guo-Yong Huang, Dong-Qiao Lei, Guang-Guo Ying","doi":"10.1016/j.aquatox.2024.107167","DOIUrl":"10.1016/j.aquatox.2024.107167","url":null,"abstract":"<p><p>Steroid hormones, including estrone (E1), androstadienedione (ADD), and androstenedione (AED), are prevalent in aquatic ecosystems and pose ecological risks due to their disruptive influence on fish populations. However, little consideration has been given to the endocrine disrupting effects of fish exposed to complex mixtures of hormones in the real world. In this study, adult female western mosquitofish (Gambusia affinis) were exposed to two concentrations of E1 (100 ng/L for E1L and 5,000 ng/L for E1H), ADD (100 ng/L for ADDL and 10,000 ng/L for ADDH), and AED (100 ng/L for AEDL and 10,000 ng/L for AEDH) as well as four binary mixture treatments (ADDL+E1L, ADDH+E1H, AEDL+E1L, and AEDH+E1H). After 42 d, their basic physiological parameters, secondary sex characteristics, gonadal health, embryo numbers, and HPG axis-related gene expression were evaluated. Results showed that the P/D ratio of hemal spines in AEDH+E1H exhibited a pronounced reduction, approximately half that of E1H. Moreover, the number of embryos in ADDH+E1H and AEDH+E1H was reduced by approximately 3-fold compared to E1H. Correspondingly, G. affinis exposure to ADDH+E1H and AEDH+E1H increased the proportion of degenerated oocytes. Exposure to combined treatments led to significant changes in the transcription of HPG axis-related genes in fish and displayed a certain degree of interaction. Furthermore, cluster heatmap analysis of target genes demonstrated that ADD+E1 and AED+E1 (both high and low concentrations) were far apart from ADD, AED and E1. Collectively, these observations imply the presence of antagonistic interactions in combined treatments, and the negative impact on the growth, maturation, and endocrine system of G. affinis varies accordingly.</p>","PeriodicalId":248,"journal":{"name":"Aquatic Toxicology","volume":" ","pages":"107167"},"PeriodicalIF":4.1,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142724554","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}
Letícia Fernanda da Silva, Caio Rodrigues Nobre, Beatriz Barbosa Moreno, Camilo Dias Seabra Pereira, Alexandre Rodrigo Nascimento Gonçalves, Nathalia Sales Soares do Nascimento, Gabriela Pustiglione Marinsek, Renata de Britto Mari, Fábio Ruiz Simões, José Hérelis Carnaúba, Rodrigo Brasil Choueri, Paloma Kachel Gusso-Choueri, Augusto Cesar
{"title":"Exposure to microplastics contaminated with pharmaceuticals and personal care products: Histological effects on Ucides cordatus.","authors":"Letícia Fernanda da Silva, Caio Rodrigues Nobre, Beatriz Barbosa Moreno, Camilo Dias Seabra Pereira, Alexandre Rodrigo Nascimento Gonçalves, Nathalia Sales Soares do Nascimento, Gabriela Pustiglione Marinsek, Renata de Britto Mari, Fábio Ruiz Simões, José Hérelis Carnaúba, Rodrigo Brasil Choueri, Paloma Kachel Gusso-Choueri, Augusto Cesar","doi":"10.1016/j.scitotenv.2024.177042","DOIUrl":"10.1016/j.scitotenv.2024.177042","url":null,"abstract":"<p><p>Pharmaceuticals and personal care products (PPCPs) are known to interact with microplastics (MPs) in aquatic environments, with substances such as the antimicrobial triclosan (TCS) and the synthetic hormone 17α-ethinylestradiol (EE2) being prevalent. These persistent contaminants are linked to toxic effects in aquatic organisms. This study aimed to investigate histological and morphometric changes in the gills of Ucides cordatus exposed to microplastics alone and microplastics contaminated with PPCPs. The experimental design included four treatment groups: 1) control (C), 2) virgin microplastics (MP), 3) microplastics fortified with triclosan (MPT), and 4) microplastics fortified with 17α-ethinylestradiol (MPE), with exposure durations of 3 or 7 days. Significant differences were observed in the histopathological indices for treatments with PPCP-fortified microplastics at 3 days (MPT and MPE) and 7 days (MPT). Notable pathologies included necrosis, fibrosis, and circulatory disorders. Exposure duration was significantly associated with morphometric changes, including secondary lamellar width in MPT and secondary lamellar length in MPE. These findings indicate that exposure to microplastics contaminated with PPCPs may impair the osmoregulatory and respiratory functions of Ucides cordatus.</p>","PeriodicalId":422,"journal":{"name":"Science of the Total Environment","volume":" ","pages":"177042"},"PeriodicalIF":8.2,"publicationDate":"2024-12-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142492323","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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}
David J Beale, Duncan Limpus, Georgia Sinclair, Utpal Bose, Nicholas Bourne, Sally Stockwell, Damian C Lettoof, Rohan Shah, Thao V Nguyen, Viviana Gonzalez-Astudillo, Christoph Braun, Albert Myburgh, Brenda Baddiley, Taka Shimada, Colin Limpus, Suzanne Vardy
{"title":"Forever chemicals don't make hero mutant ninja turtles: Elevated PFAS levels linked to unusual scute development in newly emerged freshwater turtle hatchlings (Emydura macquarii macquarii) and a reduction in turtle populations.","authors":"David J Beale, Duncan Limpus, Georgia Sinclair, Utpal Bose, Nicholas Bourne, Sally Stockwell, Damian C Lettoof, Rohan Shah, Thao V Nguyen, Viviana Gonzalez-Astudillo, Christoph Braun, Albert Myburgh, Brenda Baddiley, Taka Shimada, Colin Limpus, Suzanne Vardy","doi":"10.1016/j.scitotenv.2024.176313","DOIUrl":"10.1016/j.scitotenv.2024.176313","url":null,"abstract":"<p><p>Per- and polyfluoroalkyl substances (PFAS) are persistent environmental contaminants known to pose significant risks to human and wildlife health. Freshwater turtles (Emydura macquarii macquarii), as long-lived species inhabiting aquatic ecosystems, are particularly vulnerable to PFAS bioaccumulation. This study investigated the multifaceted impact of PFAS contamination on these turtles, focusing on metabolic disruptions, reproductive success, hatchling health, and population impacts. Comprehensive analyses, including proteomics, lipidomics, metabolomics, and histopathology, were conducted on turtles from PFAS-impacted, control, and reference sites. The findings reveal significant metabolic disruptions in PFAS-exposed turtles, with alterations in amino acid and lipid metabolism, energy production, and oxidative stress responses. Proteomic analysis identified several health biomarkers indicative of early disease progression. Despite high levels of PFAS in tissues and organs, no gross or histopathological phenotypical abnormalities were directly linked to PFAS exposure. Gravid females from contaminated sites exhibited altered egg composition, particularly in magnesium to calcium ratios, potentially affecting eggshell strength. Biochemical profiles of egg albumin and yolk indicated significant differences in metabolites and lipids between contaminated and reference sites, suggesting potential impacts on embryo development. Hatchling deformities were notably higher and with increased frequency in terms of the types of deformities at the PFAS-impacted sites, with common defects including abnormal intergular scale shapes and marginal scale counts. Furthermore, the demographic profile of the turtle population showed a lack of juvenile turtles at contaminated sites, indicating reduced recruitment and potential long-term population declines. This indicates a field-based demonstration of an Adverse Outcome Pathway, from elevated levels of PFAS in the turtles, to biochemical perturbations within the animals, and finally population effects. These findings underscore the urgent need for regulatory measures to address PFAS contamination and its detrimental effects on wildlife.</p>","PeriodicalId":422,"journal":{"name":"Science of the Total Environment","volume":" ","pages":"176313"},"PeriodicalIF":8.2,"publicationDate":"2024-12-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142611172","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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}
Bin Chen, Xiyan Xu, Shaoqiang Wang, Te Yang, Zhenhai Liu
{"title":"Corrigendum to \"Carbon dioxide fertilization enhanced carbon sink offset by climate change and land use in Amazonia on a centennial scale\" [Sci. Total Environ. 955 (2024) 176903].","authors":"Bin Chen, Xiyan Xu, Shaoqiang Wang, Te Yang, Zhenhai Liu","doi":"10.1016/j.scitotenv.2024.177435","DOIUrl":"10.1016/j.scitotenv.2024.177435","url":null,"abstract":"","PeriodicalId":422,"journal":{"name":"Science of the Total Environment","volume":" ","pages":"177435"},"PeriodicalIF":8.2,"publicationDate":"2024-12-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142611605","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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}
Xi Li, Guangyou Zhu, Mengqi Li, Ziguang Zhu, Heting Gao, Zhiyao Zhang, Tingting Li, Yifei Ai, Yan Zhang, Pengzhen Duan, Jincheng Liu, Jiakai Hou, Sheng Li
{"title":"Mechanisms of U enrichment and helium generation potential in marine black shales following U isotope-constrained Neoproterozoic Oxidation Event.","authors":"Xi Li, Guangyou Zhu, Mengqi Li, Ziguang Zhu, Heting Gao, Zhiyao Zhang, Tingting Li, Yifei Ai, Yan Zhang, Pengzhen Duan, Jincheng Liu, Jiakai Hou, Sheng Li","doi":"10.1016/j.scitotenv.2024.177405","DOIUrl":"10.1016/j.scitotenv.2024.177405","url":null,"abstract":"<p><p>Following the NOE, the early Cambrian witnessed the global deposition of marine black shales with high U concentrations. This study analyzes the Lower Cambrian Yuertusi Formation in the Tarim Basin, China, focusing on U isotopes to elucidate U enrichment mechanisms in black shales and their potential for helium generation. In wells XK-1, LT-1, and LT-3, the average U concentrations in the Yuertusi Formation black shale are 41.7 ppm, 29.21 ppm, and 275.28 ppm, respectively. U enrichment in black shales is jointly controlled by continental weathering, paleoproductivity, oceanic oxidation, and organic matter. A synchronous increase in global atmospheric oxygen levels and weathering processes, leading to the continuous weathering of land rocks rich in U and nutrient elements, which were then transported to the ocean by rivers, laying the foundation for U enrichment in black shales and the accumulation of organic matter. The δ<sup>238</sup>U values of the Yuertusi Formation range from -0.44 ‰ to 0.37 ‰, showing two phases of first positive and then negative drift in δ<sup>238</sup>U values, reflecting a process where the area of oceanic oxidation experienced an expansion followed by contraction. During the expansion of the oceanic oxidation area, the paleoproductivity and U concentration in the oceanic oxidation layer increased, allowing soluble U elements to accumulate in black shales through reduction and organic matter adsorption in deep water anoxic environments. Conversely, during the contraction of the oceanic oxidation area, the U concentration in the oceanic oxidation layer decreased, resulting in significantly lower U concentration in the deposited dolostones or limestones compared to black shales. The early Cambrian black shales enriched with U can serve as effective helium source rocks, with an estimated cumulative release of approximately 1382 × 10<sup>8</sup> m<sup>3</sup> of helium gas. The insights gained from this study are significant for understanding the redox state of the ocean following the NOE and for guiding the exploration of ultra-deep helium gas.</p>","PeriodicalId":422,"journal":{"name":"Science of the Total Environment","volume":"956 ","pages":"177405"},"PeriodicalIF":8.2,"publicationDate":"2024-12-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142602105","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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}
Wei Wang, Haojie Shi, Xingang Liu, Liangang Mao, Lan Zhang, Lizhen Zhu, Chi Wu, Wenzhu Wu
{"title":"Enhanced remediation of acetochlor-contaminated soils using phosphate-modified biochar: Impacts on environmental fate, microbial communities, and plant health.","authors":"Wei Wang, Haojie Shi, Xingang Liu, Liangang Mao, Lan Zhang, Lizhen Zhu, Chi Wu, Wenzhu Wu","doi":"10.1016/j.scitotenv.2024.177359","DOIUrl":"10.1016/j.scitotenv.2024.177359","url":null,"abstract":"<p><p>Given that acetochlor (ACT) persists in soil for extended periods, disrupting microbial community structure and causing phytotoxicity to sensitive crops, this study investigated the potential of phosphate-modified biochar (PBC-800) to remediate ACT-contaminated soil. Incorporating 0.5 % PBC-800 into fluvo-aquic, red, and black soils increased their adsorption capacities by 80.4 mg g<sup>-1</sup>, 76.6 mg g<sup>-1</sup>, and 76.0 mg g<sup>-1</sup>, respectively. Even after six months of aging, the K<sub>f</sub> values remained 1.6 to 5.1 times higher than in untreated soils. PBC-800 also accelerated ACT degradation across all three soil types, reducing residual ACT levels by 34.3 % to 76.4 % after 60 days, and shortening the degradation half-life by 5 to 7 days. High-throughput sequencing revealed that ACT reduced soil microbial diversity and disrupted community structure, while 0.5 % PBC-800 amendments promoted the growth of degradation-capable genera such as Rhodococcus, Lysobacter, and Gemmatimonas, enhancing microbial ecosystem stability. Furthermore, the amendment of soil with 0.5 % PBC-800 reduced ACT residue concentrations in maize and soybeans by 76.5 % to 82.9 %, and restored plant biomass, leaf chlorophyll content, and mesophyll cell ultrastructure to levels comparable to the control. Therefore, amending ACT-contaminated soil with PBC-800 mitigates ecological and environmental risks, boosts microbial activity, and safeguards plant health.</p>","PeriodicalId":422,"journal":{"name":"Science of the Total Environment","volume":" ","pages":"177359"},"PeriodicalIF":8.2,"publicationDate":"2024-12-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142581525","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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}
Environmental PollutionPub Date : 2024-12-15Epub Date: 2024-08-15DOI: 10.1016/j.envpol.2024.124756
Emily A Strong, Sarah L Crowley, Julia L Newth, Michelle F O'Brien, Rosa Lopez Colom, Sean A Davis, Ruth L Cromie, Stuart Bearhop, Robbie A McDonald
{"title":"Spatial and temporal variation in the prevalence of illegal lead shot in reared and wild mallards harvested in England.","authors":"Emily A Strong, Sarah L Crowley, Julia L Newth, Michelle F O'Brien, Rosa Lopez Colom, Sean A Davis, Ruth L Cromie, Stuart Bearhop, Robbie A McDonald","doi":"10.1016/j.envpol.2024.124756","DOIUrl":"10.1016/j.envpol.2024.124756","url":null,"abstract":"<p><p>The use of lead shotgun ammunition for shooting wildfowl has been restricted in England since 1999, but surveys finding lead shot in harvested birds show compliance with regulations has been low. Following the announcement in 2020 of a voluntary transition from lead to non-lead shot by UK shooting organizations, we investigated spatiotemporal variation in the composition of ammunition used for shooting mallards Anas platyrhynchos. We collected 176 harvested mallards during the 2021/22 shooting season and analyzed recent shot extracted from carcasses to determine shot composition. Using a separate collection of ducks of known provenance, we used stable isotope analysis as a means of differentiating captive-reared from wild mallards. This allowed us to understand how compliance might vary between driven game shooters, characterized by shooting birds that are flushed over a stationary line of shooters, and who primarily harvest captive-reared and released ducks, and wild duck shooters. Of 133 mallards containing recent shot, 92 (69%) had been illegally shot with lead. Analysis of this and five comparable surveys between 2001 and 2019 indicates regional and temporal variation in lead shot presence in England. In the North West and West Midlands, the likelihood of mallards containing lead shot decreased significantly over time, but no other regions showed significant changes. The use of non-lead shot types varied over time, with increases in steel shot use approximately matched by declines in bismuth shot. Mallards likely to be reared were more likely to have been shot with lead (75%) than those likely to be wild (48%). This suggests the use of lead shot is more frequent among driven game shooters than wild duck shooters. In England in 2021/22, most mallards continued to be shot with lead, suggesting that neither legislation nor voluntary approaches have been effective in substantially reducing illegal use of lead shot.</p>","PeriodicalId":311,"journal":{"name":"Environmental Pollution","volume":" ","pages":"124756"},"PeriodicalIF":7.6,"publicationDate":"2024-12-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141994868","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}
Zikuo Liu, Linyuan Song, Yu Wang, Di Zhang, Jingxuan Liang, Yuzi Song, Xianjiang Kang, Cunqi Liu, Zhao Zhao
{"title":"Impact of extreme rainfall and flood events on harmful cyanobacterial communities and ecological safety in the Baiyangdian Lake Basin, China.","authors":"Zikuo Liu, Linyuan Song, Yu Wang, Di Zhang, Jingxuan Liang, Yuzi Song, Xianjiang Kang, Cunqi Liu, Zhao Zhao","doi":"10.1016/j.scitotenv.2024.177287","DOIUrl":"10.1016/j.scitotenv.2024.177287","url":null,"abstract":"<p><p>Globally, climate change has intensified extreme rainfall events, leading to substantial hydrological changes in aquatic ecosystems. These changes, in turn, have increased the frequency of harmful algal blooms, particularly those of cyanobacteria. This study examines cyanobacterial community dynamics in the Baiyangdian Lake Basin, China, after heavy rainfall and flooding events. The aim was to clarify how such extreme hydrological events affect cyanobacterial populations in floodplain ecosystems and assess related ecological risks. The results demonstrated a significant increase in cyanobacterial diversity, exemplified by an increase of the Shannon diversity index from an average of 1.72 to 2.1 (p < 0.05). Following heavy rainfall and subsequent flooding, the average relative abundance of cyanobacteria in the microbial community increased from 7.59 % to 9.62 %, along a notable rise in the abundance of harmful cyanobacteria. The community structure exhibited notable differences after flooding, showing an increase in species richness, but a decrease in community tightness and clustering, as well as a reduction in niche overlap among harmful cyanobacteria. Environmental factors such as dissolved oxygen, water temperature, and pH were identified as crucial predictors of harmful cyanobacterial community differences and abundance variations resulting from flooding. These findings provide a critical framework for predicting ecological risks associated with the expansion of bloom-forming cyanobacteria in large shallow lake basins, particularly under intensified rainfall and flooding events. This insight is essential to anticipate potential ecological disruptions in sensitive aquatic ecosystems.</p>","PeriodicalId":422,"journal":{"name":"Science of the Total Environment","volume":" ","pages":"177287"},"PeriodicalIF":8.2,"publicationDate":"2024-12-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142567203","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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}
Lin Sun, Wudneh Ayele Shewa, Kevin Bossy, Martha Dagnew
{"title":"Simultaneous nitrification and denitrification framework for decentralized systems: Long-term study utilizing rope-type biofilm media under field conditions.","authors":"Lin Sun, Wudneh Ayele Shewa, Kevin Bossy, Martha Dagnew","doi":"10.1016/j.scitotenv.2024.177337","DOIUrl":"10.1016/j.scitotenv.2024.177337","url":null,"abstract":"<p><p>This research introduces a novel approach to achieve simultaneous nitrification-denitrification (SND) under dynamic load conditions using a cost-effective rope-type biofilm technology. The approach represents a significant advancement in wastewater treatment, particularly beneficial for remote and decentralized communities. The biofilm-based SND process was developed using a pilot-scale flow-through reactor by implementing upstream carbon management with constant-timer-based aeration control versus dynamic-sensor-based aeration control strategies. The findings indicate that adding an upstream anaerobic pretreatment process to handle excess carbon plays a substantial role in achieving a sustainable SND process under a dynamic load environment using simple aeration on-off control. The most optimal nitrification performance of 0.32 g NH<sub>3</sub>-N/m<sup>2</sup>/d (89 % removal) was achieved under a 1-hour ON/30-minute OFF aeration. The process sustained an average bulk liquid DO of 5.16 mg/L and 3.80 mg/L during the aeration ON and OFF periods, respectively, facilitating a 0.13 g N/m<sup>2</sup>/d (41 %) total inorganic nitrogen (TIN) removal, notably, implementing advanced aeration strategies driven by DO, NH<sub>3</sub>, and NO<sub>3</sub> sensors enhanced TIN removal efficiency to 72 %. The nitrification performance remained comparable (89 % removal), resulting in 3 and 10 mg N/L effluent ammonia and TIN concentration, respectively. Additionally, utilizing two multivariate approaches accounting for 82 % and 64 % of the variance, this study discerned patterns in monitored variables and performance. Additionally, the analysis underscored the difference of bulk liquid DO levels in the biofilm versus suspended systems inhibiting the SND process. Distinct bacterial communities were established in biofilms under aerobic, anaerobic, and SND conditions, with the SND reactor showing a hierarchy of functional group and enzymes, enriched sequentially from heterotrophs to denitrifiers, nitrifiers, and anammox bacteria. These innovations underline the potential of tailored control strategies to enhance a passive biofilm-based SND process efficiency under dynamic conditions, providing scalable solutions for diverse target water quality demands in remote communities and decentralized systems.</p>","PeriodicalId":422,"journal":{"name":"Science of the Total Environment","volume":" ","pages":"177337"},"PeriodicalIF":8.2,"publicationDate":"2024-12-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142581544","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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}