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201. 题目: The Conservative Mixing Behavior of Dissolved Organic Matter: Assessment of Size Distributions and Optical Properties
文章编号: N26032401
期刊: Water Research
作者: Blair Hanson, Julie A Korak
更新时间: 2026-03-24
摘要: Dissolved organic matter (DOM) is ubiquitous and influences pollutant transport, photochemistry, and water treatment. As a heterogeneous mixture, current theories suggest that DOM forms supramolecular assemblies; yet, common statistical methods assume the principles of additivity and conservative mixing. This study evaluates whether mixtures of DOM sources follow conservative mixing principles as measured by size exclusion chromatography (SEC) coupled with organic carbon, absorbance, and fluorescence detectors. Blends of DOM isolates and wastewater effluent were evaluated using one-, two-, and three-dimensional analysis techniques. Predicted chromatograms based on the linear superposition of end-members showed strong agreement with measured data, suggesting that DOM mixing largely preserves size distributions and photophysical characteristics for SEC. However, a recurring rider peak had systematic residuals that are associated with a small molecular size fraction, commonly described as low molecular weight acids, causing deviations in organic carbon concentration, absorbance <300 nm, and fluorescence emission at 420 nm (excitation 276 nm). These deviations are likely due to column interactions rather than supramolecular reassembly. Discrepancies between whole-water and SEC fluorescence data suggest that fluorophores in wastewater may be preferentially impacted by column interactions. Except for the recurring rider peak, these findings broadly support the use of SEC-derived metrics in end-member mixing analyses and the use of statistical methods that assume additivity. More fundamentally, this study suggests that if DOM supramolecular assemblies are present, they are tightly knit at the blending conditions (i.e., pH 6.8, 3 mg_C/L) and SEC ionic strength (i.e., 0.1 M), and DOM does not readily reorganize with new DOM inputs.

202. 题目: Immobilization of Pb and Cd in red soil using Fe-Mn modified sugarcane bagasse biochar: mechanisms and plant uptake.
文章编号: N26032307
期刊: Environmental Geochemistry and Health
作者: Chuang Ma, XueMei Liu
更新时间: 2026-03-23
摘要: Lead (Pb) and cadmium (Cd) in soil threaten agroecosystem safety and human health. Due to the high bioavailability and mobility of heavy metals in red soil, the risk is further increased. Biochar is widely used for heavy metal immobilization, but original biochar suffers from inherent limitations. Most existing studies of iron (Fe)-manganese (Mn) modified biochar have not focused on red soil, and the relationship with soil-plant responses remains unclear. This study aimed to evaluate and compare the efficacy of sugarcane bagasse biochar (BC) and Fe-Mn modified sugarcane bagasse biochar (FMBC) for Pb and Cd immobilization in red soil, and clarify their effect on plant uptake. BC and FMBC were applied to Pb and Cd contaminated red soil for pot experiments with pak choi (Brassica rapa chinensis) as an indicator plant. The results showed that both BC and FMBC elevated soil pH, organic matter (SOM), enzyme activities, reduced Pb and Cd bioavailability, and transformed Pb and Cd to stable fractions. FMBC outperformed BC, and the 5% FMBC treatment achieved the optimal remediation efficacy. The 5% FMBC decreased the acid-extractable Pb and Cd by 9.33 and 34.40% compared to control. The plant biomass was significantly increased, Pb and Cd content in edible shoots met the limit standards, and bioconcentration (BCF) and translocation factors (TF) were lowered. Overall, this study establishes theoretical foundations and empirical bases for the application of FMBC to immobilize Pb and Cd in red soils, thereby providing a feasible and eco-friendly approach to support sustainable agriculture and the recycling of agricultural waste.

203. 题目: Impact of a distant volcanic eruption on water-soluble organic aerosols composition and their cytotoxicity in monocytes.
文章编号: N26032306
期刊: Environmental Geochemistry and Health
作者: Antoine S Almeida, Bruno M Neves, Regina M B O Duarte
更新时间: 2026-03-23
摘要: Volcanic eruptions represent significant episodic sources of atmospheric pollutants, emitting large amounts of particulate matter (PM), sulfur dioxide, and trace metals. These emissions are associated with adverse cardiovascular and respiratory health outcomes, yet the specific chemical constituents responsible remain insufficiently defined. This study investigates the chemical composition and biological effects of water-soluble organic matter (WSOM) isolated from fine particulate matter (PM2.5) collected during a volcanic eruption and a non-volcanic reference period. Structural characterization of WSOM was performed using liquid-state nuclear magnetic resonance (NMR) spectroscopy. The cytotoxic, immunomodulatory, and oxidative effects were assessed in the human monocytic cell line THP1. A total of 25 distinct molecular structures in the two WSOM samples (volcanic event period and reference period), with 7 unique to the volcanic eruption period, including branched mono- and di-carboxylic acids, alkenes, nitro-aromatics, and 3-methyl-2,6-dinitrophenol. Both WSOM samples increased transcription of co-stimulatory molecules and proinflammatory cytokines in monocytes. WSOM exposure also elevated expression of adhesion molecules implicated in the progression of atherosclerotic plaques and increased cardiovascular disease risk. The results indicate that a short-term, long-distance volcanic event did not substantially modify the cytotoxic properties of fine aerosol WSOM in an urban environment influenced by anthropogenic emissions.

204. 题目: Coupled effects of glyphosate on soil carbon cycling regulated by dose, time, and environment: A global meta-analysis
文章编号: N26032305
期刊: Environmental Research
作者: Yu Chu, Tianhao Che, Xinran Gao, Panxing He, Yang Li, Yu Ma
更新时间: 2026-03-23
摘要: Glyphosate (GLY) is the most widely used herbicide worldwide, yet its effects on microbially mediated soil carbon-cycling processes remain controversial. Using random-effects meta-analysis, machine-learning interpretation, and path modeling, this study integrates 1,099 paired observations from 103 studies worldwide to systematically evaluate how GLY exposure conditions and initial soil physicochemical properties jointly modulate soil carbon cycling responses. Across all observations included in the meta-analysis, GLY increased soil CO₂ emission by 16.32% and soil organic carbon (SOC) by 9.98% on average. However, both the direction and magnitude of these responses were strongly context-dependent and could reverse under specific combinations of soil properties and exposure conditions. High GLY concentrations (>100 mg a.i. kg^-1) strongly stimulated microbial respiration, increasing the microbial metabolic quotient (qCO₂) by 61.22%, and were also associated with higher SOC. In contrast, medium concentrations (10-100 mg a.i. kg^-1) significantly suppressed microbial biomass. Exposure times of less than 30 days promoted SOC accumulation, 30-60 days produced the strongest respiratory response, while exposure beyond 60 days weakened the respiration response. Soil pH emerged as a key regulator: acidic conditions generally promoted CO₂ emission, whereas alkaline conditions suppressed CO₂ emission while enhancing SOC accumulation. Total nitrogen (TN) and soil organic matter (SOM) also influenced the response patterns of soil carbon processes. Overall, the effects of GLY on soil carbon cycling should not be generalized as uniform promotion or inhibition; instead, they represent context-dependent responses jointly shaped by exposure concentration, exposure time, and inherent soil properties. The observed SOC increases mainly reflect short- to medium-term responses in the compiled dataset.

205. 题目: Cascade dams amplify molecular transformation and compositional homogenization of dissolved organic matter on the Eastern Tibetan Plateau
文章编号: N26032304
期刊: Water Research
作者: Dengming He, Wanfa Wang, Philipp Maurischat, Yuanbi Yi, Yulin Qi, Xuan Hu, Shijun Tu, Shengde Yu, Jie Zeng, Qixin Wu, Hao Xia, Ding He, Si-Liang Li
更新时间: 2026-03-23
摘要: River damming globally disrupts hydrological connectivity, transforming reservoirs into critical regulators of the global carbon cycling. However, the molecular characteristics and the specific transformation processes of dissolved organic matter (DOM) in cascade reservoirs remain unclear. To address this knowledge gap, we integrated water chemistry, stable carbon isotopes, and Fourier transform ion cyclotron resonance mass spectrometry to elucidate the molecular fate of DOM across cascade river-reservoir systems on the Eastern Tibetan Plateau. Results demonstrated that cascade damming enhanced autochthonous DOM production, as estimated by a simmr-based stable-isotope mixing model, increasing the phytoplankton-derived fraction of DOM from 27 ± 10% in rivers to 31 ± 12% in cascade reservoirs (posterior mean ± SD). Simultaneously, the favorable thermodynamic condition accelerated the turnover of allochthonous DOM by enhancing both photochemical and microbial decomposition processes within the warming lentic areas. These processes amplified DOM homogenization, evidenced by a decrease in the Jaccard dissimilarity coefficient along the flow path, resulting from consuming labile fractions. Furthermore, the reduced hydrological connectivity due to dam construction facilitated the downstream transport of autochthonous DOM. It is estimated that the global export flux of autochthonous dissolved organic carbon to the oceans amounts to 141 ± 2 Tg C yr^–1. Our results highlight that the global proliferation of reservoirs fundamentally alters the biogeochemical fate of DOM, with implications for regional and global carbon cycling.

206. 题目: Advances in fulvic acid extraction from lignite: techniques, challenges, and applications.
文章编号: N26032303
期刊: Environmental Monitoring and Assessment
作者: Iqra Yousaf, Lizhen Gao, Iffat Riaz, Sidra Pervaiz, Muhammad Usman
更新时间: 2026-03-23
摘要: Fulvic acid (FA) is the main active component of humic substances (HS) due to its molecular properties, solubility, reactivity, and essential role in enhancing soil health and supporting plant growth. It forms through the breakdown of organic matter and can be sourced from various natural origins, including low-rank coal, peat, and soil. The extraction of FA from low-rank coal has attracted scientific interest because of its low cost and broad applications in agriculture, environmental cleanup, and medicine. However, extracting FA from natural sources is challenging because yields and quantities are often limited. Moreover, the quality of extracted FA depends on the extraction method, with different techniques offering varying efficiencies, requiring a detailed understanding of the process. This review explores FA's diverse properties and extraction methods, emphasizing its potential as a sustainable agent for environmental remediation and as a nutraceutical. FA possesses promising capabilities to influence the geochemical behavior of metals through adsorption, complexation, and redox reactions, helping to reduce toxicity and remove contaminants such as lead (Pb), chromium (Cr), and mercury (Hg). Its amphiphilic nature also enhances its effectiveness in agriculture by supporting crop development and soil vitality, while exerting immunomodulatory effects on human health. Various chemical and biological extraction methods for FA are thoroughly reviewed, highlighting challenges in achieving efficient industrial-scale production. Despite its potential, variability in quality due to differences in raw materials and extraction techniques necessitates further research to fully realize FA's capabilities for environmental cleanup, sustainable agriculture, and health benefits. This review offers an overview of the current state of FA research and its potential in technological development.

207. 题目: Large-scale spatial assessment of soil organic carbon, pH and their interrelation in Indian agricultural soils using Soil Health Card big data.
文章编号: N26032302
期刊: Environmental Monitoring and Assessment
作者: Saketh Kandadai, Vinay Kumar Dadhwal
更新时间: 2026-03-23
摘要: Large-scale soil sampling efforts have been undertaken in India since 2015 under the Soil Health Card (SHC) scheme. This study integrates 39 million+ soil measurements from SHC into a geospatial framework to study two important soil properties - Soil Organic Carbon (SOC) content and pH. The study provides maps of mean and uncertainty at village level for SOC content and pH in surface (0-15 cm) agriculture soils in India, and further analyzes the varying relationship between them across major Agro-Ecological Regions (AERs) in the country. The resultant spatial SOC layer also gave an opportunity to assess two global SOC maps - 1. SoilGrids (250 m) and 2. Global Soil Data for Earth System Modelling (GSDE-30 arcsec). Mean SOC content in different AERs varied from 0.39% to 1.06% while mean pH varied from 5.4 to 8.0. An AER-wise analysis indicated a spatially varying relationship between SOC and pH with 11 AERs showing negative correlation and 4 showing positive and no correlation each. The mean SOC contents from GSDE were around half that of SHC for most AERs, while those estimated by SoilGrids were more than twice that of SHC in 16 of the 19 AERs. The implications of these results for Indian SOC stock estimates and climate change mitigation potential are discussed in this paper. Overall, SHC data can complement and augment large scale soil datasets. It can find applications in a diverse set of fields like soil monitoring, carbon budgeting, soil zonation studies, as well as in crop and carbon cycle modelling studies.

208. 题目: Earthworms Enhance Global Soil Carbon Storage Through Microbial–Mineral Stabilization
文章编号: N26032301
期刊: Global Change Biology
作者: Yuanyuan Li, Jiahui Liao, Peter B Reich, Yu Fang, Jiajie Cao, Juanping Ni, Tingting Ren, Guobing Wang, Xiaoming Zou, Honghua Ruan, Han Y H Chen
更新时间: 2026-03-23
摘要: Earthworms play a dual role in the global carbon cycle: they accelerate organic matter decomposition yet are often associated with greater soil organic carbon (SOC) storage. However, uncertainty regarding the mechanisms and magnitudes through which earthworms concurrently influence SOC mineralization and stabilization has limited the integration of soil fauna into carbon models. Here, we synthesize 696 paired observations from 122 studies worldwide to resolve this uncertainty. On average, earthworms increase SOC by 5.4% (95% CI: 2.2%–9.1%), with effects strengthening over time under sustained plant‐derived carbon inputs. Earthworms enhance mineral‐associated organic carbon (MAOC) by 21.2%, while particulate organic carbon (POC) remains unchanged. These patterns suggest that earthworm activity promotes a transition from short‐term carbon mineralization to long‐term stabilization, likely mediated by the coupling of microbial processing and physical protection. Specifically, epigeic earthworms boost microbial biomass carbon, whereas endogeic species enhance macroaggregate formation, facilitating the incorporation of microbial necromass into MAOC. The magnitude and direction of these effects depend on sustained carbon inputs and earthworm functional type. Collectively, these results reconcile decades of conflicting evidence and provide the first quantitative global synthesis showing that earthworms increased soil carbon over time under sustained plant carbon inputs. This microbial–mineral formation pathway has direct implications for climate‐smart land management, soil biodiversity conservation, and the representation of earthworm bioturbation in global carbon models.

209. 题目: Cation-π Interaction and Salinity Regulate the Bubble-Mediated Transport of Microplastics in the Presence of Aromatic Dissolved Organic Matter.
文章编号: N26032203
期刊: Environmental Science & Technology
作者: Zi-Han Lang, Bo Gong, Shu-Chang Liu, Miao-Miao Tan, Xiao-Yu Liu, Yue Wang, Mei-Yan Liu, Yu-Chen Sun, Jing-Ya Ma, Xiao-Dong Sun, Jian-Lu Duan, Xian-Zheng Yuan
更新时间: 2026-03-22
摘要: Bubble-mediated ejection is a critical vector for the global transport of microplastics; yet, the interfacial physicochemical rules governing this process in complex aquatic environments remain unclear. Here, we combine single-molecule force spectroscopy, nanoscale colloidal probe measurements, and macroscopic transport experiments to resolve how aromatic dissolved organic matter, modeled by phenylalanine, regulates air-bubble interactions with nonpolar polystyrene (PS) and polar polylactic acid (PLA). Single-molecule force measurements demonstrated that cation-π interactions promote specific adsorption of aromatic organics onto PS to form a robust eco-corona, stabilizing the interfacial bond by strongly suppressing dissociation kinetics (koff: 0.01 s-1 to 3.73 s-1). This eco-corona suppresses nanoscale PS hydrophobicity and weakens bubble-particle adhesion despite minimal changes in macroscopic wettability. Crucially, we further identify a salinity-dependent regime shift in transport mechanics, where nanoscale adhesion dominates transport in freshwater, whereas colloidal stability governs fate in seawater. High salinity induces extensive aggregation of eco-corona-coated PS, causing a benthic shunt as its hydrodynamic diameter increases from 4.63 to 15.56 μm, whereas PLA remains colloidally stable and thus more amenable to vertical transport. These findings demonstrate that predictive fate models should integrate aggregation kinetics and interfacial chemistry to resolve atmospheric ejection versus sedimentation of microplastics.

210. 题目: Microplastics disrupt microalgal carbon fixation: Efficiency and underlying mechanisms.
文章编号: N26032202
期刊: Journal of Environmental Management
作者: Wenxue Xiao, Eldon R Rene, Wei Fang, Panyue Zhang
更新时间: 2026-03-22
摘要: Microalgae are ubiquitous in aquatic ecosystems and play a pivotal role in carbon fixation and cycling. Toxicity of microplastics (MPs) on microalgae in aquatic ecosystems has been widely studied, but their influence on carbon fixation capacity of microalgae remains poorly understood. In this study, the influence of polyethylene (PE) and polyvinyl chloride (PVC) MPs on carbon fixation capacity of Chlorella pyrenoidosa was investigated. During 14-day incubation, the maximum inhibition of carbon fixation was 37.0% and 39.25% for PE and PVC MPs at 50 mg/L, respectively. Moreover, MPs resulted in the decrease of dissolved organic matter (DOM) into water by destroying the algae integrity, while the increase of aromaticity and humification of DOM. The PE and PVC exposure resulted in the reduction of chlorophyll content, and the increase of intercellular oxidative stress, as evidenced by the increased production of stress-related biomarkers. Furthermore, a comprehensive transcriptomes analysis revealed that the differentially expressed genes in GO enrichment analysis were mainly membrane, photosynthetic electron transport chain, chloroplast, etc. KEGG enrichment analysis demonstrated that MPs induced the downregulation of genes involved in chlorophyll metabolism and the Calvin cycle. The findings provide valuable insights into the potential environmental impacts of MPs on aquatic carbon cycles.

211. 题目: Effects of microplastics on carbon and nitrogen cycling in coastal wetlands: A critical meta-analysis
文章编号: N26032201
期刊: Water Research
作者: Feng Yuan, Hongyu Chen, Yue Xue, Yongcheng Ding, Qiujun An, Zhian Hu, Yifei Qiu, Jianguo Tao, Jin Luo, Guanghe Fu, Teng Wang, Xinqing Zou
更新时间: 2026-03-22
摘要: Coastal wetlands play a pivotal role in carbon and nitrogen cycling and are recognized as reservoirs for microplastics (MPs). While the impacts of MPs on these processes have gained wide attention, their general patterns and mechanisms remain poorly understood. Here, we conducted a meta-analysis of 1051 data points from 34 studies. Overall, the results indicated that MPs significantly influenced certain carbon and nitrogen cycling indicators, including increases in sediment total organic carbon (partly attributable to the direct carbon contribution from MPs themselves), microbial biomass carbon, and nitrification gene abundance, while inhibiting β-1,4-glucosidase activity. However, nearly all studies were conducted under laboratory conditions using intertidal sediments. Subgroup analyses indicated that, in tidal simulation experiments better representing natural intertidal environments, MPs had no significant effects on carbon and nitrogen cycling, suggesting that laboratory designs lacking tidal dynamics may overestimate the ecological impacts. Moreover, ecological effects did not differ significantly between sediments from vegetated wetlands and unvegetated bare flats, which may be attributed to the frequent omission of vegetation-related factors, such as litter inputs and rhizosphere effects, in laboratory experiments. Therefore, caution is warranted when extrapolating laboratory findings to natural coastal wetlands. Additionally, meta-regression analyses showed MP size and concentration influenced certain carbon and nitrogen indicators, whereas exposure time affected only nitrogen cycling. This study provides a theoretical basis for a more comprehensive understanding of MP impacts on carbon and nitrogen cycling in coastal wetlands.

212. 题目: Composition and photodegradation transformation of Dissolved Organic Matter from microplastics versus natural sources: impacts on copper (Cu) and tetracycline (TC) binding behaviors
文章编号: N26032118
期刊: Environmental Research
作者: Zhaoli Sun, Xin Yao, Dongling Sang, Chen Zhang, Jiazheng Zhang, Weiwei Lü, Haoyu Ren
更新时间: 2026-03-21
摘要: Dissolved organic matter (DOM) regulates pollutant fate in aquatic ecosystems, but its behavior depends strongly on sources and photodegradation. Microplastic-derived DOM (MPDOM) is increasingly abundant and may differ from natural DOM, yet its photodegradation and pollutant complexation mechanisms remain unclear. This study compared photodegradation characteristics and Cu²⁺/tetracycline (TC) binding of MPDOM from petroleum-based (HDPE) and biodegradable (PLA) microplastics with natural DOM from leaf litter and Potamogeton crispus using EEM-PARAFAC and 2D-COS. The results showed that a unique tyrosine-like component (C1) accumulated during MPDOM photodegradation, and aromaticity decreased more in MPDOM (a₂₅₄: 12.10-46.94%) than in natural DOM (a₂₅₄: 6.31-19.64%). In terms of pollutant binding, natural DOM exhibited stronger Cu²⁺ binding affinity (LogK_Cu: 4.46-5.69) than MPDOM (LogK_Cu: 3.95-4.69), primarily driven by tryptophan-like components, while initial TC binding affinity was comparable but dominated by different protein-like components (tryptophan-like in natural DOM vs. tyrosine-like in MPDOM). Photo-activated amide groups were identified as the key binding sites for MPDOM with Cu²⁺ and TC. Notably, TC binding affinity of MPDOM weakened after photodegradation, opposite to the trend observed for natural DOM. This weakening may increase the free TC fraction and potentially promote antibiotic-resistance risks in microplastic-contaminated waters. These findings provide mechanistic insights into the dynamic interactions between MPDOM and contaminants in irradiated waters.

213. 题目: Iron-Confined Hierarchically Porous Biochar: Efficient BPA Degradation via Free Radical/Non-Radical Mechanisms from Multiple Active Sites
文章编号: N26032117
期刊: Environmental Research
作者: Jiahui Wen, Liang Zeng, Yating Long, Mengwu Xiao, Zhiqiang Huang, Manxia Lu, Zuowei Xiao, Sihan Lu, Xi Chen, Lanqing Deng
更新时间: 2026-03-21
摘要: This study developed a self-sustaining oxygen activation system based on spatially confined Fe nanoparticles in hierarchical biochar (Fe@KMBC), which effectively mitigated persistent iron leaching (<0.1 mg/L), metal catalyst aggregation, and the need for stoichiometric chemical dosages of activator in advanced oxidation processes. The dual confinement mechanism—physical entrapment within 4.23 nm mesopores and electronic coupling with oxygen-functional groups—enabled the continuous generation of •O₂^- and ¹O₂ via molecular oxygen activation and electron cycling of Fe nanoparticles, allowing Fe@KMBC to achieve exceptional BPA removal (442.2 mg/g) via radical/non-radical mechanisms at multiple active sites. Notably, the pore-architecture-mediated reactant enrichment and electron transfer to generate •O₂^- and ¹O₂ maintains high efficiency and low iron leaching after five cycles. This activator-free system, which requires no addition of PMS or H₂O₂, significantly reduces energy consumption and ecotoxicity, establishing a promising eco-engineering blueprint for the remediation of endocrine disruptors.

214. 题目: A harmonized global prediction of biodegradable dissolved organic carbon in freshwater systems using optical indices and machine learning
文章编号: N26032116
期刊: Environmental Research
作者: Chae Eun Lee, Haeseong Oh, Yongqiang Zhou, Jin Hur
更新时间: 2026-03-21
摘要: Biodegradable dissolved organic carbon (BDOC) is the most reactive fraction of dissolved organic matter (DOM) and a major driver of carbon dioxide (CO₂) emissions from inland waters, yet its large-scale assessment is constrained by incubation-based measurements. This study conducted a global meta-analysis integrating harmonized BDOC observations, optical DOM indices, and machine-learning (ML) modeling to enable scalable BDOC prediction across freshwater systems. A total of 1063 paired observations were compiled from 17 studies across eight countries, with cross-study comparability improved through correction of variable incubation periods using first-order degradation kinetics, and standardization of UV–visible absorbance wavelengths. The harmonized dataset revealed pronounced hydrological and climatic controls on BDOC dynamics. Biodegradation rate constants were consistently higher in rivers than in lakes, with maximum values observed in temperate rivers during the wet season. Seasonal analyses showed a decoupling between bulk dissolved organic carbon (DOC) and BDOC, with dry conditions favoring DOC accumulation and aromaticity, while wet conditions enhanced inputs of bio-labile DOM. Across climatic gradients, BDOC exhibited greater sensitivity to environmental variability than bulk DOC. Using DOC concentration, absorbance at 254 nm, and humification index (HIX) as predictors, nonlinear ML models outperformed linear regression. Extreme gradient boosting (XGBoost) achieved the highest predictive performance (R² > 0.6), with stronger accuracy for riverine than lacustrine systems. Overall, this study demonstrates that harmonized optical datasets combined with ML modeling provide a robust and scalable alternative to incubation-based BDOC measurements, advancing quantitative assessment of freshwater carbon biodegradability and inland-water carbon cycling.

215. 题目: Utilization of waste sludge-derived biochar in sustainable planting ecological concrete: Integrating structural, ecological, and environmental benefits
文章编号: N26032115
期刊: Environmental Research
作者: Fanrun Huang, Wei Xiong, Guoyu Jiang, Xinyan Xiong, Hongqiang Chu, Huajie Huang, Hainan Wu, Chi Zhang
更新时间: 2026-03-21
摘要: Porous ecological concrete integrates structural stability with plant growth support. However, its sustainability is often limited by high cement content and insufficient nutrient availability. Meanwhile, the continuous generation of waste sludge necessitates its effective utilization as a resource in construction materials due to the high cost of conventional disposal and its unsustainability. Sludge-derived biochar (SB), characterized by porous structure, reactive mineral phases, and intrinsic nutrient content, is a promising multifunctional modifier for ecological concrete. In this study, SBs derived from river sediment, industrial, domestic, and livestock sludge were characterized using SEM-EDS, XRD, and BET. The characterized SBs were incorporated into sustainable planting ecological concrete (SBEC) at a 10% cement replacement ratio. Hydration kinetics and microstructural evolution were analyzed using isothermal calorimetry, TGA, and ²⁹Si MAS NMR. The physical properties, vegetation compatibility (Cynodon dactylon and Festuca arundinacea), and environmental sustainability (life cycle assessment, LCA) were systematically evaluated. SB incorporation enhanced the water retention, alkalinity regulation, freeze–thaw resistance, and sustained N/P release of the resulting composite. SBECs containing industrial and domestic SBs achieved 28-day compressive strengths of 16.94 and 17.12 MPa, respectively, and exhibited the lowest strength loss during freeze–thaw cycles. In contrast, livestock SB contributed to the highest hydration degree (67.7%) in SBECs and rapid alkalinity reduction, which significantly improved root biomass and nutrient accumulation. LCA confirmed that partial cement replacement with SBs significantly reduced environmental burdens. Overall, this work provides a high-value valorization pathway for waste sludge in sustainable multifunctional concrete, with different sludge sources enabling SBECs to achieve structural stability, vegetation support, or balanced multifunctionality.

216. 题目: Source-specific organic matter modulates Anammox via humic-like DOM in mangrove sediments: Implications for eutrophication mitigation
文章编号: N26032114
期刊: Environmental Pollution
作者: Chi Zhang, Yamin Deng, Weichen Xia, Lu Yan, Xianzhong Ke, Yanpeng Zhang, Qinghua Li, Xianjun Xie, Yanxin Wang
更新时间: 2026-03-21
摘要: Anaerobic ammonium oxidation (Anammox) is a pivotal nitrogen loss pathway in coastal ecosystems, but the regulatory roles of organic matter (OM) sources and composition in mangrove sediments remain poorly understood. Here, we combined δ¹³C and C/N ratios, excitation-emission matrix (EEM) fluorescence, the ¹⁵N-tracer technique, 16S rRNA gene sequencing, hzsB gene quantification, and multivariate statistical analyses to investigate the Anammox process in Dongzhai Harbor mangrove wetland (China). Sediments were classified into three OM sources: mangrove/terrestrial, mixed, and marine/local. Mangrove-derived OM exhibited the highest potential Anammox rates (42.64–70.38 nmol N g^-1 h^-1) and hzsB gene abundance (7.80×10⁶–5.01×10⁷ copies g^-1), dominated by Candidatus Anammoximicrobium, while mixed and marine/local OM sediments showed lower activity. Anammox was primarily promoted by total organic carbon (TOC), total organic nitrogen (TON), and water content (WC) (which sustain anoxic microsites) and inhibited by salinity and NO₂^--N. Crucially, dissolved organic matter (DOM) molecular composition emerged as a key regulator: humic-like components (with high aromaticity and humification) correlated more strongly with Anammox rates (r = 0.79, p < 0.001) than protein-like DOM (r = 0.68, p < 0.01), implying that humic substances may act as electron shuttles. Anammox contributed 22.1 to 39.7% to total nitrogen loss, highlighting its substantial contribution to mangrove nitrogen cycling. Our findings highlight the primacy of OM sources and quality (rather than quantity) in regulating Anammox. Specifically, mangrove-derived humic-rich OM enhances Anammox via substrate supply and microenvironmental optimization. This study provides novel mechanistic insights into nitrogen cycling and highlights mangrove conservation and restoration as effective nature-based solutions for coastal eutrophication mitigation.

217. 题目: Climate-Driven Challenges for Production of Clean and Safe Potable Water: Concerns for Dissolved Organic Matter and Anthropogenic Pollution
文章编号: N26032113
期刊: Environmental Science & Technology Letters
作者: Hongyan Zhai, Peizhe Sun, Yingxin Zhao, Sihui Zhan, Jiacheng Luo
更新时间: 2026-03-21
摘要: Precision in situ tracking in real-time the variations in DOM concentrations and composition in source water entering a treatment facility, combined with big-data collection and AI analysis, may help water treatment plants to adopt target-oriented design and operation/maintenance. Comprehensive monitoring and quantification of anthropogenic micropollutants in stormwater runoff under different precipitation scenarios are critical for assessing, predicting, and controlling likely source water inputs for forward planning and optimizing future water treatment design/operation. Elevated DOM, DOM composition shifts, and anthropogenic micropollutants critically complicate DBP formation and speciation. It is further amplifying uncertainties in their toxicological and health risks. Characterizing DBPs, understanding DBP’s health impacts, and lowering DBP formation continue to be an indispensable work. Developing in situ and resilient purification technologies for water sources is strongly recommended. For underserved regions where water treatment facilities are often basic and underfunded, wetlands or other in situ biopurification could be an economical option. Advanced oxidation processes, which can simultaneously reduce DOM, anthropogenic micropollutants, DBPs, and pathogens, offer the potential to reduce chemical consumption and possibly prolong the service life of filtration and membrane in water treatment. Figure 1. Impacts of heavy precipitation events on safe water production. Dr. Sihui Zhan is a professor and Dean of the School of Environmental Science and Engineering at Tianjin University, China. He is a recipient of the National Science Fund for Distinguished Young Scholars and National “Ten Thousand Talents Program” Leading Talent Award in China. His research interests include innovative technologies and strategies for controlling emerging pollutants, efficient removal, and resource recovery of environmental contaminants. As the first or corresponding author, he has published over 100 papers in international journals such as PNAS, Nat. Commun., Angew. Chem. Int. Ed., and Environ. Sci. Technol. He has served as the Chair of the Professional Committee on Resource Recycling, Chinese Society of Natural Resources, Vice-Chair of the Professional Committee on Photocatalysis, China Society of Imaging Science and Technology, and associate Editor of Chinese Chemical Letters. This work was supported by the National Natural Science Foundation of China (Project No. 52270009). This article references 5 other publications. This article has not yet been cited by other publications.

218. 题目: Shift From Promotion to Inhibition: Factors Affecting Soil Organic Carbon Sequestration in Intensive Croplands of the North China Plain
文章编号: N26032112
期刊: Land Degradation & Development
作者: Jing Li, Susu Xu, Huarui Gong, Yan Xu, Shanqing Lei, Hongguang Liu, Deyao Liu
更新时间: 2026-03-21
摘要: Soil organic carbon (SOC) dynamics are critical to maintaining the productivity and stability of cropland ecosystems. Intensive agricultural regions face risks of SOC loss due to high- intensity farming. As a core grain-producing area and a typical intensive agricultural system, the North China Plain (NCP) requires a clear understanding of the long-term evolution patterns of SOC to support sustainable carbon management. However, continuous long-term dynamic datasets and mechanistic drivers—particularly interactions at the interannual scale—remain scarce. This study integrates historical data (1980s) with a 13-year continuous dataset (2007–2020) from a network of 2463 fixed sampling sites to quantify changes in SOC stock across the NCP. Using Random Forest models, Structural Equation Modeling, and time-series analysis, we identified a 40-year SOC stock increase of 16.27 Mg C ha⁻¹, with an average sequestration rate of 0.407 Mg C ha⁻¹ year⁻¹, exceeding prior model estimates (0.35 Mg C ha⁻¹ year⁻¹). Crucially, the role of precipitation as a driver underwent distinct phase transitions: Mean annual precipitation (MAP) positively promoted SOC accumulation during 2007–2010 but shifted to become the strongest negative driver in 2011–2015 due to alternating extreme rainfall and drought events, ultimately transitioning to indirect regulation via synergistic climate-nutrient effects from 2016 to 2020. These findings indicate that sustaining SOC accumulation under intensive agriculture requires climate-adaptive dynamic management strategies, including demand-based irrigation. The results reveal temporal transitions in SOC sequestration mechanisms, providing a scientific basis for climate-resilient carbon management strategies.

219. 题目: Spectroscopic analysis of the interaction mechanism between manganese(II) and microbial extracellular polymeric substances in landfill leachate treatment
文章编号: N26032111
期刊: Environmental Science: Water Research & Technology
作者: Jiasheng Li, Yuejin Wu, Jian Huang, Hua Zhang, Zuochen Sun, Tao Luo, Chunhua He
更新时间: 2026-03-21
摘要: Microbial extracellular polymeric substances (EPS) play a vital role in microbial metabolism and interact with manganese(II), which is commonly present in landfill leachate, during anaerobic biological treatment. This study investigates the molecular mechanisms underlying their interaction. The results indicate that as the manganese(II) concentration gradually increases from 0 to 200 mg L⁻¹, the protein content in the tightly bound EPS (TB-EPS) rises progressively, but then begins to decrease at higher concentrations. Meanwhile, the humic acid content in TB-EPS shows a gradual decline with increasing manganese(II) levels. In contrast, both the protein and humic acid contents in the loosely bound EPS (LB-EPS) continuously increase while polysaccharide content remained largely unaffected by manganese(II). Three-dimensional excitation–emission matrix spectroscopy revealed that the fluorescence intensity of tryptophan-like organics in LB-EPS enhanced with increasing manganese(II), whereas in TB-EPS, it increased initially and then declined. Humic acid-like fluorescence intensified in LB-EPS but weakened gradually in TB-EPS. UV-visible spectroscopy further demonstrated stronger interactions between manganese(II) and aromatic structures or unsaturated aliphatic chains in TB-EPS compared to LB-EPS. Analysis of the protein secondary structure indicated a decreased α-helix/(β-turn + random coil) ratio in TB-EPS at 200 mg L⁻¹ manganese(II), which contributed to enhanced sludge adsorption and flocculation; this trend was reversed at higher concentrations. This multi-spectral approach clarifies the molecular-level effects of manganese(II) on EPS components and provides insights for optimizing the biological treatment of landfill leachate.

220. 题目: Dissolved organic matter treatability and disinfection byproducts formation potential: Role of floc aging
文章编号: N26032110
期刊: Water Research
作者: Jiangwei Lou, Zhiyuan Jin, Jiangfeng Dai, Hang He, Pingfeng Yu, Ruyuan Jiao, Dongsheng Wang
更新时间: 2026-03-21
摘要: Enhanced coagulation is a cost-effective method for removing particulates and organic matter in drinking water treatment. In full-scale operation, flocs may be subject to extended retention in sedimentation basins or sludge storage tanks, or be recirculated, processes that can trigger the release or re-adsorption of organic matter and subsequently influence disinfection byproducts (DBPs) formation. This study examines the interfacial migration of dissolved organic matter (DOM) during the aging of polyaluminum chloride (PACl) flocs and its impact on DBP generation. It revealed the effects of aging time and pH on organic matter adsorption dynamics. Over 5 days of aging, humic substances removed by coagulation were slowly re-released into the supernatant with aluminum nanoparticles, with an average release intensity of 9% at all pH levels; while proteins occupied the vacant active sites left by the released humic substances. Due to enhanced floc crystallization and electrostatic repulsion, the release of humic acid at alkaline pH (7−8) was 1.83 times higher than at acidic pH (6−7). The released humic substances, which mainly belonged to the lignins and tannins, exhibited high unsaturation, high aromaticity, and low molecular weight (<380 Da). This reactive DOM pool directly influenced DBPs formation. After 5 days of aging, the concentrations of known DBPs (THMs, HAAs, HALs, HANs) increased by 27%, and the cytotoxicity increased by up to 31%, while the number of unknown DBPs (including C-DBPs and N-DBPs) rose by 180%. Mass difference reaction network analysis indicated that 89% of the DBPs precursors in the released DOM originated from lignins and tannins. These findings suggest that increasing the frequency of floc discharge from sedimentation tanks, maintaining slightly acidic pH conditions, and treating sludge storage tank supernatant separately are effective strategies for mitigating DBPs and enhancing finished water safety.