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121. 题目: Divergent formation pathways of soil particulate and mineral-associated organic carbon across soil depths under conservation tillage
文章编号: N26090508
期刊: Applied Soil Ecology
作者: Hong-Xuan Duan, Yu-Gang Tian, Cheng-Ze Yang, Qing Luo, Yang Liu, Zhi-Yan Hou, Rattan Lal, Yash Pal Dang, Zhi Dong, Xin Zhao, Hai-Lin Zhang
更新时间: 2026-09-05
摘要: Conservation tillage (CT) promotes soil organic carbon (SOC) sequestration by increasing residue input and enhancing physical protection. However, the biological mechanisms driving SOC fraction formation across different soil depths under CT remain poorly understood. We investigated these mechanisms using data from an 8-year field experiment in Northeast China with three treatments: rotary tillage without straw mulching (RT), no-till without straw mulching (NT), and no-till with straw mulching (NTS). We quantified SOC fractions including particulate organic carbon (POC) and mineral-associated organic carbon (MAOC), plant-derived C (PC, via lignin phenols), microbial-derived C (MC, via amino sugars), and extracellular enzyme activities. Results showed that the 0–20 cm layer was co-dominated by POC and MAOC, whereas the 20–30 cm layer was dominated by MAOC (accounting for 79–96% of SOC). Formation pathways also differed between depths: in the 0–20 cm layer, POC accumulation was primarily associated with PC accumulation, while MAOC formation involved contributions from both PC and MC. In contrast, in the 20–30 cm layer, both POC and MAOC were more closely associated with microbial-derived C. Compared with RT, NT increased PC and MC concentrations by 34% and 6%, respectively. Compared with NT, NTS further enhanced PC and MC concentrations by 35% and 73%, respectively. These percentages represent treatment comparisons averaged across the 0–30 cm soil profile, rather than layer-specific responses. Additionally, NT enhanced the activities of C- and N-acquiring enzymes, thereby accelerating residue turnover and transformation. Overall, these findings indicate that conservation tillage regulates SOC accumulation through depth-dependent and fraction-specific pathways, with plant-derived C contributing mainly to topsoil POC formation and microbial-derived C becoming more closely associated with MAOC stabilization at depth.

122. 题目: Agricultural practices reshape molecular fingerprints of dissolved organic matter in aquatic ecosystems: A case study in China's Dai Village
文章编号: N26090507
期刊: Journal of Environmental Management
作者: Yifan Cui, Jinfu Liu, Shuailong Wen, Shaojuan Du, Kyoung-Soon Jang, Ang Hu, Jianjun Wang
更新时间: 2026-09-05
摘要: Agricultural management practices significantly influence the biogeochemical cycling of dissolved organic matter (DOM) in freshwater ecosystems, yet the molecular-level signatures of DOM in conventional farming regions (CFR) versus organic farming regions (OFR) remain poorly understood. Here, an OFR with a 20-year history of organic farming and a corresponding CFR were selected to explore differences in DOM molecular characteristics and functional diversity under contrasting agricultural management regimes. We found that both CFR and OFR were dominated by CHO molecules, while CFR showed higher relative abundance of low molecular weight (<300 Da) and nitrogen-containing molecules than OFR. Unique molecules in CFR were characterized by higher proportion of lipid-like compounds, and significantly lower molecular weight, degrees of unsaturation and oxidation, while unique molecules in OFR were dominated by lignin-like compounds with higher degree of oxidation. The functional divergence and dispersion of unique molecules was significantly higher in CFR than in OFR, illustrating more convergent DOM functional traits under organic farming. Furthermore, physicochemical properties explained higher variance in DOM molecular composition in CFR (R2 = 0.92) than in OFR (R2 = 0.49), with total nitrogen and total phosphorus as dominant drivers in CFR, whereas nitrite and total organic carbon showed the highest contribution in OFR. These findings demonstrate that conventional farming promotes the accumulation of nitrogen-rich, functionally diverse DOM molecules influenced by both terrestrial inputs and autochthonous, while organic farming leads to more oxidized and recalcitrant DOM in ponds, driven primarily by terrestrial inputs.

123. 题目: Application of extracellular polymeric substances recovered from aerobic granular sludge as bio-based hydrogels for plant cultivation systems
文章编号: N26090506
期刊: Journal of Environmental Management
作者: Antonio Pescatore, Benedetta Pagliaccia, Tommaso Lotti, Claudio Lubello, Riccardo Campo, Simone Orlandini, Marco Napoli
更新时间: 2026-09-05
摘要: Wastewater treatment plants generate large amounts of excess sludge, whose management represents an environmental and economic challenge, motivating resource recovery strategies in line with European Union Directive 2024/3019. Among these, the extraction of extracellular polymeric substances (EPS) enables conversion of sludge-derived biopolymers into sustainable hydrogel materials. However, the effects of structural EPS (sEPS) on nutrient availability and plant performance remain poorly understood. This study investigated aerobic granular sludge derived sEPS as hydrogel-based substrates for in vitro seedling cultivation. Garden cress (Lepidium sativum L.) was grown in substrates containing 0, 1, 2, and 4 g TSsEPS L−1 sEPS, applied as stand-alone hydrogels (sEPS-CM) or combined with Murashige and Skoog medium, with and without sucrose (MS + sEPS-CM; MS + sEPS + S-CM). Nutrient availability, Ca/N stoichiometry, and plant responses were evaluated. In MS-based systems, increasing sEPS concentrations reduced bioavailable Ca2+ and inorganic nitrogen, inducing a shift in Ca/N stoichiometry. Germination was not affected. In stand-alone hydrogels, the best responses were observed at 1 g TSsEPS L−1, with maximum shoot and root growth and vitality, whereas 4 g TSsEPS L−1 showed inhibitory effects. Nutrient-rich systems, with increasing sEPS concentrations, reduced dry biomass, pigments, soluble sugars, and photosynthetic performance, with the strongest negative effects at 4 g TSsEPS L−1. The MS + sEPS + S system showed the highest performance, highlighting the role of carbon availability. Overall, sEPS act as structural matrices and regulators of nutrient availability. Moderate concentrations (∼1 g TSsEPS L−1) are compatible with plant development, whereas high levels induce nutrient limitation, highlighting potential as bio-based substrates for sustainable cultivation systems.

124. 题目: Palaeoenvironmental evolution and stage-dependent organic matter enrichment in the Late Permian Longtan Formation, Upper Yangtze Block, South China
文章编号: N26090505
期刊: Sedimentary Geology
作者: Hai-Feng Chen, Xin Jin, Marcello Caggiati, Ting-Cong Ren, Bo Luo, Lin-Hao Fang, Hua-Wen Cao, Yang Liu, Chang-Cheng Huang, Bin Xiao, Zi-Han Ma, Hui-Dong Yu, Hao Zou
更新时间: 2026-09-05
摘要: Middle to Late Permian marine-continental transitional successions are sensitive archives of climate, sedimentary-system change, and carbon-cycle perturbation, but remain less well constrained than coeval open-marine carbonates. Here, we investigate fine-grained sediments of the Longtan Formation at the Baoding section in the eastern Sichuan Basin, Upper Yangtze Block, South China. Stratigraphically, the Longtan Formation records an interruption of the preceding carbonate platform system and the development of a terrigenous-influenced transitional setting. We integrate organic carbon isotopes (δ13Corg), total organic carbon, total sulphur, mercury concentration, and whole-rock major and trace element data to reconstruct palaeoenvironmental evolution and organic matter enrichment. The results indicate strong source-area weathering under a warm-hot and humid climate, substantial terrigenous input, and stage-dependent changes in volcanic input, palaeosalinity, water-mass exchange, productivity, upwelling and redox conditions. Together, these variations record the stage-dependent depositional and environmental evolution of the Longtan Formation. A pronounced negative δ13Corg excursion of about 5.3‰ in the middle part of the Longtan Formation is interpreted as part of a broader Wuchiapingian carbon-cycle perturbation and provides a valuable reference for future refinement of the regional framework and assessment of its potential for global correlation. Organic matter enrichment was governed by the balance between supply and preservation, with three modes: terrigenous influence-anoxic preservation in the lower part, intermittent input-burial compensation in the middle part, and productivity-preservation coupling in the upper part. These results show how volcanic disturbance, terrigenous supply and depositional-system reorganisation jointly regulated palaeoenvironmental evolution and organic matter enrichment in a Late Permian marine-continental transitional setting.

125. 题目: Palaeoenvironmental evolution and organic matter enrichment in the Early Silurian Yangtze Foreland Basin: Tectonosequence stratigraphic insights for shale gas exploration
文章编号: N26090504
期刊: Applied Geochemistry
作者: Xinguo Li, Rui Liu, Yuxuan Wang, Junwei Pu, Hui Liu, Lu Xu, Tongtong Luo, Xiucheng Tan, Weiming Chen, Ruiying Chao
更新时间: 2026-09-05
摘要: Although large amounts of organic-rich marine shale were deposited in the foreland basin, the mechanisms governing organic matter enrichment remain debated. The Early Silurian Longmaxi shale in the Upper Yangtze Block provides critical insights into the mechanisms of organic-matter enrichment within a foreland basin. This study integrates seismic stratigraphy, sedimentology, and geochemistry to unravel the influence of tectonic and depositional dynamics on organic matter enrichment. The Longmaxi shale, deposited within a transgressive system tract, is bounded at the top by a maximum flooding surface (MFS) marked by a silty-laminated mudstone unit with a high gamma-ray peak in the lower part of a low gamma-ray response, and at the base by an angular unconformity at the Ordovician-Silurian boundary formed during forebulge migration. The Longmaxi shale consists of four parasequences, with pinch-out lines migrating northwestward toward the Chuanzhong Forebulge Uplift, reflecting westward progradation driven by high sediment flux from the Cathaysia Block. Redox-sensitive proxies (Corg/P and MoEF/UEF ratios) reveal a vertical shift from anoxic (Parasequences 1–2) to suboxic (Parasequences 3–4) conditions during the Rhuddanian sea-level rise; meanwhile, nutrient flux indicators (P and Baex concentrations) show an upward increase of primary productivity. Generally, total organic carbon (TOC) content correlates strongly with the redox-sensitive (Corg/P ratio) and sedimentation rate (Ti, Al) proxies, but weakly with the primary productivity proxy, Baex concentration. These patterns suggest that organic matter enrichment in the Early Silurian Longmaxi shale of the Upper Yangtze Block was primarily controlled by deepwater oxygen level and inorganic particle dilution. Deglaciation-driven freshwater input enhanced watermass circulation and deepwater oxygenation, thus reducing the preservation efficiency of organic matter, particularly in the foredeep adjacent to the Cathaysia Block. Additionally, although elevated sedimentation rates enhanced primary productivity via increased nutrient supply, dilution by inorganic detrital particles markedly reduced organic matter abundance in the foredeep. These findings highlight that high-quality shale gas reservoirs were most likely developed in intervals characterized by persistent anoxia and minimal detrital dilution, providing a predictive framework for sweet spot identification in foreland basin settings.

126. 题目: Soil texture regulates organic carbon sequestration via divergent accumulation pathways of plant- and microbial-derived carbon
文章编号: N26090503
期刊: Applied Soil Ecology
作者: Yiming Yun, Wenliang Yang, Xianfeng Zhang, Xiuli Xin, Xianjin Xie, Anning Zhu
更新时间: 2026-09-05
摘要: High sand content inherently restricts soil organic carbon (SOC) accumulation due to limited sorption sites, yet the specific impact of soil texture on carbon (C) sequestration remains unexplored, particularly regarding C sources, fractions, and pool sizes. Here, 35 topsoil samples (0–20 cm) spanning four textural classes along a sand-content gradient (clay loam to sand) were collected from a typical Fluvo-aquic soil region to elucidate the mechanisms of SOC sequestration regulated by texture. We determined soil physicochemical properties, SOC content and fractions, as well as plant- and microbial-derived C. Results indicated that increasing sand content significantly reduced soil nutrient concentrations and led to a sharp decline in SOC content, dropping from 12.47 ± 1.28 g kg−1 in clay loam to 5.85 ± 1.65 g kg−1 in sandy soils (P < 0.05). The SOC depletion was primarily driven by the reduction in mineral-associated organic C (MAOC, P < 0.001). Sandy texture directly reduced the retention of plant-derived C (PDC, specifically Vanillyl and Syringyl phenols), thereby primarily constraining the accumulation of easily oxidizable organic C (EOC) and driving a decline in the PDC contribution to SOC (from 31.5% to 18.7%). Meanwhile, sand-induced nutrient scarcity indirectly constrained the accumulation of microbial necromass, hindering the stabilization of fungal-dominated microbial-derived C (MDC) into MAOC despite its stable contribution (22.0%–25.3%). Ultimately, the limited SOC sequestration is attributed to the texture-regulated dual restriction on plant residue retention and microbial necromass accumulation. These findings provide a theoretical basis for enhancing the SOC sequestration potential in coarse-textured soils.

127. 题目: Grassland management pattern affects soil organic carbon content but not its mineralization on the Qinghai-Tibetan Plateau
文章编号: N26090502
期刊: Applied Soil Ecology
作者: Yizhe Peng, Jianjun Cao, Jan F Adamowski, Asim Biswas, Hong Wang, Yiyang Peng, Xiaoqing Yang, Xinhao Deng, Xiongwei Zeng
更新时间: 2026-09-05
摘要: In compliance with China's household contract responsibility system for grasslands on the Qinghai-Tibetan Plateau, grasslands are primarily managed under either the multi-household pattern (MMP) or the single-household pattern (SMP). Although the effects of these management patterns on vegetation and soil carbon have been extensively studied, their effects on soil carbon mineralization potential remain poorly tested. We conducted a 136-day laboratory incubation to compare soil carbon mineralization between MMP and SMP, integrating measurements of soil physicochemical properties, vegetation biomass, organic matter sources and stability, microbial communities, and functional genes, to identify the underlying drivers. Cumulative carbon mineralization (Ccum) did not differ significantly between MMP and SMP. Instead, Ccum varied across soil depths, with greater values in the topsoil (0–0.15 m) than the subsoil (0.15–0.30 m) under both management patterns. In the topsoil, Ccum was primarily associated with belowground biomass and lignin phenol concentrations. In contrast, subsoil Ccum was mainly explained by soil physicochemical properties and the abundance of functional genes involved in starch and lignin degradation. Within 0–0.30 m, soil physicochemical properties were the strongest direct predictor of Ccum (path coefficient = 0.58). These findings highlight that at equal stocking rates, MMP matches SMP in carbon release but boosts topsoil SOC by 17% and subsoil nitrogen retention by 29%, suggesting that MMP contributes to improved soil carbon storage and nutrient retention on the Qinghai–Tibetan Plateau.

128. 题目: Balancing benefits and risks in food waste biochar: Pyrolysis severity effects on contaminant fate, nutrient leaching, and biological safety
文章编号: N26090501
期刊: Waste Management
作者: Ojima Z Wada, Rashad Al-Gaashani, Sruthi Udayakumar, Sara Wahib, Tricia A Gomez, Tareq Al-Ansari, Khaled A Mahmoud
更新时间: 2026-09-05
摘要: Thermochemical conversion of food waste into biochar offers a compelling circular economy pathway for soil amendment, yet comprehensive safety assessments remain limited. This study assessed the stability, contaminant fate, nutrient leaching, and microbial compatibility of bone and mixed vegetable biochars pyrolyzed at 300–600 °C. Feedstock identity dominated variance in yield, ash, and carbon (η2 = 0.73–0.91), whereas temperature governed the volatile heteroatoms H, O and N (η2 = 0.44–0.74; all p < 0.001). At 600 °C, bone retained higher yield (60.3 ± 0.7 % vs 34.4 ± 0.7 %) and appreciable porosity (118.0 m2/g), whereas vegetable biochar showed negligible surface area (≤1.0 m2/g) yet preserved a carbon-rich matrix (59.5 ± 0.5 % vs 11.5 ± 1.3 % C). Vegetable biochar attained thermal stability (H/C < 0.7) by 400 °C, while bone did not cross this threshold. Bone was nutrient-dense (Ca 145,285 ± 25,963; P 73,321 ± 18,435 mg/kg), but its ions remained matrix-bound, raising leachate pH/EC only to 8.5 ± 0.18 and 235.7 ± 7.9 µS/cm versus 10.3 ± 0.08 and 1,202.5 ± 6.4 µS/cm for K-rich (25,325 ± 5,060 mg/kg) vegetable biochar, releasing far more labile ions (Na 96.4 % vs 44.8 %; p < 0.001). Mild pyrolysis (300 °C) eliminated key agrochemical and pharmaceutical contaminants (carbamazepine, pyrimethanil, o-hydroxybiphenyl) without generating EPA-priority polycyclic aromatic hydrocarbons; industrial plasticizers persisted at 600 °C, highlighting the need for upstream feedstock screening. Pyrolysis reduced dissolved organic carbon to < 10 mg/L, lowering colony counts to control levels, unlike raw bone (59-fold higher, p = 0.001). Bone biochar thus functions as a slow-release mineral scaffold, while vegetable biochar confers liming potential for acidic soils, manageable by pre-washing. Pyrolysis severity and feedstock selection are jointly critical to biochar safety.

129. 题目: Stability of stream biofilm community composition to transient shifts in dissolved organic carbon characteristics
文章编号: N26090420
期刊: Biogeosciences
作者: Oliviah Lines, Ewen Silvester, Suman Acharya, Aleicia Holland, Michael Shackleton
更新时间: 2026-09-04
摘要: . Microbial communities within biofilms are widely recognised as important contributors to ecological food webs and elemental cycles within stream systems. Yet, little is known about how these biofilm communities respond compositionally to storm-event-driven changes in dissolved organic carbon (DOC) characteristics. Alpine headwater peatland-draining streams offer a unique opportunity to investigate this response as these systems are known to export high loads of DOC during storm events, with little further upstream input. This study investigated how sub-alpine peatland-draining stream biofilm composition changed in response to storm-event-driven pulses of DOC. It was found that during the peak of each DOC pulse, the composition of DOC changed to include increased contributions of organic acids, protein-like substances and microbially derived DOC. Despite this change in DOC composition, the composition of most biofilm microbial communities did not significantly shift following each pulse; rather, differences in biofilm community composition appeared to be more closely linked to peatland stream site. The findings of this study suggest biofilm microbial communities maintain compositional stability following short-term rapid changes in stream water chemistry, and that site-specific environmental factors may be more important in determining biofilm microbial community composition in sub-alpine headwater peatland-draining streams.

130. 题目: Patterns of dissolved organic carbon (DOC) in drainage water at farm scale and impact of sediment mitigation measures on DOC concentrations
文章编号: N26090419
期刊: Journal of Soils and Sediments
作者: Maame Croffie, Owen Fenton, Demi Ryan, Russell Adams, Karen Daly
更新时间: 2026-09-04
摘要: Purpose Minimising nutrient loss in water and sediment along surface and near surface pathways on farms can be achieved through installation of mitigation measures such as sediment ponds or leaky dams. However, there is limited information on how these in-drain mitigation measures influence dissolved organic carbon (DOC) concentrations along the drainage network. The objective of this multi-farm study was to evaluate the impact of mitigation measures installed to control nutrient transport on DOC concentrations in drainage water. Methods Grab samples were collected monthly from two farms with pre-installed sediment ponds and two farms with barrier measures (leaky dams) installed in the drainage ditches in 2023 and 2024 for nutrient mitigation. Filtered samples were analysed for DOC concentrations. Results The results showed that DOC concentrations in the drainage ditch varied spatially due to regional differences in soils and landscape. On the two farms with sediment ponds the mean DOC concentrations for the downstream points were higher than the closest upstream points of the sediment ponds, implying that the measures did not reduce DOC concentrations at the outlet. Comparatively, on the two farms with leaky dams installed there were significant differences (p < 0.05) in the mean DOC concentrations between the closest upstream and downstream points of the leaky dams. In one of the farms, there was a significant reduction (p < 0.05) in DOC concentrations while in the other farm there was an increase of DOC concentrations in the downstream point, assumed locally to be caused by additional sources. Also, DOC concentrations on all farms varied temporally, influenced by a combination of high temperatures and rainfall in July 2023. Conclusion Leaky dams which are cost-effective to install, reduced DOC concentrations at most in-ditch locations when compared to sediment ponds which require machinery and expert labour for installation. Therefore, farmers can implement in-expensive mitigation measures, which target nutrient and sediment in-ditch losses on their farms, but importantly, these actions have co-benefits for also minimising DOC losses.

131. 题目: Machine Learning Attribution of Atmospheric Black Carbon in a Coastal City: Source Variability and the Sea–Land Breeze Recirculation Mechanism
文章编号: N26090418
期刊: Environmental Science & Technology
作者: Hao Yu, Xingyue Guo, Xinyu He, Mengyuan Luo, Dan Yao, Wenkang Gao, Guangxuan Yan, Pengtuan Hu, Xue Li, Menglin Liu, Xu Han, Zhiguo Cao
更新时间: 2026-09-04
摘要: Black carbon (BC) variability in coastal environments reflects the combined effects of emission sources, regional transport, and mesoscale circulation. This study selected the typical coastal city of Qingdao as the study area, collected BC online observation data for one year in 2021, and integrated it with the Aethalometer model, trajectory analysis, and Random Forest (RF) machine learning framework to examine these mechanisms. The annual mean BC concentration was 1.78 ± 1.29 μg m–3, with fossil fuel combustion contributing 88.2% of the total mass, while the biomass burning contribution increased to 19% in winter. Source-resolved attribution showed distinct meteorological responses. Fossil-fuel black carbon (BCff) was more strongly associated with wind-controlled ventilation and transport, whereas biomass burning BC (BCbb) responded more strongly to low-temperature conditions. Under sea–land breeze (SLB) conditions, BC enhancement was most evident at wind speeds of 2.0 to 3.5 m s–1. Diurnal persistence, directional shifts in elevated fossil fuel BC, and interactions between wind speed and wind direction further supported return transport and reaccumulation within coastal circulation. These findings provide process-based insight into source-dependent BC variability and SLB-related reaccumulation in coastal environments.

132. 题目: Manganese Oxides Incubated in Acidic Forest Soil Retain More Organic Carbon Than Iron Oxides
文章编号: N26090417
期刊: Environmental Science & Technology
作者: Kristen Bidas, Hui Li, Fernanda Santos, Erin C Rooney, Benjamin Reinhart, Lilin He, Changwoo Do, Qian Zhao, Ryan Tappero, Elizabeth Herndon
更新时间: 2026-09-04
摘要: Iron (oxyhydr)oxides are well-recognized contributors to soil carbon (C) storage, but the effects of manganese oxides on carbon storage and transformation are relatively unexplored. Here, the relative capacities of Fe and Mn oxides to bind and stabilize soil organic C were directly compared using an in situ incubation experiment. Quartz sands coated with either poorly crystalline Mn(III/IV) oxides or Fe(III) oxides, or left uncoated, were buried in a temperate forest soil for up to one year. Chemical extractions, X-ray absorption and photon spectroscopies, scanning electron microscopy, and neutron scattering were used to evaluate organic and mineral associations and transformations during the incubation. At the end of the 1-year study, Mn oxide stored ∼11× more carbon (42.0 ± 14.3 mg C/m2 oxide) than Fe oxide (3.72 ± 0.37 mg C/m2 oxide) per unit surface area. Manganese oxidation state changed over time, likely reflecting reactions between organic C and Mn oxide, while Fe oxidation state remained unaltered. Total organic C that was associated with Mn oxide was relatively enriched in carboxylic and O-alkyl-C compared to Fe oxides and quartz, either due to preferential sorption or oxidation on the mineral surface. Mn oxides also sorbed high amounts of Ca despite being incubated in an acidic, base-cation depleted soil, which potentially facilitated C sorption. Our study demonstrates that Mn oxides, with the assistance of Ca-bridging, have a greater potential to stabilize organic C than Fe oxides in acidic environments despite higher reactivity.

133. 题目: Coupled effects of vegetation and environmental factors on dissolved organic matter properties in coastal wetlands
文章编号: N26090416
期刊: Catena
作者: Zihan Zheng, Yingying Jiang, Tingcang Hu, Chao Ma, Xin Yao, Dietrich A Volmer, Yulin Qi
更新时间: 2026-09-04
摘要: Coastal wetlands are important blue carbon sinks, yet the mechanisms by which vegetation zonation and associated environmental gradients regulate dissolved organic matter (DOM) dynamics remain poorly understood. Here, we investigated soils from six vegetation zones along the sea–land gradient in the Yellow River Delta coastal wetland, including Spartina alterniflora (SA), bare flat (BF), inundated Suaeda salsa (I-SS), non-inundated Suaeda salsa (NI-SS), Tamarix chinensis (TC) and Phragmites australis (PA). Optical spectroscopy, FTIR and FT-ICR MS were combined to characterize changes in DOM concentration, composition and reactivity. Soil DOC exhibited a non-linear pattern along the gradient, first decreasing and then increasing from sea to land, with the lowest values in I-SS and the highest values in SA. This pattern reflected the combined effects of vegetation-derived carbon inputs, microbial processing and salinity-related environmental filtering. Spectral and molecular evidence further revealed pronounced DOM differentiation among vegetation zones. SA and BF were enriched in aliphatic and sulfur-containing compounds, showing relatively fresh molecular characteristics and potentially higher reactivity. By contrast, TC was characterized by more aromatic, oxygen-rich and structurally transformed compounds, suggesting more extensive oxidative processing and greater potential for persistence. NI-SS displayed transitional characteristics, with both fresh organic inputs and post-depositional transformation. Overall, DOM shifted from relatively fresh and potentially reactive fractions in seaward zones toward more aromatic, structurally complex and potentially persistent fractions in landward zones. These findings demonstrate that vegetation type, together with hydrological and microbial processes, jointly regulates DOM dynamics and carbon cycling along coastal wetland gradients.

134. 题目: Dynamic effects of oxytetracycline pollution on greenhouse gas emissions from wetlands: The synergetic regulatory roles of nutrients, DOM and microbiota
文章编号: N26090415
期刊: Journal of Environmental Chemical Engineering
作者: Xuecheng Wang, Yanye Li, Yang Li, Lixia Wang, Mingzhe Gao, Deshou Cun, Qichao Zhou, Junjun Chang
更新时间: 2026-09-04
摘要: Oxytetracycline (OTC), a typical tetracycline antibiotic frequently detected in wetlands as an emerging pollutant, can alter greenhouse gas (GHG) emissions from wetland systems. However, its temporally dynamic effects and underlying mechanisms remain poorly understood. In this study, the effects of OTC pollution at two levels, 50 and 500 μg kg−1 in sediment, on GHG emissions from wetlands at short-term (30 d) and long-term (80 d) periods and the synergetic regulatory roles of nutrients, dissolved organic matter (DOM) and microbial communities were assessed through a plant-free wetland microcosm experiment. The results showed that OTC notably stimulated CO2, CH4, and N2O emissions during the short-term exposure (P < 0.05), thereby substantially increasing the global warming potential (GWP) of the wetlands, with a stronger effect observed at the high-pollution level. After 80 d of OTC exposure, only CO2 emissions from these microcosms remained significantly elevated. Random forest analysis showed that increased CO2 emission was mainly associated with variations in sediment NO3--N, NO2--N, DOC, dissolved total nitrogen (DTN), humic-like and protein-like DOM components, and xylA gene abundance. Short-term CH4 increases were primarily related to humic-like and protein-like DOM components, sediment DOC, NO3--N, and NO2--N, whereas N2O increases were associated with nosZ abundance, DTN, and NO3--N. The findings demonstrated that OTC pollution notably altered nutrient, DOM, and microbial properties in the wetlands, especially during short-term exposure, and then considerably increased the GWP of wetlands. This study provides a scientific basis for wetland management under emerging pollutant stress.

135. 题目: Development and validation of detection method for PFAS in petroleum and petrochemical groundwater under high organic matter interference
文章编号: N26090414
期刊: Journal of Environmental Chemical Engineering
作者: Xingnan Zhou, Hui Luan, Tao Gu, Zi Long, Fangfang Ding, Kun Tong, Ting Cai, Xinwei Wang
更新时间: 2026-09-04
摘要: To address the challenge posed by conventional Per- and polyfluoroalkyl substances (PFAS) detection methods in petrochemical plant groundwater with high oil, salinity, and organic matter, this study developed a trace detection method integrating selective adsorption, deep purification, and anti-interference analysis, achieving accurate quantification of 18 PFAS. The approach specifically addressed technical bottlenecks in determining long-chain PFAS and mitigated matrix interference from oils. By optimizing solid-phase extraction (SPE) conditions, along with ultrasound-assisted extraction and vessel rinsing, the recoveries of 18 PFAS were significantly enhanced, with increases of 0.34–38.35% for the C8-C14 PFAS. Additionally, ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) conditions were optimized to achieve chromatographic separation of all 18 PFAS within 12minutes, significantly suppressing matrix effects and co-eluting interferences. The method demonstrated recoveries of 70.31–124.80%, intra- and inter-day relative standard deviations (RSDs) below 20%, method detection limits (MDLs) of 0.27–1.58ng/L, and method quantification limits (MQLs) of 0.81–4.74ng/L. When applied to groundwater samples from an oilfield and a refinery in China, target PFAS were successfully detected, with surrogate recoveries ranging from 71.11 to 127.51% and measured concentrations between ND and 5946.49ng/L. The predominant compounds detected were C4-C8 perfluoroalkyl carboxylic acids. This work provides an efficient and reliable technical framework for trace detection and source analysis of PFAS in oil-rich, high-complexity aquatic environments.

136. 题目: Boron-doped biochar with dual C-B-O/O-B-O sites as a super-anchor and electron-accelerator for nZVI-activated persulfate oxidation of imidacloprid
文章编号: N26090413
期刊: Environmental Research
作者: Zhengming Yang, Zhuochao Wang, Taiwen Li, Yang Xu, Tianyu Xu, Han Ding, Chuangshi Zhang, Yuzhuang Chen, Qiang Li, Rui Fang, Hongliang Cao
更新时间: 2026-09-04
摘要: Removing imidacloprid from water by persulfate oxidation remains challenging because the iron-based activators commonly used in these systems are prone to aggregation, passivation, and loss of reactivity. Among available advanced oxidation processes, nZVI-activated peroxydisulfate (PDS) is attractive for IMI degradation, but its performance is often compromised by inefficient oxidant utilization and poor catalyst durability. Herein, boron-doped biochar (BBC) with atomically dispersed functional sites was engineered to enhance nZVI catalytic performance. C-B-O sites served as robust anchoring sites, exhibiting a calculated Fe-binding energy of 391.98 kJ/mol and contributing to nZVI stabilization and improved activity retention after air exposure. Concurrently, O-B-O sites created polar microenvironments that promoted PDS enrichment and accelerated interfacial electron transfer, yielding an electron efficiency of 0.62 e− per PDS molecule. This dual-site architecture promoted the generation of O2·-, 1O2, SO4·-, and ·OH, as evidenced by radical-scavenging and electron paramagnetic resonance measurements. PBQ quenching caused the most pronounced suppression of IMI removal, indicating an important role of O2·-, whereas the characteristic TEMP-1O2 signal confirmed the involvement of a 1O2-associated non-radical pathway. DFT calculations further showed that the selected reaction pathways of O2·-, 1O2, SO4·-, and ·OH toward IMI exhibited different intrinsic energy barriers. Collectively, these results support the important involvement of O2·--mediated oxidation and 1O2-associated non-radical processes in IMI transformation under the investigated conditions. The catalyst achieved 91% IMI removal within 160 min and retained >96% of its initial activity after 30 days of air exposure. These findings provide a practical interfacial regulation strategy for designing carbon-supported iron catalysts with improved stability and enhanced PDS activation performance for persulfate-based water purification.

137. 题目: Iron-bound organic carbon formation governs the dual role of iron in anaerobic digestion of waste activated sludge: A stage-specific dosing strategy for enhanced methane recovery
文章编号: N26090412
期刊: Environmental Research
作者: Feifei Chu, Zhaofu Liu, Fangmei Cheng, Xiaomeng Zhang, Liyan Wei, Xinhou Zhang, Yun Chen, Lei Zhao, Fei Yang, Nan Shen
更新时间: 2026-09-04
摘要: Iron salts are widely used in sludge treatment, but their dual role in stimulating methanogenesis and immobilizing bioavailable organic carbon during anaerobic digestion remains insufficiently understood. This study investigated the effects of FeCl3 dosage and dosing timing on methane production, iron-bound organic carbon (Fe-OC) formation, and microbial metabolic activity during anaerobic digestion of waste activated sludge (WAS). The methane yield increased from 92.5 mL g−1 TS in the control to 108.9 mL g−1 TS at 20 mg g−1 TS, but decreased to 65.3 and 54.0 mL g−1 TS at 80 and 100 mg g−1 TS, respectively. High FeCl3 dosages promoted the substantial immobilization of organic carbon into the solid phase, where Fe-OC accounted for up to 67.6% of the TOC (at 100 mg g−1 TS). This profound carbon sequestration significantly restricted substrate bioavailability for methanogenic conversion. Furthermore, dosing iron during active digestion (day 5) yielded the highest methane production (147.8 mL g−1 TS), achieving a 73.1% increase over the control and outperforming day-0 and day-10 dosing by 37.4% and 58.8%, respectively. The dosing-time experiments showed that FeCl3 addition during the active digestion stage was more favorable than addition at the initial or late stage. The superior methane recovery achieved by day-5 Fe addition is attributed to a synergistic combination of reduced Fe-OC formation, optimized microbial community richness, sustained methanogen populations, and maximized enzymatic and electron transfer efficiencies. This study provides a practical strategy for improving methane recovery from WAS.

138. 题目: Effects of different biochar application rates on CH4 emissions and Microbial Carbon Pump (MCP) mediated carbon sequestration in paddy fields: a quantitative modeling approach
文章编号: N26090411
期刊: Journal of Environmental Management
作者: Yuefeng Li, Hongyu Chen, Jie Chen, Weiqin Jiang, Xiaoling Liu, Jie Liang, Ke Zhang, Bing Jiang, Hongbing Luo, Wancen Xie, Xiaochan An, Wei Chen, Zimu Yang, Xiaohong Zhang
更新时间: 2026-09-04
摘要: Biochar amendment is a proven strategy for mitigating methane (CH4) emissions and enhancing soil carbon sequestration in rice paddies. However, the depth-dependent dynamics of microbial carbon pump (MCP)-driven recalcitrant organic carbon (ROC) formation and the underlying microbial mechanisms remain poorly characterized, particularly in the purple paddy soils of the central Sichuan Basin, China. To address this gap, we developed a novel quantitative MCP-driven ROC model and conducted a field experiment with four biochar treatments (CK, C2, C4, and C6 t ha−1) to investigate CH4 emissions, methane-cycling microbial community, and soil carbon fractions across a 0–80 cm profile. Biochar amendment significantly reduced CH4 emissions by 57.88–84.51% (peaking at 6 t ha−1) and increased methanogen and methanotroph diversity by 1.30–1.66 times. Although the concentrations of soil organic carbon (SOC), dissolved organic carbon (DOC), microbial biomass carbon (MBC), and absolute ROC decreased significantly with depth, the ROC/SOC ratio consistently increased. Crucially, our quantitative model revealed that biochar stimulated both the in vivo turnover and ex vivo modification pathways of the MCP by supplying essential labile substrates, explaining up to 92% of the variance in deep-soil carbon fractions. In conclusion, this study demonstrates that biochar serves as an effective dual-action strategy: mitigating CH4 emissions via microbiome regulation while enhancing long-term carbon sequestration through intensified MCP-driven ROC formation across the entire soil profile.

139. 题目: Solid waste-derived biochar: An effective additive for enhancing CO2 absorption, suppressing NH3 slip, and saving energy in mild-temperature ammonia solutions
文章编号: N26090410
期刊: Journal of Cleaner Production
作者: Yu Pan, Longjie Yu, Jiahui Lei, Zehuang Zhang, Jianlong Jin, Qunxing Huang
更新时间: 2026-09-04
摘要: Ammonia-based CO2 capture is a promising technology due to the high absorption capacity and low regeneration energy consumption. However, its large-scale application is hindered by slow CO2 absorption rate, high ammonia loss, and large refrigeration investment (particularly in Chilled ammonia process (CAP)). To address these challenges, a low-cost functional additive was prepared by converting textile dyeing sludge and corncob into gradient porous biochar. Under optimal conditions, the addition of biochar produced at 800 °C (SC800) increased CO2 uptake by 3.88% to 5.82% and decreased ammonia slip by 46.52% to 79.54% compared with the ammonia solution alone. The optimal operation temperature of the modified absorption system was elevated to 25 °C, which could potentially reduce the energy consumption by 0.010–0.138 GJ/t CO2 captured compared to CAP. Molecular dynamics (MD) simulation indicated that the biochar promoted diffusion and mass transport of CO2 and NH3 molecules within the pore channels. Correlation analysis revealed that biochars with higher mesopore volume and quaternary nitrogen content, together with lower pyrrolic nitrogen content, exhibited better performance on CO2 absorption enhancement and NH3 slip inhibition. The absorption–desorption cycling experiments further demonstrated the potential of SC800 for practical CO2 capture applications, with only a 5.16% decreased in CO2 uptake and an 11.60% increase in NH3 slip after 5 cycles. Furthermore, the resulting mixture of biochar and fine NH4HCO3 crystals showed potential as a nitrogen-stabilized fertilizer. This work provides a sustainable route for converting solid wastes into high-value additives for more efficient and flexible ammonia-based CO2 capture.

140. 题目: Extracellular polymeric substances: overlooked contributors to soil organic carbon persistence
文章编号: N26090409
期刊: Soil Biology and Biochemistry
作者: Yichao Wu, Yuwei Yi, Minsu Kim, Samuel Bickel, Ming Zhang, Ke Dai, Chunhui Gao, Chenchen Qu, Chuisi Kong, Mengxi Feng, Ke-Qing Xiao, Hans-Curt Flemming, Yu-Rong Liu, Wenfeng Tan, Qiaoyun Huang, Chao Liang, Peng Cai
更新时间: 2026-09-04
摘要: Microbial contributions to the persistence of soil organic carbon (SOC) are often attributed to the long-term accumulation of microbially derived products, primarily cellular residues. Beyond cellular products, microbes also synthesize and secrete a group of ubiquitous, adhesive macromolecules known as extracellular polymeric substances (EPS). Although the involvement of soil EPS in SOC persistence has long been suggested, their quantitative contribution and underlying mechanisms remain poorly resolved. In this review, we synthesize current knowledge to highlight that, although EPS quantified using existing methods account for approximately 2% of SOC, their production often matches or exceeds microbial cellular biomass production, indicating that EPS represent a major microbial carbon flux to soil. We outline four mechanisms by which EPS contribute to SOC stabilization: the direct formation of (i) mineral-associated organic matter and (ii) geopolymers through mineral-catalyzed Maillard-type reactions, and the indirect protection of SOC through (iii) enhanced soil aggregation and (iv) modification of soil pore structure to physically constrain decomposition. We propose that EPS-mediated stabilization represents an important, yet underrecognized, component of microbial control over SOC persistence and explicitly incorporate EPS into the soil microbial carbon pump (MCP) framework. This framework distinguishes the in vivo extracellular route of EPS production from the in vivo cellular route of biomass production, providing a process-based basis for developing testable hypotheses on how cellular and extracellular microbial carbon fluxes jointly regulate SOC formation and persistence. Key research priorities include developing robust approaches for soil EPS extraction and quantification, incorporating EPS dynamics into SOC models, and obtaining a mechanistic understanding of environmental and microbial controls on EPS production and degradation. Addressing these gaps will significantly refine our understanding of microbial contributions to the terrestrial carbon cycle and inform strategies to enhance soil carbon storage.