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541. 题目: Warming accelerates soil organic carbon mineralization in thawed seasonally frozen ground by reshaping carbon fractions
文章编号: N26072801
期刊: Environmental Monitoring and Assessment
作者: Peng Wang, Shenghao Ai, Qinqing Yang, Jingyao Xiao, Xiaoyan Ai, Jinqiang Ma, Yingwei Ai
更新时间: 2026-07-28
摘要: Seasonally frozen ground (SFG) strongly regulates soil organic carbon (SOC) dynamics, yet the vulnerability of thawed SFG soils to warming remains unclear. We conducted a 45-day laboratory incubation using alpine meadow soils from the Qinghai–Tibet Plateau under three temperature treatments (5, 15, and 25 ℃). We quantified SOC mineralization temperature sensitivity (Q₁₀), assessed changes in carbon fractions and extracellular enzyme activities, and applied random forest (RF) analysis and partial least squares path modeling (PLS-PM) to identify key drivers and pathways regulating SOC mineralization. The Q₁₀ values of thawed SFG soils ranged from 0.53 and 4.69 (1.72 ± 0.94). Warming significantly altered the size of the potentially mineralizable carbon pool and changed the contents of dissolved organic carbon (DOC) and particulate organic carbon (POC), with DOC decreasing by 94.91–97.88%, POC declining by up to 19.37%, and SOC decreasing by approximately 48% at 25 ℃. Warming increased the activities of β-D-cellobiosidase (CBH) and phenol oxidase (POX) and reshaped carbon–enzyme relationships. It weakened the coupling between DOC and labile carbon-degrading enzymes but strengthened the negative associations of CBH with DOC, MAOC, and SOC, suggesting a shift in microbial carbon acquisition from labile substrates toward more recalcitrant particulate and mineral-associated pools. RF identified SUC, DOC, CAT, CBH, and POX as the dominant predictors of SOC mineralization rate, while PLS-PM showed that warming promoted SOC mineralization both directly and indirectly through changes in carbon fractions. These results indicate that SOC mineralization in thawed SFG soils is governed by labile carbon availability. Continued warming may accelerate the conversion of SFG from a carbon sink to a carbon source, with implications for regional climate feedbacks.

542. 题目: From Salt‐Affected Marginal Land Resource to Remediation Agent: Halophyte‐Derived Biochar for Ameliorating Cd‐Contaminated Acidic Soil
文章编号: N26072608
期刊: Land Degradation & Development
作者: Shaoqing Ge, Zhenyong Zhao, Ke Zhang, Changyan Tian
更新时间: 2026-07-26
摘要: Cadmium (Cd) contamination of acidic soils poses a significant threat to ecosystem stability and crop health. This study evaluated the potential of biochar derived from the halophyte Salicornia europaea (SBC), a salt‐tolerant plant that grows on saline‐alkali marginal land, to remediate Cd‐contaminated acidic soil. A pot experiment was conducted using acidic soil spiked with 3 mg kg −1 Cd and amended with SBC at 0%, 1%, and 2% ( w/w ). The results showed that compared to the control, 1% and 2% SBC treatments increased the rhizosphere soil pH by 0.7 and 1.4 units, respectively, and significantly enhanced organic matter content and cation exchange capacity. In addition, these treatments reduced the concentration of available Cd in rhizosphere soil by 14.0% and 33.9%, respectively. Furthermore, biochar promoted plant growth and increased the photosynthetic rate, while Cd accumulation in plants was significantly reduced by 51.3% and 52.6%. Metabolomic analysis revealed that SBC upregulated the tryptophan metabolic pathway, with indoleacetic acid and 5‐hydroxyindoleacetic acid being the predominant metabolites. Their accumulation in rhizosphere soil was associated with enhanced plant stress tolerance and growth. Although the soil electrical conductivity increased with SBC addition, no negative effects on plant growth were observed. These findings indicate that SBC can effectively immobilize Cd, improve soil quality, and facilitate plant growth in acidic contaminated soils, thus offering a promising strategy for sustainable remediation. This approach suggests a potential pathway for utilizing resources from marginal lands to remediate acidic contaminated soils, thereby contributing to sustainable land management and environmental protection.

543. 题目: New insights into biochar-promoted Mn(VII) oxidation of diclofenac: A unique electron transfer mechanism
文章编号: N26072607
期刊: Chemical Engineering Journal
作者: Yankun Liu, Xianhuai Huang, Kun Wang, Yuchao Tang, Beiping Zhang
更新时间: 2026-07-26
摘要: Permanganate (Mn(VII)) selectively oxidizes contaminants containing electron-rich functional groups. However, Mn(VII) reactivity toward many recalcitrant compounds remains limited. Herein, biochars derived from different feedstocks and pyrolysis temperatures enhanced Mn(VII)-mediated diclofenac (DCF) degradation across pH 5–9. DCF degradation strongly depended on the feedstock type, graphitization degree, and solution pH. Mechanistic analyses revealed distinct pH-dependent pathways. Under acidic conditions, reactive manganese species (RMnS), including MnO2 and Mn(III), mainly contributed to accelerated DCF degradation. In contrast, under neutral and alkaline conditions, DCF adsorbed onto biochar CO groups to form metastable biochar-DCF* complexes with lower reduction potentials than pristine DCF. This process increased the susceptibility of DCF to oxidation and facilitated electron transfer to Mn(VII), which differed from the previously reported pathway involving high-potential Mn(VII)–catalyst complexes. These findings reveal the pH-dependent roles of RMnS-mediated oxidation and biochar–contaminant complex-mediated electron transfer, highlighting a biochar-specific mechanism for Mn(VII)-mediated contaminant degradation.

544. 题目: Optimization of 3D-printed structures incorporating stainless steel mesh in Sono-Fenton process for coagulation-resistant DOM and micropollutant removal
文章编号: N26072606
期刊: Separation and Purification Technology
作者: Seung-Woo Nam, Jun-Yeoul Choi, Ji-Haeng Jeong, Su-Hyeong Bong
更新时间: 2026-07-26
摘要: Advanced oxidation processes (AOPs) exhibit high degradative potential but often suffer from narrow operating windows, incomplete mineralization, excessive sludge production, and limited scalability—particularly when treating coagulation-resistant dissolved organic matter (CR-DOM; SUVA 2–3 L/mg∙m) in wastewater effluents. CR-DOM represents a refractory fraction that resists conventional coagulation and is more recalcitrant than typical organic matter. To address these limitations, a heterogeneous sono-Fenton process using stainless steel mesh (SSM) and FeSO₄ was optimized via Taguchi design. Optimal conditions (pH 3, 7 mg/L FeSO₄, 25 mg/L H₂O₂, 85 g/L SSM, 580 kHz ultrasound) achieved 72% CR-DOM removal with minimal sludge generation. Incorporation of vertically 3D-printed SSM structures further enhanced removal to 94% through improved cavitation and mass transfer. Hydroxyl radical (• OH) dominance was confirmed using coumarin fluorescence and radical scavenging tests, indicating that •OH is an important reactive species contributing to CR-DOM oxidation. In a CR-DOM matrix co-spiked with bisphenol A (BPA, 50 μg/L), the hybrid system achieved 93% BPA removal and substantial TOC reduction, outperforming conventional AOPs, including homogeneous Fenton. The system showed strong synergistic effects, increasing apparent reaction rate constants by over 10-fold compared to conventional sono-Fenton while maintaining low specific electrical energy consumption. The integration of statistical Taguchi design with 3D-printed SSM architecture not only improves process robustness and reaction control but also enhances the scalability of lab-scale AOP research, offering a practical, energy-efficient pathway for multipollutant treatment in controlled laboratory systems and providing a basis for future validation in real wastewater matrices.

545. 题目: Niche differentiation and interaction between earthworm functional groups shape distinct soil carbon fate
文章编号: N26072605
期刊: Soil Biology and Biochemistry
作者: Kai Ma, Caide Huang, Jie Huang, Yuquan Wei, Zhangliu Du, Jia Cao, Weixin Zhang, Yvan Capowiez, Yuhui Qiao
更新时间: 2026-07-26
摘要: Soil organic carbon (SOC) dynamics are strongly regulated by biological processes, with earthworms serving as key ecosystem engineers. However, the mechanisms by which different ecological groups of earthworms jointly mediate SOC redistribution and stabilization remain poorly understood. To address this, a controlled macrocosm experiment with a full-factorial design was established and combined with 13C isotope tracing to systematically evaluate how epigeic earthworms (Eisenia fetida), anecic earthworms (Amynthas carnosus), and their mixed assemblages influence SOC distribution and transformation under straw input. Results showed that earthworms did not simply increase or decrease SOC but promoted carbon redistribution from active pools (dissolved organic carbon, DOC and microbial biomass carbon, MBC) to more stable pools (particulate organic carbon, POC and mineral-associated organic carbon, MAOC). The mixed-earthworm treatment achieved the highest SOC accumulation (4.33 g kg−1), 18–27% higher than single-species treatments, with ∼23.3% of the SOC increment derived from wheat straw. SOC exhibited a “decrease-then-increase” pattern, suggesting that earthworm activity triggered initial priming followed by stabilization. Epigeic species enhanced surface decomposition and labile carbon turnover, whereas anecic species promoted deep-soil carbon stabilization via aggregate formation and organo–mineral associations. Their coexistence generated complementary effects coupling rapid decomposition with carbon retention. Notably, earthworm casts contained up to 5.53 g kg−1 SOC—20–35% higher than the surrounding soil—and showed a compositional shift from DOC and MBC toward POC and MAOC. This indicates that earthworm casts play a crucial mediating role in the transformation of labile organic matter into stable carbon pools. Overall, this study provides the first quantitative evidence that earthworm functional diversity and the distinct contributions of casts collectively regulate SOC redistribution and persistence. These findings address gaps in how functional interactions and cast-specific processes are represented in SOC models, underscoring the need to explicitly incorporate such biogenic mechanisms into predictions of soil carbon sequestration and carbon–climate feedbacks.

546. 题目: Biochar enhances anaerobic oxidation of methane coupled with Cr(VI) reduction: Pyrolysis temperature-dependent electron transfer pathways and regulatory mechanisms
文章编号: N26072604
期刊: Bioresource Technology
作者: Lianfu Liang, Yepu Li, Xiaofeng Fu, Rui Lin, Keying Liu, Zhiqiang Zhao
更新时间: 2026-07-26
摘要: Anaerobic oxidation of methane (AOM) coupled with Cr(VI) reduction offers a promising strategy for synergistic remediation of methane and chromium co-contamination, but is constrained by inefficient interspecies electron transfer (IET). Biochar can facilitate IET via its tunable electrochemical properties, yet how pyrolysis temperature governs this process remains unclear. Herein, biochars prepared at 300 °C (BC300) and 800 °C (BC800) were compared to elucidate their regulatory mechanisms on AOM-coupled Cr(VI) reduction. Biochar amendment significantly improved Cr(VI) removal: BC800 achieved complete reduction of 50.0 mg/L Cr(VI) within 34 days, versus 77.4 % for BC300 and 39.6 % for the control. Electrochemical analysis revealed that BC300 facilitated mediated interspecies electron transfer via redox-active functional groups as electron shuttles, whereas graphitized BC800 facilitated direct interspecies electron transfer (DIET) via its high conductivity, markedly reducing electron transfer resistance and enhancing electron transport system activity. Microbial and metagenomic analyses revealed BC800 enriched Methanospirillum and Geobacter, and upregulated genes encoding DIET-related PilA protein and c-type cytochromes. These findings elucidate a complete electron route, where Methanospirillum transfers electrons generated from methane oxidation to Geobacter via BC800 acting as an electron conduit, and then Geobacter delivers electrons to extracellular Cr(VI) through conductive pili to complete the reduction process, verifying DIET as the core enhancement mechanism. This study demonstrates the prominent application superiority of high-temperature conductive biochar, and provides a robust scientific basis for rational design of functional carbon materials for synergistic methane mitigation and heavy metal remediation.

547. 题目: Advanced modification of biomass-derived biochar for selenium capture: from molecular adsorption mechanisms to circular economy perspectives
文章编号: N26072603
期刊: Separation and Purification Technology
作者: Anand Harsh Dwivedi, S L Neeraja, Hamidha Kunnath, P V Nidheesh
更新时间: 2026-07-26
摘要: Water contamination by toxic elements such as selenium, poses a serious global concern, as it creates problems for aquatic ecosystems, food safety and human health through exposure from drinking water sources, even at low concentrations. Industrialization, mining activities and agricultural runoff are the major sources of selenium in natural waters, which results in ecological damage and bioaccumulation in food chain. Conventional treatment methods face challenges such as high operational cost, limited selectivity, and generation of secondary pollutants. Biochar, a carbon-rich material derived from biomass, along with its modifications has emerged as a promising adsorbent for removing selenium oxyanions due to its porous structure, more functional groups, high surface area, and properties enhanced by modification. However, the removal of selenium by biochar is still in progress considering its practical applicability and efficacy for selenium adsorption. Here we review various effects of selenium oxyanions on the human health, advances in the modification of biochar for selenium oxyanion removal, indicating how modifying the biochar enhances the adsorption, selectivity, and stability. This review also examines the dual health implications of selenium speciation alongside different strategies of biochar functionalization including acid-alkali treatment which optimizes pores on the surface and adds functional group density, metal and metal oxide, which improve the surface charge and electrostatic interactions, nanocomposites modification enhances the redox activity and active site density, whereas magnetic modification streamlines phase separation and material recovery. Different modifications add various mechanism such as electrostatic interaction, surface complexation, and redox reaction for the adsorption of selenium oxyanions, with regeneration study confirming its potential reusability. Finally, the conclusion and future perspectives include the issues of scale-up, adsorption of selenium during column studies, and safe disposal of selenium laden biochar as a sustainable, circular economy solution for water purification and environmental protection.

548. 题目: Identification of Organic Radicals in Aqueous Environments by DIPPMPO Spin Trapping Coupled with High-Resolution Mass Spectrometry
文章编号: N26072602
期刊: Environmental Science & Technology
作者: Xuewen Luo, Yangjian Zhou, Liangke Gong, Yanheng Pan, Shuangshuang Cheng, Xin Yang
更新时间: 2026-07-26
摘要: Organic radicals are key reactive intermediates that govern pollutant transformation and biogeochemical cycling in aquatic environments, yet their direct identification remains challenging because of structural diversity, low concentrations, and transient lifetimes. This study introduces a robust analytical workflow that integrates the spin-trapping agent 5-(diisopropoxyphosphoryl)-5-methyl-1-pyrroline N-oxide (DIPPMPO) with ultraperformance liquid chromatography-quadrupole time-of-flight mass spectrometry (UPLC-QTOF-MS) for the systematic detection and identification of organic radicals in complex aqueous matrices. Systematic validation confirmed the high stability and linear concentration response of DIPPMPO-radical adducts, while characteristic neutral-loss patterns (42.0470 and 166.0759 Da) provided structural confirmation across multiple organic radical classes, including phenoxyl, semiquinone, acyloxyl, peroxyl, and alkyl radicals. Applied to both engineered and natural aqueous systems, the workflow successfully identified organic radicals generated during UV-irradiated bisphenol A degradation and in sunlight-exposed dissolved organic matter (DOM). The results illustrate its ability to trace pollutant-derived organic radicals and map diverse DOM-generated organic radicals, offering new insights into transformation pathways. By delivering enhanced specificity, structural insight, and semiquantitative capability, this approach advances the mechanistic understanding of radical-mediated processes and provides a versatile platform for studying transient reactive intermediates in water treatment and environmental redox systems.

549. 题目: Interconversion of Organic Carbon Transfer and Oxidative Mineralization in Fenton-Like System Triggered by Variable Curvature Supported Atomic Cobalt
文章编号: N26072601
期刊: Applied Catalysis B: Environment and Energy
作者: Hanxuan Zeng, Yibo Che, Taoyi Wang, Xinyi Hu, Xiaoyan Ma, Lin Deng, Shiqing Zhou, Haojie Zhang, Jing Deng
更新时间: 2026-07-26
摘要: This work demonstrates a convenient strategy for the interconversion of the organic carbon transfer process (OCTP) and oxidative mineralization process (OMP) in atomic cobalt mediated Fenton-like systems via flexible strain engineering. CoN1O2 active sites anchored on carbon nanospheres of varying curvatures were used to activate peroxymonosulfate (PMS) for the differentiated removal of phenol (PhOH). While over 80% of PhOH was removed in all systems, the low curvature catalyst recovered over 90% of PhOH as polymers, whereas the high curvature catalyst achieved efficient mineralization and avoided performance deterioration. Combined characterization and calculations reveal that strain-induced curvature regulates the catalytic mechanism by modulating both the geometric and electronic structures. Geometrically, co‑occupation of PhOH and PMS on the active sites promotes direct two‑electron transfer for OCTP, whereas mutually exclusive occupation generates singlet oxygen via single‑electron transfer for OMP. Electronically, the strong strain reduces the lowest unoccupied molecular orbital energy by weakening the ligand field strength, enhancing electron accessibility and driving the mechanistic transition. This work provides an experimental knob for regulating the carbon cycle in heterogeneous Fenton-like reactions, enabling tunable water purification for diverse application needs.

550. 题目: Sequential doping strategy for all-biomass derived N/P co-doped biochar: Unraveling the divergent capture mechanisms in antibiotic removal
文章编号: N26072517
期刊: Bioresource Technology
作者: Chengyu Li, Qihang Wang, Kunxiang Zhang, Hong He, Lvxin Peng, Jun Mu
更新时间: 2026-07-25
摘要: Biochar doping is widely applied for enhancing antibiotic removal from water, but most approaches still rely on synthetic chemicals and exhibit limited control over the incorporation of heteroatoms. Herein, a novel all biomass derived N/P-doped biochar (NP-CKBC) was fabricated from cork, chitin, and phytic acid via a sequential doping strategy for enhancing tetracycline (TC) and sulfamethoxazole (SMX) adsorption. The sequential doping utilized chitin-derived N to pre-stabilize the carbon skeleton, enabling subsequent phytic acid etching to form an interconnected porous network with ultra-thin walls and a high pore volume (1.16 cm3/g). Furthermore, this synergistic process simultaneously enhanced both graphitization and defect density, embedding abundant N/P active sites within the robust framework for efficient antibiotic capture. Driven by its hierarchical porous architecture and synergistically enriched N/P active sites, NP-CKBC achieved high adsorption capacities for TC (439.81 mg/g) and SMX (355.52 mg/g), rapid equilibrium kinetics (∼30 min), strong anti-interference ability, and superior continuous adsorption performance. Experimental characterizations and DFT calculations reveal that TC is captured via EDA and π-π interactions, whereas SMX is anchored through hydrogen bonding and electrostatic attraction. This work provides a sustainable strategy for preparing biochar from green biomass, offering a promising solution aimed at eliminating antibiotics within complicated aqueous systems.

551. 题目: Highly dispersed La on biochar-based self-support framework for rapid and selective phosphate removal: Performance and mechanism
文章编号: N26072516
期刊: Bioresource Technology
作者: Yicong Chen, Xu Yang, Shengfan Liao, Dong Xia, Xin He, Qingbiao Li, Yuanpeng Wang
更新时间: 2026-07-25
摘要: Metal-doped biochar is a promising phosphate adsorbent for mitigating phosphate-driven eutrophication and valorizing biomass, but its adsorption performance, selectivity and stability are strongly governed by the biochar-metal structure. Herein, the biochar was embedded into carbon nanofiber’ networks to construct a self-supporting biochar-carbon nanofiber framework (C-ACF). The C-ACF was first functionalized with an amine-rich HCCP-PEI polymer layer to obtain PCP@C-ACF, which was then used to anchor highly dispersed La species, yielding the performant La-loaded adsorbent PCP-La@C-ACF. Expectantly, PCP-La@C-ACF exhibited outstanding phosphate adsorption kinetics and selectivity, achieving phosphate uptake of 63.5 mg P·g−1 within 1 min (9.3-fold that of La(OH)3) and an equilibrium capacity of 93.9 mg P·g−1, along with broad pH tolerance and marked reusability. Under fixed-bed operation, PCP-La@C-ACF maintained the effluent phosphate concentration below 0.2 mg P·L−1 (removal rate > 99.4%). Owing to the loaded La species, markedly improved phosphate selectivity under high concentrations of Cl−, NO3–, and SO42− was achieved, with selectivity coefficients against NO3– and SO42− being 14- and 32-fold higher than La-free PCP@C-ACF. Molecular dynamics simulations rationalize that such dispersed La species enhance adsorption selectivity/rate by promoting phosphate dehydration and improving interfacial diffusion efficiency.

552. 题目: Effects of the co-application of biochar and trace elements on cadmium passivation and nitrogen biogeochemical processes in contaminated soil cultivated with soybean
文章编号: N26072515
期刊: Ecotoxicology and Environmental Safety
作者: Jin Ju Lee, Gyu Ri Kim, Ik-Young Choi, Prakash Basnet, Goontaek Lee
更新时间: 2026-07-25
摘要: Cadmium (Cd) contamination of soil poses food safety concerns through its bioaccumulation and by disrupting biological nitrogen (N) fixation; therefore, reducing productivity and altering microbial community structure. This study evaluated the co-application of biochar (BC) with molybdenum (Mo), iron (Fe), or sulfur (S) to regulate Cd accumulation, N fixation, nitrification, rhizosphere microbial communities, and plant physiological responses in Cd-contaminated soybean cultivation. The effects of BC co-application differed depending on the trace element supplied. Indeed, BC–Mo treatment increased rhizosphere porewater (hereafter, porewater) inorganic N concentrations, suggesting enhanced N mineralization and nitrification-related transformation, but was associated with increased plant Cd burden and stress responses. Furthermore, BC–Fe₂O₃ treatment maintained a nitrate (NO₃⁻)-dominant porewater N composition but reduced total inorganic N accumulation and did not recover nitrogenase activity. By contrast, BC–FeS₂ co-application was the only Cd-contaminated treatment that maintained nitrogenase activity at control-comparable levels. This treatment shifted porewater inorganic N composition toward the control, with a NO₃⁻/NO₂⁻ ratio of 2.39, closer to the control value of 1.82 than other BC-based treatments (3.65–7.11), and was associated with the lowest genus-level loss and retention of N-fixation- and nitrification-associated taxa. Phytohormone responses further suggest alleviated stress under BC–FeS₂ conditions. Overall, this treatment was the most effective treatment for simultaneously maintaining nitrogenase activity and porewater inorganic N balance under Cd-contaminated conditions. To conclude, BC–FeS₂ co-application may represent a potentially useful amendment approach for mitigating Cd risk while supporting N fixation and nitrification, although further validation under controlled-temperature or field conditions, including appropriate single-amendment controls, is needed.

553. 题目: Soil texture governs mineral-associated organic carbon, while temperature drives contrasting particulate carbon responses in maize and rice croplands
文章编号: N26072514
期刊: Agriculture, Ecosystems & Environment
作者: Shuaixiang Zhao, Susanne Schmidt, Yunting Fang, Zhi Quan, Jing Tian, Shuqi Qin, Feng Zhou
更新时间: 2026-07-25
摘要: Uncovering soil organic carbon (SOC) fractions and their controlling factors in croplands is critical for reversing soil degradation and mitigating climate change. However, such understanding remains limited for contrasting dryland and paddy systems, especially over large areas of farmer-managed fields. Here, we conducted a farmer survey across Northeast China, a region representing one quarter of China’s croplands, and collected 384 topsoil samples (0–20 cm) from maize and rice fields to discern patterns and drivers of mineral-associated and particulate organic carbon (MAOC and POC). In both systems, MAOC dominated the SOC pools, exceeding POC by 80% in maize (7.6 ± 2.5 vs. 4.2 ± 2.4 g C kg−1 soil) and by 66% in rice (8.3 ± 2.5 vs. 5.0 ± 1.9 g C kg−1 soil). Soil clay and silt contents showed the strongest positive associations with MAOC, explaining 43% and 32% of its variations in maize and rice soils, respectively. Clay and silt contents were also the primary determinants of POC in rice soils, explaining 23% of the variation. In contrast, mean annual temperature was the dominant factor controlling POC in maize soils, accounting for 35% of variation. Notably, POC declined with increasing temperature in maize soils but increased in rice soils, possibly attributable to contrasting balances between temperature-induced crop carbon inputs and microbially driven carbon losses. Overall, our findings reveal divergent controls on SOC fractions in dryland maize and paddy rice systems and provide a basis for developing crop-specific strategies to support climate-smart soil management in Northeast China.

554. 题目: Carbon source-driven anaerobic assimilation of dye-derived dissolved organic nitrogen: A low-carbon strategy with performance and mechanism insights.
文章编号: N26072513
期刊: Environmental Research
作者: Xumeng Lin, Huahan Huang, Ying Wu, Ling Xiong, Yang Meng, Faheem Ahmed Ghori, He Cui, Yinchuan Yang, Hong Chen, Gang Xue
更新时间: 2026-07-25
摘要: This study demonstrates that supplementing external carbon sources enables a sustainable anaerobic strategy for removing dye-derived dissolved organic nitrogen (DON). At a chemical oxygen demand/total nitrogen (COD/TN) ratio of 40 and an 8 h hydraulic retention time, a glucose-fed system achieved superior removal efficiencies (85.72% TN, 94.71% COD) compared to those of an acetate-fed system (51.68% TN, 90.20% COD). Mass balance showed that glucose facilitated greater assimilation of TN (85.65%) and total organic carbon (91.20%) into biomass than acetate (51.71% and 88.10%, respectively). Amino acid content increased by 44.17% in the glucose system versus 25.43% in the acetate system. Functional consortia (e.g., norank_Thermodesulfovibrionia, norank_Anaerolineae) were enriched in the glucose-fed system. Mechanistically, glucose metabolism activated the Embden-Meyerhof-Parnas pathway and the reductive tricarboxylic acid cycle, enhancing the supply of precursors (e.g., pyruvate) and energy (ATP, NADH) for protein biosynthesis, whereas acetate metabolism was limited in these aspects. These findings reveal a potential low-carbon DON removal mechanism that captures nitrogen into microbial protein, bypassing the energy-intensive gasification steps required in conventional treatment processes.

555. 题目: Nanoconfined humic acid-supported nZVI enhances imidacloprid remediation without compromising soil microbiome or exacerbating ARG health risks.
文章编号: N26072512
期刊: Environmental Research
作者: Na Li, Jiaming Yi, Lin Zhu, Du Chen, Meizhen Wang, Dan Huang
更新时间: 2026-07-25
摘要: Pesticide contamination of agricultural soils poses persistent risks to ecosystem function and agricultural sustainability, yet the application of reactive nanomaterials for remediation remains constrained by physicochemical instability and uncertain ecological consequences. Here, we synthesized a nanoconfined humic acid-supported nZVI composite (HA-nZVI) and evaluated its performance in imidacloprid (IMI)-contaminated soil through kinetic analysis, interfacial characterization, metagenomic sequencing, and dual-dimensional ARG risk assessment. HA nanoconfinement improved particle dispersion, increased active-site accessibility, and facilitated interfacial electron shuttling. These effects accelerated predominantly abiotic IMI dissipation, raising the degradation rate by 3.8-fold relative to the unamended control and shortening the half-life to 18.56 d. Despite the accelerated removal, dominant phylum-level abundances fluctuated by less than 3%, suppression of plant-beneficial bacteria (PBB) observed with pristine nZVI was alleviated, and no measurable increase in human- or livestock-associated ARG risk was detected among the 525 identified ARG subtypes. Collectively, these findings show that HA nanoconfinement can couple improved pesticide dissipation with microbiome compatibility and resistome safety, supporting the design of iron-based nanomaterials for sustainable agricultural remediation.

556. 题目: Biochar for mitigating the oxytetracycline stress of Nitrite-DAMO system: Microbial metabolic mechanisms and metagenomics research.
文章编号: N26072511
期刊: Environmental Research
作者: Juqing Lou, Jingxuan Chen, Yiru Zheng, Qi Su, Zihang Zhu, Jinhao Zhu
更新时间: 2026-07-25
摘要: Denitrifying anaerobic methane oxidation (DAMO) serves as a critical biogeochemical nexus linking the global carbon and nitrogen cycles to mitigate greenhouse gas emissions. However, ubiquitous antibiotics in DAMO habitats and wastewater systems presents a severe ecological threat, exacerbating methane emissions, nitrogen accumulation, and biotoxicity. Investigating mitigation strategies and mechanisms is essential for addressing these real-world environmental challenges. This study focused on the nitrite-dependent anaerobic methane oxidation (Nitrite-DAMO) system to investigate the comprehensive effects of biochar on denitrification performance and microbial metabolic characteristics under long-term oxytetracycline (OTC) stress (1 mg/L and 10 mg/L), along with the potential mechanisms. Results indicated that biochar significantly mitigated OTC toxicity and effectively enhanced both denitrification and methane oxidation performances. Average denitrification rates in biochar-amended groups reached 0.86 and 0.73 mg/(L·d), while the methane oxidation capacities increased to 2.27 and 1.76 times those of the non-biochar groups. Biochar established physicochemical barriers against antibiotic stress by stimulating extracellular polymeric substances (EPS) and enhancing electron transport system activity (ETSA). High-throughput sequencing and metagenomic analysis revealed that biochar drove microbial community succession, enriching functional bacteria (Candidatus Methylomirabilis and Thauera), while significantly upregulating the abundance of functional genes involved in nitrogen and carbon metabolism pathways (nirK, pmoA/B/C). Crucially, biochar suppressed the proliferation of potential hosts and disrupted transposons-mediated horizontal gene transfer (HGT), thereby substantially mitigating the accumulation and dissemination risks of antibiotic resistance genes (ARGs). The synergistic mitigation mechanisms elucidated herein provide theoretical guidance for in-situ regulation strategies to reduce methane emissions in antibiotic-contaminated wetlands, paddy fields, and river sediments.

557. 题目: Fe-functionalized sewage sludge biochar coupled with H2O2 for efficient antibiotic removal and potential pathogen reduction in wastewater.
文章编号: N26072510
期刊: Journal of Environmental Management
作者: Antonio Faggiano, Raffaella Sabatino, Oriana Motta, Francesco Di Nezio, Giulia Borgomaneiro, Antonio Proto, Valeria Comite, Paola Fermo, Gianluca Corno, Andrea Di Cesare, Antonino Fiorentino
更新时间: 2026-07-25
摘要: The overuse and misuse of antibiotics have led to their increasing release into aquatic ecosystems, promoting the selection and spread of antibiotic-resistant bacteria and potentially pathogenic microorganisms. In this study, biochars derived from sewage sludge and spent coffee grounds were produced, functionalized with iron, and coupled with H2O2 for the treatment of real municipal wastewater containing levofloxacin, doxycycline, and ampicillin. Response Surface Methodology identified sewage sludge biochar produced at 650 °C as the most effective material, and the optimized heterogeneous oxidation conditions were 30 g L-1 Fe-SSBC650 and 120 mg L-1 H2O2. Under these conditions, the Fe-SSBC650/H2O2 system achieved near-complete removal of the selected parent antibiotics after 60 min, with Ct/C0 decreasing to 0.03 ± 0.02, corresponding to approximately 97% removal. In the validation experiment, antibiotic concentrations followed the trend UW > WP > FeBC > BP, with the BP treatment achieving >99% abatement of the target compounds. The optimized treatment also strongly affected bacterial community composition and significantly reduced the relative abundance of potentially pathogenic bacteria compared with untreated wastewater and control treatments. Conversely, antibiotic resistance genes and class 1 integrons showed inconsistent responses, indicating that parent-antibiotic removal did not necessarily correspond to a parallel reduction in antibiotic resistance markers. These findings indicate that Fe-functionalized sewage-sludge-derived biochar coupled with H2O2 is a promising preliminary platform for parent-antibiotic removal and bacterial community modulation in real wastewater, while further optimization is required to improve catalyst management, assess transformation products, and address antibiotic resistance mitigation.

558. 题目: Variability in site-specific pyrethroid KOC and KDOC partition coefficients and implications for predicted aquatic toxicity.
文章编号: N26072509
期刊: Environmental Toxicology and Chemistry
作者: Berkley N Anderson, Thomas M Young
更新时间: 2026-07-25
摘要: The equilibrium partitioning methodology has been used to estimate the bioavailable or freely dissolved concentrations (Cfree) of pyrethroid insecticides in both sediments and the water column of aquatic systems. Typically, single default values for the organic carbon-water (KOC) and dissolved organic carbon-water (KDOC) partition coefficients are used to estimate the bioavailability of a given pyrethroid across sample sites. However, sorption capacities can vary across samples due to the varying quality of organic carbon among other factors. In this study, KOC and KDOC coefficients were experimentally measured for 6 pyrethroids (bifenthrin, cyfluthrin, cypermethrin, esfenvalerate, lambda-cyhalothrin, and permethrin) in 19 streambed sediment samples collected across California, USA. The purpose of this study was to examine the variability of site-specific coefficients, compare site-specific with established default coefficients, and use statewide sediment/water chemistry and Hyalella azteca toxicity testing data to assess the variability in predicted pyrethroid toxic units and organism survival. Across all pyrethroids tested, measured site-specific log KOC values ranged from 5.32 to 7.11 and log KDOC values ranged from 5.28 to 7.41. Toxic units estimated using site-specific coefficients and default coefficients derived from the geometric means of measured values, explained a comparable amount of the variance in reported H. azteca survival and closely aligned with 50% organism survival. We recommend the use of the default coefficients derived from this study, which are reflective of 19 unique sediment samples. However, the uncertainties associated with site-specific considerations should be acknowledged.

559. 题目: Divergent controls on particulate and mineral-associated organic carbon in tropical forests of southern China
文章编号: N26072508
期刊: Plant and Soil
作者: Dong Qiao, Licong Dai, Meihua Yang, Yue Jiao, Qiaoyan Chen, Rong Shang, Zhongmin Hu
更新时间: 2026-07-25
摘要: Background and Aims Particulate organic carbon (POC) and mineral-associated organic carbon (MAOC) are functionally distinct SOC fractions with different formation pathways and environmental controls, yet their dominant drivers in tropical forests remain poorly understood. This study aimed to quantify their spatial variability and determine how forest succession, soil nutrient status, and physicochemical properties are associated with these fractions in tropical natural forests on Hainan Island, southern China. Methods We combined field surveys of 40 plots spanning a forest successional gradient with multi-source environmental data to assess relationships of POC and MAOC with forest succession, climate, topography, and soil physicochemical properties. Results Soil total phosphorus (TP) was the strongest predictor of MAOC, explaining about 31.4% of its variation. In contrast, clay content (5%–51%) showed relatively weak association with MAOC despite substantial variation in soil texture among sites. By comparison, soil total nitrogen (TN) contributed most to POC variation (35.2%), followed by forest age (19.9%); POC increased significantly along the successional gradient. Conclusion POC and MAOC exhibited contrasting environmental associations in tropical natural forests. TN was the strongest predictor of POC, followed by forest age, suggesting that forest succession may influence POC through coordinated changes in vegetation-derived carbon inputs and soil nitrogen accumulation. In contrast, MAOC was most strongly associated with TP, while clay content and forest succession showed weak relationships, indicating that soil phosphorus status better explains MAOC variability than particle-size composition or successional development in strongly weathered tropical soils.

560. 题目: Biochar modulates methanotrophic metabolism to enhance methane oxidation and mitigate greenhouse gas emissions
文章编号: N26072507
期刊: Bioresource Technology
作者: Qinqin Hao, Jia Tang, Peng Zhang, Oumei Wang, Fanghua Liu
更新时间: 2026-07-25
摘要: Methanotrophs represent the major biological sink for methane, yet the direct effects of biochar on methanotrophic metabolism remain unclear. This study investigated how biochars produced at different pyrolysis temperatures influence methane oxidation activity, metabolite production, and metabolic pathways in a methanotrophic pure culture and validated the effects in wetland soil microcosms. Biochar amendment enhanced methane consumption, with 400 °C biochar showing the strongest effect and increasing the methane oxidation rate by 25%, likely due to its greater retention of redox-active surface functional groups. Moreover, 400 °C biochar reduced formate accumulation and promoted biomass synthesis, suggesting improved downstream processing and assimilation of methane-derived carbon. Transcriptomic analysis showed upregulation of rsxG/rnfG and rnfD by 4.73- and 3.99-fold, respectively, together with increased multiheme c-type cytochrome expression (2.15-fold), suggesting improved redox regulation during rapid methane oxidation. Biochar was most effective at 0.2 g L−1, reducing inhibition caused by carbon dioxide accumulation. In wetland soil slurries, 400 °C biochar enhanced methane mitigation and reduced carbon dioxide production, accompanied by increased relative abundances of methanotroph-related and putative carbon-fixing bacterial taxa. These findings provide new mechanistic insights into biochar-mediated regulation of microbial methane oxidation and highlight its potential as a promising amendment for mitigating methane emissions in wetland ecosystems.