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141. 题目: Synergy between lacustrine groundwater discharge and dissolved organic matter in regulating seasonal CH4 and CO2 emissions in an ice–covered lake–groundwater system
文章编号: N26090116
期刊: Journal of Hydrology
作者: Yuanzhen Zhao, Lijuan Hu, Shen Qu, Heyang Sun, Chengcheng Xia, Chao Gu, Xu Yang, Zhongli Wang, Limin Duan, Xiaomin Liu, Ruihong Yu
更新时间: 2026-09-01
摘要: Lakes in cold regions that experience seasonal ice cover are potential hotspots of greenhouse gas (GHG) emissions. However, the synergistic roles of groundwater, as a concealed external source, and dissolved organic matter (DOM) in regulating CH4 and CO2 dynamics and emissions remain poorly understood. Based on year–round observations at Ulansuhai Lake, this study revealed seasonal differences in the regulatory effects of lacustrine groundwater discharge (LGD) and microbially derived DOM. During the ice–free period, the LGD rate was low (5.53 mm/d). CO2 dynamics were primarily controlled by microbial decomposition of DOM, whereas CH4 dynamics were mainly influenced by direct LGD input and were positively correlated with DOM aromaticity and humification. During the ice–covered period, the LGD rate increased markedly, reaching a maximum of 18.09 mm/d, and became the sole external source of CO2. In contrast, CH4 was predominantly regulated by DOM, driven positively by humic component C2 and the humification index (HIX), a process facilitated by anaerobic microbial fermentation. Flux calculations indicated that, during the ice–free period, water–air emissions of both gases exceeded the corresponding LGD–derived inputs. However, when considering only the LGD pathway, its regulatory effect was stronger for CH4 than for CO2. During ice cover, water–air gas exchange ceased, while LGD–derived CO2 inputs (0.049–1.720 mmol/m2/d), together with CH4 produced via DOM–driven anaerobic fermentation, sustained greenhouse gas accumulation beneath the ice. These findings identify LGD as a concealed driver of CH4 and CO2 emissions with seasonal shifting roles and highlight its importance in carbon budget assessments of seasonally ice–covered lakes in cold regions. This study advances understanding of groundwater–derived carbon inputs in lake carbon cycling and provides both hydrological and biogeochemical insights for compiling greenhouse gas emission inventories from seasonally ice–covered lakes.

142. 题目: Unlocking endogenous silicon in N-doped swine manure biochar through Si–O–C interface engineering for enhanced peroxymonosulfate activation
文章编号: N26090115
期刊: Journal of Environmental Chemical Engineering
作者: Siyu Zhang, Yangxiang Xiong, Yixuan Zhao, Xu Cao, Tianqi Wang, Ping Zhang
更新时间: 2026-09-01
摘要: Bisphenol A (BPA) pollution severely threatens aquatic ecology and human health, and peroxymonosulfate (PMS)-based advanced oxidation processes are efficient for refractory organic pollutant remediation. Our previous study realized the in-situ synthesis of nitrogen-doped swine manure biochar (NBC) for enhanced PMS catalysis, yet abundant endogenous silicon in swine manure remains inert as SiO2 and fails to contribute to catalysis, restricting the full resource utilization of livestock waste. Targeting this bottleneck, we herein develop a facile ball-milling coupled with HF etching strategy to activate intrinsic silicon on NBC without exogenous dopants. This approach converts inert SiO2 into reactive Si–O–C interfacial sites while preserving the original nitrogen-doped carbon framework, yielding a Si modified biochar (Si-NBC). Benefiting from the synergistic effect of Si–O–C bridges and inherent nitrogen active sites, the optimized Si-NBC achieves 98% BPA removal within 20 min and 42% total organic carbon mineralization, with a rate constant 18-fold higher than pristine NBC. It performs robustly across pH 3–9, tolerates common coexisting anions, and maintains removal above 90% for 72 h in a continuous-flow reactor. Mechanistic investigations reveal a synergistic non-radical regime: singlet oxygen, generated at C–C and graphitic N sites, dominates the oxidative process, while an electron-transfer pathway, mediated by graphitic N and Si–O–C bridges, accelerates interfacial charge shuttling. Degradation intermediates exhibit markedly reduced ecotoxicity compared to parent BPA. By leveraging in-situ interfacial engineering of biomass-derived carbons, this work both valorizes the underutilized silicon in livestock waste and establishes a mechanistic rationale for the design of high-performance, eco-friendly PMS catalysts.

143. 题目: Agriculture on a converted boreal Podzol increased soil carbon stocks and altered subsoil soluble organic matter quality and burst respiration profiles
文章编号: N26090114
期刊: Geoderma
作者: Maxwell Jamie Derek Locke, Amana Jemal Kedir, Chad W Cuss, Louis-Pierre Comeau, Adrian Unc
更新时间: 2026-09-01
摘要: Climate change favours the expansion of agriculture into boreal regions through forest conversion. This land use change (LUC) leads to rapid declines in soil organic carbon (SOC). However, when managed over the long term, there may be potential for SOC recovery. Additionally, there is growing interest in subsoils, as they may be capable of long-term SOC storage. While Podzols dominate boreal regions, the explicit assessment of LUC and long-term management on SOC in boreal Podzols remains understudied. This study assessed the impact of LUC and long-term agricultural management on bulk and water-extractable organic matter (WEOM) pools and respiration with depth. A farm-level chronosequence (0, 5, 34 and 60 years) was evaluated on a boreal Podzol: five years after LUC, SOC stocks (0–70 cm) decreased by 51.6% but were comparable to pre-LUC levels at 34 yr, with a similar, albeit statistically not significant, pattern in the subsoil (30–70 cm). As with SOC, LUC impacted WEOM-C significantly only in the 0–10 cm layer, which decreased and did not recover over time. Down to 40–50 cm, WEOM became more aromatic, while the contribution of a protein-like component decreased with age, possibly supporting the formation of resistant SOC. Burst respiration maxima shifted from 48 hr and 72 hr towards 24 hr with increasing age, statistically significant down to 40 cm. These patterns appeared to be driven by increases in aromatic WEOM-C, constraining respiration later in the burst test. While LUC Podzols have potential for SOC recovery, even if meaningful increases above the natural baseline are unlikely under standard farming practices, changes in subsoil WEOM quality and respiration patterns are evident. Thus, subsoil sampling ought to be included in any comprehensive SOC assessments for farmed boreal Podzols.

144. 题目: Bio-cementation boosts organic carbon sequestration in coastal saline soils via aggregation, humification, and chemoautotrophs enrichment
文章编号: N26090113
期刊: Bioresource Technology
作者: Caiqin Wang, Daiye Fu, Jiacong Zheng, Xinyi Gao, Jiashi Shao, Zhanfei He, Duman Imanmadi, Daoyong Zhang, Xiangliang Pan
更新时间: 2026-09-01
摘要: Formation of soil aggregates is crucial for coastal saline soils, as it improves the physicochemical characteristics of soil, and significantly influences the stability of soil organic carbon (SOC) and soil ecological functions. Applying organic fertilizer is a common way to improve these soils, but its exclusive use often exacerbates soil carbon emissions. This study evaluated the effects of microbially induced carbonate precipitation (MICP), an environmentally benign bio-cementation technique, combined with organic fertilizer application (the MICPOF group) on SOC transformation and sequestration in coastal saline soils through a 90-day greenhouse incubation experiment. After 90 days of incubation, compared with the control group (CK), MICPOF significantly improved soil properties: it increased the mean weight diameter (MWD) of aggregates by 79.43 %, reduced exchangeable sodium (E-Na) by 15.36 % and raised mineral-associated organic carbon (MAOC) by 24.95 %. All these effects outperformed those of the OF group (organic fertilizer application alone). Notably, cumulative CO2 emissions in MICPOF were about 26 % and 44 % lower than in CK and OF, respectively. Analysis of the SOC composition demonstrated that bio-cementation promoted humification and increased the abundance of biorefractory substances, including lignin, tannins, and aromatic compounds. Metagenomic analysis further indicated that MICPOF elevated the abundance of chemoautotrophic microorganisms (e.g., Muriiphilus and Sulfurivermis). Functional genes related to the Calvin cycle, a key carbon sequestration pathway, were 39.37 % and 29.11 % more abundant in MICPOF than in CK and OF, respectively. These findings demonstrate that bio-cementation is a highly effective strategy for reclaiming coastal saline soils and substantially enhancing their carbon sequestration potential.

145. 题目: Artificial humic acid reshapes microbial C-N metabolism and nitrogen partition in microplastic-contaminated soils
文章编号: N26090112
期刊: Journal of Hazardous Materials
作者: Qihe Gao, Shuang Ai, Meiling Zhang, Yu Li, Yantong Li, Yadong Ma, Jiale Zhang, Fan Yang, Kui Cheng
更新时间: 2026-09-01
摘要: Microplastics pose a serious threat to soil ecosystems, particularly nitrogen cycling. Among the diverse types of microplastics, polypropylene (PP) and polylactic acid (PLA) are frequently detected in agricultural soils. Artificial humic acid (A-HA), a humic-like substance derived from lignocellulosic waste, may regulate soil carbon and nitrogen dynamics, but its effects on nitrogen partitioning and microbial C-N metabolic potential under different microplastic stresses remain unclear. Here, a 90-day microcosm experiment integrating soil physicochemical analyses, dissolved organic matter characterization, bacterial community profiling, and metagenomics was conducted in PLA- and PP-contaminated soils. At day 15, 600 mg kg−1 A-HA decreased nitrate (NO3⁻-N) by 11.36% and 6.46% in PLA- and PP-contaminated soils, respectively, while increasing soluble organic nitrogen (SON) by 17.32% and 23.89%. A-HA also enriched Nitrospira and Steroidobacter and altered the abundance of genes associated with nitrogen transformation, assimilation, and carbon metabolism, including nrfA, GLU, gltB, and icd. Increased abundance of nrfA suggested greater dissimilatory nitrate reduction to ammonium (DNRA) potential, while enrichment of NADP+-dependent icd indicated altered potential for 2-Oxoglutarate generation in the TCA cycle. Overall, A-HA modified nitrogen partitioning toward soluble and microbial organic pools and was associated with coordinated changes in microbial C-N metabolic potential under microplastic exposure.

146. 题目: Transformation of polystyrene-microplastic-derived dissolved organic matter into colloids and microparticles: Roles of microbial activity and UV irradiation
文章编号: N26090111
期刊: Water Research
作者: Haeseong Ko, Cheolyong Kim, Heejong Son, Inseong Hwang
更新时间: 2026-09-01
摘要: Transformations of polystyrene-microplastic-derived dissolved organic matter (PS-DOM) in aquatic systems and the implications for the fates of nanosized polystyrene (PS) were investigated focusing on the roles of microbial activity and UV irradiation. PS-DOM, composed of oxygenated and hydrophobic products and nanosized PS, were found to undergo self-assembly and aggregation to form colloids and microparticles, meaning PS-DOM can act as a precursor for the formation of particulate organic matter. Microbial activity markedly enhanced both self-assembly and aggregation, causing marked increases in the particle size and molecular weight. UV irradiation promoted PS-DOM transformations through photo-oxidation and the generation of hydrophilic products, but prolonged UV exposure caused partial breakdown of the microparticles that formed. Nanosized PS actively participated in these transformation processes and underwent reversible hydrophilic–hydrophobic conversions under UV irradiation. After 21 d of incubation under dark/UV and biotic/abiotic conditions, nanosized PS supplied approximately 20% of the total organic carbon content, indicating that transformed PS-DOM gave a stable total organic carbon content. The results indicated that self-assembly and aggregation assisted by microbial processes and UV irradiation play critical roles controlling PS-DOM transport, persistence, and environmental behaviors.

147. 题目: Spontaneous dark transformation of amino acids in microdroplets: An overlooked pathway for atmospheric organic nitrogen cycling
文章编号: N26090110
期刊: Atmospheric Environment
作者: Tao Wang, Hanyao Chang, Yaohao Hu, Xinyu Huang, Guohua Zhang, Xinming Wang, Ping'an Peng, Xinhui Bi
更新时间: 2026-09-01
摘要: Amino acids, as important constituents of atmospheric organic nitrogen, play significant roles in global biogeochemical cycles. Their atmospheric fate has traditionally been attributed to photochemical processes, whereas the role of the unique chemistry in microdroplet remains poorly understood. Here, we used a microdroplet generation apparatus coupled with online electrospray ionization mass spectrometry to study the spontaneous transformation of three representative amino acids (tryptophan, serine, and cysteine). By varying reaction time, initial concentration and sheath gas pressure, we confirmed that these reactions occur specifically in microdroplets. Products analysis by a triple quadrupole mass spectrometer revealed spontaneously generated OH radicals as the primary driver, yielding distinct products such as hydroxylated monomers and dimers, that differs from that of bulk-phase oxidation. Quantitative assessment further revealed that high salinity, acidic pH, and oxidative atmospheres significantly accelerate the reactions, with notable compound-specific effects. High salinity most prominently enhanced serine transformation (∼7%), acidic condition (pH 3.0) maximally promoted tryptophan conversion (∼11%), and O2 primarily accelerated oxidation pathway of cysteine (∼17%). These findings reveal that the spontaneous transformation of amino acids in microdroplets, modulated by salinity, acidity, and oxygen availability, represents a previously unrecognized pathway for organic nitrogen conversion in the atmosphere. This work provides experimental evidence for integrating such processes into atmospheric chemistry models to reassess the cycling and lifetime of organic nitrogen.

148. 题目: Drought and bark beetle disturbances drive contrasting water, organic matter and nutrient fluxes of beech, maple, and spruce in Central Germany
文章编号: N26090109
期刊: Forest Ecology and Management
作者: Karin Potthast, Alexander Tischer, Marie-Cécile Gruselle, Susan Trumbore, Beate Michalzik
更新时间: 2026-09-01
摘要: Extreme climate events are increasingly impacting Central European forests. The 2018 drought and heat wave intensified tree mortality and bark beetle outbreaks. We examined how these disturbances altered water, organic-matter (OM), and nutrient fluxes in mixed beech (Fagus sylvatica)–maple (Acer pseudoplatanus) forests and Norway-spruce (Picea abies) stands on shallow, calcareous soils in central Germany. From 2018–2020 we collected bi-weekly samples of throughfall, stemflow, and free-draining lysimeter samples from different soil depths. The samples were analysed for pH, electrical conductivity (EC), dissolved and particulate organic carbon (DOC; POC), total dissolved nitrogen (DN), and nutrients. Linear mixed-effects models revealed strong species responses: mixed beech-maple exported more DN and calcium to deeper soil layers than spruce stands, whereas spruce had significantly higher DOC fluxes at all depths. Radiocarbon signatures indicated that spruce DOC is dominated by recent carbon inputs, while beech/maple DOC incorporates older, previously more stabilized OM. Drought-induced premature leaf fall, subsequent re-wetting events, bark-beetle infestation, and canopy opening contributed to amplify export of OM and nutrients to deeper soil horizons. Bark-beetle infestation of spruce stands mobilized phosphorus from the organic layer. Tree species, the post-drought monitoring phase, and soil depth together explained more than 65% of the variance in water, DOC, DN, Ca, pH, and EC fluxes, confirming that species-specific controls dominate post-drought biogeochemical dynamics. These findings underscore the vulnerability of common Central European forests to the combined pressures of drought and biotic stressors and highlight the importance of incorporating species-specific considerations into forest management adaptations.

149. 题目: Molecular Mechanisms of Ni(II) Adsorption and Cr(VI) Reduction by Extracellular Polymeric Substances: Experimental Evidence and Density Functional Theory Calculations
文章编号: N26090108
期刊: Journal of Environmental Chemical Engineering
作者: Mian Xu, Tiantian He, Ziqi Luo, Wenxuan Yang, Yingqi Dai, Yicheng Xie, Yibo Wang, Meng Niu, Di Cao
更新时间: 2026-09-01
摘要: Extracellular polymeric substances (EPS) are promising natural adsorbents for heavy-metal remediation because of their abundant functional groups and environmental compatibility. However, most studies have focused on macroscopic adsorption performance, whereas the molecular mechanisms governing the immobilization of metal cations and oxyanions remain poorly understood. Here, EPS derived from Shinella zoogloeoides were investigated through batch adsorption experiments, spectroscopic characterization, density functional theory (DFT) calculations, and complementary analytical techniques. This integrated approach links macroscopic adsorption behavior with atomic-scale reaction pathways and reveals the distinct immobilization mechanisms of Ni(II) and Cr(VI). Adsorption of both metals was well described by the Freundlich isotherm model (R² = 0.9901 and 0.9928) and the pseudo-first-order kinetic model (R² = 0.9919 and 0.9899), indicating adsorption on heterogeneous active sites. Competitive adsorption experiments demonstrated a clear preference for Ni(II). XPS and FTIR analyses identified carboxyl, hydroxyl, and amino groups as the primary active sites and confirmed the reduction of Cr(VI) to Cr(III) during adsorption. DFT calculations further revealed fundamentally distinct reaction pathways. Ni(II), acting as a Lewis acid, was immobilized through stable coordination with oxygen-containing functional groups, with binding energies reaching as high as −44.5364kcal/mol. In contrast, Cr(VI) underwent proton-coupled electron transfer to form Cr(III), which was subsequently stabilized through carboxyl coordination and hydrogen bonding. These findings establish two distinct immobilization pathways—Ni(II) coordination adsorption and PCET-mediated Cr(VI) reduction and immobilization—and provide a mechanistic foundation for the rational design of selective, efficient, and environmentally compatible bioadsorbents for the remediation of complex heavy-metal pollution.

150. 题目: Spatiotemporal controls on soil organic carbon stocks in subtropical grazing lands: An uncertainty-aware digital soil mapping approach
文章编号: N26090107
期刊: Geoderma
作者: Chang Zhao, Jiayi Song, José C B Dubeux, Sabine Grunwald, Igor L Bretas, Hao-Yu Liao, Nikolaos Tziolas, Joel B Harley, Alina Zare, Ebrahim Babaeian, Liza Garcia, Luana M D Queiroz, Cristian T E Mendes
更新时间: 2026-09-01
摘要: Accurate spatial quantification of soil organic carbon (SOC) stocks and their associated uncertainties is vital for climate mitigation and sustainable grazing management. However, regional SOC mapping remains challenging due to complex soil–landscape interactions, dynamic environmental processes, and limited field observations. This study advances regional SOC mapping by developing a parsimonious, uncertainty-aware digital soil mapping framework to estimate topsoil (0–20 cm) SOC stocks across Florida’s grazing lands at 30 m resolution. Grounded in the STEP–AWBH soil-forming framework, the approach explicitly operationalizes time-invariant and dynamic controls through spatiotemporal feature construction. SOC stocks were modeled using Quantile Regression Forests to generate point estimates and 90 % prediction intervals, with model performance evaluated using spatial cross-validation. A baseline model trained with contemporary samples achieved modest results (R2 = 0.45; RMSE = 8.92 t ha−1), whereas cross-temporal spiking with legacy grazing land samples improved both point prediction accuracy (R2 = 0.57; RMSE = 7.88 t ha−1) and uncertainty estimation, yielding better-calibrated prediction intervals and a lower continuous ranked probability score. In contrast, unconstrained spiking across heterogeneous land uses degraded model performance, underscoring the importance of land-use compatibility and target-domain relevance when integrating legacy soil data. SHAP-based interpretation revealed that SOC variability was associated with pedological properties, including available water capacity and soil order, and temporal signatures of hydroclimate, soil moisture dynamics, and vegetation phenology related to persistence, variability, and long-term trends. Total topsoil SOC storage for Florida’s grazing lands was estimated at 33.95 Tg, with a mean stock of 19.12 t ha−1. The resulting high-resolution SOC stock and uncertainty maps are hosted on an open-access interactive GIS platform, providing a robust baseline for monitoring and managing soil carbon in subtropical grazing systems.

151. 题目: Effect of iron-loaded biochar on medium-chain fatty acid production from waste activated sludge
文章编号: N26090106
期刊: Bioresource Technology
作者: Tianru Lou, Mingyang Liu, Yanan Yin, Jianlong Wang
更新时间: 2026-09-01
摘要: Conductive materials can enhance medium-chain fatty acid (MCFA) production from waste activated sludge (WAS), but the influence of their addition timing remains unclear. Here, a biochar-supported zero-valent iron composite (ZVI/BC) was added either before acidification (the AC group) or before chain elongation (CE; the CE group) in a two-stage anaerobic fermentation system. Adding ZVI/BC before acidification yielded the highest caproate production of 10.0 g/L as chemical oxygen demand, 64.5 % and 119.5 % higher than those in the control and CE groups, respectively. This advantage was accompanied by marked extracellular polymeric substance (EPS) restructuring, including divergent changes in soluble chemical oxygen demand and total organic carbon in the tightly bound fraction and enrichment of soluble microbial byproduct-like and humic-like substances. Microbial analysis further showed that early ZVI/BC addition was associated with a distinct community, with higher relative abundances of Firmicutes and the genera Romboutsia, Paraclostridium, and Clostridium_sensu_stricto in the AC group. Meanwhile, cytochrome c and reduced nicotinamide adenine dinucleotide increased by 10.5 % and 14.0 %, suggesting endpoint changes in redox-related components and intracellular reducing-power availability. Functional prediction indicated higher acetyl coenzyme A-related precursor potential in the AC group. Overall, adding ZVI/BC before acidification was more effective than adding it before CE, providing a practical strategy to improve caproate production from WAS.

152. 题目: Biochar as an additive to improve the biomethanation of soybean straw: on-field implementation and cost benefit analysis aiding circular bioeconomy
文章编号: N26090105
期刊: Bioresource Technology
作者: Sugato Panda, Sayak Chakravorty, Mayur Shirish Jain
更新时间: 2026-09-01
摘要: Soybean straw, an underutilized lignocellulosic residue generated at over 500 million tonnes annually, was converted into biochar through controlled carbonization at 250-550 °C, and the soybean straw-derived biochar produced at 450 °C (BC450) was applied as a same-feedstock additive to enhance the biochemical methane potential of soybean straw. Characterized by a mesopore-dominated surface (BET surface area 15.85 m2 g−1, peak pore diameter 3.82 nm, zero microporosity) and balanced elemental composition (C 52.32%, O/C 0.61) BC450 was dosed at 4.21, 4.57, and 5.09 g L−1 in 35-day mesophilic batch assays. The 4.21 g L−1 dose achieved the highest cumulative methane yield (1,019 NmL, net inoculum-corrected yield of 401.5 L CH4 kg−1 straw), nearly double that of conventional unamended agricultural-residue digesters. The Modified Gompertz model best described methane kinetics (R2 = 0.9994), revealing a markedly shortened lag phase (5.14 days) and rapid attainment of 90% methane potential (T90 = 24.8 days) relative to untreated lignocellulosic substrates. Process monitoring confirmed effective buffering, with pH recovering to 7.35–7.66 by Day 30 and volatile fatty acids declining by up to 77% between Days 15 and 30. FTIR, FESEM-EDS, and ICP-OES analyses revealed progressive biochar-substrate biotransformation and trace-metal redistribution consistent with active methanogenesis. A techno-economic assessment across the contexts of Germany, India, and Sub-Saharan Africa demonstrated simple payback periods of 3.2, 0.3, and 4.8 years, respectively, alongside GHG abatement of 1,786 t CO2-eq yr−1 at 5 tonnes per day scale. These findings establish soybean straw-derived biochar as an economically viable, circular-economy additive for accelerating and stabilizing biomethanation.

153. 题目: Anthropogenic river management drives decadal shifts in organic carbon sequestration in the Yellow River Estuary
文章编号: N26090104
期刊: Marine Pollution Bulletin
作者: Xiaotian Liu, Xiaosong Zhong, Zongqing Lv, Xiangbin Ran
更新时间: 2026-09-01
摘要: Estuaries serve as critical global hotspots for organic carbon (OC) burial. This study investigates multi-decadal deltaic OC dynamics in relation to historical river diversion and water-sediment regulation (WSR) in the Yellow River Estuary, using sediment cores BH-0 and NS-29 analyzed via organic geochemical proxies and elemental chemostratigraphy. The sedimentary records reveal a transition from a natural, terrigenous-dominated setting to a managed system regulated by altered sediment delivery and marine productivity. Prior to the 1976 channel diversion, the BH-0 site received massive fluvial loads, sustaining high sedimentation and accumulation rates but low OC concentrations. The 1976 diversion redirected the sediment plume southward to the Qingshuigou channel; the post-diversion sediment deficit at BH-0 coincided with a lower long-term OC burial flux and carbon‑nitrogen decoupling. Conversely, this hydrographic rearrangement directed sediment and OC transport toward the NS-29 site, establishing an efficient sink sustained by synchronized carbon and nitrogen burial. After 2002, both cores recorded increased TOC and TN concentrations despite the continued decline in basin-scale sediment supply, while their local burial patterns remained contrasting. Changes in TOC-TN relationships and sedimentary geochemical indicators further suggest shifts in organic matter inputs, accumulation, and preservation between the two depositional settings. By revealing a spatial reorganization, rather than a uniform change, in coastal OC burial, our study provides a new perspective on how anthropogenic river management influences blue carbon cycling and carbon budgets in heavily regulated river-dominated deltas worldwide.

154. 题目: Construction of biochar heterojunctions decorated with nanoscale zero-valent copper and CeOx for synergistically enhanced Fenton-like degradation of glyphosate
文章编号: N26090103
期刊: Journal of Environmental Chemical Engineering
作者: Bo Zuo, Yue Ma, Yudie Guo, Ruipu Wang, Li Guo, Shuxin Huang, Yuchi Chen, Junxia Yu
更新时间: 2026-09-01
摘要: Glyphosate has received a great deal of attention due to its persistence in the environment and its potential carcinogenicity. Traditional Fenton catalytic methods for glyphosate removal are often hindered by the aggregation and passivation of catalysts, and the formation of toxic intermediates, such as aminomethylphosphonic acid (AMPA). In this study, a synergistic heterojunction comprising nano-zero-valent copper (nZVC) and CeOx was engineered on a biochar (BC) interface (nZVC/CeOx@BC) to investigate the behavior and mechanism of glyphosate degradation. The results showed that glyphosate removal reached 96.9% within 20 min, and complete degradation was achieved within 60 min in the nZVC/CeOx@BC/H2O2 system. Importantly, the catalyst could be used in a pH range of 2–10, and the degradation efficiency of this catalyst remained above 95% even after six cycles. DFT calculations and experimental results revealed that the heterostructure facilitates interfacial electron transfer through the formation of electron bridges and the reversible Ce(III)/Ce(IV) redox couple. This enhanced electron-transfer pathway promoted the continuous activation of H2O2 and generation of reactive oxygen species, thereby accelerating the oxidation and degradation of glyphosate while suppressing active-site deactivation and improving catalyst stability. Moreover, the degradation pathway was diverted towards the formation of the environmentally benign compound glycine (70.95 μM, conversion rate ≈ 60%), thus suppressing the formation of AMPA (0.18 μM, conversion rate ≈ 0.15%). This study highlights the crucial role of interfacial electron-transfer-enhanced heterojunctions in regulating glyphosate degradation pathways and provides an effective strategy for efficient glyphosate degradation.

155. 题目: Nonradical pathway in peroxymonosulfate-based Fenton-like reactions triggered by the active Fe-Cu dual sites encapsulated in endogenous N-rich biochar
文章编号: N26090102
期刊: Journal of Environmental Chemical Engineering
作者: Rui Yang, Chaoting Jiang, Wangbo Wang, Xianshu Zhou, Fangshu Xie, Mingming Ta, Tuo Wang, Haifang Cai, Juan Guo, Weihuang Zhu
更新时间: 2026-09-01
摘要: Fabricating a high-performance catalyst for peroxymonosulfate (PMS) activation via efficient nonradical pathways remains a crucial challenge. Herein, we developed a new strategy to fabricate an efficient PMS activator (FeCu@NBC700) with synergistic Fe-Cu dual sites encapsulated in nitrogen (N) self-doped biochar derived from waste soybean dregs. The FeCu@NBC700 catalyst achieved 98.55% tetracycline (TC) removal and 90.56% PMS utilization within 60 min, with excellent stability across varying pH conditions, realistic water matrices, and continuous-flow operation. Characterizations confirmed that the N-rich carbon matrix (NBC700) facilitated the in-situ formations, enhanced stabilizations, and full dispersions of low-valence Fe(0)/Fe(II) and Cu(0)/Cu(I) species, which participated as main active components for PMS activation. Density Functional Theory (DFT) calculations on the Fe-Cu bimetallic system showed electronic coupling converges their d-band centers, optimizes PMS adsorption energy (-4.45 eV), and promotes multi-electron transfer (1.45 e⁻). Mechanistic studies, including quenching tests, electron paramagnetic resonance (EPR) tests, galvanic oxidation process (GOP), and methyl phenyl sulfoxide (PMSO) probing experiments, demonstrated that TC degradation proceeded via a multiple nonradical pathway dominated by singlet oxygen (¹O2) from superoxide (O2•−) disproportionation, supplemented by an electron transfer pathway (ETP) and participation of high-valent metal species (HMS). Ecological Structure-Activity Relationship (ECOSAR) analysis and seed germination tests confirmed significant reductions in the toxicity of degradation intermediates. This work provides an insight into bimetallic synergy for multi-pathway nonradical oxidation applied in PMS-based Fenton-like reactions and a waste-valorization design paradigm.

156. 题目: Interactive effects of landscape position and soil diversity drive the spatial variability of soil organic carbon concentration in subalpine soils of Switzerland
文章编号: N26090101
期刊: Geoderma
作者: Bence Dienes, Orly Mendoza, Kristina Bright, Gino Licini, Meret Aeppli
更新时间: 2026-09-01
摘要: Subalpine soils store a significant amount of soil organic carbon (SOC), yet the factors driving its landscape-scale variability remain poorly constrained. Although topography, soil type, soil texture, and moisture are recognised as key drivers of SOC concentration, their interactive effects in subalpine environments remain largely unexplored. In particular, the extent to which soil type shapes landscape-scale SOC patterns remains unclear. In this study, we assessed SOC concentration, soil type, soil moisture, soil texture and elemental composition across 100 plots in two subalpine sites in the Swiss Alps. Using factor analysis, we generated three standardised continuous predictors from our dataset, namely, mineral content, sedimentary rock influence and texture index. We investigated the joint influence of these continuous predictors on SOC variability at the landscape scale in a linear mixed-effects model with topographic position (plain vs. slope areas), soil depth and soil type as additional categorical predictors. We found that soil type diversity was greater on the plain than on the slope, reflecting a greater hydrological heterogeneity. Plains supported a broad spectrum of soils, ranging from organic-rich Histosols to mineral-rich Fluvisols, while Cambisols dominated slopes. Although plains exhibited higher moisture and SOC concentration, and slopes were characterised by higher clay fractions and lithogenous elements, topographic position was not a significant predictor for the spatial distribution of SOC. Our linear mixed-effect model identified mineral content as the strongest predictor of SOC concentration, followed by the texture index and sedimentary rock influence. SOC concentration decreased as mineral content and sedimentary rock influence increased, and as the texture index shifted towards a lower proportion of clay-sized particles. Crucially, while mineral content integrates much of the variability described by the categorical variables included in the model, soil type diversity effectively captures the range of mineral content that drives SOC concentration across our sampling locations and soil depth. Our findings suggest that relying strictly on topographic position to assess SOC spatial variability overlooks important nuances in soil property distribution. We therefore suggest combining topographic position and soil type assessment into a robust framework for predicting landscape-scale SOC variability in subalpine environments.

157. 题目: Sustained algal-bacterial interactions promote accumulation of recalcitrant particulate carbon with accelerated radiocarbon aging signatures
文章编号: N26083120
期刊: Nature Communications
作者: Hanshuang Zhao, Zenghu Zhang, Xiuting Feng, Shailesh Nair, Huamao Yuan, Jinming Song, Xiuzhen Li, Nianzhi Jiao, Yongyu Zhang
更新时间: 2026-08-31
摘要: Algal-bacterial interactions regulate the production and fate of marine particulate organic carbon (POC), yet their capacity to generate long-lived carbon sinks remains unclear. Using a two-year, nutrient-self-sustaining co-culture of Synechococcus and its mutualistic microbiota, we demonstrate that sustained algal-bacterial interactions promote the progressive accumulation of recalcitrant POC. Continuous release of algal-derived organic substrates, coupled with repeated microbial enzymatic reworking, produced inert organic particles, with ~26% resisting remineralization and forming a stable recalcitrant particulate carbon pool. Radiocarbon (Δ14C) analyses revealed an apparent age offset exceeding 400 years for POC formed within only two-year experiment. This “aged” signature likely results from algal assimilation of fossil-fuel-14C-depleted atmospheric CO2 followed by accumulation in generated recalcitrant POC. By demonstrating that apparent radiocarbon age can become decoupled from actual residence time, these results provide insights into the interpretation of “old” marine POC and highlight the important roles of algal-bacterial interactions in ocean particulate carbon sequestration.

158. 题目: The potential role of carbonate dissolution and cation competition in regulating dissolved organic carbon leaching during wet-dry cycles in Karst soils
文章编号: N26083119
期刊: Frontiers in Environmental Science
作者: Zeyan Wu, Ruofan Wang, Qiang Li, Zhongcheng Jiang, Chunwei Liu, Qingyu Xu, Xinqi Liu, Qiang Li
更新时间: 2026-08-31
摘要: Karst soils represent significant carbon sinks, yet their stability is increasingly threatened by intensified wet-dry cycles under climate change. Although Ca 2+ derived from carbonate weathering can stabilize soil organic carbon through cation bridging, the efficacy of this mechanism under conditions of multi-cation competition and varying intensities of Ca 2+ inputs remains poorly understood. To clarify the role of carbonate weathering-derived cations on dissolved organic carbon (DOC) leaching, three sequential leaching experiments (S1–S3) were conducted using a lysimeter device packed with karst soil to model wet-dry cycles. Natural multi-cation karst water was applied via a simulated rainfall apparatus. Leachate was collected at 5-min intervals over 60 min (12 samples per experiment). Results showed that DOC concentrations declined over time by 53.8%–61.9% within 60 min, a pattern potentially linked to the “Birch effect” induced by drying–rewetting. Successive concentration peaks showed a declining trend, potentially reflecting a progressively reduced availability of labile organic matter under repeated leaching. Based on Pearson correlation analysis, calcite saturation index, and ion ratio analysis, three distinct regulatory stages were suggested: during the S1 stage, the relatively high intensity of carbonate dissolution appeared to release substantial Ca 2+ , potentially saturating the soil cation bridging capacity, while adsorbed Na + , K + , and Mg 2+ seemed to displace weakly bound DOC via ion exchange. In S2, as carbonate dissolution appeared to weaken, Ca 2+ release decreased, and the reduced availability of soil Ca 2+ may have led to unsaturated bridging sites, possibly reflecting a transition from Ca 2+ release to retention, while correlations among Na + and K + were decreased. In S3, carbonate dissolution further weakened, Ca 2+ limited, and Na + , K + , and Mg 2+ again drove DOC leaching through ion exchange. Overall, this preliminary study suggests that carbonate dissolution may influence soil Ca 2+ levels and exchange site saturation, possibly affecting the interplay between Ca 2+ cationic bridging and ion exchange competition by Na + , K + , and Mg 2+ in regulating DOC leaching. Site-specific Ca amendment and CO 2 degassing may be worth considering in karst soil carbon management. However, these exploratory findings from a single lysimeter with non-independent sequential leaching and an inferred “Birch effect” require validation through future in situ and long-term studies.

159. 题目: Anaerobic–aerobic switching triggers humic-mediated hydroxyl radical generation in activated sludge: evidence for an Fe–quinone redox network
文章编号: N26083118
期刊: Environmental Science: Water Research & Technology
作者: Taiki Yatsu, Riho Suzuki, Miki Yatsugi, Takahiro Kawai, Yusuke Miyake, Kohji Maeda, Xue Chu, Yasuro Fuse
更新时间: 2026-08-31
摘要: Humic substance (HS)-amended activated sludge systems often exhibit altered and sometimes improved treatment performance, but the redox and biochemical mechanisms underlying these effects remain poorly understood. Here, we examine whether hydroxyl radical (·OH) generation emerges in activated sludge supplemented with HSs operated in alternating anaerobic and aerobic phases at circumneutral pH. Using terephthalate as a chemical probe, sharp ·OH pulses were repeatedly activated immediately upon transition from anaerobic to aerobic conditions and reactivated following subsequent redox cycles, indicating reversible and sustainable redox dynamics within the sludge matrix. During anaerobic operation, Fe(ii) accumulated to millimolar concentrations predominantly in a solid-associated form and was rapidly consumed upon aeration coincident with ·OH formation. Inhibition experiments identified H2O2 and superoxide as key intermediates in a Fenton-type reaction. Microbial reduction of anthraquinone-2,6-disulfonate demonstrated that the indigenous microbial consortium actively reduces humic-like redox moieties under anaerobic conditions, confirming the role of microbial electron shuttling. These results suggest that HS-induced ·OH generation may contribute to the enhanced treatment effects sometimes observed in HS-amended sludge systems. Based on iron redox dynamics and simple energetic considerations, we propose a conceptual framework in which coupled humic–iron redox cycling links anaerobic electron accumulation to aerobic release of oxidative capacity. This study provides experimental evidence that regenerable radical generation can emerge as a system-level property of real activated sludge under process-relevant redox oscillations.

160. 题目: An Easy and Reliable Method for Calibrating Combustion-Based Total Organic Carbon Analyzers for Solid Samples Containing Less than 100 μg of Carbon Using Polystyrene Microspheres
文章编号: N26083117
期刊: Analytical Chemistry
作者: Guillaume Bucher, Lina Büngener, Dora Mehn, Douglas Gilliland
更新时间: 2026-08-31
摘要: Combustion-based total organic carbon (TOC) analyzers for solid samples are interesting tools for estimating the mass of microplastics in environmental samples. However, the low concentration of microplastics to be quantified may require TOC calibration below 100 μg of carbon (μgC), which could be laborious and tedious. This study proposes a fast, reliable, and easy-to-use calibration procedure that uses monomodal, compact polystyrene (PS) microspheres with nominal diameters of either 200 or 250 μm. Calibration curves obtained with the PS microspheres within the range of 8 to 50 μgC were linear and statistically equivalent to the reference calibration curve obtained with a diluted glucose solution. This demonstrates the effectiveness of this approach. This calibration procedure was successfully used to quantify the carbon content and accurately determine the size of unknown PS microspheres. The average size recovery was 98% ± 2% for 13 randomly selected particles ranging from 400 to 525 μm in diameter. Additionally, the study showed that the increase in carbon content following durable Nile Red staining of PS microspheres can be assessed using TOC analysis. This increase is likely due to organic solvent being trapped in the polymeric structure when PS particles are heated above their glass transition temperature. This alternative calibration procedure could improve the accuracy and ease of TOC analysis in various fields, including the monitoring of low microplastic content in environmental samples.