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181. 题目: Observed associations between recovery of soil organic matter, nitrogen, and potassium and microbial community reassembly along a 30-year vegetation restoration chronosequence in eroded subtropical red soils
文章编号: N26083005
期刊: Plant and Soil
作者: Cheng Lin, Yiqun Wu, Yang Xiao, Xiangzhou Zheng
更新时间: 2026-08-30
摘要: Background and Aims Vegetation restoration rehabilitates eroded subtropical red soils, but long-term dynamics of soil fertility and microbial community recovery remain unclear. This study evaluated changes across a 30-year restoration chronosequence. Methods Using a space-for-time substitution design (0, 12, 20, and 30 years) in a severely eroded region of southern China, we measured soil physicochemical properties, microbial diversity, community assembly, and predicted functions. Results After 30 years, soil organic matter increased by 435% (to 22.03 g/kg), total nitrogen by 343% (0.62 g/kg), and available potassium by 461% (95.33 mg/kg). Bacterial ACE diversity rose from 518.7 to 1123.7, and fungal from 59.3 to 364.1. Community composition shifted from oligotrophic taxa (e.g., Candidatus Eremiobacterota) in degraded soil to copiotrophic taxa (e.g., Planctomycetota, Bryobacter) and symbiotic fungi (e.g., Glomeromycota, Basidiomycota) in later stages. Redundancy analysis identified available potassium and phosphorus as key factors for bacterial reassembly, while pH and total phosphorus associated more with fungal communities. Functional predictions indicated higher relative abundance of ASVs with predicted nitrogen-fixation versus denitrification capacities after long-term restoration. Correlation analysis revealed significant associations between bacterial phyla and soil nutrients. Conclusion Long-term vegetation restoration was associated with the rebuilding of soil fertility and a shift toward diverse, functionally structured microbial communities dominated by copiotrophic and symbiotic taxa. Although causal inference is precluded by the space-for-time substitution design with one site per restoration stage, our findings reveal observational associations between vegetation restoration and the recovery of soil organic matter and key nutrients within this specific chronosequence.

182. 题目: Root Fe plaque mediates microbial Fe cycling: trade-off effects on soil organic carbon preservation and mineralization in flooded paddy soil
文章编号: N26083004
期刊: Plant and Soil
作者: Yuyao Luo, Jianbo Chen, Chengshuai Liu, Manjia Chen, Xinyu Li, Zixian Wang, Jiangtao Qiao, Fei Huang, Hui Tong
更新时间: 2026-08-30
摘要: Background and aims Root iron (Fe) plaque is a key interface between the rhizosphere and soil that critically influences organic carbon cycling. However, the mechanisms through which Fe plaque drives carbon preservation and mineralization, as well as its role in rhizosphere-mediated carbon emissions, remain poorly understood. Methods We quantified Fe plaque abundance, carbon-degrading enzyme activity, CO2 and CH4 emission rates, Fe-bound soil organic carbon (Fe-SOC), microbial community structure, and functional gene abundance to investigate SOC transformation in a pre-induced Fe plaque treatment (IP) and a non-pre-induced control (CK) under flooded paddy soil conditions. Results Fe plaque significantly increased soil CO2 and CH4 emissions by 27.4% and 31.2% (p < 0.01), respectively. Geobacter-related Fe-reducing bacteria (FeRB) copy numbers were 32.5% and 19.9% (p < 0.05) higher in rhizosphere soil and roots of the IP treatment than in CK, respectively. Carbon-degrading enzyme activities were also elevated by 13.7%-37.2% in IP. Fe-SOC showed a phase-dependent pattern, increasing to 2.86 g kg−1 during the first 3 days in IP, significantly higher than CK (p < 0.01), but subsequently decreasing by 62.3% from days 3 to 28. These results indicate an early Fe-associated carbon-preservation response followed by later destabilization of Fe-associated carbon and enhanced carbon mineralization under increasingly reducing conditions. Conclusion Fe plaque acted as a phase-dependent regulator of SOC dynamics rather than a permanent carbon sink. Enhanced initial plaque formation was associated with short-term Fe-associated carbon retention, but prolonged flooding promoted Fe-SOC destabilization and greater carbon mineralization. These findings highlight the need to consider redox-dependent Fe–C cycling when evaluating SOC storage and greenhouse-gas emissions in paddy soils.

183. 题目: Adsorption Performance and Mechanism of Ni(II) by EDTA-Catalyzed Mg/Al Hydroxide-Modified Biochar
文章编号: N26083003
期刊: Water, Air, & Soil Pollution
作者: Weiping Sima, Jiang Qu, Qibin Xu, Hengjun Tang, Lin Wang
更新时间: 2026-08-30
摘要: With the acceleration of industrialisation, heavy metal pollution has become an increasingly severe problem. Among various heavy metals, nickel ions not only disrupt ecological balance but also pose a significant threat to human health. Consequently, developing efficient methods for removing nickel ions from wastewater has become a key focus in environmental research. To address this challenge, this study successfully synthesised magnesium–aluminium layered double hydroxide-modified biochar (MBC) using ethylenediaminetetraacetic acid (EDTA) as a catalyst and distiller's grains as raw material. Subsequently, the adsorption characteristics of MBC towards Ni(II) and its underlying mechanism were thoroughly analysed. Experimental results indicate that under reaction conditions of pH 6.0, a biochar dosage of 1.25 g/L, and initial Ni(II) concentrations ranging from 25 to 150 mg/L, MBC exhibits optimal adsorption performance for Ni(II). The adsorption capacity of MBC for Ni(II) reaches 78.10 mg/g, achieving a removal rate as high as 97.62%. These results clearly demonstrate that Mg–Al layered double hydroxide (LDH)-loaded biochar exhibits outstanding removal performance for Ni(II). By fitting adsorption kinetics and isotherm models, we confirmed that Ni(II) adsorption onto biochar conforms to pseudo-second-order kinetics and Langmuir isotherm models. Furthermore, adsorption mechanisms were investigated in depth using characterisation techniques such as Fourier Transform Infrared Spectroscopy (FTIR) and X-ray Photoelectron Spectroscopy (XPS). Results confirmed that MBC adsorption of Ni(II) primarily occurs through the synergistic effects of surface coordination, electrostatic interactions, complexation, ion exchange, and π-electron interactions. Collectively, these findings provide crucial theoretical support for the application of modified biochar in treating heavy metal-contaminated wastewater.

184. 题目: Depth-dependent differentiation of plant- and microbial-derived carbon formation pathways drives soil organic carbon responses to straw incorporation and asymmetric warming in paddy soils
文章编号: N26083002
期刊: Plant and Soil
作者: Pan Hou, Qiaogang Yu, Qi Shen, Zhaoming Chen, Qiang Wang, Jun Zhou, Xiaofang Zhu, Lijun Gao, Kangqi Lei, Jingwen Gao, Junwei Ma, Feng Wang
更新时间: 2026-08-30
摘要: Background and Aims Asymmetric warming and straw incorporation are key drivers of soil organic carbon (SOC) in paddy soils, yet their combined effects on plant- and microbial-derived carbon (C) across soil depths remain unclear. We examined how these factors regulate SOC across depths. Methods A four-year straw × warming experiment was conducted in a rice–wheat paddy. In topsoil (0–20 cm) and subsoil (20–40 cm), lignin phenols and amino sugars were measured as biomarkers of plant- and microbial-derived C, together with phospholipid fatty acids and C-acquiring enzymes. Random forest analysis identified predictors of each C pool. Results Straw incorporation increased topsoil SOC by 8.8% while warming reduced it by 6.1%, with a significant interaction offsetting the warming-induced loss; subsoil SOC was unaffected by straw but rose 6.2% under warming. In the topsoil, straw raised total lignin phenols and microbial necromass C by 24.1% and 26.6%, with fungal necromass C increasing more than bacterial. In the subsoil, warming raised lignin phenols by 23.3% via suppressed oxidative decomposition and microbial necromass C by 12.4%, mainly through a 53.4% increase in bacterial necromass C. The SOC/total nitrogen ratio and fungal biomass were the top topsoil predictors, versus oxidative enzymes and bacterial biomass in the subsoil. Conclusion Straw incorporation sustains topsoil SOC by promoting fungal necromass that offsets warming-induced lignin loss, whereas asymmetric warming raises subsoil SOC by suppressing lignin decomposition and stimulating bacterial necromass. Both plant- and microbial-derived C pathways should therefore be integrated into SOC models for paddy systems under future climate.

185. 题目: Four Decades of Straw and Manure Application Differentially Alter DOM Composition and Transport Risk in a Vertisol
文章编号: N26083001
期刊: Water, Air, & Soil Pollution
作者: Xin Yang, Yanfeng Zhang, Min Xia, Peixuan Wang, Zhibin Guo, Lin Jin, Linchuan Zhan, Daozhong Wang, Keke Hua
更新时间: 2026-08-30
摘要: Dissolved organic matter (DOM) loss from agricultural systems undermines soil carbon sequestration and water quality. While organic amendments are vital for soil fertility and crop productivity, their effects are highly amendment-specific. Critically, the quantitative relationship between long-term amendment types and the chemical composition of DOM-which governs its environmental mobility-remains poorly defined. Here, we quantified Dissolved Organic Carbon (DOC) concentration, DOM optical properties and fluorescent components in surface runoff and leachate from a 41-year field experiment on a Vertisol. Over three consecutive years, DOM from six fertilization regimes [no fertilizer (CK), mineral fertilizer (NPK), and NPK with low straw (NPK + LS), high straw (NPK + HS), pig manure (NPK + PM), or cattle manure (NPK + CM)] was characterized using excitation-emission matrix fluorescence with parallel factor analysis (EEM–PARAFAC). Contrasted with NPK, manure amendments markedly increased DOC concentrations and altered its composition. DOM in surface runoff increased by 25.4–44.7%, accompanied by a 16–28% rise in protein-like (C3) fluorescence. In leachate, DOC concentrations rose by 51.9–58.5%, while humic-like (C4) fluorescence nearly doubled (increases of 94.3–105.7%). Moreover, E2/E3 values were significantly reduced by 7.17–20.48% in surface runoff and 14.71–29.66% in leachate, whereas HIX (humification index) and BIX (bioavailability index) were increased by 35–90% and 44–65% in both pathways. Our study reveals manure, particularly cattle manure, poses a greater risk for DOM loss by increasing its concentration in leachate and runoff and altering its chemical properties compared to straw return. Straw return is therefore recommended as a sustainable strategy to reduce DOM pollution risk and enhance agricultural resilience to extreme precipitation.

186. 题目: Residual Disinfectant Controls The Biostability of Drinking Water Independent of The Concentration of Assimilable Organic Carbon
文章编号: N26082906
期刊: ACS ES&T Water
作者: Apoorva Goel, Timothy M LaPara, Raymond M Hozalski
更新时间: 2026-08-29
摘要: Assimilable organic carbon (AOC), residual disinfectant, and temperature were investigated as predictors of biological stability in 18 drinking water distribution systems (DWDSs). Surface water-supplied DWDSs exhibited significantly higher (p < 10–4) AOC concentrations (median = 50 μg/L; range = < LOD to 720 μg/L) compared to groundwater-supplied systems (median = 16 μg/L; range = < LOD to 156 μg/L). AOC levels were significantly higher (p < 10–4) during the summer months (August 2024 to October 2024) in surface water-supplied DWDSs than during the fall (October 2024 to December 2024). In contrast, AOC concentrations in groundwater-supplied DWDSs were similar during the summer and fall. Multivariate statistical analyses showed that residual disinfectant concentration was the strongest predictor of biostability, despite AOC concentrations in some systems being higher than the suggested threshold for biostability (50 μg/L) in disinfected DWDSs. Notably, decreases in AOC concentrations corresponded with increases in bacterial concentrations (measured as 16S rRNA gene copies) in systems where the residual disinfectant concentration was negligible at the distal location. This study, therefore, demonstrates that residual disinfectant concentration is a better predictor of biostability within DWDSs than AOC, even when AOC concentrations are significantly higher than the previously suggested threshold for biostability.

187. 题目: Effect of Biomass-Derived Biochar on Reactive Rejuvenated Styrene–Butadiene–Styrene-Modified Bitumen During Multiple Aging and Rejuvenation Cycles
文章编号: N26082905
期刊: ACS Sustainable Chemistry & Engineering
作者: Xiangjie Niu, Song Xu, Yiwen Zhang, Zihao Zeng, Zhilong Cao, Lei Fang, Hongyan Ma, Yan Yuan
更新时间: 2026-08-29
摘要: Reactive rejuvenation can restore the bitumen phase and reconstruct the styrene–butadiene–styrene (SBS) phase in aged SBS modified bitumen (SMB). However, reactive rejuvenated SMB still undergoes repeated aging during service. To enhance the aging resistance of reactive rejuvenated SMB, biomass-derived biochar was incorporated into the reactive rejuvenator to develop a biochar-modified reactive rejuvenator (BRR). The effect of biomass-derived biochar on reactive rejuvenated SMB during multiple aging and rejuvenation cycles (MARC) was investigated through physical property test, rheological test, toughness test, SARA fraction analysis, fluorescence microscopy test, and molecular dynamics simulations. Results show that BRR can restore the compositional balance of the bitumen phase and reconstruct the SBS phase in aged SMB, but its rejuvenation efficiency gradually declines with increasing MARC cycles. The large specific surface area and porous structure of particulate biochar absorb and stabilize light fractions in rejuvenated SMB, thereby weakening their dispersion and solubilization effects on heavy fractions and increasing the relative proportion of heavy fractions. This strengthens the rutting resistance of reactive rejuvenated SMB at the expense of its deformation resistance and low-temperature cracking resistance. Biochar can improve the aging resistance of rejuvenated SMB by protecting the bitumen phase rather than the SBS phase. This protection is attributed to its ability to absorb and stabilize light fractions in rejuvenated SMB, which reduces their loss during multiple aging cycles and retards the transition of the bitumen phase toward a gel-like colloidal structure.

188. 题目: Interfacial Unlocking by Functionalized Artificial Humic Acid Enables Sustainable Low-Temperature Pyrolytic Remediation of Petroleum-Contaminated Soil
文章编号: N26082904
期刊: Environmental Science & Technology
作者: Haohao Bian, Shunyu Yin, Jiamin Qi, Qunying Wang, Xiaona Ren, Xiaoyan He, Yidong Cai, Zhiguo Guo, Junmei An, Davronbek Bekchanov, Xintai Su, Changchun Ge
更新时间: 2026-08-29
摘要: Pyrolytic remediation of petroleum-contaminated soil (PCS) often requires high temperatures, which increase energy demand, limit resource recovery, and impair post-treatment soil functionality. This high-temperature dependence reflects not only the cracking resistance of heavy hydrocarbons, but also strong oil–soil interfacial locking that restricts their release and conversion. Here, we tested whether targeted interfacial regulation could lower remediation severity in PCS by using functionalized artificial humic acid (FAHA) as an interface-active mediator. Potassium citrate and lignin directed the molecular evolution of artificial humic acid, while Fe complexation introduced additional reactivity during pyrolysis. Under optimal conditions, FAHA2 at 0.5 wt % lowered the remediation threshold from 480 to 390 °C. Multiscale analyses suggested that FAHA reorganized the oil–mineral interface, weakened direct mineral–petroleum interactions, and facilitated lower-temperature release of interfacially constrained petroleum fractions. During pyrolysis, FAHA-bound Fe likely evolved from Fe–S-associated with Fe–O-rich coordination environments that could further facilitate hydrocarbon conversion. Compared with direct high-temperature pyrolysis, the FAHA-assisted pathway better preserved soil functionality and showed a lower estimated gross process-carbon burden under the defined accounting boundary. These results highlight sequential interfacial–thermochemical coupling as a design principle for more sustainable remediation of interface-dominated contaminated matrices.

189. 题目: Small Suspended Particulate Organic Carbon from Kelp Farming: A Neglected Pathway for Microbially Persistent Carbon Retention
文章编号: N26082903
期刊: Environmental Science & Technology
作者: Hongmei Li, Xiuting Feng, Shengkang Liang, Jianfu Man, Wei Shao, Shengrong Huang, Zhenwei Yan, Ding He, Yongyu Zhang
更新时间: 2026-08-29
摘要: Seaweed farming is increasingly recognized for its potential role in ocean carbon dioxide removal, yet the fate of small suspended particulate organic carbon (sPOC, 0.7–20 μm) released during macroalgal growth remains poorly constrained. Here, we investigated sPOC production, transformation, and microbial persistence in Sanggou Bay, China, one of the world’s most intensive Saccharina japonica cultivation systems. During the farming season, sPOC concentrations increased by 103.4% and 117.0% in surface and bottom waters, respectively, relative to the nonfarming period, accompanied by shifts in sPOC molecular composition toward kelp-derived signatures. In situ mesocosm experiments showed increasing sPOC release with kelp development, reaching 13.4–63.5 μmol L–1 over 64 h across growth stages. The 180-day microbial incubations revealed that 18.1–55.6% of kelp-derived sPOC was retained in three microbially persistent carbon pools: recalcitrant sPOC (R-sPOC; 7.6–27.3%), recalcitrant dissolved organic carbon (4.6–9.7%), and bicarbonate-associated inorganic carbon (5.9–18.6%). Residual R-sPOC exhibited molecular characteristics associated with enhanced microbial resistance, with formula-level evidence of direct kelp release and microbial transformation (48.2% and 51.8%, respectively). These findings identify sPOC as a neglected, mechanistically distinct carbon-retention pathway in seaweed farming and provide a basis for assessing its potential contribution to longer-term blue carbon sequestration.

190. 题目: Ecological Restoration of the Soil-Like Function in the Bauxite Residue: Natural Microbiomes Mediated Molecular Transformation of Dissolved Organic Matter
文章编号: N26082902
期刊: Environmental Science & Technology
作者: Yifan Jiang, Luyuan Chen, Hongjun Dong, Qishuang Li, Wenwei Zhao, Feng Zhu, Jun Jiang, Yufei Zhang, Shiwei Huang, Shengguo Xue
更新时间: 2026-08-29
摘要: Soilization of bauxite residues offers a scalable route for long-term carbon management and ecological restoration. However, the microbial processes that transform exogenous organic inputs into stable soil-like carbon pools remain poorly resolved. Here, we combined cross-ecosystem meta-analysis, machine-learning prediction, native synthetic community (SynCom) construction, 13C-labeled straw microcosms, field validation, Fourier transform ion cyclotron resonance mass spectrometry, and genome-resolved metagenomics to unravel microbiome-mediated carbon transformation at the dissolved organic matter (DOM) molecular scale. Our meta-analysis revealed that alkaline industrial wastes retained soil-like DOM signatures but were enriched in microbial humic- and protein-like components, indicating active yet incomplete carbon processing. Guided by these patterns, native SynCom inoculation increased 13C incorporation into total organic carbon (TOC) and dissolved organic carbon (DOC), enlarged biodegradable and adsorbable DOC fractions, and shifted DOM from recalcitrant aromatic pools toward oxygenated carbohydrate-, tannin-, and phenolic-like molecular classes. Genome-resolved analyses linked this transformation to complementary polymer degradation and nutrient-cycling functions across fungal and bacterial guilds, including enriched carbohydrate-active enzymes in straw-carbon-utilizing metagenome-assembled genomes. Null model and thermodynamic analyses further showed that microbial communities were constrained by homogeneous selection, whereas DOM molecules were diversified through variable selection and redox-dependent transformation. Field-scale validation confirmed that SynCom promoted TOC and DOC accumulation and humic-like, high-density DOM fractions under alkaline conditions. Together, these findings establish a mechanistic framework in which functional microbiomes couple plant carbon depolymerization, DOM molecular diversification, and mineral-interactive carbon stabilization, providing a microbiome-guided strategy for carbon sequestration and soilization in the bauxite residue.

191. 题目: Estimation Accuracy Obviously Increased of Soil Organic Carbon Content Based on Habitat Patches Scale Using Interpretable Machine Learning in Southwest China
文章编号: N26082901
期刊: Land Degradation & Development
作者: Wei Zhou, Jieyun Xiao, Haotian Liu, Lu Xu, Keming Wang
更新时间: 2026-08-29
摘要: Although machine learning models have been successfully applied to estimate soil organic carbon (SOC), the lack of interpretability research has resulted in the absence of mechanistic explanations for these models. Therefore, in this study, we adopted the following workflow: first, we divided the whole study area into several subregions using land cover types and habitat patch types based on cluster analysis, and then the model driving features of SOC estimation were selected using the recursive feature elimination (RFE) technique. Second, we compared the estimation accuracy and stability of three machine learning models, and explored the optimal feature combinations and model architecture. Finally, the Shapley additive interpretation (SHAP) model was introduced to interpret the selected SOC content estimation model to verify its reliability. The results showed that the divided modeling framework based on habitat patch type achieved the best performance in SOC content estimation: the maximum increase in R 2 reached 27%, and RMSE decreased by 20% (Habitat Patch 3 vs whole study area). The optimal model combination based on RFE‐RF demonstrated good estimation accuracy across the four habitat patches, with R 2 values of 0.36, 0.49, 0.62, and 0.59, and RMSE values of 22.04, 9.59, 11.67, and 14.57, respectively. Meanwhile, we analyzed the impacts of each input feature on the model prediction from both global and local perspectives. The results showed that DEM, precipitation, and air temperature were the key factors influencing the estimation of SOC content. The SHAP model successfully revealed the relationship between feature variables and SOC, effectively compensating for the limitations of the machine learning model in terms of interpretability.

192. 题目: Heteroaggregation-driven regulation of levofloxacin adsorption by nano-biochar–goethite complexes in aquatic environments
文章编号: N26082507
期刊: Environmental Science: Processes & Impacts
作者: Fengfeng Ma, Yani Cai, Qing Li, Ranxi Li, Wengang Wang
更新时间: 2026-08-25
摘要: The heteroaggregation of naturally occurring substances is crucial for the transportation, transformation, and fate of biochar nanoparticles (BNPs). This study systematically investigates the heteroaggregation behavior between BNPs and goethite (GT), with particular emphasis on their colloidal stability, interaction energetics, and the resulting effects on levofloxacin (LEV) adsorption. BNPs exhibited the highest colloidal stability at pH 7.5. In mixed systems, the coexistence of BNPs and GT enhanced the dispersion of GT particles while simultaneously diminishing the stability of BNPs. The maximum energy barriers (Φmax) for homo- and hetero-aggregation followed the order GT–GT (−10.4 × 10−18 J) < BNPs–GT (2.85 × 10−18 J) < BNPs–BNPs (6.4 × 10−17 J), indicating that GT tends to undergo homopolymerization prior to subsequent heteroaggregation with BNPs. Both Na+ and Ca2+ promoted BNP–GT heteroaggregation, with Ca2+ exhibiting a markedly stronger effect as evidenced by the lower critical coagulation concentration (CCC). When BNP concentration remained below the critical threshold (40 mg TOC per L), BNP effectively enhanced GT dispersion. However, above this threshold, extensive heteroaggregation occurred, forming large and compact heteroaggregates. Heteropolymer formation partially shielded the surface functional groups of BNPs, thereby restricting LEV access to available adsorption sites. Nonetheless, at elevated LEV concentrations, LEV molecules were able to penetrate the heteropolymer matrix or induce structural rearrangements, enabling access to internal sites and enhancing overall adsorption capacity. Interestingly, at low BNP concentrations, the BNP–GT mixture improved LEV removal by inhibiting GT agglomeration and exposing additional adsorption sites. In contrast, at high BNP concentrations, the formation of large heteroaggregates occluded active sites and diminished LEV adsorption efficiency. Overall, this study provides mechanistic insights into BNP–mineral interactions in natural waters and elucidates their implications for the environmental transport and fate of antibiotics. These findings advance the current understanding of nanoparticle–mineral heteroaggregation processes and offer important guidance for predicting contaminant mobility in aquatic environments.

193. 题目: Changes in Molecular Chemistry of Stream Organic Matter and Low Molecular Weight Disinfection Byproduct Precursors Following Initial Post-Fire Rainstorms
文章编号: N26082506
期刊: ACS ES&T Water
作者: William Bahureksa, Charles C Rhoades, Timothy S Fegel, Holly K Roth, Kenneth Hickenbottom, Jacob P VanderRoest, David Hanigan, Amy M McKenna, Michael J Wilkins, Thomas Borch
更新时间: 2026-08-25
摘要: Forested ecosystems are vulnerable to wildfires which have short- and long-term effects on downstream water quality, including changes to dissolved organic carbon (DOC) transport and disinfection byproduct (DBP) formation downstream, which can be exacerbated by high-intensity rainstorms. To evaluate short-term changes to streamwater composition and characteristics, we sampled three streams feeding into the Cache la Poudre River within the perimeter of the 2020 Cameron Peak Fire before, during, and after the first postfire summer storm season. Streams were distinguished by the proportion of their upstream watershed that burned at moderate to high severity (<25%, 25–50%, or >50%). DOC concentration and turbidity demonstrated storm-driven responses that were greatest in the 25–50% burn area stream. Nitrogen-containing species were enriched in streams during the storm and poststorm periods, depending on burn area. Chlorination experiments measured low molecular weight (C1 – C2) DBPs, where streams from subcatchments with more extensive burns were greater in DOC and DBPs formed across all events. However, DOC released during the storms formed less DBPs on a DOC-normalized basis in all streams. These results demonstrate that DBP formation following wildfire disturbance is primarily driven by storm-mediated increases in DOC loading rather than enrichment in highly reactive pyrogenic material.

194. 题目: Machine-Learning-Assisted Auto-Fluorescence Cell-Sorting-Based Fast Differentiation and Quantification of Extracellular Polymeric Substances in the Microalgae and Bacteria Consortium
文章编号: N26082505
期刊: Environmental Science & Technology
作者: Libo Xia, Xiaocai Cui, Tian Ren, Ting Ran, Lingfang Huang, Beibei Wu, Peng Cai, Yun Zhou
更新时间: 2026-08-25
摘要: Extracellular polymeric substances (EPS) are crucial in microalgae-bacteria consortia (MBC)-based wastewater treatment. Revealing the roles of EPS depends on reliable and accurate differentiation, extraction, and quantification of EPS from microalgae and bacteria in the MBC. Autofluorescence-based cell sorting (AFCS) coupled with thermal extraction can achieve the above goals, but it is time-consuming and costly, and invoves unignorable EPS loss (0.4–3.9%) during cell sorting. In this work, the raw data of microalgae (3.42 ± 0.14 mg/g TSS – 52.38 ± 0.47 mg/g TSS) and bacteria (2.95 ± 0.17 mg/g TSS – 48.94 ± 0.21 mg/g TSS) EPS from a series of MBC are obtained using AFCS with thermal extraction. Machine learning regression models are applied for microalgae and bacteria identification, and EPS concentration simulation and prediction. Results showed that, based on the total EPS concentrations and the fluorescence scattering characteristics (obtained from flow cytometry) of the MBC before and after heating, machine learning regression models enabled accurate prediction of EPS concentrations from microalgae (k-Nearest Neighbors, R2 = 0.975, P < 0.001) and bacteria (eXtreme Gradient Boosting, R2 = 0.953, P < 0.001) in the MBC, without cell sorting or EPS loss. This study provides an innovative method for rapid and accurate quantification of total EPS in microalgae and bacteria without requiring physical separation of the MBC, thereby laying a crucial foundation for in-depth analysis of EPS-based interaction mechanisms and functional regulation of microalgae and bacteria within the MBC during wastewater treatment.

195. 题目: Microplastic-Derived Dissolved Organic Matter: Environmental Chemistry and Ecological Consequences
文章编号: N26082504
期刊: Environmental Science & Technology
作者: Jing Wang, Peng Li, Weimin Zhu, Jialiang Gu, Zihan Fan, Jun Ma, Nanqi Ren, Defeng Xing
更新时间: 2026-08-25
摘要: Microplastics (MPs) are widely recognized as particulate hazards, yet environmental aging releases a time-evolving pool of MP-derived dissolved organic matter (MP-DOM) that engages in photochemical and redox reactions. This work provides a critical overview of the aging mechanisms of MPs and the release characteristics of MP-DOM, with emphasis on its molecular properties and the intrinsic and extrinsic factors driving DOM release. Particular attention is given to the strong polymer dependence of MP-DOM, as different plastic classes can generate dissolved mixtures with distinct release kinetics, chemical profiles, and environmental reactivities. Insights into the unstable characteristics of MP-DOM are translated into measurable physicochemical reactions by evaluating its photochemical reactivity and interactions with natural minerals. Importantly, high methodological heterogeneity in experimental protocols hampers reliable comparisons across studies, underscoring the need for standardized leaching procedures in MP-DOM quantification and characterization. The role of MP-DOM in influencing the behavior of environmental pollutants, such as organic contaminants, metals, and antibiotic resistance genes, is critically assessed, particularly its contribution to disinfection byproduct formation, an ongoing concern in water quality management. Recent advances in understanding the ecological and biogeochemical impacts of MP-DOM are synthesized, highlighting its effects on cellular toxicity, microbial responses, and disruptions in element cycling and greenhouse gas emissions. Future directions include standardized aging protocols, rapid source attribution methods, and transferable models for predicting MP-DOM fate and ecological consequences under multistressor conditions. This review provides an updated synthesis of MP-DOM by linking its environmental behavior to ecological fate, advancing our understanding of the long-term ecological impacts and toxicity of plastics.

196. 题目: Tracing Combustion Regime Shifts through Char and Soot Black Carbon Records in Beibu Gulf Sediment Cores: Burial Flux Controls and Carbon Storage Assessment
文章编号: N26082503
期刊: Environmental Science & Technology
作者: Liwei Mo, Ruijie Zhang, Li Zhang, Jing Guo, Jingyu Wang, Zhehong Ji, Pan Wei, Quanfa Ye, Yinghui Wang, Kefu Yu
更新时间: 2026-08-25
摘要: Black carbon (BC) in marine sediments provides a unique archive of combustion history and a reservoir for long-term carbon storage. However, the distinct roles of char BC (CBC) and soot BC (SBC) in combustion-source tracing and carbon-cycle assessment remain poorly resolved in marginal seas. Here, we analyze four sediment cores from the Beibu Gulf, South China Sea, using benzene poly(carboxylic acid) (BPCA) and chemothermal oxidation at 375 °C (CTO-375) methods to resolve subtype-specific BC records. CBC accounted for 52–57% of the estimated total BC burial across all settings, consistent with sustained biomass-burning contributions. SBC exhibited higher spatiotemporal variability and sensitivity to fossil fuel expansion, particularly near industrial zones. Estimated BC burial fluxes varied spatially, largely reflecting differences in representative sedimentation rates rather than BC content. Notably, nearshore sites exhibited higher burial despite lower BC content. Centennial-scale profiles revealed that SBC effectively traced regional transitions from biomass to fossil fuel combustion, while CBC preserved the long-term fire legacy. These findings highlight the complementary roles of CBC and SBC in reconstructing combustion histories and assessing BC burial in marginal seas. Burial of biomass-derived BC can contribute to net atmospheric CO2 sequestration, whereas fossil-derived BC burial represents the transfer of fossil carbon into long-term sedimentary storage.

197. 题目: Transformation of Dissolved Organic Matter by Aqueous Fe(IV) under Acidic Conditions: Bulk-to-Molecular Insights into Reaction Kinetics and Mechanisms
文章编号: N26082502
期刊: Environmental Science & Technology
作者: Zhen Wang, Wenbo Liu, Yunho Lee, Jin Jiang
更新时间: 2026-08-25
摘要: Aqueous Fe(IV) has emerged as a significant nonradical oxidant in iron-based oxidative water treatment, yet its reaction kinetics and mechanisms with dissolved organic matter (DOM) remain largely unexplored. Herein, second-order rate constants (k) for Fe(IV) reactions with DOM and DOM-relevant model compounds were determined under acidic conditions using a competition kinetics method performed on self-assembled quenched-flow apparatuses. At pH 3.0, k for 15 DOM isolates ranged from (2.1 ± 0.2) × 104 MC–1 s–1 to (11.6 ± 0.9) × 104 MC–1 s–1 and correlated strongly with the electron-donating capacity of DOM. Similarly, k for nine para-substituted phenolic compounds correlated linearly with the Hammett constant σ+, EHOMO, and vertical ionization potential, supporting Fe(IV) selectivity toward electron-rich substrates. Across pH 1.0–3.5, k for DOM increased monotonically from the 104 to 105 MC–1 s–1 scale. In contrast, k for 11 model compounds representing major DOM moieties spanned 101–107 M–1 s–1 and exhibited moiety-specific pH dependences, indicating that individual DOM components contribute differently to overall Fe(IV)-DOM reactivity. Fluorescence spectroscopy revealed broad-spectrum oxidation of DOM fluorophores, whereas high-resolution mass spectrometry showed that Fe(IV) preferentially transformed unsaturated moieties, oxidized nitrogen/sulfur-containing functionalities, and fragmented moderate-molecular-weight molecules. These findings provide a bulk-to-molecular kinetic and mechanistic basis for predicting Fe(IV) fate in DOM-containing waters and optimizing Fe(IV)-based advanced oxidation processes.

198. 题目: A Kinetic-Molecular Framework for Resolving Electron-Donating Moieties in Natural and Effluent Organic Matter
文章编号: N26082501
期刊: Environmental Science & Technology
作者: Quan Gao, Yanheng Pan, Qinglong Fu, Shuangshuang Cheng, Xin Yang
更新时间: 2026-08-25
摘要: The redox activity of dissolved organic matter (DOM) plays a critical role in natural and engineering aquatic systems. Although phenolic moieties are typically recognized as the dominant electron-donating moieties (EDM) in naturally occurring DOM (NOM), the chemical nature and reactivity of EDM in wastewater-derived DOM (EfOM), remain poorly understood. In this study, a kinetic categorizing framework was developed for resolving the composition of EDM within DOM by using the second-order rate constants for the reactions of the radical cation of 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS•+) (kapp, ABTS•+) with DOM isolates and a suite of model electron-donating compounds. Our results reveal that NOM contains a larger fraction of rapidly reacting ABTS•+ reducible components with kapp, ABTS•+ > 1 × 103 M–1 s–1, accounting for more than 50% of the total EDM. In contrast, EDM in EfOM mainly consist of antioxidants with relatively low redox activity (kapp, ABTS•+ < 10 M–1 s–1), accounting for 70% of the total EDM. Combining kinetic categorization and Fourier transform ion cyclotron resonance mass spectrometry analysis, the results suggest that EDM in EfOM are associated with nitrogen- and/or sulfur-containing heteroatom compounds. This novel method has important implications for understanding the aquatic redox chemistry of DOM and developing source-adaptive water oxidative treatment strategies in engineering systems.

199. 题目: Black carbon emissions and climate impacts of cost-saving Arctic transit shipping through 2050
文章编号: N26082417
期刊: Nature Sustainability
作者: Wen Yi, Nikita Strelkovskii, Tingkun He, Weiwei Zhang, Xiaotong Wang, Elena Rovenskaya, Xueqing Wang, Yihang Gong, Zhenyu Luo, Kebin He, Huan Liu
更新时间: 2026-08-24
摘要: As climate change accelerates, emerging Arctic routes offer economic gains by shortening voyages but pose climate risks through black carbon deposition on snow and ice. Here we assess Arctic transit shipping at the global scale. Among 295 port pairs with reduced distance, only 249 achieve positive net economic benefits when accounting for fuel, transit, insurance, capital costs and turnover profits. By 2050, Arctic transit shipping could generate up to US$2.3 billion annually. Black carbon emissions are expected to reach 2,200 tons, with a regional maximum temperature response of 2.0–2.9 mK per US$1 billion of economic benefit. Rising fuel prices are expected to increase the economic attractiveness of Arctic transit shipping. Faster energy transitions could enable earlier decoupling of economic benefits from climate impacts, whereas slower transitions may require adjustments such as transit fees and insurance premiums to limit climate risks.

200. 题目: Plot‑Scale Assessment of Sewage Sludge and Biochar Effects on Soil Properties, Soil Erodibility, and Runoff in Contrasting Textural Soil
文章编号: N26082416
期刊: Water, Air, & Soil Pollution
作者: Shamsollah Ayoubi, Mitra Hajabedi, Mohammad Reza Mosaddeghi
更新时间: 2026-08-24
摘要: Population growth is expected to increase by 65% by 2050, placing additional pressure on soil and water resources, particularly in erosion-prone areas like Iran. This study addresses a gap in soil management by comparing the effects of raw sewage sludge and its biochar derivative on soil erodibility, hydraulic properties, and erosion dynamics. The comparison was conducted across two distinct soil textures: silty clay loam (SiCL) and sandy clay loam (SCL). A controlled plot-scale experiment, utilizing simulated rainfall at an intensity of 60 mm h⁻1, tested four amendment rates (0–2 wt. %). Key soil properties, including organic carbon, shear strength, and hydraulic conductivity, were measured, along with runoff and sediment yield. The results revealed that the soil texture affected the response to treatments. Biochar proved more effective than sludge in SCL, reducing soil loss by 47.72% at a 2% application rate. In contrast, sewage sludge was more effective in improving aggregate stability and hydraulic conductivity (Ks) in SiCL. Specifically, organic carbon increased by 56.77% with the addition of sludge in SiCL, which was strongly correlated with reduction in bulk density (r = − 0.73, p < 0.01) and runoff (r = − 0.65, p < 0.01). However, the hydrophobicity of biochar in SCL increased runoff, showing the trade-offs between the two treatments. Regression models revealed that soil organic matter (SOM) and Ks were the primary predictors of runoff (R2 = 0.62) and soil loss (R2 = 0.60). This study demonstrates that biochar is more effective in coarse-textured soils, while sewage sludge is more effective in fine-textured soils, providing new evidence for improving erosion mitigation practices and highlighting the need for soil-specific amendment strategies to protect agricultural resilience.