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81. 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.

82. 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.

83. 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.

84. 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.

85. 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.

86. 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.

87. 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.

88. 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.

89. 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.

90. 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.

91. 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.

92. 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.

93. 题目: Agricultural management reshaped topsoil organic carbon dynamics across diverse crop rotation systems in China
文章编号: N26072506
期刊: Soil and Tillage Research
作者: Yue Pu, Lin Yang, Wenkai Cui, Xiang Li, Feixue Shen, Chenghu Zhou
更新时间: 2026-07-25
摘要: Agricultural intensification has profoundly transformed soil organic carbon (SOC) dynamics in China, yet the mechanisms driven by management and environmental factors remain poorly understood across rotation systems. Leveraging national soil profile datasets from the 1980s and 2010s and a pseudo soil sample pairing approach, we quantified the spatiotemporal variations of topsoil SOC and disentangled the role of management dynamics versus natural controls via interpretable machine learning. Topsoil SOC increased by a median of 2.5 g kg−1 over three decades. Spatially, fertilizer N input and straw C input demonstrated negative relationships with SOC, suggesting long-term negative effects under N-replete conditions coupled with patterns of prioritized historical fertilization in low-C soils. These negative associations appeared weaker in more intensive rotation systems where positive interactions between rotation and N fertilization were observed. Temporally, however, increased fertilizer N input were strongly associated with SOC accumulation, especially in soils with low initial SOC and straw C input. Notably, we identified a threshold of ∼15 g N m−2 yr−1, beyond which the marginal benefit of further N input increase for C sequestration weakened. Our results highlight the dominance of management intensity in reshaping SOC dynamics from non-experimental evidence, underscore the need to incorporate management dynamics into global C cycling modeling.

94. 题目: Development of Novel Bacteria Immobilized Pistachio Shell Biochar for the Removal of Phenol and Dye From Wastewater
文章编号: N26072505
期刊: Clean - Soil Air Water
作者: Prapthi Subhas Mally, Thrisha Alva, Nandini Ibbedu Vedamurthy, Vaishakh Nair
更新时间: 2026-07-25
摘要: This study explores the application of Pseudomonas putida immobilized on pistachio shell biochar (PSB) for the removal of phenol and malachite green (MG) dye from artificially polluted water. The PSB was prepared via pyrolysis at 300°C, 450°C, and 600°C and characterized to determine its suitability as a microbial carrier. The PSB prepared at 450°C exhibited optimal surface properties for bacterial immobilization. The P. putida immobilized PSB (IPSB) was used for the removal of phenol and MG dye via both adsorption and microbial degradation. The maximum removal efficiencies were 84.12% for 75 mg/L concentration of phenol at a pH of 6 after 24 h and 99.35% for 200 mg/L concentration of MG dye at a pH of 8 after 4 h of reaction with an IPSB dosage of 0.5 g/L. Reusability tests demonstrated that IPSB performance reduced to 61.32% for phenol removal and 76.97% for MG dye after five successive cycles. Mechanistic analysis revealed a synergistic removal process involving adsorption by PSB and microbial degradation by P. putida . The findings suggest that IPSB offers a sustainable and effective approach for treating phenol‐ and MG dye–contaminated water.

95. 题目: Chromatography Coupled to High-Resolution Mass Spectrometry Analysis Reveals Flaws in van Krevelen Compound Class Assignments in DOM
文章编号: N26072504
期刊: Environmental Science & Technology
作者: Maria G Digernes, Alexander J Craig, Tsz Yung Patrick Wong, Erik Bergström, Murat V Ardelan, Jeffrey A Hawkes
更新时间: 2026-07-25
摘要: High-resolution mass spectrometry (HRMS) is a powerful tool for determining molecular formulas in dissolved organic matter (DOM). In the biogeochemical field, it is common to assign DOM molecular formulas to prospective chemical classes based on elemental ratios alone, with these classes based on known biomolecules or empirical classifications (e.g., carboxyl-rich alicyclic molecules). However, accurate identification of molecular origin remains challenging due to DOM’s extreme isomeric diversity and the inability of HRMS to provide information about chemical connectivity, calling into question the accuracy of assignment or quantification. To address the lack of chemical connectivity gained from HRMS alone, we used liquid chromatography-HRMS to determine whether retention behavior is consistent with biochemical class assignment. Problematically, all examined classes displayed very broad retention profiles, indicating diversity of chemical functionality within their defined elemental ratios. Furthermore, retention behavior matched poorly with known biochemical class hydrophobicity data, particularly for “carbohydrates” and “peptides”. Additionally, differences in retention profiles of various compound classes and molecular formulas between terrestrial and marine samples show that molecular formulas are constituted by different groups of isomers between environments. We recommend an overhaul of standard practice in the use of HRMS data for biogeochemical investigation of DOM, relying less on assignment to prospective classes and more on chemical understanding, which can be developed through the implementation of chromatography and tandem MS methods using modern equipment and workflows.

96. 题目: Greenland Emissions Contribute to Black Carbon Aerosols in the Arctic Marine Boundary Layer
文章编号: N26072503
期刊: Environmental Science & Technology
作者: Xiaomi Teng, Mao Du, Congbo Song, Yuqing Dai, Vipul Lal Chandani, David C S Beddows, Manuel Dall’Osto, Darrel Baumgardner, Roy M Harrison, James Brean, Mingxi Yang, Yangmei Zhang, Weijun Li, Zongbo Shi
更新时间: 2026-07-25
摘要: Black carbon (BC) is an important short-lived climate forcer that contributes to Arctic warming, yet observations of BC in the Arctic marine boundary layer remain sparse. Here, we report shipborne measurements of refractory BC (rBC) mass and particle mixing state during a cruise from southeast to west Greenland in May–June 2022. Using a single-particle soot photometer (SP2XR) and transmission electron microscopy (TEM), we characterize both rBC concentrations and individual-particle morphology, representing one of the first ship-based SP2XR data sets in the Arctic marine boundary layer. rBC concentrations were highest in the Greenland coastal region (2.4 ng m–3), compared with the open ocean (1.7 ng m–3) and the marginal ice zone (0.6 ng m–3). Mixing-state analysis shows that 54% of soot particles in coastal air masses were externally mixed, consistent with relatively fresh emissions, whereas most soot particles over the open sea and sea-ice regions were internally mixed, indicative of aged, transported aerosol. FLEXPART modeling suggests BC enhancements along the Greenland coast. Our data indicate that Greenland acts as a regional source of BC to the Arctic marine boundary layer in late spring and early summer, when midlatitude transport is weak.

97. 题目: Significant contribution of petrogenic organic carbon to suspended particulate organic carbon in the Beaufort Sea
文章编号: N26072502
期刊: Limnology and Oceanography
作者: Dahae Kim, Jung‐Hyun Kim, Sujin Kang, Yeon‐Sik Bong, Kyung‐Hoon Shin
更新时间: 2026-07-25
摘要: Remobilized terrestrial organic carbon from permafrost‐affected landscapes is increasingly recognized as a key component of Arctic carbon cycling. In this study, we investigated the sources of particulate organic carbon in the surface mixed layers across the Mackenzie Trough by combining dual‐isotope analyses (Δ 14 C org , δ 13 C org ) with molecular biomarkers (lignin phenols). Building on previous sediment‐based source apportionment approaches, we assessed their applicability to suspended particulate matter collected along a shelf‐to‐slope transect in the Canadian Beaufort Sea. To address uncertainties in end‐member composition, we implemented a Monte Carlo‐based mixing model that integrates multiple geochemical tracers, including Δ 14 C org , δ 13 C org , 3,5‐dihydroxybenzoic acid to vanillyl phenols (3,5‐Bd/V) ratio, and lignin phenol concentrations. Our results showed that petrogenic organic carbon contributed substantially, ranging from 11% to 53%, to particulate organic carbon in both the upper and lower polar mixed layers. These findings provide direct evidence for the presence of petrogenic organic carbon in Arctic surface waters and highlight its active role in shelf carbon dynamics. The persistence of this ancient, refractory carbon pool in suspension emphasizes the need to include petrogenic organic carbon in assessments of terrestrial carbon mobilization, transformation, and burial in a rapidly warming Arctic.

98. 题目: Long‐Term Combined Application of Biochar and Chemical Fertilizers Enhances Potassium Supply Capacity in Continuous Cropping Soils
文章编号: N26072501
期刊: Land Degradation & Development
作者: Hangming Guo, Shunguo Liu, Zefang Zhu, Kangbo Xu, Jing Wang, Wenda Wang, Na Li, Jinfeng Yang
更新时间: 2026-07-25
摘要: Sustaining soil potassium (K) supply in intensive continuous cropping systems is increasingly challenging because long‐term crop removal often exceeds the natural replenishment capacity of soil K‐bearing minerals, leading to progressive depletion of plant‐available K pools. Biochar has been proposed as a promising amendment for improving soil nutrient retention and K cycling, yet its long‐term effects on the mineralogical and kinetic mechanisms regulating soil K supply remain poorly understood. Here we report a 9‐year field experiment in a continuous maize monoculture on brown soil, comparing biochar applied alone (C) or coapplied with fertilizer (CNPK) against fertilizer alone (NPK) and an unfertilized control. Relative to sole application of fertilizer, CNPK increased maize K uptake and grain yield by 35.9% and 7.7%, respectively. Compared with NPK, CNPK enhanced water‐soluble, exchangeable, and nonexchangeable K by 147.2%, 28.6%, and 6.0%, respectively. Mechanistically, x‐ray diffraction analysis of the < 2 μm clay fraction revealed a 4.8 percentage‐point increase in illite abundance under CNPK relative to NPK, accompanied by K redistribution from edge sites (e‐sites; −0.8%) to more readily releasable planar sites (p‐sites; +1.6%). Kinetic modeling with organic‐acid extractants demonstrated that CNPK enhanced both cumulative K release and apparent rate constants in fast and slow phases, indicating improved K bioavailability. These coupled mineralogical and kinetic effects strengthen the intensity, capacity, and potential of soil K supply, enabling more efficient long‐term K use. Our findings suggest that biochar‐fertilizer coapplication represents a viable strategy for enhancing K availability in intensive maize systems, with future research needed to optimize biochar characteristics and application protocols across diverse pedoclimatic conditions.

99. 题目: Biochars derived from different biomasses activate peroxymonosulfate to degrade metformin: Surface complexation mediates electron transfer to generate 1O2
文章编号: N26072116
期刊: Chemical Engineering Journal
作者: Wenxiong Wu, Baowei Zhao, Zichao Qu, Ke Yang, Biwen Wang, Xiaohu Liang, Yin Zhang
更新时间: 2026-07-21
摘要: Metformin has been present in aquatic environments due to widespread use and the incomplete removal in water treatment plants, posing potential risks. Most studies have focused on activating persulfate (PS) with a single biochar (BC) modified in different ways to construct advanced oxidation processes (AOPs), while neglecting the variations in catalytic efficiency and mechanisms among BCs derived from different biomasses sources. Therefore, in this study, BCs prepared at 700 °C from corn straw, walnut shells, and cow manure were selected as representative materials to activate PS for MET degradation. Different reaction conditions and influencing factors were investigated, and the dominant reactive species, active sites, and degradation pathways were explored. The experiments showed that in the CSB700, WSB700, and CMB700/PMS systems, 88.5%, 91.6%, and 83.9% of MET were degraded within 11 min, respectively. Non-radical pathways (singlet oxygen and electron transfer) and surface-bound radicals on BCs played the dominant roles in MET degradation. The Cdouble bondO bonds and defect structures on the surface of BCs served as the main reactive sites. DFT calculations revealed that MET is prone to radical-induced electron transfer oxidation at the methyl group, while the C and N atoms are susceptible to nucleophilic reactions. In addition, WSB700 exhibited abundant pore structures, a high degree of graphitization, high Cdouble bondO content, and high capacitance and electron transfer rates, resulting in its better PS activation performance than CSB700 and CMB700. This study provides a theoretical basis for the selection of catalysts (WSB700) in PS-AOPs for the degradation of water plant wastewater.

100. 题目: Molecular characterization and chlorination reactivity of microplastics-derived dissolved organic matter revealed by ultrahigh-resolution mass spectrometry and machine learning
文章编号: N26072115
期刊: Chemical Engineering Journal
作者: Yizhi Pei, Kongyan Luo, Junmin Gao, Kaifeng Rao, Yiping Xu, Haifeng Zhang, Mei Ma
更新时间: 2026-07-21
摘要: Microplastics-derived dissolved organic matter (MPs-DOM) comprises a chemically heterogeneous pool of dissolved organic compounds released during the environmental degradation of microplastics. Despite growing interest in the environmental implications of MPs-DOM, its molecular composition and reactivity are still poorly characterized. In this study, Fourier-transform ion cyclotron resonance mass spectrometry (FT-ICR MS) was employed to characterize MPs-DOM released from polystyrene (PS), polyamide (PA), and poly(butylene adipate-co-terephthalate) (PBAT), as well as their transformation products formed during chlorination, and a reactivity prediction model was developed based on reaction networks. The results showed that all microplastics released MPs-DOM under dark conditions, while UV irradiation altered MPs surface functional groups and the molecular composition of the released MPs-DOM, leading to differences in chlorination reactivity between the dark and UV conditions. CHO dominated DOM derived from PS and PBAT, whereas PA-DOM was relatively enriched in CHNO compounds, indicating that MPs-DOM exhibited high molecular complexity and source dependent characteristics. Both aging and chlorination induced pronounced molecular transformations, leading to a significant increase in O/C ratios. The reaction network analysis linked 111 chlorine-containing DBP molecules to 127 precursors, including 122 polymer-specific precursors, with 63, 23, and 35 detected in PS, PA, and PBAT, respectively. A machine learning model based on extreme gradient boosting (XGBoost) successfully identified double bond equivalent (DBE) and nominal oxidation state of carbon (NOSC) as the primary molecular features associated with highly reactive MPs-DOM, achieving an overall prediction accuracy of 73.53%. This work provides a molecular-level understanding of the composition, formation mechanisms, and chlorination behavior of MPs-DOM, improving our understanding of the environmental behavior and potential risks associated with MPs-DOM.