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581. 题目: Iron-modified rice husk biochar immobilizes arsenic in paddy soils and suppresses grain accumulation: Mechanistic evidence from soil biogeochemistry and root ultrastructure
文章编号: N26072102
期刊: Journal of Environmental Chemical Engineering
作者: Md Imran Ullah Sarkar, Md Tofail Hosain, Ravi Naidu, Mohammad Mahmudur Rahman
更新时间: 2026-07-21
摘要: Arsenic (As) mobilization in flooded paddy soils poses a critical food-safety risk due to its efficient uptake by rice. This study evaluated iron-modified rice husk biochar (Fe-MRHB) as an amendment for controlling As speciation, mobility, and accumulation across the soil-porewater-root-grain interface in two contrasting paddy soils (neutral pH and acidic). Iron modification increased Fe content and introduced Fe-bearing phases and oxygen-containing functional groups, enhancing redox buffering and sorptive capacity of Fe-MRHB. Fe-MRHB reduced pore-water As by 28–62% and lowered As(III):As(V) ratios, indicating enhanced oxidation of mobile As(III) and reduced As bioavailability. Iron-plaque development on rice roots increased by up to 67%, while plaque-associated As declined by 40–55%. XPS analysis confirmed mixed-valence Fe species with a shift in As speciation toward less mobile forms at root surfaces, while TEM-EDS of root vascular tissue showed reduced As deposition in cell walls and restricted intracellular diffusion. Fe-MRHB substantially altered bacterial community composition in flooded soils. Consequently, rice grains exhibited declines of up to 55% in total As and 47% in inorganic As. Multivariate analyses identified pore-water EC, Eh, and DOC, together with soil EC and S, as dominant drivers of grain As accumulation. Collectively, Fe-MRHB disrupted As mobilization pathways and limited its accumulation in rice grains through coupled changes in pore-water chemistry, bacterial community composition, and root-surface processes. This study provides comprehensive mechanistic evidence supporting Fe-modified biochar as a viable means of mitigating As risks in rice cultivation, thereby contributing to a safer food supply.

582. 题目: Multi-spectroscopy reveals coal-derived DOM fingerprints for mine-water source identification
文章编号: N26072101
期刊: Environmental Technology & Innovation
作者: Zepeng Wan, Yanqing Wu, Peng Lu, Shun Yang, Yangcheng Xu, Tianyuan Chen, Baisheng Nie
更新时间: 2026-07-21
摘要: Mine water source identification and water-inrush tracing in deep coal mines remain challenging due to the complex hydrogeological conditions. Coal-derived dissolved organic matter (Coal-DOM) has emerged as a potential organic tracer, yet its temperature-dependent release characteristics under deep mining conditions are poorly understood. This study investigates the release of Coal-DOM from coals of varying metamorphism (long flame coal, lean coal, anthracite) at 25 °C and 50 °C using DOC analysis, EEM spectroscopy, and FT-ICR MS. Results show that elevated temperature significantly enhances DOC release, most markedly in anthracite (from 9.1 to 13.5 mg-C/L). For low-rank coals, temperature promotes the release of polar, protein-like DOM, increasing molecular diversity (from 3,877 to 7,876 formulas) and oxidation state (O/C from 0.31 to 0.40). In contrast, anthracite releases DOM dominated by aliphatic compounds (>75%), a signature reinforced at higher temperatures. These rank-specific molecular fingerprints exhibit clear media-specificity, demonstrating their potential as supplementary organic tracers for discriminating mine water sources and tracing water-inrush pathways in complex deep mining environments.

583. 题目: Molecular and compound-specific δ13C signatures of terrigenous organic matter along the Southwestern Atlantic Margin
文章编号: N26072018
期刊: Organic Geochemistry
作者: Ligia Dias de Araujo, Felipe S Freitas, Rafael A Lourenço, Natalia Venturini, Satie Taniguch, César C Martins, Michel M de Mahiques, Márcia C Bícego
更新时间: 2026-07-20
摘要: Continental margins are efficient sinks for organic carbon, integrating marine production with terrigenous organic matter (OM) supplied by riverine systems. Identifying and distinguishing terrestrial OM sources is therefore essential for understanding land-ocean carbon transfer. Here, molecular distributions and compound-specific δ13C values of long-chain n-alkanes were analyzed in surface sediments along the Southwestern Atlantic Margin (SAM; 23°–37°S) to characterize terrigenous OM inputs under modern environmental conditions. The combined use of n-alkane indices (ACL25–33, Norm31) and homolog-specific δ13C values reveals three main continental contributions: (i) grassland-dominated OM exported by the Río de la Plata (RdlP), (ii) tropical rainforest-derived OM from rivers draining the São Paulo Bight, and (iii) arid vegetation-derived OM from the Paraíba do Sul River basin. OM associated with the RdlP and Paraíba do Sul rivers shows higher ACL25–33 and Norm31 values and relatively enriched δ13C signatures, whereas rainforest-derived OM is characterized by lower molecular indices and more depleted δ13C values. Spatial patterns indicate that RdlP-derived OM extends farther northeastward and toward the continental slope than previously recognized, while local riverine inputs and shelf circulation promote strong mixing within the São Paulo Bight. Systematic offsets between δ13C values of n-C29 and n-C31 further suggest that homolog-specific isotopic signatures reflect hydroclimatic controls and grass inputs rather than simple C3-C4 mixing alone. By defining representative molecular and isotopic end-members for major terrigenous OM sources to the SAM, this study provides a robust geochemical framework for tracing continental inputs in marine sediments and establishes a reference for paleoenvironmental reconstructions of vegetation, hydroclimate, and land-ocean carbon exchange.

584. 题目: Upstream Inputs and Sludge Line Recirculation Drive Dissolved Organic Nitrogen Accumulation in Industrial Wastewater Treatment Systems
文章编号: N26072017
期刊: Water Research
作者: Lei Tianyu, Sille B Larsen, Cai Siying, Kjellberg Kasper, Krist V Gernaey, Flores-Alsina Xavier
更新时间: 2026-07-20
摘要: As effluent total nitrogen (TN) limits become increasingly stringent, dissolved organic nitrogen (DON) is emerging as a structural capacity constraint in highly optimized industrial wastewater treatment systems because conventional nitrification–denitrification primarily targets inorganic nitrogen species. The challenge is particularly acute in the biotech industries, where DON could originate from residual proteins in fermentation broths, downstream purification losses, biomass washing, and alkaline stabilization. This study develops and validates an integrated modeling framework to predict effluent dissolved organic carbon (DOC) and DON under full-scale industrial conditions while preserving COD, N, P, and metal (S, Al, Ca, Mg, Na, K) mass balance consistency. The largest industrial wastewater treatment system in Northern Europe was simulated using an upstream–plantwide mechanistic framework integrating anaerobic digestion (ADM), activated sludge (ASM), and physicochemical (PCM) models. Process extensions representing alkaline-induced solubilization and conservative transport of soluble inert DOC/DON fractions were implemented. Calibration used a dedicated short-term measurement campaign (DataS) and reconciled plant-wide mass balances. A complementary multiple linear regression (MLR) layer, developed from 22 years of operational data (DataH), was integrated to strengthen long-term predictive robustness. Ten operational scenarios (S0–S9) were evaluated, including upstream DOC/DON redirection in ultrafiltration/reverse osmosis (UF/RO) retentate and/or spent biomass, and sludge-line management to avoid DOC and DON recirculation. The integrated framework reproduced plant-wide mass balances with < 13 % deviation across treatment units. Model predictions show that DOC and DON discharge patterns are strongly controlled by upstream and biosolids-line reconfiguration, with concentrations decreasing from 200 to 50 mg COD/L for DOC and from 11 to 4 mg N/L for DON across scenarios. The regression layer further confirmed prediction reliability with R2 > 0.79 between DOC/DON effluent concentrations and key operational drivers, including flow rates, COD loads, and alkaline stabilization intensity. Economic assessment indicates that avoiding DOC/DON recirculation can reduce operational expenditures (OPEX) by up to 13% (S8), and external retentate treatment may increase costs by up to 90%. Sustainability indicators further show that operational reconfiguration reshapes plant-wide resource use and environmental performance. In total, DON represents a critical structural constraint on the expansion of industrial wastewater treatment capacity. Unless DON formation is reduced through upstream or sludge-line reconfiguration, compliance constraints (DON < 5 mg N/L) will limit the plant’s effective treatment capacity and narrow it to a point where capital-intensive tertiary treatments such as granular activated carbon (GAC) polishing may become unavoidable. Such measures could increase OPEX with a factor of three and add approximately 1000 tons CO2-eq/year GHG emissions. The proposed framework provides a robust decision-support tool for designing expansion strategies that balance regulatory compliance, economic performance, and environmental sustainability.

585. 题目: Long-term effects of glyphosate on substrates with varying organic matter content: an ecotoxicological assessment under laboratory conditions.
文章编号: N26072016
期刊: Environmental Science and Pollution Research
作者: Olga Bemowska-Kałabun, Anna Zawadzka, Małgorzata Wierzbicka
更新时间: 2026-07-20
摘要: The study aimed to determine the time required for glyphosate and its primary decomposition product, AMPA, to degrade in substrates with varying organic matter content, and to identify when the toxic effects of these substances diminish due to decomposition in the tested substrates. Additionally, the study investigated how nitrogen and phosphorus levels change during the decomposition of glyphosate and AMPA in relation to the organic matter content of the substrates. Ecotoxicological assessments were conducted using biotests (Phytotoxkit, Lemna, and Microtox). Chemical analyses of substrates with different organic matter contents were performed to measure glyphosate and AMPA levels, as well as various forms of nitrogen and phosphorus. The experiments were carried out under laboratory conditions over a time course from 0 to 24 months after herbicide application. It has been shown that sand is the substrate in which glyphosate and AMPA degrade most slowly (up to 24 months). The presence of undegraded glyphosate and AMPA in sand resulted in the longest-lasting toxic effects on test organisms in the bioassays conducted with this substrate. In agricultural soil, however, undecomposed glyphosate and AMPA had a toxic effect on the studied organisms only for a short period after the herbicide was applied, due to the rapid degradation of glyphosate and AMPA (3 months). There was an increase in the levels of phosphorus and nitrogen in the substrates after the herbicide was added, compared to the control. Although the experiments were conducted under laboratory conditions, the observed increase in nitrogen and phosphorus content in the tested substrates following the degradation of glyphosate and AMPA suggests that there may be potential implications for processes in the natural environment. This could be particularly relevant in areas where high doses of glyphosate have been used over many years. Additionally, it appears that in substrates with lower organic matter content, the degradation of glyphosate and AMPA might take longer, potentially leading to a more extended toxic effect on living organisms compared to substrates with higher organic matter. These observations could, in some cases, contribute to the development of increased tolerance to glyphosate in plants from such areas. However, further studies would be necessary to fully understand these effects.

586. 题目: Moderate straw addition enhances the water stability of artificially reconstructed soil aggregates by regulating pore structure and organic carbon fractions.
文章编号: N26072015
期刊: Journal of Environmental Management
作者: Jianle Zhang, Yingsong Yang, Kai Guo, Haiyue Li, Xiaofeng Zhao, Yanhui Wang, Feng Ai, Xiao Deng, Binbin Li, Mingxiang Xu
更新时间: 2026-07-20
摘要: Soil aggregates underpin key soil ecological functions, yet their natural recovery is inherently slow. Artificial aggregate reconstruction using straw as an organic binding agent and structural support provides a potential pathway for accelerating soil structure restoration, although its effectiveness remains unclear. This study examined the effects of six straw addition levels (0, 1%, 3%, 5%, 7%, and 9%, w/w) on water stability, organic carbon fractions, and pore characteristics of reconstructed aggregates during a one-year incubation. The results showed that moderate straw addition (3%-5%) retained the highest proportion of water-stable macroaggregates and produced the highest mean weight diameter (MWD). At day 30, MWD under the 5% treatment was 1.97 mm, 7.88 times that of the control and 121.57% higher than that of the original field-soil aggregates, and it remained relatively high under moderate addition at day 365. Excessive straw addition increased soil organic carbon (SOC), particulate organic carbon (POC), mineral-associated organic carbon (MAOC), and pore abundance, but these gains were not effectively converted into higher water stability. By contrast, moderate straw addition was associated with a more favorable combination of carbon accumulation and pore structure, characterized by stronger connectivity, more 5-20 μm pores, and few localized macropores. Variance partitioning analysis revealed that the shared explanatory fraction of carbon fractions and pore structure accounted for 54.9% of MWD variation. These findings indicate that reconstructed aggregate water stability was better explained by carbon-pore relationships than by carbon accumulation or pore production alone, providing a reference for straw-based soil structure restoration strategies.

587. 题目: Synergistic oxidation and adsorption of humic acid by electro-activated ferrous: Process exploration, mechanism insights, and practical applications.
文章编号: N26072014
期刊: Journal of Environmental Management
作者: Hui Jiang, Xin Yao, Hongjie Ran, Yuanyuan Huang, Letong Zhou, Ying Yang, Sen Yang, Hailong Kang
更新时间: 2026-07-20
摘要: Conventional drinking water treatment processes exhibit limited efficiency in removing humic acid (HA), making it difficult to effectively suppress the formation risk of disinfection by-products (DBPs). To address this issue, an electrochemical pretreatment system integrating synergistic oxidation, flocculation, and co-precipitation processes was developed. This system employs electro-activated ferrous (EAF) to enhance HA removal and thereby mitigate the formation of DBPs precursors at the source. Using a Ti/TiO2-Ta2O5-IrO2 anode and a graphite cathode, under the conditions of 30 mg L-1 Fe2+ dosage, 3 mA cm-2 current density, and 2 cm electrode spacing, the removal rate of natural organic matter reached 92.62% ± 1.99%. Analysis via three-dimensional excitation-emission matrix fluorescence spectroscopy (3D-EEM) and ultraviolet-visible absorption spectroscopy (UV-Vis) collectively confirmed that macromolecular HA underwent significant oxidative cleavage and adsorption removal in the reaction system. Hydroxyl radicals (·OH) attacking HA molecules were identified as the key mechanism driving oxidative degradation. Meanwhile, the continuous redox cycling of iron species (Fe2+/Fe3+) in the system facilitated this process, and the resulting Fe3+ effectively removed HA and their degradation products through flocculation. Furthermore, the coexistence of Fe, O, and C elements within the flocs, along with the identified coordination structures between HA and Fe(OH)3, directly confirms the binding of organic matter, such as HA, onto iron hydroxide flocs. Finally, the applicability of this technology was validated in real water samples, and its disinfection efficacy was evaluated through microbial diversity analysis.

588. 题目: Freeze-thaw-induced destabilization of organic matter in Mollisols after decadal mineral fertilization
文章编号: N26072013
期刊: Soil Biology and Biochemistry
作者: Dan-Dan Wang, Zhiming Zhang, Peng He, Shan-Shan Dai, Minghui Liu, Yu Luo, Tida Ge, Ekaterina Filimonenko, Yakov Kuzyakov, William R Horwath, Lu-Jun Li
更新时间: 2026-07-20
摘要: Long-term mineral fertilization regulates the quantity and quality of soil organic matter (SOM) by altering soil properties and microbial processes. However, how long-term mineral fertilization modulates SOM stability, particularly its response to seasonal freeze-thaw (FT) cycles in agroecosystems, remains nearly unknown. Here, we investigated the combined impacts of 26-year mineral fertilization (N, P, and K) and FT events on the stability of particulate and mineral-associated organic matter (POM and MAOM, respectively) in a Mollisol. The results showed that FT events reduced POM recalcitrance (indicated by the aromatics/polysaccharides ratio and the aromatics/aliphatics ratio) and thermal stability (assessed by the temperatures of 50% mass loss and 50% stored energy release), with the most pronounced effects observed under high-rate mineral fertilization. This destabilization resulted from imbalanced carbon accumulation in POM (15%) and MAOM (9.1%) under fertilization compared to unfertilized soils, combined with a decrease in aromatic compounds and an increase in non-aromatic compounds. Mechanistically, fertilization-induced SOM destabilization, soil acidification, and increased available phosphorus, along with FT-driven rises in the fungal-bacterial ratio and the resource-microbe carbon:nitrogen imbalance, accelerated the decomposition of recalcitrant POM compounds during FT periods. Moreover, continuous maize (Zea mays L.) monoculture had a more pronounced negative response to FT events than the maize-soybean (Glycine max (L.) Merr.) rotation. In contrast, MAOM maintained its persistence across FT events independent of fertilization regime. Collectively, our findings demonstrate that mineral fertilization increases the disruptive effects of seasonal FT events on SOM persistence primarily by destabilizing the POM fraction.

589. 题目: Energy storage in humic acids promotes electron delivery from electrode to microbes
文章编号: N26072012
期刊: Chemical Engineering Journal
作者: Yaya Sun, Fangzhi Jiang, Xuedong Zhang, Salma Tabassum, Hongbo Liu
更新时间: 2026-07-20
摘要: Microbial electrochemical systems (MES) present excellent performances in utilizing external electricity to overcome the thermodynamic limits of conventional bio-reactions, but severely constrained by the transfer barriers of electrode electrons in their scale-up applications. The new approach of using humic acids (HAs) as conductive media could bypass the bottleneck of traditional electron supply modes centered on solid electrodes. Results showed that methane production could be boosted by 106.1% in anaerobic digestion (AD) driven by the discharge of HAs. Mechanism analysis showed that except for electron shuttles, HAs also has pseudocapacitive effects, and could efficiently obtain electrical energy from the electrode and store into its electroactive functional groups. Upon electrode charging, HAs achieved efficient pseudocapacitive storage of 140.7 F/g, driven by reversible Faradaic reactions. Molecular biology testing indicated charged HAs would approach microbial interface and couple with the cell electron transfer chain, subsequently smoothly delivering electrons to the microbes. This study found HAs played a role similar to biobatteries, reducing the electrode-microbe interfacial Tafel slope to 0.31 V/dec and yielding a 336.9% increase in bioavailable electrons delivered to microbes. Moreover, verification tests even obtained a 389.1% increase of acetate yield in the electron-dependent photocatalytic CO₂ reduction system. Obviously, energy storage of HAs could smooth electron delivery from electrode to microbes, providing a new strategy for solving the electron transfer barrier faced by the scale-up applications of MES.

590. 题目: Hierarchical porous pine needle biochar via synergistic regulation of activator and temperature for efficient iodine capture from gas and aqueous phases
文章编号: N26072011
期刊: Chemical Engineering Journal
作者: Yanfei Li, Dai Wu, Wenjie Pang, Mingru Bao, Liang He, Lili Jiang, Shudong Geng, Jianping Li
更新时间: 2026-07-20
摘要: The collection and storage of radioactive iodine isotopes in nuclear waste represent a critical safety challenge facing the modern nuclear industry. However, conventional iodine adsorbents still suffer from various limitations, including high cost, complex preparation, limited adsorption capacity, and poor reusability, which greatly restrict their practical application in nuclear waste treatment. Biomass-derived carbon materials have shown great promise for radioactive pollutant remediation owing to their abundant availability, eco-friendliness, and excellent performance. In this study, hierarchically porous biochar (PNC-9) was successfully synthesized from pine needles by regulating the potassium salt type and pyrolysis temperature. PNC-9 exhibited a remarkably high specific surface area of 2473.12 m2/g, representing an enhancement of over 147-fold compared to the pristine precursor. The material exhibits rapid iodine adsorption kinetics, with an adsorption capacity of 4.102 g·g−1 in iodine vapor within 2.5 h and 4.275 g·g−1 in aqueous solution in just 20 min. Furthermore, a biochar-supported sponge material (PNC-9@MS) was fabricated, demonstrating a saturated adsorption capacity of up to 2.289 g·g−1 and good reusability over seven cycles. The iodine-loaded and regenerated PNC-9 samples were characterized by SEM, BET, FT-IR, Raman, XPS, and DFT analyses, revealing the capture mechanism of different iodine species (I2, I3−, and I5−) by the adsorbent. These findings offer valuable insights for dual-phase iodine capture and establish the developed biomass-derived carbon as a cost-effective adsorbent with a versatile preparation strategy extendable to other biomass sources.

591. 题目: Sources of Water-Soluble Organic Carbon in Aerosols at the Cape Point GAW Station
文章编号: N26072010
期刊: ACS Earth and Space Chemistry
作者: Mishka Rawatlal, Kurt A M Spence, Marié E Smith, Casper Labuschagne, Katye E Altieri
更新时间: 2026-07-20
摘要: Aerosols play a major role in climate by influencing both radiative forcing and cloud condensation nuclei (CCN) formation, with organic aerosols comprising a large fraction of the global natural aerosol burden (∼20–70%). Despite this importance, long-term observations of water-soluble organic carbon (WSOC), particularly in size-segregated aerosols from natural sources, remain scarce in the southern hemisphere. Here, we present size-resolved WSOC measurements from an eight-month observational campaign (April to November 2018) at the Cape Point Global Atmosphere Watch (GAW) station, a remote coastal site at the southern tip of Africa, ideally suited for elucidating marine, continental, and mixed aerosol sources. Weekly aerosol samples were classified using air mass back trajectories, radon-222 and carbon monoxide concentrations, wildfire observations, and satellite-derived chlorophyll-a to assess source influences. Across all air mass classifications, WSOC concentrations were consistently higher in the fine mode (<1 μm) than in the coarse mode (>1 μm) aerosols (0.58 ± 0.55 μg/m3 vs 0.20 ± 0.22 μg/m3, respectively). Fine mode WSOC concentrations were highest during periods influenced by biomass burning (0.87 ± 0.49 μg/m3) and continental outflow, while marine and modified marine air masses exhibited lower fine mode WSOC concentrations. However, periods of enhanced marine biological activity were associated with increased fine-mode WSOC concentrations. The observed predominance of WSOC in the fine mode across marine, modified marine, and continental air masses highlights the importance of secondary formation and atmospheric aging processes, rather than direct primary emissions, in controlling WSOC concentrations at Cape Point. Overall, WSOC levels at this coastal site reflect an integration of natural and anthropogenic sources, transport history, and atmospheric processing. These results establish a regional baseline for WSOC aerosols in southern Africa and contribute to a broader understanding of organic aerosol formation in a data-sparse southern hemisphere coastal environment.

592. 题目: Soil aggregate fractionation modulates Mollisol organic carbon biomineralization and CO2 emission during freeze-thaw cycles
文章编号: N26072009
期刊: Applied Geochemistry
作者: Wenjuan Zou, Kunfu Pi, Hongyan Li, Qianyong Liang, Lifen Liu, Fereidoun Rezanezhad
更新时间: 2026-07-20
摘要: Freeze-thaw cycles (FTCs) strongly regulate soil carbon dynamics in cold regions. Soil aggregates are core structural units that protect soil organic carbon (SOC) and regulate its biomineralization. While previous studies provide a good understanding of bulk soil properties, it remains elusive how aggregate size distribution modulates SOC biomineralization under repeated freeze-thaw cycles (FTCs). Cold-region Mollisols, which are characterized by high SOC concentration and strong aggregation, provide an ideal system to address this gap. Destructuring Mollisol aggregates enables disentangling size-dependent carbon protection mechanisms for preventing SOC from biodegradation. Here, joint field investigations and controlled FTCs incubation experiments were conducted using physically separated Mollisol aggregates to disentangle size-dependent carbon protection mechanisms. The results present new evidence that aggregate-mediated SOC biomineralization under FTCs exhibits a pronounced size-dependent pattern. Large macroaggregates (LMA) experienced severe physical disintegration during FTCs, exposing protected SOC and releasing 40% - 60% more cumulative CO2 than microaggregates (MIA). Small macroaggregates (SMA) showed moderate structural breakdown but comparatively low SOC biomineralization due to biochemical constraints. MIA remained structurally stable, accumulated microbially-derived dissolved organic matter, and acted as a stable carbon sink through organo-mineral associations and microbial adaptation. A modified dual-pool kinetic model further reveals that SOC loss from LMA was primarily driven by physical fragmentation, while SOC retention in MIA was governed by chemical stabilization and microbial resilience. Overall, our results highlight that aggregate hierarchical structure exerts critical control on SOC turnover and CO2 emission in cold-region Mollisols. Carbon biogeochemical models should integrate aggregate-level processes to accurately predict soil carbon dynamics in cold-region terrestrial ecosystems.

593. 题目: Effects of Landscape Pattern on Spatial Distribution of Soil Organic Carbon Content in a Typical Lakeside Oasis
文章编号: N26072008
期刊: Land Degradation & Development
作者: Ke Quan, Xinguo Li, Xiangyu Ge
更新时间: 2026-07-20
摘要: Knowledge of the factors influencing the spatial distribution of farmland soil organic carbon (SOC) content contributes to a better understanding of human impacts on soil, which is crucial for improving soil quality and mitigating climate change. Intensive agricultural production has significantly altered the landscape patterns of oasis farmlands, yet its effects on the spatial distribution of SOC content remain unclear. The study employed Ordinary Kriging interpolation and stepwise regression analysis using 71 surface soil samples (0–20 cm) from the Bosten Lake lakeside oasis in Xinjiang to investigate the effects of climate, topography, and landscape pattern on SOC content. Results showed that climate factors explained only 15% of SOC content variation ( R 2 = 0.15), with mean annual precipitation (MAP) exhibiting a significant negative effect. Incorporation of landscape pattern indices increased model explanatory power to 28% ( R 2 = 0.28, representing a 13% increase), with Contagion Index (CONTAG) and Mean Contiguity Index (CONTIG‐MN) showing significant negative influences, while aggregation‐related indices contributed positively to SOC accumulation under arid wind‐erosion conditions. The study quantitatively evaluated the contribution of landscape patterns to the spatial variation of SOC content in an arid lakeside oasis, where such relationships remain poorly understood, and reveals the positive role of moderately aggregated landscapes under wind‐erosion conditions. The findings provide a scientific basis for improving long‐term SOC sequestration, optimizing agricultural landscape management, and supporting sustainable development in arid oasis regions.

594. 题目: Pyrolysis of heavy metal-enriched plant residues: stabilization of Pb/Zn/Cd and MnFe2O4-modified biochar for Congo red adsorption
文章编号: N26072007
期刊: Environmental Geochemistry and Health
作者: Liying Jiang, Baolin Fang, Kejia He, Yuhao Cao, Mengjie Yang
更新时间: 2026-07-20
摘要: Phytoremediation of heavy metal-contaminated soils generates large quantities of metal-enriched plant residues that require safe disposal. Herein, we report an integrated valorization strategy for Sedum alfredii Hance residues: pyrolysis for heavy metal stabilization, followed by magnetic modification on the resulting biochar for Congo red (CR) adsorption. Pyrolysis was conducted at 400–900 °C, and the transformation behavior of Pb, Zn, and Cd was evaluated. The results demonstrated that pyrolysis effectively converted the acid-soluble/exchangeable fractions of Pb, Zn, and Cd into more stable residual forms, and their leaching concentrations decreased significantly with increasing pyrolysis temperature. Biochar produced at ≥ 700 °C exhibited no phytotoxicity in wheat seed germination tests. To enhance its adsorptive performance, the biochar pyrolyzed at 700 °C was magnetically modified with MnFe2O4. The modification improved the pore structure and surface function groups, facilitating CR adsorption. The resulting MnFe2O4-SBC biochar possessed a specific surface area of 91.68 m2/g and a maximum CR adsorption capacity of 199.89 mg/g, following the Langmuir isotherm and pseudo-second-order kinetic models. After five adsorption–desorption cycles, MnFe2O4-SBC retained high CR adsorption capacity, with minimal metal leaching. Mechanistic analysis revealed that adsorption was governed by electrostatic attraction, ion exchange, hydrogen bonding, π-π interactions, and surface complexation. Collectively, this study demonstrates that pyrolysis is a viable route for the safe disposal and value-added utilization of hyperaccumulator residues, turning a disposal burden into a functional biochar material.

595. 题目: Regional contrasts in phytoplankton communities and organic carbon pools: Hydrographic forcing and zooplankton grazing in the Cosmonaut and Cooperation Seas
文章编号: N26072006
期刊: Marine Pollution Bulletin
作者: Cuiting Li, Dong Li, Jun Zhao, Ji Hu, Xinliang Wang, Guijun Guo, Jianming Pan, Bin Wu, Peisong Yu, Weiping Sun, Guanbei Wu, Haifeng Zhang, Changfeng Zhu
更新时间: 2026-07-20
摘要: The Cosmonaut and Cooperation Seas are considered important sectors of the Southern Ocean carbon sink, yet interactions among hydrographic forcing, phytoplankton communities and organic carbon (OC) pools remain insufficiently constrained during the early sea-ice retreat period. During CHINARE-36 (December 2019-January 2020), we investigated 55 stations across 9 transects using measurements of macronutrients, phytoplankton pigments (UPLC and CHEMTAX), organic carbon (POC and DOC), remote sensing, and hydrographic observations. Distinct regional differences in stratification and mixed layer depth were observed between the two regions, suggesting contrasting mixed-layer environments associated with the Weddell Gyre and Prydz Bay Gyre. Higher phytoplankton biomass occurred in the Cosmonaut Sea, with enhanced Hapt-HighFe biomass, whereas the Cooperation Sea exhibited lower biomass and a greater contribution of Diatoms-B. These patterns are consistent with differences in light-mixing environments. POC was strongly correlated with chlorophyll a (r = 0.76, p < 0.01), indicating phytoplankton as a major POC source. Variations in depth-integrated POC/Chl a ratios indicated differences in POC-phytoplankton biomass coupling, with elevated values suggesting possible detrital or non-algal particulate contributions. DOC dominated total organic carbon, with DOC/TOC exceeding 90% in both regions, and likely reflected combined influences of phytoplankton release, particle degradation, microbial remineralization, and hydrographic processes. Chlorophyll degradation and possible grazing-related pigment signals were generally limited regionally. Overall, this integrated comparison of two gyre-influenced East Antarctic sectors shows that phytoplankton community structure, POC-phytoplankton coupling, and DOC-POC partitioning were closely associated with inferred light-mixing environments, providing a regional framework for evaluating phytoplankton-carbon coupling during the early sea-ice retreat period.

596. 题目: Unlocking the microplastics amplification effect: How biochar counters heavy metal risks by driving speciation shifts and reversing soil property degradation
文章编号: N26072005
期刊: Ecotoxicology and Environmental Safety
作者: Feng Han, Li-Qi Ma, Si-Yu Liu, Zheng Li, Yi-Kai Wang, Jian Su, Jie Chen
更新时间: 2026-07-20
摘要: Microplastics and heavy metal co-contamination exacerbate risks to soil-plant ecosystem, yet remediation mechanisms remain unclear. This study demonstrated polystyrene microplastics reduce soil pH and soil organic (SOM), while increasing redox potential and zeta potential, suppressing urease, alkaline phosphatase, and sucrase activity, causing declines in soil total nitrogen, available phosphorus and potassium, inhibiting lettuce growth and increasing Pb and Cd significantly. Applying wood chip and straw biochar reversed soil pH to alkaline condition, enhanced reductivity, increased SOM by 47.68-50.46%, restored enzyme activity by 73.35-242.76%, improved nutrient availability, and significantly reduced Pb and Cd accumulation. Key mechanisms first revealed involve biochar synchronously correcting microplastic-induced soil acidification, organic matter loss, and dispersion through synergistic pH, SOM, and zeta potential adjustments. Biochar alleviated ecological hazards through dual pathways whereby increased SOM activated soil enzymes and phosphorus availability, promoted chlorophyll synthesis, and increased biomass by 23.46-29.23%; while it mitigated plant antioxidant enzyme increases, reduced malondialdehyde and free proline, alleviated membrane damage. Biochar facilitated Pb(II) conversion from exchangeable to organic-bound and residual fractions by enhancing two key factors: pH and SOM, achieving up to 89.04%, thereby reduced stem and leaf Pb accumulation by 25.38-29.45%, yet failed to fully offset Cd activation by microplastics. Wood chip biochar outperformed straw biochar in Pb immobilization and oxidative stress mitigation; both offered limited Cd remediation. This study elucidates the mechanisms by which organic matter hubs and pH govern the regulation of heavy metal speciation, providing a theoretical bases for the targeted remediation of co-contaminated soils.

597. 题目: Soil organic carbon loss as CO2 at depths up to 90 cm: Insights from δ13C isotopic profiles in a wheat–maize rotation
文章编号: N26072004
期刊: Catena
作者: Yuying Wang, Chunsheng Hu, Wenxu Dong, Xiaoxin Li, Yuming Zhang, Pengfei Wu, Jiafa Luo
更新时间: 2026-07-20
摘要: Quantifying depth-dependent characteristics of the carbon dioxide (CO2) pool and carbon (C) isotopic compositions of CO2 and soil organic carbon (SOC) may decipher depth-dependent sources of subsoil CO2 pool. We determined in-situ CO2 concentrations, fluxes, and δ13C values (13C/12C ratio) of CO2 and SOC within the 0–300 cm soil profile from 2019 to 2022 under a wheat–maize rotation on the North China Plain (NCP). During the wet-warm maize season, CO2 concentrations, fluxes, and δ13C–CO2 values were significantly higher than those in the dry-cold wheat season. The CO2 concentrations increased significantly with depth, whereas the CO2 fluxes and δ13C–CO2 values showed the opposite trend. The majority of positive CO2 fluxes occurred within the top 90 cm layer, indicating that this layer was the main source of soil respiration at the soil–atmosphere interface. The δ13C–CO2 signatures across the profile derived using the Keeling plot approach fell within the δ13C–SOC range of the 30–90 cm layer, suggesting consistency with an important contribution from SOC decomposition within this depth. Depth-dependent CO2 characteristics were associated with interactions among soil temperature, moisture, and dissolved organic carbon (DOC). We highlight that the CO2 pool within 0–300 cm is consistent with an important contribution from SOC-derived respiration in the 30–90 cm layer, in addition to root respiration in the 0–30 cm layer. Our study provides evidence that the subsoil SOC pool at depths up to 90 cm may be converted into CO2 under intensive wheat–maize rotation.

598. 题目: Phanerochaete chrysosporium activates different phosphorus-enriched biochar for heavy metal removal: synergistic mechanisms of microbially induced phosphate precipitation
文章编号: N26072003
期刊: Journal of Environmental Chemical Engineering
作者: Jingyi Gong, Yayuan Liu, Liang Hu, Zuopei Jiang, Yiqin Li, Hongbo Zhao
更新时间: 2026-07-20
摘要: Microbially induced phosphate precipitation (MIPP) is a promising strategy for heavy metal remediation, yet the influence of phosphorus (P) source solubility on the synergistic efficiency between P-enriched biochar (BC) and microorganisms remains poorly understood. In this study, four types of P-enriched sludge biochar were prepared using potassium dihydrogen phosphate (MKP), tricalcium phosphate (TCP), calcium phytate (PAC), and nano-hydroxyapatite (nHAP), and subsequently integrated with the P-solubilizing fungus Phanerochaete chrysosporium (PC) to form composite mycelial pellets. The results demonstrated that the HAP@BC + PC system exhibited the superior Pb(II) removal efficiency of 93.4%. Mechanism analysis revealed that PC actively activated recalcitrant P-sources (HAP and PAC) via the secretion of low-molecular-weight organic acids and soluble microbial products (SMPs), creating a micro-scale P-replenishment environment that sustained the formation of stable minerals such as Pb10(PO4)6(OH)2. In contrast, the highly soluble MKP led to premature P-leaching and diminished synergistic efficiency, posing risks of water eutrophication. This work elucidates the interaction mechanisms between diverse P-sources and fungal metabolism, providing a theoretical framework for designing high-performance and slow-release MIPP systems for sustainable heavy metal removal, and provides a strategic selection of P-sources to avoid secondary P-pollution and eutrophication.

599. 题目: Alternate wetting and drying irrigation combined with biochar reduces greenhouse gas emissions and improves carbon balance in water‑scarce rice agroecosystems
文章编号: N26072002
期刊: Agriculture, Ecosystems & Environment
作者: Damián Fernández-Rodríguez, David Paulo Fangueiro, David Peña Abades, Luis Vicente Gil, Ángel Albarrán Liso, Manuel Pérez, Jose Manuel Rato-Nunes, Antonio López-Piñeiro
更新时间: 2026-07-20
摘要: This 3-year field study investigated the effects of different water management strategies and biochar application on greenhouse gas (GHG) emissions in a Mediterranean rice agroecosystem. The experiment compared a conventional flooding (CF) rice cultivation agroecosystem, CF cultivation amended with holm oak (Quercus ilex L.) biochar (CF-B), alternate wetting and drying (AWD) managed at –20 kPa with (AWD-B) and without biochar (AWD), and severely stressed AWD managed at –70 kPa with (AWDS-B) and without (AWDS) biochar. Biochar was applied at a rate of 35 t ha−1 during the first year of the study. Methane (CH4), carbon dioxide (CO2) and nitrous oxide (N2O) emissions were monitored throughout the experimental period, and global warming potential (GWP), yield-scaled GWP (GWP-y), and net ecosystem carbon balance (NECB) were calculated for each treatment. CF rice cultivation exhibited the highest CH4 emissions, which were markedly reduced under AWD, regardless of the severity threshold. Furthermore, under traditional flooding regimes, the biochar incorporation markedly reduced CH4 emissions. In addition, the transition from continuous flooding to intermittent irrigation did not result in substantial changes in N2O emissions, with values < 3.62 N2O-N kg ha−1. Biochar application effectively mitigated these N2O emissions, particularly in CF-B and AWD-B treatments. Over the final 2 years of the study, AWD-B exhibited the lowest GWP and GWP-y values. After 3 years of study, regardless of the irrigation regime, biochar ageing decreased carbon outputs and enhanced NECB values (33% compared with the initial treatments). These results suggest that integrating agroecosystem management practices, such as intermittent irrigation and holm oak biochar application, is an effective approach for mitigating GHG emissions and improving the carbon balance of Mediterranean rice systems while enhancing adaptation to the availability and efficient use of local natural water resources.

600. 题目: Compact CNN-Transformers match larger models for spatially-robust soil organic carbon mapping at regional scale
文章编号: N26072001
期刊: Geoderma
作者: Valerian Fourel, Martin Wiesmeier, Nafiseh Kakhani, Thomas Scholten
更新时间: 2026-07-20
摘要: Soil Organic Carbon (SOC) is a global reservoir in the carbon cycle, and accurate regional monitoring is needed for soil assessment and climate-change mitigation. Most Digital Soil Mapping (DSM) studies treat SOC as a static spatial target and report accuracy on random data splits, which spatial autocorrelation inflates. We evaluate a family of architectures, gated and ungated CNN-Transformer hybrids, plain Transformers, CNN–LSTM, Random Forest, and XGBoost, on 16,514 Bavarian topsoil samples (2007–2023) with a 43-band multi-temporal covariate stack, under 10-fold longitude-blocked spatial cross-validation. Every attention model clusters within one fold standard deviation, so a compact gated CNN-Transformer (87k parameters, ) comes within one fold standard deviation of a 45.1M-parameter pure Transformer () at roughly fewer parameters. Neither the convolutional front-end nor the gated residual network yields a separable gain, and added capacity does not help. Tree ensembles trail only modestly on the full domain (Random Forest 0.342, XGBoost 0.317). This edge is modest (0.05–0.07 in fold-mean , within the fold-to-fold spread) but consistent in sign across longitude-, latitude-, and cluster-blocked folds, and it is land-use stratified: on cropland alone, a low-variance regime, gradient-boosted trees are far stronger ( versus ), reproducing prior cropland-only Bavarian studies. The appropriate regional product is therefore a land-use-stratified map with tree ensembles on cropland and attention models on the high-variance organic remainder, rather than a single model. The contribution is thus not a new architecture for SOC mapping but a rigorous, spatially-validated architecture comparison and the land-use-dependent inversion of model performance it reveals. The recommended compact model produces a wall-to-wall 2023 SOC map of Bavaria at 250 m resolution.