论文检索

总访问量：6512597次

总访客量：603381人

所有论文

61. 题目: Microbial extracellular residues are a major source of mineral-associated soil carbon
文章编号: N26101207
期刊: Nature Geoscience
作者: Peipei Qian, Yichao Wu, Jingyi Ren, Xiaoyu Cheng, Zhijun Liu, Caroline L Peacock, Chao Liang, Xuefeng Zhu, Xiaojuan Feng, Marc A Redmile-Gordon, Xianjin He, Ke-Qing Xiao, Yong-Guan Zhu, Ming Zhang, Ke Dai, Chunhui Gao, Chenchen Qu, Yu-Rong Liu, Wenfeng Tan, Qiaoyun Huang, Peng Cai
更新时间: 2026-10-12
摘要: Soil microbes play a crucial role in soil organic carbon storage by processing plant-derived carbon and producing microbial carbon, which can accumulate over time and form a substantial fraction of the soil organic carbon stock. Whereas the contribution of microbial cellular residues, the remains of dead microbial cells, to soil carbon storage is well established, the role of extracellular residues remains poorly quantified. Here we develop an 18O-H2O isotope-tracing method to quantify the production of extracellular polymeric substances, mucus-like mixtures of sugars, proteins and other biopolymers released by microbes and apply it across a national-scale survey of cropland soils in China. We find that extracellular polymeric substances constitute a major microbial carbon input to soils, with production rates comparable to those of microbial cellular residues and they exhibit statistical associations with mineral-associated organic carbon across soils. In 13C-labelling microcosm experiments, carbon derived from extracellular polymeric substances is incorporated into the mineral-associated organic carbon pool at rates comparable to or exceeding those of microbial cellular residues. These results identify the extracellular pathway as an important and previously underappreciated mechanism contributing to the mineral-associated carbon pool and provide mechanistic insights into how microbiomes shape the fate of soil carbon under global change.

62. 题目: Rapid disinfection byproduct formation from microplastics-derived dissolved organic matter during short-term chlorination: Polymer-dependent pathways
文章编号: N26101206
期刊: Journal of Hazardous Materials
作者: Tengfei Li, Jingqi Xu, Rui Li, Menglei Zhao, Jianchao Zhang, Xingli Zhang, Wei Zou, Tiecheng Wang
更新时间: 2026-10-12
摘要: Microplastics-derived dissolved organic matter (MPs-DOM) has emerged as a potential precursor of disinfection byproducts (DBPs), yet its behavior under realistic short-term chlorination remains poorly understood. Here, we investigated the formation patterns of both conventional and unknown DBPs from polystyrene (PS) and polyethylene terephthalate (PET) leachates under short contact times, combining bulk DBP analysis with Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS). Abundant traditional DBPs were formed rapidly, with trihalomethanes (THMs) as the dominant species. In comparison, PS-DOM showed higher chlorine consumption but PET-DOM produced higher DBP yields and a broader spectrum of species, accounting for 14.63 µg/mg DOC of total 15 DBPs subtypes versus 8.56 µg/mg DOC of total 12 DBPs subtypes for 60 min. For unknown DBPs, molecular-level analysis revealed that PET-DOM generated a more diverse pool of DBPs enriched in oxidized compounds, whereas DBPs derived from PS-DOM were relatively more unsaturated and aromatic-like. Further analysis reflect distinct transformation for two DOM during chlorination. PS-DOM underwent decarbonization, and mono-halogenation dominated its DBP formation. In contrast, PET-DOM exhibited oxidation transformation, with mono- and multi-halogenation contributing comparably to DBP formation. These findings demonstrate that DBP formation from MPs-DOM is highly dependent on polymer structure and can occur rapidly under short-term chlorination. And the elevated DBP formation potential of PET-DOM highlights a greater risk of PET MPs in aquatic environments.

63. 题目: Multifunctional potential of Bacillus vallismortis C-305 for cyanobacterial bloom suppression: Algicidal activity, organic matter transformation, and plant stress mitigation
文章编号: N26101205
期刊: Environmental Research
作者: Lei Chen, Edidiong Okokon Atakpa, Yukun Wu, Lei Wu, Jin Li, Hongfu Wei, Xingxu Chen, Yu Qin, Bainiang Zhang, Peng An, Shirou Cao, Xiaowei Chen, Xingchen Li, Faqin Dong, Lei Zhou, Amal Mohamed Omer, Xiaoyu Liu, Ying Han
更新时间: 2026-10-12
摘要: Harmful algal blooms (HABs), particularly those caused by Microcystis aeruginosa, pose severe threats to aquatic ecosystems and agricultural irrigation safety. Biological control using algicidal bacteria offers an environmentally sustainable alternative to conventional mitigation strategies. In this study, a highly efficient algicidal bacterium, Bacillus vallismortis strain C-305, was isolated and evaluated for its inhibitory activity against M. aeruginosa. Strain C-305 exhibited strong algicidal activity and was accompanied by significant alterations in algal cellular integrity and extracellular organic matter (EOM) fluorescence characteristics. Metabolite analysis identified extracellular compounds, including erucamide, with demonstrated inhibitory activity against M. aeruginosa. Furthermore, immobilization of C-305 in sugarcane bagasse–alginate beads improved its applicability in a rice cultivation system exposed to algal-contaminated water, resulting in enhanced plant growth performance and alleviated oxidative stress responses compared with untreated conditions. These findings demonstrate the potential of B. vallismortis C-305 as a multifunctional biological agent, integrating algicidal activity, organic matter transformation, and plant-associated benefits within a microbial-based strategy for HAB management.

64. 题目: Hydrological Regime Controls DOM and WEOM Dynamics in Contrasting Mid-channel Bars: Insights from the Middle Yangtze River
文章编号: N26101204
期刊: Water Research
作者: Haoyang Shi, Cheng Chen, Linxu Song, Yu Hu, Man Hu, Ting Li, Chengcheng Bao, Xinxin Zhu, Anli Zhang, Huiqun Cao, Hui Guo, Wenjun Yang
更新时间: 2026-10-12
摘要: Riverine sandbars are critical ecological units within rivers, yet their biogeochemical responses to dam-regulated hydrological regimes remain poorly understood. This study investigated the divergent dynamics of dissolved organic matter (DOM) and its sediment-bound counterpart, water-extractable organic matter (WEOM), in two geomorphologically contrasting mid-channel bars—Sanba Sandbar (SBS) and Wugui Sandbar (WGS)—in the middle Yangtze River across four hydrological periods. By integrating three-dimensional fluorescence spectroscopy, UV–vis absorption spectroscopy, and partial least squares structural equation modeling (PLS-SEM), we revealed their distinct functional roles. The results showed that the frequently inundated sandbar (SBS) exhibited high sensitivity to hydrological pulses. Its DOM characteristics were cyclically “reset” by the flood peak and subsequently shifted rapidly toward autochthonous sources stimulated by flood-driven nutrient pulses, reflecting a weak biogeochemical “memory.” In stark contrast, the relatively stable, vegetated sandbar (WGS) displayed strong biogeochemical resilience. Its response may have been primarily internally mediated, buffering hydrological disturbance and potentially triggering a pronounced “first flush” of stored terrestrial organic matter upon initial inundation, thereby functioning as a biogeochemical processor with a strong “memory.” PLS-SEM analysis indicated that at SBS, inundation extent was a direct external driver, whereas at WGS, increased inundation extent may have indirectly regulated organic matter dynamics by altering internal sediment physicochemical conditions. These findings suggest that the hydrological regime is a key driver of DOM and WEOM dynamics in sandbars, while the geomorphic characteristics of sandbars modulate the magnitude of this response. The contrasting behaviors between SBS and WGS provide new insights into the spatiotemporal dynamics of organic matter in large alluvial rivers.

65. 题目: Anthropogenic activities dominate dissolved organic matter dynamics via direct rather than nutrient-mediated pathways in a karst river
文章编号: N26101203
期刊: Journal of Hydrology
作者: Yuekai Ding, Jing Zhang, Rui Liu, Maofei Ni, Weihua Yuan
更新时间: 2026-10-12
摘要: As a major reactive carbon pool in aquatic ecosystems, dissolved organic matter (DOM) is highly sensitive to anthropogenic disturbances. However, the specific anthropogenic pathways regulating DOM dynamics remain poorly constrained, particularly in environmentally sensitive karst river systems. Here, we combined optical characterization with partial least squares path modeling to disentangle the seasonal linkages between anthropogenic activities and riverine DOM dynamics. We show that anthropogenic activities influenced DOM primarily through direct inputs, deviating from the nutrient-mediated pathways commonly reported in non-karst rivers. This dominance persisted across seasons despite substantial variability in nutrient conditions. Notably, population was associated with increased DOC and enhanced DOM humification, whereas mines were associated with DOC and chromophoric DOM enrichment, revealing that anthropogenic organic carbon in karst rivers may be propagated primarily through transport rather than nutrient-driven transformation. Building on this pattern, we propose a conceptual segmented DOM accumulation–consumption framework, in which direct anthropogenic inputs favor DOM preservation and accumulation, whereas stronger nutrient-mediated regulation promotes DOM transformation and consumption. Our findings highlight that anthropogenic activities should be explicitly considered as key regulators of carbon fate in karst river systems.

66. 题目: Radiocarbon and molecular constraints on the sources and fates of dissolved organic matter in the Bohai Sea
文章编号: N26101202
期刊: Water Research
作者: Yeongjin Ryu, Zhenwei Yan, Yuanbi Yi, Julian P Sachs, Zhao Liang Chen, Si-Liang Li, Sheng Xu, Ding He
更新时间: 2026-10-12
摘要: The ocean contains a reservoir of dissolved organic matter (DOM) comparable to the atmospheric carbon pool, yet molecular characterization remains challenging owing to its chemical complexity. We measured the radiocarbon content (Δ14C) of solid-phase extracted DOM (SPE-DOM) from the Bohai Sea with Fourier-transform ion cyclotron resonance mass spectrometry (FT-ICR-MS). Bulk dissolved organic carbon concentrations and SPE-DOM Δ14C gradients indicated pre-aged terrestrial carbon inputs near the Yellow River mouth, with molecular shifts reflecting both physical mixing and localized biogeochemical processes. Covariance between individual formula intensities and Δ14C values provided the basis for classifying the DOM pool into two regimes. Negatively correlated formulas (8–14% of total intensity) were highly oxidized and low-molecular-weight, with an apparent Δ14C value of −751 ± 181‰ (corresponding to ∼3,000–35,000 yr BP with 95% confidence interval), suggesting pre-aged terrestrial or sediment-associated carbon as important sources. Conversely, positively correlated formulas (14–23% of total intensity) were less oxidized and higher-molecular-weight, with an apparent Δ14C value of −74 ± 100‰. Their partial overlap (approximately 44%) with known terrestrial formulas indicates mixed autochthonous and terrestrial sources. Comparison with the Yangtze River Estuary and a global open-ocean dataset demonstrated that the same molecular formulas can be associated with DOM having a wide range of radiocarbon ages and environmental histories. Only 20% of negatively correlated formulas were widely distributed globally, whereas 60% of positively correlated formulas were detected at all depths throughout the Atlantic and Pacific Oceans, overlapping with known terrestrial formulas. This divergence underscores that terrigenous organic matter exhibits highly variable reactivity depending on its molecular characteristics and sources.

67. 题目: Photochemical Aging of Atmospheric Black Carbon Promotes Nitrate Coating in a Chinese Megacity
文章编号: N26101201
期刊: Geophysical Research Letters
作者: Yonghong Wang, Yiqun Cao, Zixiao Wu, Shuying Li, Zhanyu Su, Peng Zhang, Quan Liu, Jun Liu, Tianzeng Chen, Hao Li, Xinghua Zhang, Biwu Chu, Qingxin Ma, Yujing Mu, Guangzhi He, Hong He
更新时间: 2026-10-12
摘要: Black carbon (BC) aerosol critically influences climate and haze, yet the mechanisms driving its coating and light absorption enhancement remain poorly understood. Here, we show that BC in Beijing is coated by ammonium nitrate via photochemistry. Laboratory experiments, quantum calculations, and machine learning reveal a new pathway: hydroxyl groups on photoaged BC surfaces promote nitric acid formation in the presence of NO 2 , which then neutralizes with ammonia to produce ammonium nitrate. Mie simulations demonstrate that this coating drives enhanced light absorption alongside haze intensification. Our findings bridge a key gap between laboratory studies and field observations, elucidating the aging and coating mechanisms of BC in a typical megacity.

68. 题目: Response of anaerobic digestion of nitrogen-rich substrates to Fe/N co-modified biochar: Process performance, Microbial communities and Key metabolic pathways
文章编号: N26101116
期刊: Journal of Environmental Chemical Engineering
作者: Lu Di, Xiaofeng Ji, Guanghe Lu, Keyi Li, Deli Zhang, Weiming Yi, Fuli Yang, Fang Wang
更新时间: 2026-10-11
摘要: Ammonia inhibition, microbial community imbalance, and low methane yield are major challenges in anaerobic digestion (AD) of nitrogen-rich substrates. In this study, nitrogen-modified biochar (NBC), Fe-modified biochar (Fe3O4@BC), and Fe/N co-modified biochar (Fe3O4@NBC) were applied to the AD of chicken manure to investigate the regulatory mechanisms on methane production and microbial metabolic networks. The results showed that Fe3O4@NBC synergistically enhanced hydrolysis-acidogenesis and syntrophic acetate oxidation (SAO) through porous structural optimization and electron transfer enhancement. Fe3O4@NBC markedly enriched SAO-associated bacteria, particularly Alkaliphilus and norank_Christensenellaceae, with relative abundance increases of 51.71% and 42.04%, respectively. The predicted relative abundances of genes encoding hexokinase and polyphosphate glucokinase increased by 82.35% and 108.49%, respectively, suggesting enhanced potential for glucose phosphorylation. The increased predicted abundances of key genes involved in the Wood-Ljungdahl pathway, together with the enrichment of SAO bacteria, suggested that the SAO-hydrogenotrophic methanogenesis (SAO-HM) pathway was enhanced. The enrichment of Methanosarcina and the enhanced electron-transfer properties of Fe3O4@NBC further suggested that direct interspecies electron transfer (DIET) contributed to methane production under high-ammonia conditions. Overall, Fe3O4@NBC enhanced methane production by synergistically promoting organic matter degradation, SAO metabolism, and DIET, thereby effectively alleviating ammonia inhibition in the AD system.

69. 题目: Biochar supported iron sulfide to activate persulfate for rapid 1,4-dithiane/1,4-thioxane oxidation and functional potential shifts in soil
文章编号: N26101115
期刊: Journal of Environmental Chemical Engineering
作者: Lihong Xie, Pengfei Guo, Xiaohui Wang, Yongbing Zhu, Tingting Zhang
更新时间: 2026-10-11
摘要: Corrosion of buried chemical munitions in landfills expedites sulfur mustard release, whose sequential transformation yields the refractory 1,4-dithiane and 1,4-thioxane, posing a critical and unresolved risk to soil. Here, we synthesized a biochar-supported sulfur-vacancy-rich iron sulfide catalyst (FeSx/BC) and applied it to activate peroxydisulfate (PDS) for generating reactive oxygen species to degrade 1,4-dithiane and 1,4-thioxane in soil. At an application dosage of 0.75% (w/w) of both FeSx/BC and PDS, the system removed 99.4% and 98.2% of 1,4-dithiane and 1,4-thioxane within 120 min, respectively. Meanwhile, the application of FeSx/BC+PDS enriched putative degraders of 1,4-dithiane and 1,4-thioxane, such as Nocardioides and Pseudarthrobacter. Functional gene predicted by PICRUST2 revealed significant upregulation of genes involved in carbon cycling (korA, gltA, sdhA and SGA1) and pollutants degradation (hpaB, pobA, tsdA and doxD), indicating that FeSx/BC+PDS not only stimulated bacterial carbon metabolism but also supplied supplementary carbon to sustain co-metabolic degradation of 1,4-dithiane and 1,4-thioxane. Furthermore, phytotoxicity assays demonstrated that FeSx/BC+PDS system markedly increased shoot and root elongation before remediation, underscoring the green credentials of this technology for the remediation of contaminated soils. Overall, our research provided a green and promising technology for the remediation of explosive-contaminated sites.

70. 题目: From sink to source: long-term soil carbon trends in cropland soils under high organic matter inputs
文章编号: N26101114
期刊: Geoderma
作者: David I Schubert, René Dechow, Christopher Just, Michael Diepolder, Axel Don, Ingrid Kögel-Knabner, Florian Ebertseder, Martin Wiesmeier
更新时间: 2026-10-11
摘要: SOC in European croplands has declined over recent decades, affecting CO2 emissions and soil functioning. A more detailed understanding of the relative contribution of agricultural management and climate change in these losses is lacking. We analyzed SOC dynamics over 29 years (1994–2023) in a long-term field experiment in Puch, Germany, comparing organic amendments (green manure, three compost types) combined with different mineral N fertilization levels. We further examine how recent climate change may have influenced SOC trajectories during the experimental period. Organic amendments significantly increased SOC content, with fine sized compost achieving the highest levels, 33% above the non-amended control, which showed the lowest SOC. High mineral N fertilization also significantly enhanced SOC content by 7–9%, though its effect (η2 = 9.7%) remained smaller than that of organic amendments (η2 = 68.3%), despite substantially increasing crop yield and associated crop residue C input. SOC content increased until 2012 but substantially declined in all treatments thereafter despite high C inputs from organic amendments and rising C inputs from crop residues. This decline coincided with rising temperatures and more frequent droughts at the site. RothC model configurations that explicitly accounted for climatic controls best reproduced observed SOC trajectories, suggesting that climate-related effects may have contributed to the observed SOC decline. Although compost application mitigated SOC decline on croplands, additional measures are required to fully prevent climate-induced losses. The long–term effectiveness of organic amendments depends on amendment properties and climatic conditions. This pattern raises questions about SOC accumulation under combined influences of organic matter inputs and climatic warming.

71. 题目: Photothermal-enhanced bisphenol A degradation in iron doped alginate biochar bead activated peroxymonosulfate Fenton-like system with amplified singlet oxygen contribution
文章编号: N26101113
期刊: Bioresource Technology
作者: Jingjing Liu, Guilong Gao, Xinyu Zhou, Xinfeng Jing, Zimo Jiang, Lijie Xu, Ying Zhang, Zepeng Rao, Jiangtao Shi, Lu Gan
更新时间: 2026-10-11
摘要: Herein, iron-doped biochar microspheres ((AB + Fe)-C) were prepared from alginate biomass precursor, which was as a Fenton-like catalyst for peroxymonosulfate (PMS) activation to degrade bisphenol A (BPA) in water with the assistance of photothermal effect. The results indicated that under simulated sunlight irradiation, (AB + Fe)-C/PMS system exhibited remarkable enhanced BPA degradation efficiency, in which the pseudo-first-order rate constant was 2.4-fold higher in photothermal-assisted system (0.17 min−1) than photothermal-absent system (0.072 min−1). Further investigation revealed that photothermal energy could significantly elevate the local temperature of catalyst surface and accelerate Fe2+/Fe3+ redox cycling, reducing the PMS activation energy as a result. Besides, further mechanistic studies confirmed that non-radical mechanisms predominantly contributed BPA degradation in the reaction system, and photothermal effect prominently amplified the contribution proportion of single oxygen (1O2). (AB + Fe)-C/PMS/photo system therefore exhibited high performance in a wide pH tolerance and various water matrices, as well as notable oxidation selectivity towards electron-rich pollutants (R2 = 0.87 for HOMO-ln k correlation, k for observed rate constant, min−1), demonstrating broad application prospects. This study offers a robust strategy for advancing practical organic pollutant degradation in water by upgrading the performance of biochar based Fenton-like catalyst with photothermal technology.

72. 题目: Mechanistic insights into the role of lignin units in chromium adsorption on low-temperature pyrolyzed biochar
文章编号: N26101112
期刊: Bioresource Technology
作者: Yan Wang, Wang Xiang, Hanwen Wang, Xinyang Wang, Xiaoping Rao
更新时间: 2026-10-11
摘要: Biochar synthesis typically demands high pyrolysis temperatures, incurring substantial energy penalties. Therefore, elucidating how pyrolysis temperature drives structural evolution and dictates adsorption performance is highly desirable. In this work, we demonstrated that a low-temperature pyrolysis regime (300°C) coupled with sodium hydroxide pre-treatment successfully fabricates a superior bamboo-derived biochar, yielding a competitive Cr(VI) adsorption capacity of 39.68 mg/g. Comprehensive mechanistic insights via kinetic modeling and multi-spectroscopic characterizations revealed that the remediation process is dictated by a multi-step chemisorption pathway, including electrostatic interactions, surface complexation, and chemical reduction. Uniquely, GC–MS and FTIR analyses unveiled the decisive role of specific lignin units—particularly Syringyl (S-type) monomers selectively retained under this low-temperature regime—as the key functional active sites. This finding was further validated by Density Functional Theory (DFT) calculations, which demonstrated that the oxygen-containing functional groups intrinsic to these lignin units provide a highly favorable thermodynamic pathway for anchoring HCrO4− through stable Cr − O coordination bonds and robust hydrogen-bonding networks. These insights provide a molecular-level understanding of the role of ancestral lignin units during low-temperature biochar activation, validating a commercially viable and low-carbon roadmap for industrial heavy metal decontamination.

73. 题目: Decoupling EPS functionality from quantity for sustained performance in solid biological treatment systems using biochar as a tuning agent
文章编号: N26101111
期刊: Bioresource Technology
作者: Jiang Wu, Qiyong Xu, Chongchong Ran, Jie Wang, Nan Zhao, Yuxin Qu, Huaihai Chen, Jae Hac Ko, Dandan Huang
更新时间: 2026-10-11
摘要: Excessive accumulation of extracellular polymeric substances (EPS) in solid biological treatment systems often causes pore clogging and mass transfer limitation, compromising long-term performance in pollutant transformation. Whether EPS functionality can be decoupled from its quantity, and how such decoupling might be achieved, remain poorly understood. In a 300-day column experiment using landfill cover soil with active methanotrophic communities, five types of biochar were applied as soil amendments to create distinct EPS secretion scenarios and methane removal performance profiles. It demonstrates that EPS functionalitycan be decoupled from its quantity through three distinct microbial investment strategies: functional minimization, achieving the most stable communities and highest methane removal efficiency (98 %) with minimal EPS (0.74 mg g−1); active construction, sustaining high performance (91 %) despite high EPS accumulation (3.51 mg g−1); and passive defense, exhibiting high EPS (3.29 mg g−1) but progressive functional decline (from 92 % to 62 %). These strategies are governed by two critical biochar properties; one is carbon stability, shaping soil dissolved organic carbon dynamics, and the other is salt ion content, determining osmotic stress intensity. Iron modification validated this framework by reducing labile carbon and enhancing carbon stability, redirecting an otherwise inefficient biochar toward a successful decoupling pathway. Collectively, these findings reveal that the EPS quantity-function relationship is context-dependent rather than monolithic, providing a basis for optimizing long-term performance in solid biological treatment systems through EPS functionality management.

74. 题目: Dissolved organic nitrogen molecular transformation and microbial mechanisms in a completely autotrophic nitrogen removal over nitrite (CANON)-based algal–bacterial symbiotic system
文章编号: N26101110
期刊: Bioresource Technology
作者: Dong Wei, Fang-Shuai Zhai, Chuan-fu Zhao, Yong-fang Zhang, Qin Wei, Shou-qing Ni
更新时间: 2026-10-11
摘要: Sunlight-driven CANON-based algal–bacterial symbiotic system (CANON-AB) achieves efficient nitrogen removal through algal oxygen production and assimilation. However, dissolved organic nitrogen (DON), as a major fraction of residual total dissolved nitrogen, remains poorly understood in CANON-AB. This study investigated DON transformation and microbial mechanisms in CANON-AB compared with conventional CANON. After 140 days operation, CANON-AB increased average dissolved inorganic nitrogen (DIN) removal efficiency from 83.6 % to 98 %, reducing effluent nitrate from 27.4 ± 8.3 to 0.7 ± 0.8 mg/L. Meanwhile, DON concentration decreased by 54.8 % in CANON-AB (1.4 ± 0.2 mg/L) compared with CANON (3.1 ± 0.2 mg/L). FT-ICR MS revealed that algae integration reduced DON molecular diversity from 1396 to 723 formulas, with preferential removal of carbohydrates, condensed aromatics, tannins, and sulfur-containing DON molecules. Metagenomic analysis demonstrated enhanced DON mineralization potential in CANON-AB, with DON transformation genes enriched by 1.1–2.4 times higher compared with CANON. These results reveal a coupled mineralization–assimilation mechanism driving DON removal in CANON-AB, providing new insights into nitrogen cycling in sustainable wastewater treatment.

75. 题目: Molecular transformation of dissolved organic matter during landfill leachate treatment by microbial electrolysis cell-anaerobic digestion system
文章编号: N26101109
期刊: Bioresource Technology
作者: Yushan Peng, Hang Yu, Faqian Sun, Xiaowu Huang, Liangliang Wei, Chongjun Chen
更新时间: 2026-10-11
摘要: The complex dissolved organic matter (DOM) in landfill leachate posed significant challenges for conventional biological treatment. In this study, a microbial electrolysis cell-anaerobic digestion (MEC-AD) system was constructed to explore DOM transformation pathways. An orthogonal experimental design was employed to evaluate the effects of applied voltage, anode-to-cathode area ratio, and stainless-steel cathode mesh size. Under an applied voltage of 1.2 V, an anode-to-cathode area ratio of 1:1, and a cathode mesh size of 200 mesh, the highest overall COD removal efficiency of 60.2% was observed. Spectroscopic analysis showed a reduction in biodegradable soluble microbial byproducts during treatment. GC–MS showed changes in the profiles of representative aliphatic and aromatic compounds. FT-ICR MS analysis revealed compositional reorganization of DOM, characterized by the disappearance of a fraction of protein- and lipid-like DOM and the persistence or relative enrichment of more unsaturated and aromatic constituents. Microbial community analysis revealed the relative enrichment of hydrolytic and fermentative bacteria (e.g., norank_f__Anaerolineaceae) as well as bacteria potentially involved in electron transfer (e.g., Thiobacillus). Metagenomic analysis suggested functional potential for amino acid metabolism, fatty acid degradation, glycolysis, and pyruvate metabolism. In contrast, the relatively low abundance of aromatic compound degradation functions was consistent with the persistence of refractory aromatic DOM. This study revealed that MEC-AD treatment was associated with differential transformation and molecular reorganization of landfill leachate DOM, and provided molecular-level insights beyond conventional bulk organic matter removal.

76. 题目: The Divergent Roles of Humic- and Fulvic-Acid DOM in Regulating Hg Methylation/Demethylation in Paddy Soils
文章编号: N26101108
期刊: Environmental Research
作者: Mahmoud A Abdelhafiz, Bo Meng, Jiang Liu, Zhengdong Hao, Tao Jiang, Xinbin Feng
更新时间: 2026-10-11
摘要: Understanding mercury (Hg) methylation and demethylation processes in paddy soils is crucial for controlling food contamination and health risks, yet the roles of dissolved organic matter (DOM) fractions remain unclear. A year-long field study, followed by an incubation experiment using Hg isotope tracers (202HgII and Me200Hg), was conducted to investigate how the humic acid (HA) and fulvic acid (FA) fractions regulate these processes. Field correlation results showed significant relationships between DOM properties and MeHg levels (p < 0.001), which varied with the dominant characteristics of DOM in paddy soils. The prevalent humification compounds reduced MeHg production, whereas enriching paddy soil with autochthonous DOM increased Hg methylation and MeHg production. The average methylation rate constants (Km-202HgII) for Hg-bound FA (Hg-FA) and Hg-bound HA (Hg-HA) treatments were 0.91 ± 0.22 and 0.40 ± 0.06 10−3 d−1, respectively, and the average demethylation rate constants (Kd-Me200Hg) were 0.28 ± 0.07 and 0.36 ± 0.11 d−1. Incubation results revealed that Hg-FA, with low aromaticity and molecular weight, had significantly higher methylation rates than Hg-HA (p < 0.05), suggesting greater bioavailability. Conversely, high-molecular-weight HA, with greater aromaticity and humic character, reduced net methylation potential and promoted MeHg degradation. Hg methylation and demethylation in response to the same DOM fraction varied across the studied sites, highlighting the distinct roles of each fraction's properties in paddy soils. This study broadens the understanding of DOM's roles in Hg fate in rice paddies, demonstrating that net MeHg production is governed by the balance between FA-promoted methylation and HA-promoted demethylation, challenging the traditional view that total DOM concentration is the primary controlling factor.

77. 题目: Valorization of humins into Fe-doped biochar for efficient peroxymonosulfate activation: Interfacial electron transfer governing radical and non-radical oxidation
文章编号: N26101107
期刊: Separation and Purification Technology
作者: Cunjie Xia, Zhiming Li, Haoxin Zhang, Jianglong Liu, Baoliang Chen
更新时间: 2026-10-11
摘要: Persulfate-based advanced oxidation processes, particularly peroxymonosulfate (PMS) activation, have emerged as promising technologies for the degradation of refractory organic contaminants in water systems. However, developing efficient and stable catalysts remains a challenge, and the use of carbon-rich industrial byproducts, such as humins, in environmental catalysis remains largely unexplored. In this study, humins were utilized as a sustainable carbon precursor to fabricate Fe-doped biochar (Fe@BC) via a metal-organic complexation strategy coupled with controlled pyrolysis. Comprehensive characterization and density functional theory (DFT) calculations were employed to systematically evaluate the catalytic performance of Fe@BC toward PMS activation and to further elucidate the roles of Fe species, carbon defects, and interfacial electron transfer. Among the prepared catalysts, Fe@BC-t800 exhibited the highest catalytic activity, achieving 98% removal of ciprofloxacin (CIP) within 8 min with a kinetic rate constant of 0.9683 min−1. Mechanistic investigations demonstrated that PMS activation is driven by the synergistic interaction between Fe active sites and the defective carbon matrix, enabling both radical and non-radical oxidation pathways dominated by singlet oxygen (1O2) and superoxide radical (•O2−). DFT results further reveal that Fe incorporation strengthens PMS and pollutant adsorption and accelerates interfacial electron transfer. This work provides a sustainable strategy for converting humins into high-performance catalysts for PMS activation and offers mechanistic insights into the rational design of carbon-based materials for advanced wastewater treatment.

78. 题目: Self-limiting stibnite weathering in suboxic humic sediments triggers Sb2O3-like-dominated passivation and decoupled genotoxic-phytotoxic damage in Elodea canadensis
文章编号: N26101106
期刊: Journal of Hazardous Materials
作者: Patricia Ponce-Peña, Ana P Rivera-Torres, Luis A Ceniceros-Morales, René H Lara, Gerardo A Anguiano-Vega, Hugo Ramírez-Aldaba, Roberto Briones-Gallardo, Edgar D Moreno-Medrano, Israel Labastida, Fabiola S Sosa-Rodríguez, Jorge Vazquez-Arenas, Manuel Sánchez-Cárdenas, Luis Lartundo-Rojas, Ivan A Reyes-Domínguez
更新时间: 2026-10-11
摘要: Antimony (Sb) is a priority pollutant whose mobility and toxicity are linked to the environmental weathering of stibnite (Sb2S3). This study combined a 10-week hydrochemical investigation (SbT, SO42-, pH, Redox) with surface (AFM, SEM, Raman, XPS, Zeta-potential (ζ)), electrochemical (EIS, CV, CA, Tafel plots), and ecotoxicological (genotoxicity, phytotoxicity) analyses to elucidate weathering mechanisms under suboxic humic sedimentary conditions. A critical Sb release pulse peaked at 2 weeks (∼60 μg·L−1), followed by progressive passivation. Raman and XPS confirmed the formation of an Sb2O3-dominated layer, while Electrochemical Impedance Spectroscopy showed charge-transfer resistance (Rct1) increasing from 782.8 to 20,069 Ω2. Negative surface charge (-33 to −53 mV) indicated that OH- (and SO42-) ions competitively occupied reactive surface sites, electrostatically repelling humic polyanions and confining Sb species to the solution. Ecotoxicological assays on Elodea canadensis (1–2000 mg·kg−1 Sb2S3) revealed an asynchronous recovery phenomenon: while chlorophyll a exhibited physiological recovery after 21 days (3.05 μg·g⁻¹ at 50 mg·kg−1), comet assays demonstrated cumulative genotoxicity (35.66 ± 16.63–244.50 ± 5.92 A.U. at 2000 mg·kg−1 Sb2S3). This decoupling proves that physiological recovery can mask persistent genomic damage, highlighting the limitations of single photosynthetic biomarkers for evaluating long-term ecological risks.

79. 题目: Nitrogen cycling regulates arsenic mobilization in alluvial-lacustrine aquifer systems: DOM molecular signatures and thermodynamic constraints
文章编号: N26101105
期刊: Journal of Hazardous Materials
作者: Qingfeng Chen, Yijun Yang, Chenhao Dong, Qixiang Wang, Shiyao Liu, Yao Du, Huaming Guo, Yanxin Wang
更新时间: 2026-10-11
摘要: High arsenic (As) groundwater is co-occurred with elevated ammonium (NH4+) in aquifers worldwide. However, the underlying nitrogen cycling processes regulating As mobilization in groundwater remain elusive. Here, hydrochemistry, stable isotopes, FT-ICR MS, and thermodynamic modelling were integrated to investigate the NH4+ production pathways and their impacts on As mobility within the alluvial-lacustrine aquifer. Hydrochemistry and isotopic data identified that groundwater NH4+ was primarily produced through OM mineralization and dissimilatory nitrate reduction to ammonium (DNRA), and both processes contributed to As enrichment which reached up to 1603 μg/L. FT-ICR MS analysis revealed that OM mineralization depleted CHON2 and highly unsaturated compounds, while DNRA preferentially consumed labile aliphatic compounds. Thermodynamic potential factors (FT) further evidenced that OM mineralization faced thermodynamic constraints (0.26 < FT < 0.99) that are highly dependent on the molecular properties of OM and the crystallinity of Fe(III) oxides, whereas DNRA experienced less thermodynamic limitations (FT > 0.99). Notably, thermodynamically favorable organic compounds such as highly unsaturated compounds and N-containing OM could promote OM mineralization, which simultaneously produce NH4+ and facilitate the reductive dissolution of Fe(III) oxides to release As into groundwater. These findings could provide novel insights into coupled C-N-Fe cycling on As mobilization within alluvial-lacustrine aquifer systems.

80. 题目: Heavy metal accumulation, lability and ecological risk in sediments across contrasting depositional settings within a surface-flow wetland: Associations with organic carbon fractions and porewater biogeochemistry
文章编号: N26101104
期刊: Journal of Hazardous Materials
作者: Yuman Ma, Yanxia Wang, Chunming Zhang, Rui Wu, Pengming Liu, Xue Liu, Qibin Liang, Lei Hou
更新时间: 2026-10-11
摘要: Contrasting depositional settings can generate differences in heavy metal accumulation, ecological risk, and lability, but their relationships with organic carbon (OC) fractions and porewater biogeochemistry remain unclear. We investigated inlet, interior, and outlet sediments of the Luoshijiang constructed surface-flow wetland, Southwest China, integrating 210Pb-based depositional characterization, metal and risk assessments, diffusive gradients in thin films, porewater measurements, diffusive fluxes, modeled speciation, OC fractions, and bacterial indicators. Most total metal contents decreased from inlet to outlet, while OC, readily oxidizable carbon, and total glomalin-related soil protein increased. Co showed the strongest contamination, whereas Cd contributed 52.7–58.0% of potential ecological risk. Contemporary metal lability did not consistently parallel total metal accumulation. Cd, Cu, and Pb showed net diffusive influx into sediments, whereas Mn showed net efflux and Zn shifted between source and sink behavior. Modeled Cd was dominated by S-bearing inorganic complexes, Co, Mn, Ni, and Zn by free ions and carbonate/hydroxide complexes, and Cu and Pb by fulvic-acid-bound forms. Associations of OC fractions, total phosphorus, Anaeromyxobacter abundance, and Cd S-bearing complexes with metal accumulation or lability varied among depositional settings. These findings show that accumulated metal burden, ecological risk, and contemporary lability provide complementary information for wetland sediment assessment.