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21. 题目: Programming interfacial electron transfer at Shewanella oneidensis – Magnetic biochar hybrids for selective tetracycline–ciprofloxacin co-removal
文章编号: N26041003
期刊: Journal of Environmental Chemical Engineering
作者: Lei Wang, Yudong Li, Dongle Cheng, Jian Zhang, Huu Hao Ngo, Wenshan Guo, Jie Li, Huaqing Liu, Yanlong Wang, Aiyun Guo
更新时间: 2026-04-10
摘要: Antibiotic residues persist in waters and require effective, low-chemical remediation strategies. Here we create a contacted system that brings Shewanella oneidensis (MR-1) into controlled association with nitrogen doped magnetic biochar to promote interfacial electron transfer. In a mixed tetracycline-ciprofloxacin matrix, the contacted system was superior to the single biochar or microbial system. Meanwhile, the MR-1 activity was maintained within the range of 3–20 mg/L and pH 5–8, with the best performance near pH 5-6. Electrochemical and spectroscopic signatures are consistent with interfacial electron transfer from MR-1 to surface Fe centers, accompanied by Fe3⁺/Fe2⁺ redox cycling and coupling of adsorption with reduction. Dissolved Fe2+ after reaction followed similar trends and increased with carrier loading, and excitation-emission matrices showed humic-like extracellular polymers that may assist electron shuttling. Electronic-structure analysis is consistent with the observed differences between tetracycline and ciprofloxacin, with tetracycline more readily accepting the first electron at chelating diketone sites, whereas the fluorinated moiety and associated bond stability may constrain ciprofloxacin conversion. Overall, the results suggest an interface-controlled route to antibiotic co-removal under mild conditions and provide design insights linking pollutant electronics, Fe site density, and operating pH to interfacial electron flow.

22. 题目: Effects of biochar application frequency on soil nutrients and crop quality: evidence from eight-year field experiments in two contrasting soils
文章编号: N26041002
期刊: Environmental Technology & Innovation
作者: Caibin Li, Jiuquan Zhang, Minggang Xu, Jianxin Dong, Shuai Wang, Pengzhi Li, Heqing Cai
更新时间: 2026-04-10
摘要: Eight-year consecutive field experiments were conducted at two locations (Heishi and Linquan, Bijie, Guizhou, China) to investigate the optimum biochar application frequencies for sustaining soil nutrients and crop quality. A randomized complete block design with three treatments (annual, biennial, triennial) and three replicates was established using flue-cured tobacco as a test crop. Biochar derived from tobacco stems was applied at a rate of 7.5 Mg ha⁻¹ per application according to treatment frequency, and multi-component fertilizer was applied each year. Soil samples were collected at 12 times for nutrients and enzyme activity analyses. Results showed that annual application significantly increased soil pH by 0.67 to 0.70 compared to triennial treatments, and soil organic carbon (SOC) by 38%–62% in Hapludult and 17%–46% in Dystrudept. Annual application substantially increased available K by 35%–53% increases over triennial treatments. However, annual application also elevated soluble chloride (Cl⁻) by 56%–134%. Structural equation modeling revealed that frequency primarily controlled pH, SOC, and soluble Cl. Soil enzyme activities increased by 18%–45% under annual versus triennial applications. For tobacco leaves, annual application increased total sugar accumulation, while biennial and triennial applications improved potassium/chlorine (K/Cl) ratios. Site-specific responses were evident, with Hapludult showing stronger frequency effects than Dystrudept. These findings suggest that a 2 to 3 years biochar application interval, tailored to soil type, provides optimal balance between soil nutrient enhancement, microbial activity, and tobacco quality while mitigating excessive Cl accumulation.

23. 题目: Enhanced near-surface soil labile carbon and microbial indicators under cover crops and crop diversification in long-term no-till systems
文章编号: N26041001
期刊: Geoderma
作者: Sainfort Vital, Sutie Xu, Namrata Ghimire, Peter Sexton, Jixiang Wu, Christopher Graham, Lan Xu, Mengistu Geza
更新时间: 2026-04-10
摘要: No-till systems improve soil functions and are widely adopted in South Dakota cropping systems. However, these cropping systems have become increasingly simplified due to reduced small grain adoption, potentially reducing carbon inputs and microbial diversity. Therefore, this study aimed to (i) quantify the effects of crop rotations and cover cropping on soil organic carbon (SOC), total nitrogen (TN), and their labile fractions across the 0–80 cm soil profile, and (ii) assess how these management practices affect microbial properties in the topsoil (0–7.5 cm), using a long-term no-till (>30 years) field experiment in South Dakota. Main treatments included a corn (Zea mays L.)–soybean [Glycine max L. (Merr)]–oat (Avena sativa L.)–rye (Secale cereale L.) rotation (CSOR) and a corn–soybean rotation (CS) in a randomized complete block design with four replicates. Each rotation plot was split into cover crops (CC) and no cover crops (NCC). Near-surface SOC concentrations, microbial biomass carbon, and enzyme activities were increased by CC but showed little response to rotations. Both CSOR and CC increased TN, water-extractable carbon and nitrogen, and permanganate-oxidizable carbon in the topsoil. The CSOR promoted bacterial and total microbial phospholipid fatty acid abundance during the corn phase in fall and promoted arbuscular mycorrhiza fungi in spring under CC. In the fall, CC increased all microbial groups in both rotations, with greater benefits under CSOR in spring. Overall, at this long-term no-till site, cover crops and, to a lesser extent diversified rotations, can improve near-surface SOC concentrations, labile carbon, and microbial indicators.

24. 题目: Solvent-Selective Complexity Reduction of Effluent Dissolved Organic Matter for 1H NMR Spectroscopy
文章编号: N26040904
期刊: Analytical Chemistry
作者: Sepehr Shakeri Yekta, Alex Enrich Prast, Mattias Hedenström, Tobias Sparrman, Luka Šafarič, Giacomo Carraro, Helena Rodrigues Oliveira, Thuane Mendes Anacleto, Annika Björn, Norbert Hertkorn
更新时间: 2026-04-09
摘要: Processing of biomass residues for material and energy recovery generate effluents containing complex organic mixtures. Analyses of bulk parameters are conventional for characterization and classification of such effluents, where the limited information offered impedes the development of molecular level management practices. This study assessed the potential of solvent-selective complexity reduction of effluent dissolved organic matter (DOM) from anaerobic bioprocessing of biomass residues for ¹H NMR spectroscopy. The DOM were acquired after filtration and drying of samples from seven full scale anaerobic bioreactor facilities with effluents used as biofertilizer. The ¹H NMR spectra of DOM in indigenous solvent (water) revealed source dependent characteristics primarily due to variable abundance of aliphatic CCH in lipids and peptides, OCCH in carbohydrates, and olefinic and aromatic subunits. Dimethyl sulfoxide solubilized larger proportion of nonfunctionalized aliphatic and aromatic molecules, with ¹H NMR features also varying depending on the DOM source. Methanol, however, reduced the ¹H NMR spectral variability and dissolved sets of aliphatic and aromatic molecules from the dried DOM with similar ¹H NMR features irrespective of their origin. Among the other solvents studied, the reactive dissolution by trifluoroacetic acid decomposed aliphatic units while enriching aromatics (i.e., C_arH:CCH of 0.7 compared to 0.2 in water), also forming small (oligo)saccharides and peptide fragments. Acetone, dichloromethane, and acetonitrile extracted alkyl-rich molecules with varying degrees of functionalization. Acetonitrile separated a fraction enriched in aliphatic carboxylic acids, while dichloromethane mainly dissolved nonfunctionalized aliphatic hydrocarbons. It is proposed that a simple process of filtration, drying, and dissolution of effluent DOM in different solvents substantially reduces the complexity and heterogeneity of the organic mixtures enabling the structural discrimination of diverse molecular classes by ¹H NMR spectroscopy.

25. 题目: Green synthesis of a highly efficient phenol composite adsorbent based on urea/magnesium nitrate co-activated biochar: adsorption performance and mechanism analysis
文章编号: N26040903
期刊: Separation and Purification Technology
作者: Jie Wu, Keran Li, Zhengyi Zhao, Weixing Wang, Dianlin Wang
更新时间: 2026-04-09
摘要: Expanding industrialization has escalated phenolic wastewater discharge, presenting unique environmental challenges. We developed N-doped porous biochar from peanut shells via Mg(NO₃)₂/urea activation, featuring high porosity and enhanced affinity for phenolic compounds. This biochar was incorporated into a sustainable gel matrix of oxidized peanut shell cellulose/chitosan, creating a BPA-imprinted functional composite (MBCN@aCeS) through molecular imprinting. Systematic evaluation revealed exceptional BPA removal performance. Comprehensive characterization (FTIR, SEM, TGA, XPS) elucidated its pore architecture and functional group configurations. Three-factor, three-level RSM optimization generated predictive equations, indicating a maximum capacity of 202.75 mg/g. BPA adsorption followed Freundlich isotherm and pseudo-second-order kinetics, with rate limitation governed by liquid-film and intra-particle diffusion. Mechanistic studies traced contaminant pathways from aqueous phase to active sites, while spectral evidence confirmed π-π stacking and hydrogen bonding as dominant mechanisms. Critically, cyclic tests (>91% regeneration after 5 cycles) and dynamic column experiments validated significant engineering applicability for industrial implementation.

26. 题目: Highly selective adsorption of methylene blue and malachite green by a biochar-sodium alginate composite: experimental and molecular-level mechanistic insights
文章编号: N26040902
期刊: Separation and Purification Technology
作者: Zhiju Chen, Bin Wang, Shiyun Guo, Yueli Wen, Maohong Fan, Haodong Yang, Xugang Li, Wei Huang, Abuliti Abudula, Guoqing Guan
更新时间: 2026-04-09
摘要: Persistent cationic dyes in textile wastewater, such as methylene blue (MB) and malachite green (MG), pose serious environmental hazards, driving the requirements for development of sustainable adsorbents. In this study, a biochar/sodium alginate (PBC-Fe/SA) composite with a stable alginate network was prepared by crosslinking phosphoric- and ferric salt-modified porous biochar from distiller's grains with sodium alginate. By using the obtained composite under optimized conditions (0.5 g/L, 120 min, pH 12 for MB, pH 7 for MG), the maximum adsorption capacities reached 1546.65 mg/g for MB and 1720.29 mg/g for MG. Thermodynamic, isotherm, and kinetic analyses confirm that the adsorption is spontaneous and chemisorption-dominated. Combining spectroscopic characterization and density functional theory (DFT) calculations, it reveals that the superior adsorption performance with high selectivity under competitive conditions owes to the synergistic electrostatic interactions and hydrogen bonding within the alginate network, as well as pore-filling contributions from the porous biochar structure. Even after five regeneration cycles, the removal efficiency remains above 77%, indicating a certain degree of reusability. This work demonstrates that the coupling of agro-waste-derived biochar with natural polysaccharides enables to produce high-performance, sustainable adsorbents. Also, it is expected to provide mechanistic insight into targeted cationic dye removal from wastewater by using the developed adsorbents.

27. 题目: Warming Reduces the Positive Effect of Nitrogen Addition on Soil Organic Carbon in Grasslands
文章编号: N26040901
期刊: Ecology Letters
作者: Ting‐Shuai Shi, Pablo García‐Palacios, Scott L Collins, Josep Peñuelas, Jordi Sardans, Kailiang Yu, Wen‐Bin Ke, Caixia Zhang, Jian‐Sheng Ye
更新时间: 2026-04-09
摘要: Nitrogen (N) addition can increase soil organic carbon (SOC) in some grasslands, however, it is unknown whether N addition may enhance SOC in a warmer climate at broad spatial scales. We conduct a field experiment to test how N addition and warming interactively influence SOC in a temperate semiarid grassland. N addition significantly increases SOC by 14%, while simultaneous N addition and warming significantly decreases SOC by 25% relative to N-only addition. This result is further supported by a global meta-analysis, which shows that N addition (1 g N m⁻² yr⁻¹) increases SOC content by 0.2% relative to ambient conditions in grasslands, but the positive effect of N on SOC significantly declines at a rate of 0.06% per °C of increased mean annual temperature. Our field experiment and meta-analysis suggest that warming may reduce or even eliminate the positive effect of N addition on SOC in grasslands.

28. 题目: A Loose Nanofiltration Membrane from Aqueous Monomer 8-Amino-1-naphthol-3,6-disulfonic acid for Highly Selective Separation of Natural Organic Matter from Minerals in Drinking Water
文章编号: N26040813
期刊: Journal of Membrane Science
作者: Fang Feng, Kai Li, Gang Wen, Ying Liu, Jiawei Hui, Tinglin Huang
更新时间: 2026-04-08
摘要: Loose nanofiltration (LNF) offers a promising solution for producing high-quality drinking water by selectively removing natural organic matter (NOM) while permeating beneficial minerals. Herein, we presented a molecular design strategy to fabricate a novel polyamide-polyester LNF membrane via interfacial polymerization (IP) of trimesoyl chloride (TMC) and an aqueous monomer, 8-amino-1-naphthol-3,6-disulfonic acid (ANDSA). Mechanistically, the steric hindrance of the bulky naphthalene skeleton prevents tight polymer chain packing, inherently creating a loose separation structure. The optimized ANDSA-0.5 membrane achieved a high water permeability of 62.4 L·m^-2·h^-1·bar^-1 and excellent rejection (>90%) for both humic acid (HA) and tannic acid (TA), while maintaining low salt rejection (<13.0%) for various electrolytes (Na₂SO₄, MgSO₄, MgCl₂, CaCl₂, and NaCl). Furthermore, the membrane exhibited superior antifouling performance, with a flux recovery ratio (FRR) of 84.1% after three filtration-cleaning cycles using HA/CaCl₂ foulants, significantly outperforming the piperazine (PIP) control membrane (73.5%). Moreover, the membrane exhibited a low irreversible fouling tendency, enabling sustained operational performance through simple hydraulic cleaning cycles. Compared to the commercial NF270 membrane, the ANDSA-0.5 membrane achieved an approximately 5-fold higher water permeability, along with enhanced antifouling properties and superior NOM/mineral ions selectivity, offering a novel strategy for fabricating high-performance LNF membranes.

29. 题目: Predicting Summer River Hypoxia from DOM Fluorescence Signatures Using Interpretable Machine Learning and Kinetic Validation
文章编号: N26040812
期刊: ACS ES&T Water
作者: Huifeng Zhu, Nitao Gu, Guanyi Zhang, Huajun Feng, Lingfeng Zhou, Dongping Shi, Mei Li, Ying Kang, Yingyu Tan, Ganghui Tong, Xubiao Yu
更新时间: 2026-04-08
摘要: Summer hypoxia increasingly occurs in subtropical urban rivers even where conventional pollutants are effectively controlled, suggesting overlooked drivers of oxygen loss. We integrate approximately 10 years of monitoring data from rivers in southeastern China (666 EEM fluorescence records) with interpretable machine learning (XGBoost-SHAP), 432 incubation assays, and Streeter–Phelps-based kinetic analysis to identify controls on dissolved oxygen (DO) decline. The models show strong predictive performance and consistently identify temperature and a tryptophan-like DOM component (C1) as dominant predictors of DO variability. SHAP interaction analysis indicates that the influence of C1 on DO becomes stronger under warm conditions. Incubation experiments further demonstrate rapid oxygen consumption associated with protein-like DOM, supporting its role as a highly bioavailable microbial substrate. Incorporating C1 into the Streeter–Phelps framework substantially improves model performance (R2 ≈ 0.85–0.98), linking fluorescence-resolved DOM to DO dynamics. These results suggest that bioavailable protein-like DOM, likely associated with diffuse sewage inputs, plays a key role in summer oxygen depletion. Monitoring and controlling bioavailable DOM may therefore improve hypoxia mitigation and urban river management.

30. 题目: Structure-dependent radical–nonradical transition in endogenous and exogenous Fe single-atom anchored biochar derived from hyperaccumulators for peroxymonosulfate activation
文章编号: N26040811
期刊: Journal of Hazardous Materials
作者: Fangzhou Li, Botu Xiong, Ziren Wan, Jia Deng, Yusheng Peng, Lina Zhang, Chunli Zheng, Guanghe Li, Fang Zhang
更新时间: 2026-04-08
摘要: Exploring single-atom catalysts (SACs) with green synthesis via endogenous approach has attracted increasing attention for environmental remediation. Herein, endogenous Fe single-atom anchored biochar (FeN3O1-ZBC) and exogenous Fe single-atom anchored biochar (FeN4-BC) were synthesized using hyperaccumulators (Sedum alfredii) for peroxymonosulfate activation, enabling a systematic comparison of the mechanistic and energy efficiency differences. Radicals (•OH and SO4•−: 74.1%) predominantly contributed to the FeN4-BC/PMS system, and the energy efficiency exhibited a concentrated interquartile range (IQR) across different pollutants. In contrast, the electron transfer process (ETP, 82.6%) was the dominant mechanism in the FeN3O1-ZBC/PMS system, where spontaneous oxygen doping in the Fe coordination environment enhanced electron transfer capacity by modulating the surface potential and optimizing the energy level distribution of Fe 3d orbitals. FeN3O1-ZBC exhibited a broader IQR in energy efficiency compared to FeN4-BC, with significant selectivity for electron-rich pollutants and a minimum electric energy per order (EE/O) of just 0.64 kWh·m−3·order−1. This work deepens the understanding of structure–function relationships in single-atom catalysts and provides new insights into the formation mechanism and catalytic efficiency of endogenous single-atom catalysts derived from heavy metal–contaminated biomass.

31. 题目: Inhibiting Cr(VI)-mediated ARG dissemination in wastewater: Synthetic antioxidant-, extracellular polymeric substance-, and nuclease-producing microbiome targeting ROS, MGEs, and ARG-MRG co-occurrence
文章编号: N26040810
期刊: Journal of Hazardous Materials
作者: Bo Deng, Zi-He Ren, Chong-Yang Ren, He-Ping Zhao
更新时间: 2026-04-08
摘要: Heavy metals (HMs) trigger the sustained enrichment and dissemination of antibiotic resistance genes (ARGs) by exerting selective pressure, and there is an urgent need for effective and environmentally friendly control strategies. Herein, we found that long-term (180 d) hexavalent chromium [Cr(VI)] stress (10 mg/L) could facilitate the enrichment of multidrug-resistant plasmids (e.g., bla_TEM and sul1) and significantly increase (p < 0.05) the conjugative transfer frequency. Subsequently, we constructed a synthetic carotenoid- and extracellular nuclease gene exeM-producing microbiome centered on Deinococcus radiodurans R1, which synthesizes and secretes extracellular polymeric substances (EPS) via the Wzx/Wzy-dependent pathway, thereby alleviating environmental oxidative stress by adsorbing Cr(VI) (over 85%) and scavenging ROS (approximately 18–26-fold). qPCR results demonstrated that the synthetic microbiome effectively reduced ARG abundances, along with the mobile genetic elements traG and intI1 (by more than one order of magnitude, MGEs) and the metal resistance gene chrA (by more than two orders of magnitude, MRG). Electron microscopy and metagenomic analysis demonstrated that the synthetic microbiome could further reduce the co-occurrence of ARGs and MRGs (e.g., tetA, chrA, and chrB) by impairing plasmid integrity and preserving cell membrane integrity (ompC, oprC, plsB, and fabR), thus inhibiting horizontal gene transfer. In addition, it reduced the abundance of Pseudomonadota (the host harboring ARGs and MGEs, p < 0.05) by 33–48%. This study provides a sustainable bioremediation strategy for controlling the dissemination of ARGs in heavy metal-polluted wastewater.

32. 题目: Influence of biochar feedstock and particle size on cementitious composites incorporating biochar as a partial cement replacement
文章编号: N26040809
期刊: Journal of Cleaner Production
作者: Mohammed AlSieedi, Zhangfan Jiang, Ahmad Al-Bodour, Mert Atilhan, Lisa M Colosi, Gabriel Arce, Osman E Ozbulut
更新时间: 2026-04-08
摘要: This study investigates the potential of biochar as a sustainable partial replacement for cement in cementitious composites, aiming to reduce embodied carbon while maintaining or improving material performance. Biochars derived from rice husk, softwood, and hardwood were examined across three particle size ranges (<38 μm, 53–149 μm, and 149–300 μm). A comprehensive characterization was performed to assess their elemental composition, crystalline structure, surface morphology, functional groups, and porosity. Cementitious composites incorporating 5% and 10% biochar by weight of cement were prepared and evaluated in terms of compressive strength, hydration behavior, and thermal conductivity. A cradle-to-gate life cycle assessment was conducted considering cement production, biochar processing, and pyrolysis operations; upstream biomass cultivation and harvesting, long-distance transportation, construction, use phase, and end-of-life stages were excluded. Results show that influence of biochar on performance is highly dependent on feedstock type and particle size. Compressive strength results demonstrated that mortars incorporating rice husk biochar maintained up to 97% of the control strength, whereas hardwood and softwood biochars led to reductions of up to 32% and 47%, respectively, particularly at finer particle sizes and higher dosages. Among the biochars evaluated, rice husk biochar produced at approximately 550 °C and ground to a particle size range of 53–149 μm achieved the greatest reduction in thermal conductivity, with values up to 54% lower than the control mixture at a 10% cement replacement level. In addition, life cycle assessment revealed that rice husk biochar offered the most favorable balance between mechanical performance and environmental impact, achieving up to 33% reduction in global warming potential. The results demonstrate that biochar–cement composites offer practical potential for energy-efficient and low-carbon construction applications, particularly in non-structural and semi-structural elements where reduced thermal conductivity and environmental impact are prioritized.

33. 题目: Removal of PFAS and 1,2,4-TCB from firefighting-contaminated sites by iron-modified biochar microspheres loaded with microbes
文章编号: N26040808
期刊: Journal of Cleaner Production
作者: Binglu Teng, Zhenhua Zhao, Jiangxuan Wu, Liling Xia, Yuan Jiang, Yipin Geng
更新时间: 2026-04-08
摘要: The co-contamination of PFAS and 1,2,4-trichlorobenzene (1,2,4-TCB) in fire fighting-contaminated sites has long been an overlooked issue, posing potential toxicity risks to ecosystems and human health. The combined use of biochar adsorption and biodegradation has garnered significant attention in the field of organic pollutant removal. However, the sustained removal performance of the composite system toward sites co-contaminated with PFAS and 1,2,4-TCB, as well as its effects on soil microbial communities, remain to be systematically investigated. This study developed an iron-modified biochar sphere coupled microbial consortium system (Fe/BCM-DB) for degradation. A 180-day remediation experiment was conducted at different profiles of a PFAS and 1,2,4-TCB co-contaminated site under pilot-scale conditions. The study investigated the sustained remediation effects of composite systems on co-contaminated sites, the underlying removal mechanisms, and the response of microbial communities. The removal of pollutants by Fe/BCM-DB involves two core mechanisms: adsorption and biodegradation. The research results indicate that the maximum removal rates achieved across different profiles were 98.42% for PFOS, 93.14% for PFOA, 46.57% for PFHxA, 32.81% for PFBS, 28.73% for PFBA, and 90.84% for 1,2,4-TCB. The diversity of the soil microbial community increased significantly after remediation, providing core biological support for the gradual restoration of its ecological functions. Fe/BCM-DB effectively remediates sites co-contaminated with PFAS and 1,2,4-TCB, representing a promising approach to remediation.

34. 题目: Empirical evaluation and recommendations for equivalent soil mass adjustment of soil organic carbon stocks
文章编号: N26040807
期刊: Geoderma
作者: Eric Potash, Adam C von Haden, Luke Bergschneider, Michael S Douglass, Lenarth Ferrari, Rosa Ibarra Lopez, Adriana Reconco Martinez, Andrew J Margenot
更新时间: 2026-04-08
摘要: Measuring changes in fixed depth (FD; e.g. 0–30 cm) soil organic carbon (SOC) stocks is problematic if soils have compacted or expanded, i.e. if bulk density (BD) has changed. In theory, equivalent soil mass (ESM) remedies this. But in practice ESM is an approximation whose accuracy (systematic error) has not been evaluated empirically or compared to the FD baseline. We sampled 72 soil cores (0–75 cm) across six sites (central USA) of two regionally representative soils (Mollisols and Alfisols). SOC concentration and BD were measured at 2.5 cm depthwise intervals (dataset provided) to support this novel empirical evaluation of ESM accuracy. Under moderate BD changes (± 2.5 cm, or about 0.1 g cm−3), 0–30 cm FD measurements had systematic errors up to 8% (5 Mg ha−1), which would substantially distort SOC stock change estimates. Linear ESM using those single layer measurements improved accuracy somewhat in Mollisols but not Alfisols. Measuring a 30–35 cm “correction layer” substantially reduced systematic error in both soil types using linear and especially spline ESM (< 1.5% or 0.5 Mg ha−1). Of practical importance, pooling the correction layer did not sacrifice accuracy while substantially reducing ESM cost. For deeper soils (60 cm), FD was less inaccurate but ESM with multiple layers further improved accuracy. We conclude with recommendations on when and how to use ESM for accurate and cost-effective SOC stock change estimation in the two major soil types of central USA. However, caution is warranted when estimating SOC changes with short timescales, more extreme BD changes (e.g. ± 5 cm), and other soil types.

35. 题目: Lability of riverine particulate organic carbon increased by water storage and extreme drought-heatwave events
文章编号: N26040806
期刊: Geochimica et Cosmochimica Acta
作者: Jixuan Lyu, Caroline L Peacock, Yifan Zhang, Tao Liu, Yong Shi, Xiaomei Xu, Shengjing Liu, Yubing Qu, Shuo Zhang, Guang Yang, Dong Peng, Chonghao Chen, Xin Zhou, Yanxu Zhang, Jianhua Gao
更新时间: 2026-04-08
摘要: Rivers are increasingly affected by dams and reservoirs, which impact the source and transport of riverine particulate organic carbon (POC), and by extreme events, which present an important climatic stressor for river ecosystems. How and to what extent water regulation and extreme events affect POC lability, however, remain poorly constrained. By studying the POC characteristics within the Yangtze River Basin in normal and extreme drought-heatwave years, we find that during a normal year water storage by the Three Gorges Reservoir increases the proportion of algae-derived POC (by 26 ± 4%) compared to water drainage, leading to a higher proportion of labile POC and younger POC age. During the extreme drought-heatwave year, the drought-heatwave event increases proportions of algae-derived POC and labile POC (by 19 ± 11% and 18 ± 8%, respectively) in the whole Yangtze River Basin, with a greater increase in the Three Gorges Reservoir (by 34 ± 7% and 29 ± 3%, respectively; compared with the non-Three Gorges Reservoir areas, P < 0.01), whilst resulting in a 29 ± 6% reduction in export POC flux to the East China Sea. We use our findings from the Yangtze River Basin to assess the global impact of dams and reservoirs, and estimate that the global riverine export POC flux has decreased from pre-dam 190 ± 5 Tg C/yr to post-dam 97 ± 48 Tg C/yr. We also posit that the additional increase in POC lability and decrease in export POC flux during an extreme drought-heatwave event in the Yangtze River Basin occurs in other major river systems as well. Combined we assert that more frequent extreme drought-heatwave events will compound the effects of damming, resulting in an increasingly labile and thus more readily remineralized riverine POC source and a decreasing export POC flux into the near-shore environment. Our results provide critical insights into assessing and mitigating the effects of combined damming and extreme drought-heatwave events on the organic carbon cycle in river systems.

36. 题目: Hierarchical Excitation-emission Matrix (EEM) Decomposition: Relaxed Implementation of Kasha’s Rule to Enhance Resolution
文章编号: N26040805
期刊: Water Research
作者: Yongmin Hu, Sema Karakurt-Fischer, Eberhard Morgenroth
更新时间: 2026-04-08
摘要: Excitation-emission matrix (EEM) fluorescence spectroscopy is widely used for characterizing environmental samples and shows potential in water quality monitoring. Parallel factor analysis (PARAFAC) is currently the dominant method for EEM decomposition. However, it imposes strict adherence to Kasha’s rule and is limited in resolving highly overlapping fluorophores, restricting its ability to interpret spectral shifts and sub-fluorophore level heterogeneity. Here, we propose a Hierarchical EEM Decomposition (HED) framework that relaxes Kasha’s rule, enabling controlled spectral flexibility and improved decomposition resolution of chemically distinct components within the same fluorophore group. Applied to EEM datasets from wastewater and greywater treatment systems, HED revealed excitation-dependent emission behavior in long-wavelength DOM fluorescence consistent with charge transfer (CT) model assumptions, which PARAFAC cannot capture. HED also successfully deconvoluted signals with distinct chemical sources from overlapping tryptophan-like DOM fluorescence, as evidenced by the alignment of the deconvoluted signal pattern with the degree of treatment of wastewater and the improved estimation of bacterial and DOC concentrations for greywater. Furthermore, the integration of prior knowledge (e.g., target concentrations) as soft constraints enhanced model interpretability and predictive power. HED introduced in this work offers a physically grounded alternative to existing decomposition approaches, providing opportunities for high-resolution, interpretable EEM-based monitoring of complex water matrices.

37. 题目: Nitrogen-doped sludge biochar for periodate activation: Synergistic radical/non-radical pathways for rapid sulfadiazine degradation
文章编号: N26040804
期刊: Separation and Purification Technology
作者: Zhiyi Zhang, Qingzhen Wan, Juan Ren, Banghai Liu, Xiangyu Yang, MengChun Gao, Yangguo Zhao, Liang Guo, Chunji Jin
更新时间: 2026-04-08
摘要: Sludge-derived biochar (SBC) effectively activates periodate (PI) to degrade sulfadiazine (SDZ) in water. Despite the demonstrated potential of biochar-based catalysts in PI activation, their efficiency remains constrained by factors such as reaction conditions, radical generation efficiency, and the formation of reaction byproducts. The structural characteristics and catalytic activity of nitrogen-doped biochars (NBCs) under various conditions were investigated using XRD, SEM, BET, FTIR, Raman spectroscopy, XPS, and elemental analysis. Experimental results indicate that the removal of SDZ was limited in systems with NBC alone (22.31%), PI alone (24.01%), or SBC/PI (36.89%). In contrast, the NBC/PI system achieved complete SDZ removal (100%) within 30 min, exhibiting a degradation efficiency more than 4.2 times greater than that of PI alone. Nitrogen doping enhances catalytic performance by expanding the specific surface area, optimizing pore structure, and increasing the number of surface-active sites. The oxygen-containing functional groups (–OH, Csingle bondO, and Cdouble bondO) are likely primarily derived from the pyrolysis process itself, and these groups, along with nitrogen species, strengthen the interaction between the catalyst and PI. In the NBC/PI system, SDZ degradation involves the synergistic action of multiple reactive oxygen species (ROS), including IO₃•, O₂•−, 1O₂, and a small amount of •OH. Among these, IO₃•, O₂•−, and 1O₂ play major roles, while non-radical pathways such as electron transfer serve a supplementary function. The introduced nitrogen species, particularly graphitic nitrogen, facilitate electron transfer and enhance the interaction between NBC and PI. The synergistic combination of radical and non-radical degradation pathways enables efficient and stable oxidation. This study provides a foundation for nitrogen-doped carbon materials in PI-based oxidation systems and a practical strategy for removing refractory antibiotics.

38. 题目: Tracking spatiotemporal variations in porewater dissolved organic matter in a planted mangrove chronosequence using FT-ICR MS
文章编号: N26040803
期刊: Organic Geochemistry
作者: Ryu Sumioka, Chadtip Rodtassana, Sasitorn Poungparn, Hiroshi Nishimura, Ken’ichi Shinozuka, Toshiyuki Ohtsuka, Nobuhide Fujitake, Morimaru Kida
更新时间: 2026-04-08
摘要: Mangroves are important sources of Dissolved Organic Matter (DOM) that contribute to marine carbon sequestration. Porewater acts as a key intermediate reservoir through which mangrove-derived DOM is mobilized and transported to adjacent coastal waters. Despite this importance, the spatiotemporal variability in porewater Dissolved Organic Carbon (DOC) concentration and molecular composition within mangrove ecosystems remains poorly understood. This study applied a chronosequence approach across four mangrove plantations of different ages (10–18 years) in Thailand to investigate the spatiotemporal variability in DOC concentration and molecular composition using ultrahigh-resolution mass spectrometry (FT-ICR MS). Temporal variation was inferred across this 10–18-year age sequence, including mudflats as a reference, while spatial variation was assessed along seaward-to-landward transects within each plantation. DOC concentrations increased landward but showed no significant dependence on forest age, indicating that porewater DOC is primarily regulated by spatial gradients associated with tidal dilution and vegetation distribution rather than by forest development. In contrast, DOM molecular composition responded to both distance from the seaward edge and forest age. At landward sites in older forests, the relative abundances of aromatic and sulfur-containing compounds increased, coinciding with a molecular index indicative of sulfidic porewater. The enrichment of sulfur-containing compounds and high values of the molecular index under sulfate-reducing redox conditions are consistent with abiotic sulfurization of porewater DOM. This study shows that mangrove forest development alters the quality of porewater DOM, with implications for the contribution of mangrove-derived recalcitrant carbon to porewater pools, carbon cycling, and long-term carbon persistence in blue carbon ecosystems.

39. 题目: Organic matter supply triggers rapid microbial-driven changes in carbon-nitrogen cycling in subterranean estuary sediments
文章编号: N26040802
期刊: Marine Chemistry
作者: Danqing Sun, Longyun Lai, Yueming Wu, Ying Wu, Jian Li, J Severino P Ibánhez, Shan Jiang
更新时间: 2026-04-08
摘要: Excessive carbon and nitrogen emissions from human activities have exerted unpredictable impacts on coastal belts at a global scale. To investigate carbon transformations and the coupling between carbon and nitrate reactivity in subterranean estuaries (STEs), laboratory flow-through reactor (FTR) experiments were conducted with permeable sandy sediments. These included a control and five experimental treatments with different dissolved carbon sources (~500 μmol/L (equivalent to μM) final concentration), including fucoidan, chitosan, oligosaccharide, Phragmites australis extracts, and Laminaria japonica extracts. After 48 h incubation, ca. 80 μM nitrate (NO3−) was added in all treatments to further identify carbon‑nitrogen coupling in STEs. The modified FTR cells used in this study permitted us to follow changes in both the circulating water and the sediment. The results suggested that the composition and concentration of dissolved organic carbon (DOC) during the tidal cycle could affect NO3− removal by regulating the sediment microbial community composition. Sandy STEs would preferentially maintain high DOC metabolic rates under aerobic conditions to sensitively regulate chemical oxidation/reduction and microbial community domestication, which enhances the adaptation to NO3− removal. For example, the degradation of DOC in the oligosaccharide treatment stimulated the NO3− removal capacity of aerobic denitrifying bacteria (Chryseobacterium and Delftia). Sufficient electron donors eliminated nitrogen limitation and increased denitrification capacity in sandy STEs. Domesticated sandy sediments would be better adapted to high NO3− loads, demonstrating the complexity of carbon‑nitrogen coupling under natural conditions.

40. 题目: Unraveling the effect of alkaline recovery conditions on the complexity and diversity of extracellular polymeric substances (EPS) from aerobic granular sludge towards effective waste-to-value strategies in wastewater treatment
文章编号: N26040801
期刊: Chemical Engineering Journal
作者: Benedetta Pagliaccia, Yuemei Lin, Emiliano Carretti, Lucrezia Caselli, Claudio Lubello, Tommaso Lotti
更新时间: 2026-04-08
摘要: Extracellular polymeric substances (EPS) are essential for the structural and functional stability of aerobic granular sludge (AGS). Their complexity makes comprehensive characterization challenging and dependent on the recovery approach. This study thus investigates how alkaline extraction conditions influence the recoverability and properties of AGS-derived EPS, especially regarding structural EPS (sEPS) and related hydrogels. An advanced methodological framework was applied to compare NaOH- and Na2CO3-based extractions through a holistic assessment of multi-scale characterization data. The biochemical composition, molecular weight distribution and thermal behavior of EPS and/or sEPS were studied by complementary techniques (e.g. methods for protein/carbohydrate determination, size exclusion chromatography and thermogravimetry). An innovative physicochemical approach coupling small-angle X-ray scattering (SAXS) and rheology was employed to investigate the nano-scale arrangements and mechanical features of sEPS hydrogels. The NaOH-based extraction resulted in lower EPS/sEPS yields, promoting a shift towards lower molecular weight sEPS fractions. The Na2CO3-based method preserved larger and more thermally resistant macromolecules, suggesting milder chemical effects on the recovered EPS/sEPS. SAXS revealed that the sEPS hydrogel network consisted of 3D mass fractals and highly ordered lamellar, multilayered domains – more pronounced for Na2CO3-based protocol – potentially associated with lipopolysaccharide assemblies. NaOH-extracted sEPS formed stiffer hydrogels. The NaOH-based protocol likely induced harsher hydrolysis/partial degradation of specific EPS constituents (e.g. large proteins and lipidic fractions), which may not significantly contribute to, or even compromise, the hydrogel stiffness. Overall, this work demonstrates the critical role of alkaline extraction in determining EPS/sEPS yield and properties, providing valuable insights for the rational design of EPS-based biomaterials and recovery strategies.