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181. 题目: Decoding the Role of Organic Matter in Groundwater Feammox Processes: Insights from the Yangtze River Paleochannel
文章编号: N25053008
期刊: Water Research
作者: Chi Zhang, Yamin Deng, Yao Du, Hang Chen, Ruiyu Fan, Yanxin Wang
更新时间: 2025-05-30
摘要: Groundwater nitrogen (N) contamination is becoming increasingly severe worldwide. Anaerobic ammonia oxidation coupled with iron-reduction processes (Feammox) has great potential as an effective method for N removal in groundwater systems. However, previous studies on nitrogen removal by Feammox have generally focused on surface sediment soils, and the quantification of this process in groundwater remains inadequate. Moreover, the impact of native organic matter (OM) within the groundwater system on the Feammox process remains uncertain. The paleochannel of the middle reaches of the Yangtze River was selected as a representative study area for this research. The occurrence of Feammox and other N cycle (non-Feammox) processes in regional groundwater was identified and differentiated through the analysis of δ¹⁵N/δ⁵⁶Fe isotopes and 16S rRNA functional gene quantification, along with hydrochemical characteristics. These findings indicate that the groundwater in the study area is characterized by anoxic conditions and slight acidity. The occurrence of Feammox is substantiated by an increase in δ¹⁵N_NH4, which coincides with the concurrent increase of Fe(II) concentrations and δ⁵⁶Fe values in the groundwater, alongside the predominance of Acidimicrobiaceae bacterium A6. ¹⁵N isotope-labeled incubation experiments demonstrated that the potential rate of N removal via the Feammox process in the groundwater system ranged from 0.09 to 0.16 mg N kg^-1 d^-1. Correlation results suggested that the functional microorganisms facilitating the Feammox process are closely linked to environmental factors associated with organic matter activity. Terrestrial humic substances present in groundwater, characterized by a high degree of unsaturation, aromaticity, humification, elevated biological activity, and nitrogen-rich composition, may act as pivotal drivers of the Feammox process.

182. 题目: The Droplet Activation Parameterization for Black Carbon-Containing Particles in Steady State
文章编号: N25053007
期刊: Geophysical Research Letters
作者: Zhouyang Zhang, Jiandong Wang, Nicole Riemer, Jiaping Wang, Chao Liu, Yuzhi Jin, Zeyuan Tian, Sunan Shen, Bin Wang, Ganzhen Chen, Bin Zhao, Jianlin Hu, Minghuai Wang, Hang Su, Shuxiao Wang, Yafang Cheng, Aijun Ding
更新时间: 2025-05-30
摘要: The model representation of black carbon (BC) mixing state—referring to how BC is combined with other aerosol components within individual particles—introduces significant uncertainty in estimating BC's climate impacts. The cloud condensation nuclei (CCN) properties of BC-containing (BCc) particles are influenced by the amount of secondary aerosol coating, which is unevenly distributed across BC cores. This distribution complicates accurate predictions of CCN activities. The size distribution of BCc particles remains approximately unchanged as they continuously undergo both growth and deposition, forming a steady state. Based on this, we develop a droplet activation parameterization to predict the number distribution of BCc particles with respect to hygroscopicity and dry particle diameter. The predicted results demonstrate good agreement with those directly obtained from observations and simulations. This study evaluates the BC activation behavior accurately by using a few parameters, facilitating improved assessment of BC's indirect radiative effects in large-scale models.

183. 题目: Afforestation-driven soil organic carbon stabilization in a hyper-arid desert: nonlinear dynamics and microbial drivers across a 22-year chronosequence
文章编号: N25053006
期刊: Environmental Research
作者: Xinping Dong, Akash Tariq, Corina Graciano, Zhihao Zhang, Yanju Gao, Maierdang Keyimu, Mengfei Cong, Guangxing Zhao, Jingming Yan, Weiqi Wang, Jordi Sardans, Josep Peñuelas, Fanjiang Zeng
更新时间: 2025-05-30
摘要: Desertification and soil carbon loss threaten arid ecosystem sustainability, yet the long-term stability of soil organic carbon (SOC) following afforestation in hyperarid regions remains poorly understood. Here, we investigated SOC dynamics across a 22-year Populus alba chronosequence at the Taklimakan Desert edge, combining physical fractionation (particulate- (POC) and mineral-associated organic carbon (MAOC) with microbial phospholipid fatty acid (PLFAs) and enzymatic analyses. Afforestation significantly increased SOC content by 50.97%–108.05%, with MAOC surging 100.94%–160.59% after 22 years (P<0.01). SOC stability (MAOC/POC ratio) peaked at 12 years before declining. Random forest modeling identified total nitrogen (TN) and available phosphorus (AP) as key drivers. Meanwhile, microbial metabolic limitations, assessing by the stoichiometric of soil extracellular enzymes, shifted from phosphorus limitation to carbon-phosphorus colimitation suppressed decomposition activity, enhancing SOC stability. This study provides the quantification of nonlinear SOC stability trajectories in hyperarid plantations, offering critical insights for optimizing afforestation age to enhance the stability of SOC. Our findings advance mechanistic understanding of SOC persistence in water-limited ecosystems and directly inform desertification control policies under climate change scenarios.

184. 题目: Vertical microbial fluxes in a modern permanently redox‐stratified lake provide insights into organic carbon sequestration and benthic–pelagic coupling during the Proterozoic Eon
文章编号: N25053005
期刊: Limnology and Oceanography
作者: Ashley B Cohen, Vanja Klepac‐Ceraj, Kristen Bidas, Felix Weber, Arkadiy I Garber, Lisa N Christensen, Milana Yagudaeva, Jacob A Cram, Michael L McCormick, Gordon T Taylor
更新时间: 2025-05-30
摘要: Microbial processes regulating carbon cycling in ancient oceans remain poorly understood, yet characterizing these processes is critical for understanding early Earth biogeochemistry. Here, we investigate microbial communities associated with sinking particles regulating carbon cycling in meromictic Fayetteville Green Lake, a mid‐Proterozoic marginal ocean analog. The lake's photic zone spans oxic through sulfidic conditions, where prokaryotic photoautotrophs contribute to sinking fluxes and organotrophs mediate remineralization across redox and irradiance gradients. To characterize microbial communities in the sinking flux over time and redox condition, we sequenced 16S rRNA amplicons recovered from sediment traps throughout the lake's water column over the course of an annual photoautotroph bloom. Purple sulfur bacteria dominated deep fluxes, while cyanobacteria and green sulfur bacteria contributed variably across depths but were more abundant in suspended communities. As the bloom waned, chemoautotrophic Epsilonbacteraeota gained dominance in deeper fluxes, possibly due to niche partitioning. The shallow flux was remineralized by microbes exposed to temporally fluctuating biogeochemical conditions. Putative temporal changes in the availability and quality of organic matter and terminal electron acceptors thus promoted a succession of low‐diversity communities with few dominant hydrolytic and acidogenic clades. Unchanging conditions at depth promoted higher diversity microbial communities with niches for specialists dominated by sulfur‐metabolizing and fermentative clades. These findings improve our understanding of carbon cycling in the ancient ocean and offer insights into future shifts under climate change and meromixis in lakes.

185. 题目: Sources, Reactivity and Burial of Organic Matter in East China Sea Sediments, as Indicated by a Multi-geochemical Proxy Approach
文章编号: N25053004
期刊: Biogeosciences
作者: Xihua Yu, Shengkang Liang, Guicheng Zhang, Shanshan Li, Haifang Huang, Haoyang Ma
更新时间: 2025-05-30
摘要: . Large-river estuaries and adjacent seas play an important role in material exchanges and interactions in the land-ocean continuum and thereby impact global marine biogeochemistry. Due to the highly dynamic and complex transport and transformation processes of organic matter (OM), its distribution, sources, and reactivity in this region, especially under the multiple pressures of intense human activities and climate change, are not fully understood. An East China Sea transect, ranging from the mouth of the Changjiang River to the Okinawa Trough (OT), was selected to investigate the sources and reactivity of OM in surface sediments using multi-geochemical proxies. Carbon (C) to nitrogen (N) ratios and stable isotopic signatures, total hydrolyzable amino acids, neutral sugars and organic carbon (OC)-normalized total lignin-phenol indicated that OM in nearshore surface sediments derived primarily from terrestrial vascular plants, while offshore OM was dominantly derived from marine production. In the estuary vegetation mainly consisted of gymnosperms, whereas nonwoody angiosperms were dominant in offshore regions. Hydrodynamics, i.e., Changjiang Diluted Water and the Kuroshio Current markedly impacted sediment characteristics along this transect. The degree of OM degradation increased seaward, and sedimentation rates and OC burial fluxes were highest in Changjiang prodeltaic sediments and lowest in the OT. These results based on multi-biomarkers will advance our understanding of OC sources and burial during transport and deposition processes from estuaries to the deep oceans.

186. 题目: A novel kaolin coated with ferrihydrite-artificial humic acid for the removal of lead from water and weakly acid barren soil: Preparation, characterization, performance and mechanism
文章编号: N25053003
期刊: Journal of Environmental Chemical Engineering
作者: Xinru Xu, Guanghao Dongye, Shishun Wang, Zhiyuan Feng, Wenbo Liang, Fangjun Lou, Shuang Gai, Fan Yang
更新时间: 2025-05-30
摘要: Industrial development has led to frequent heavy metal pollution, adversely impacting the ecological environment and the utilization of productive agricultural resources. Given these concerns, it is imperative to develop a structurally stable lead adsorbent to ensure environmental safety. Consequently, in this study, a highly stable kaolin-coated ferrihydrite-artificial humic acid composite (Fh-AHA-G1.0) was developed for the remediation of Pb²⁺ in aqueous environments by using a co-precipitation process. The composite was also applied to lead-contaminated weakly acidic barren soils to evaluate its immobilization effect on Pb²⁺ in the soil environment. The adsorption mechanism of Fh-AHA-G1.0 for Pb²⁺ in contaminated water was investigated through adsorption experiments, and according to Langmuir fitting, the maximum adsorption capacity of Pb²⁺ was 123.86 mg/g. The adsorption mechanisms included ion exchange, surface chemical complexation, and lattice substitution. Furthermore, to evaluate the broad applicability of Fh-AHA-G1.0, the material was tested for its ability to immobilize Pb²⁺ in weakly acidic barren soils, demonstrating a significant ameliorative effect on lead-contaminated weakly acidic barren soils. The incorporation of 2% Fh-AHA-G1.0 led to a substantial reduction in the effective lead content of the soil, reaching 54.2%, while concurrently enhancing the soil index. These findings underscore its promise as a potential soil amendment. Hence, Fh-AHA-G1.0, as an environmentally friendly, cost-effective, and efficient adsorbent, not only reduces lead pollution in water bodies but also serves as a soil conditioner to enhance the physicochemical properties of weakly acidic barren lead-contaminated soils while immobilizing soil lead, demonstrating broad application potential in agricultural practices.

187. 题目: Relationships between the concentration of particulate organic nitrogen and the inherent optical properties of seawater in oceanic surface waters
文章编号: N25053002
期刊: Biogeosciences
作者: Alain Fumenia, Hubert Loisel, Rick A Reynolds, Dariusz Stramski
更新时间: 2025-05-30
摘要: . The concentration of particulate organic nitrogen (PON) in seawater plays a central role in ocean biogeochemistry. The limited availability of PON data obtained directly from in situ sampling methods hinders development of a thorough understanding and characterization of spatiotemporal variability in PON and associated source and sink processes within the global ocean. Measurements of inherent optical properties (IOPs) of seawater, which can be performed over extended temporal and spatial scales from various in situ and remote-sensing platforms, represent a valuable approach to address this gap. We present the analysis of relationships between PON and particulate IOPs, including the absorption coefficients of total particulate matter, ap(λ); phytoplankton, aph(λ); and non-algal particles, ad(λ), as well as the particulate backscattering coefficient, bbp(λ). This analysis is based on an extensive field dataset of concurrent measurements of PON and particulate IOPs in the near-surface oceanic waters and shows that reasonably strong relationships hold across a range of diverse oceanic and coastal marine environments. The coefficients ap(λ) and aph(λ) show the best ability to serve as PON proxies over a broad range of PON from open-ocean oligotrophic to coastal waters. The particulate backscattering coefficient can also provide a good proxy for PON in open-ocean environments. The relationships presented here demonstrate a promising means to assess PON from optical measurements conducted from spaceborne and airborne remote-sensing platforms and in situ autonomous platforms. In support of this potential application, we provide the relationships between PON and spectral IOPs at light wavelengths consistent with those used by satellite ocean color sensors.

188. 题目: Persulfate activation by biochar for trace organic contaminant removal from urban stormwater
文章编号: N25053001
期刊: Water Research
作者: Yiling Zhuang, Stefan B Haderlein, Holger V Lutze, Chen Sun, Friedrich Fink, Andrea Paul, Stephanie Spahr
更新时间: 2025-05-30
摘要: Persistent and mobile trace organic contaminants (TrOCs) in urban stormwater are difficult to remove through sedimentation- or sorption-based treatment and pose a risk to aquatic ecosystems and drinking water supplies. We demonstrate that the chemical oxidant peroxydisulfate (PDS) can be activated by shrimp shell biochar at pH 7 to form reactive species that selectively react with widespread stormwater contaminants. Of 11 TrOCs tested, oxidative transformation was observed for 1,3-diphenylguanidine, 2-hydroxybenzothiazole, 1H-benzotriazole, 5-methyl-benzotriazole, and diuron during water treatment with biochar and PDS. Laboratory batch experiments conducted with street runoff and a synthetic water showed that the water matrix, containing up to 7.5 mg/L dissolved organic carbon and 100 mM chloride, had a minor effect on the formation of reactive species and contaminant transformation. Using a set of scavengers and probe compounds, we provide evidence for singlet oxygen (¹O₂) as the predominant reactive species in the biochar/PDS system, which is in agreement with the selectivity of the process to oxidize electron-rich organic contaminants. The results of our study inform new strategies for stormwater treatment using heterogeneous oxidation processes for the abatement of persistent and mobile organic contaminants.

189. 题目: Rainfall-mediated CO2 flux dynamics in the Three Gorges Reservoir: Dominance of enzyme activity over carbon degradation and algal dynamics under dissolved organic carbon inputs
文章编号: N25052810
期刊: Journal of Environmental Chemical Engineering
作者: Kaikai Deng, Yixuan Li, Peng Yan, Bin Chen, Guijiao Lin, Qiang He, Jinsong Guo
更新时间: 2025-05-28
摘要: Rainfall significantly influence the physicochemical properties of aquatic systems through surface runoff inputs. These changes, along with changes in dissolved organic carbon (DOC) concentration and microbial metabolic activities, collectively regulate CO₂ flux dynamics at the water-air interface. However, the key factors driving CO₂ flux variations remain inadequately understood. In this study, based on previous observations in the Three Gorges Reservoir (TGR), where rainfall-induced runoff drove shifts between CO₂ sources and sinks, a series of continuous flow experiments were conducted. During the first continuous flow experiment, we found that DOC—particularly indole-3-acetic acid (IAA)—had a significant impact on CO₂ flux. To further investigate these effects, a second continuous flow experiment was conducted with varying IAA concentrations. The results indicated that during the early stage of the experiment (Day2 to Day6), the addition of IAA significantly enhanced CO₂ flux (P < 0.01). Specifically, the input of 8 mg·L^-1 IAA resulted in a CO₂ flux range of -0.01 to 0.51 mmol·m^-2·h^-1, compared to the overall carbon sink of the control group (-0.13 to 0.00 mmol·m^-2·h^-1). Analysis revealed that the CO₂ flux was influenced by factors such as carbon degradation, algal dynamics, and enzymatic activity. Partial least squares (PLS) analysis further quantified the relative contributions of these factors, ranking them as follows: enzymatic activity > carbon degradation > algal biomass. This study provides critical insights into the dynamic mechanism of rainfall-mediated CO₂ source and sink fluxes, establishing a quantitative framework for predicting reservoir carbon flux responses under rainfall events, thereby advancing more precision carbon accounting.

190. 题目: The impact of converting rice cultivation to greenhouse vineyard cultivation on the dynamic of organic carbon in coastal soil
文章编号: N25052809
期刊: Soil and Tillage Research
作者: Yu Tian, Jingjing Liu, Shenggao Lu
更新时间: 2025-05-28
摘要: The conversion of rice to greenhouse vineyard cultivation leads to an increase in the amount and frequency of fertilization, as well as a reduction in tillage intensity, which significantly affects soil organic carbon turnover and sequestration. In this study, four types of soils were selected in the coastal area of southeast China based on a sequence of greenhouse vineyard cultivation years of 0, 8, 18, and 36. The study fractionated the soil into four organic fractions: free mineral-associated organic carbon (f-MAOC), occluded mineral-associated organic carbon (o-MAOC), free particulate organic carbon (f-POC), occluded particulate organic carbon (o-POC), using particle size and density separation. The organic carbon content and natural abundance of 13C were measured for each of these fractions, as well as for the bulk soil. Key findings include a significant increase in bulk soil organic carbon with extended greenhouse vineyard cultivation. o-MAOC and o-POC contents increased initially, then declined after 18 years. Notably, f-POC content significantly rose after 36 years, reaching 9.91 g kg−1. The δ13C values for f-MAOC, o-MAOC, and f-POC showed similar increasing trends, peaking after 18 years. The carbon flow analysis revealed the main carbon turnover pathway from f-POC to o-MAOC, with reverse transfers occurring after 18 and 36 years. It highlighted a saturation limit in the sequestration capacity of occluded organic carbon and significant accumulation of labile organic carbon due to long-term greenhouse vineyard cultivation. Additionally, accumulation of f-POC was primarily influenced by fungal diversity and specific microbial taxa (Ascomycota), whereas the stabilization of occluded carbon fractions was regulated by both microbial communities and aggregate formation processes. These findings offer new insights into carbon management in agricultural soils.

191. 题目: Biochar-loaded iron oxide as a novel electrode for the electro-Fenton degradation of sulfaquinoxaline: Performance evaluation, mechanistic insights, and toxicity transformation
文章编号: N25052808
期刊: Journal of Environmental Management
作者: Xiaowen Li, Sufang Wang, Jierong Zheng, Xin Fan, Jilong Qin, Yu Yang, Aijuan Zhou, Rui Li, Houfen Li, Xingfa Li, Xiuping Yue
更新时间: 2025-05-28
摘要: In this work, carboxymethyl cellulose (CMC)-modified biochar (BC)-supported Fe3O4 was prepared for the degradation of sulfaquinoxaline (SQX) in a heterogeneous electro-Fenton process. The degradation rate of 10 mg/L SQX reached 94.2 % after 180 min of Fe3O4(CMC)/BC treatment, compared to 61.2 % with Fe3O4/BC. CMC allowed Fe3O4 particles to be more evenly distributed on the biochar surface, and its electron transfer capacity effectively activated the in situ generated H2O2 on the electrode with a maximum H2O2 yield of 17.9 mg/L. The produced 1O2 and ⋅O2− are the primary contributors to SQX degradation. The aniline of SQX is susceptible to electrophilic attack, whereas quinoxaline is susceptible to free radical attack, with bis-methylation, heterocyclic oxidation, and amino oxidation being the major reactions in the decomposition of SQX. Toxicity assessment by ECOSAR and T.E.S.T. modeling showed that all the intermediates were considerably less biotoxic than the parent compound. Density functional theory calculations showed that the O2 adsorption and H2O2 decomposition processes are spontaneous reactions, and the intermediates absorbed on the Fe atom have an increased energy potential and a tendency to be less active. The results of material cycling tests and metal ion leaching experiments confirmed the good reusability of the prepared cathode. Additionally, Fe3O4(CMC)/BC achieved excellent performance in livestock wastewater (SQX removal of 93.4 % and COD removal of 79.9 %), demonstrating the possibility of practical application. This study offers a theoretical foundation for the use of novel composite cathode materials to degrade persistent pollutants.

192. 题目: B-doped lotus pollen biochar photothermal activating periodate for acetaminophen degradation by non-radical pathway: Significance of thermal effect from the photothermal process
文章编号: N25052807
期刊: Separation and Purification Technology
作者: Lei Qin, Shuyuan Hu, Huan Yi, Wenjun Wang, Cui Lai, Shiyu Liu, Dengsheng Ma, Tao Tong, Hao Deng, Guangjie Lv
更新时间: 2025-05-28
摘要: Periodate (PI)-based advanced oxidation emerges as a key solution for environmental remediation. However, existing activation methods are energy-intensive, driving demand for sustainable alternatives. In this study, a photothermal activation method for PI based on B-doped lotus pollen biochar (CB500) was developed to degrade acetaminophen (ACE). In the CB500/PI photothermal activation system, ACE could be completely degraded within 15 min, which was 17.71 times faster than light activation system. Quenching experiments, electron paramagnetic resonance, and electrochemical tests proved singlet oxygen (¹O₂) was the main reactive species. Photothermal contribution analysis revealed that thermal effects predominated in the system. Besides, the system showed a high resistance to interference. Its degradation capability was almost unaffected by natural organic matter (NOM) and maintained excellent degradation performance over a wide pH range. Moreover, this system exhibited potential for ACE degradation in actual water samples. This work provides novel insights into the advancement of photothermal PI activation.

193. 题目: Shrub Afforestation Increases Microbial‐Derived Carbon in Arid Regions
文章编号: N25052806
期刊: Land Degradation & Development
作者: Mengfei Cong, Zhihao Zhang, Guangxing Zhao, Xinping Dong, Weiqi Wang, Zhaobin Mu, Akash Tariq, Corina Graciano, Jordi Sardans, Josep Peñuelas, Fanjiang Zeng
更新时间: 2025-05-28
摘要: Soil organic carbon (SOC) primarily originates from microbial and plant‐derived carbon (C). Afforestation activities significantly influence the retention of these C sources. However, in arid regions where SOC is particularly sensitive to external disturbance, the impact of afforestation on microbial‐ and plant‐derived C, and their relative contributions to SOC, remains poorly understood. To address this knowledge gap, we investigated the relative contributions of microbial‐ and plant‐derived C to SOC in three soil layers (0–20 cm, 20–60 cm, and 60–100 cm) by analyzing amino sugars and lignin phenol content. This analysis was conducted following the afforestation of Tamarix ramosissima at 3, 7, and 10 years in barren lands located within a desert–oasis ecotone on the southern edge of the Taklimakan Desert. Our results indicate that afforestation increased levels of SOC, nutrients (including ammonium nitrogen, nitrate nitrogen, and available phosphorus), and both microbial‐ and plant‐derived C across all soil layers. Specifically, microbial‐derived C content increased by 2.15–2.32 times, while plant‐derived C content increased by 41.06%–5.59 times. This resulted in a 28.26%–1.4 times increase in microbial‐derived C contribution to SOC. However, it reduced the relative contribution of plant‐derived C to SOC in the 0–60 cm soil layer by 7.6%–76.38%. Notably, the opposite pattern emerged in deeper soil layers (60–100 cm), where afforestation increased the plant‐derived C contribution to SOC by 2.23–4.31 times. Soil nutrients were identified as the primary factor influencing plant‐derived C accumulation. The alleviation of microbial nitrogen limitation (indicated by an increased vector angle) contributed to the accumulation of microbial‐derived C. These findings suggest that T. ramosissima afforestation enhances SOC sequestration, primarily through the accumulation of microbial‐derived C. This underscores the importance of microbial‐derived C to SOC dynamics in arid regions following afforestation.

194. 题目: Impact of fulvic acids on lead adsorption and transport behavior in cationic surfactant modified bentonite-loess liners.
文章编号: N25052805
期刊: Environmental Geochemistry and Health
作者: Jiawei Wu, Yun Chen, Haijian Xie, Abdelmalek Bouazza, Huaxiang Yan
更新时间: 2025-05-28
摘要: The high concentration of fulvic acid (FA) derived from natural matter in landfill leachates has generated increasing interest, as it plays a significant role in influencing the mobility of potentially toxic elements in landfill groundwater environments. This study examines the adsorption and transport behavior of FA on landfill unmodified and modified loess soil liners, analyzing key factors (initial concentration, organ-bentonite content, reaction time, and soil-water ratio) using a Box-Behnken design-based Response Surface Methodology (RSM-BBD). Additionally, the research objective includes evaluating the adsorption of lead (Pb2⁺), providing a comprehensive assessment of the soil liners' performance against both organic and inorganic contaminants. RSM-BBD analysis showed that the higher the hexadecyltrimethylammonium chloride-modified bentonite (HTMAC-B) content, the larger the adsorption capacity of the mixed soil for FA, which proved that FA was mainly adsorbed on the HTMAC-B. Loess + HTMAC-B exhibited the highest capacity, which can be 30.6 times that of loess. The presence of Pb2+ notably enhanced the adsorption capacity of FA on the loess with HTMAC-B mixture. However, the increase in HTMAC-B content resulted in a decrease in the equilibrium adsorption of FA in the FA-Pb2+ dual-contaminant system, mainly due to the reduction of adsorbed COO-Pb+ and (COO)2-Pb complexes. When the HTMAC-B content reached 20%, the breakthrough time of Pb2+ in the modified liner was shortened by 82%. The use of 5% content of HTMAC-B was identified as appropriate to achieve excellent retardation performance for multi-component pollutants such as organics, organic acids and potentially toxic elements. These insights contribute to understanding how geochemical mitigation of humic substances affects the mobility of potentially toxic elements, and from an engineering perspective, the alternative materials presented in this study may facilitate the construction of thinner liners that meet system requirements while exhibiting excellent adsorption performance for multi-component contaminants.

195. 题目: Enhanced lignocellulose degradation and composts fertility of Flammulina filiformis residue and eco-friendly insect (Protaetia brevitarsis) composting by microbial agents-loaded biochar
文章编号: N25052804
期刊: Chemical Engineering Journal
作者: Ying Zhang, Shuaichun Huang, Yuan Cheng, Lingyun Liu, Changtian Li, Guangjie Zhang, Yu Li
更新时间: 2025-05-28
摘要: The protracted duration and limited by-product diversity of aerobic composting pose escalating economic challenges in the management of crop and livestock residues. This study investigated the nutrient recovery and nitrogen cycling in Protaetia brevitarsis bio-composting process using microbial agents-loaded biochar (RWBC), and its effects on organic fertilizer and insect protein production. Results showed that the addition of RWBC enhanced nutrient transformation and lignocellulose degradation during bio-composting, leading to a 53.75% increase in total nitrogen content. RWBC initially enriched nitrogen-converting microbes such as Mycothermus, Flavobacterium, Thermobacillus, Planococcus and Taibaiella, subsequently strengthened synergistic interactions within larval intestinal microbiota, and ultimately reduced composting duration while improving safety and efficiency, decreased the relative abundance of Fusarium. This study highlights the use of insect-assisted composting to enhance by-product diversity, promote composting safety, and establish an effective approach for sustainable crop and livestock waste management.

196. 题目: Effects and mechanisms of warming on the relationship between soil organic matter degradation and methylmercury production in Hg-contaminated soil
文章编号: N25052803
期刊: Geoderma
作者: Siqi Zhang, Sihua Zhu, Shanyi Tian, Jianxu Wang, Yongguang Yin, Jitao Lv, Yongmin Wang, Tao Jiang, Zhenwu Tang, Dingyong Wang
更新时间: 2025-05-28
摘要: The degradation of soil organic matter (SOM) is an essential process that not only drives the production of greenhouse gases (GHGs) but also influences the environmental fate of pollutants, such as mercury (Hg), specifically methylmercury (MeHg) production. However, the relationship between these processes and their response to warming remains unclear. To address this gap, we conducted a 60-day microcosm incubation period using mimic-contaminated soils with varying Hg levels to investigate the effects of warming on SOM degradation and MeHg production. These results indicate that Hg stress does not significantly affect GHG production but increases the temperature sensitivity (Q10) of SOM degradation. This implies that warming increases the feedback of carbon release in contaminated soil, particularly when considering seasonal temperature dynamics or prospective global warming scenarios. Additionally, warming can significantly promote GHG production. However, warming did not significantly affect MeHg production, except in the high Hg treatment (i.e., HgH), due to minimal changes in the Hg fractions that regulate MeHg production. Furthermore, regardless of temperature changes, the relationship between GHGs and MeHg shifted from positive to negative as Hg levels increased. This highlights the need to balance carbon emission reduction and pollutant treatment policies to effectively reduce risks in contaminated sites. In conclusion, in terms of the current development of C management strategies for mitigating climate change and enhancing carbon sequestration, the turnover of SOM and its ecological implications for contaminated soils should be revisited. Future research should incorporate contaminated soils into global carbon models to improve SOM turnover predictions in terrestrial systems.

197. 题目: Impact and Mechanisms of Microbial Communities and Environmental Factors on the Composition and Structure of DOM in Lake Ice, Water, and Sediments
文章编号: N25052802
期刊: ACS ES&T Water
作者: Yingru Tao, Weiying Feng, Qiwei Gu, Tengke Wang, Fanhao Song, Tingting Li
更新时间: 2025-05-28
摘要: Microbial communities serve as crucial mediators of dissolved organic matter (DOM) dynamics in seasonally ice-covered lakes. This comparative study of a saline plateau lake (Lake Daihai) and an eutrophic freshwater lake (Lake Wuliangsuhai) revealed distinct winter microbial patterns, with sediment communities exhibiting 2–3 times higher diversity than ice or water habitats. Fluorescence characterization identified fundamental differences in DOM sources, where saline lake DOM showed mixed terrestrial-autochthonous signatures (fluorescence index: 1.4–1.9), contrasting with the strongly microbial-derived DOM (FI > 1.9) in freshwater systems. Vertical profiling demonstrated progressive humification downward through ice layers, while microbial functional predictions indicated sustained amino acid metabolism despite subzero temperatures. The unique halotolerant community structure of the saline lake contrasted sharply with the psychrophilic Flavobacterium-dominated assemblages in freshwater habitats, reflecting differential adaptation to environmental stressors. Dissolved oxygen and salinity emerged as primary drivers of community composition, while phosphorus availability influenced specific functional groups involved in organic matter processing. These findings highlight the resilience of microbial-mediated carbon cycling under ice cover and provide critical baseline data for predicting ecosystem responses to changing winter conditions in inland waters.

198. 题目: Dissolved organic carbon replenishment enhances organic matter mineralization under extremely saline-sodic conditions following straw incorporation
文章编号: N25052801
期刊: Applied Soil Ecology
作者: Jisheng Xu, Tantan Zhou, Zepeng Xuan, Qingxia Wang, Yunpeng Zhou, Jiabao Zhang, Bingzi Zhao
更新时间: 2025-05-28
摘要: Soil sodicity, in combination with salinity, enhances organic matter solubility and impacts organic carbon dynamics. However, the mechanisms of organic carbon mineralization in saline-sodic soils, especially in extremely sodic environments, remain unclear. We conducted a three-month incubation experiment using a randomized block design to clarify this mechanism. With 13C-labelled maize straw as the substrate, we compared organic matter mineralization and the priming effect (PE) in two saline-sodic soils (exchangeable sodium percentage 50.1 % and 36.5 %, respectively) with that in a nonsaline soil (exchangeable sodium percentage 4.3 %). Soil samples were collected at 4, 14, 59, and 103 days to analyze dissolved organic carbon (DOC), microbial biomass, and bacterial community composition. Notably, despite similar cumulative CO2 emissions across all soils over 103 days, the saline-sodic soils displayed distinct temporal dynamics in organic carbon mineralization. In the initial four days, they had reduced primed CO2 and straw-derived CO2, but these disparities narrowed by the end of the incubation. Additionally, in saline-sodic soils, despite lower microbial biomass and diversity, higher DOC levels were observed. DOC concentrations significantly increased over time after straw addition and showed a significant positive correlation with total CO2 emissions (including native soil CO2, primed C, and straw-derived CO2). Moreover, DOC concentration was positively correlated with genera whose abundance surged following straw addition under extremely sodic conditions. Partial least squares path modeling illustrated that DOC concentration had a more significant direct impact on total CO2, straw-derived CO2, and PE in saline-sodic soils compared to the nonsaline soil, and indirectly affected them by modulating microbial co-occurrence network modules. Our study thus emphasizes the pivotal role of DOC in facilitating mineralization and priming in saline-sodic soils, offering energy and substrates to microbial communities.

199. 题目: Deciphering biochar-driven membrane fouling mitigation mechanisms in high-solids AnMBRs: A multi-perspective analysis using computational fluid dynamics and interface thermodynamics
文章编号: N25052710
期刊: Chemical Engineering Journal
作者: Chengfan Jiao, Shaowen You, Zhen Lei, Feixiang Zan, Qian Li, Yu-You Li, Rong Chen
更新时间: 2025-05-27
摘要: To investigate the effects and mechanisms of biochar in high-solids anaerobic membrane bioreactors (AnMBRs), this study systematically analyzed membrane fouling by integrating fouling characterization with multi-perspective analytical methods. The addition of biochar significantly reduced the membrane fouling rate by 25.8%-40.7%. Notably, biochar not only altered the morphological structure of the fouling layer but also modified its composition and enhanced its hydrophobic properties. Compared to the control reactor, biochar addition decreased the thickness of the fouling layer by 14.8% while forming a denser cake layer with improved retention performance. Moreover, the protein-to-polysaccharide (PN/PS) ratio of the fouling layer in the biochar-amended reactor was consistently higher across all fouling stages, ranging from 1.15 to 2.13 times that of the control reactor. These improvements were attributed to the enhanced hydrodynamic conditions at the membrane surface, facilitated by biochar addition, which increased dynamic pressure by 22.3%–58.9% and improved the resistance of foulants to membrane adhesion, as demonstrated by computational fluid dynamics (CFD) simulations. Additionally, biochar enhanced the surface characteristics of both the sludge and the fouling layer, increasing the interaction energy between them. This raised the energy barrier to foulant adhesion by 7.20%–26.76%, as quantified using the extended Derjaguin-Landau-Verwey-Overbeek (XDLVO) theory. This systematic analysis of the dynamic membrane fouling process provides novel insights and theoretical support for employing biochar to mitigate membrane fouling in high-solids AnMBR systems.

200. 题目: Permafrost carbon controlled by vegetation and climate in the Tibetan Plateau
文章编号: N25052709
期刊: Environmental Earth Sciences
作者: Xin Zhang, Shihang Zhang, Hongjin Chen, Jian-rong FAN
更新时间: 2025-05-27
摘要:

Soil organic carbon (SOC) in the active layer (0–2 m) of the Tibetan Plateau (TP) permafrost region is sensitive to climate change, with significant implications for the global carbon cycle. Environmental factors—including parent material, climate, vegetation, topography, soil, and human activities—inevitably drive SOC variations. However, vegetation and climate are likely the two most influential factors impacting SOC variations. To test this hypothesis, we conducted experiments using 31 environmental variables combined with the recursive feature elimination (RFE) algorithm. These experiments showed that RFE retained all vegetation variables [Land cover types (LCT), normalized difference vegetation index (NDVI), leaf area index (LAI), and gross primary productivity (GPP)] as well as two climate variables [Moisture index (MI) and drought index (DI)], supporting our hypothesis. We then analyzed the relationship between SOC and the retained vegetation and climate variables using random forest (RF), Shapley additive explanations (SHAP), and GeoDetector models to quantify the independent and interactive drivers of SOC distribution and to identify the optimal conditions for SOC accumulation. The RF model explained 68% and 42% of the spatial variability in SOC at depths of 0–1 m and 1–2 m, respectively, with SOC stocks higher in the southeast and lower in the northwest. Additionally, SOC stock at 0–1 m was significantly higher (p < 0.05) than at 1–2 m in alpine meadows, alpine wet meadows, and swamp meadows. Conversely, SOC stock in alpine deserts, steppe meadows, and barren land did not differ significantly between the two depths (p > 0.05). Spearman correlation coefficients results indicated that NDVI, LAI, GPP, and MI had highly significant positive correlations with SOC (p < 0.01), whereas DI had a highly significant negative correlation with SOC (p < 0.01). SHAP analysis revealed environmental thresholds for SOC variations, with notable shifts at NDVI (0.40), LAI (7), GPP (250 g C m⁻² year⁻¹), MI (0.40), and DI (0.50). The spatial distribution of these thresholds aligns with the 400 mm equivalent precipitation line. Additionally, GeoDetector results emphasized that interactions between climate and vegetation factors enhance the explanatory power of individual variables on SOC variations. The swamp meadow type, with an NDVI range of 0.73–0.84, LAI range of 11.06–15.94, and MI range of 0.46–0.56, was identified as the most favorable environment for SOC accumulation. These findings are essential for balancing vegetation and climate conditions to sustain SOC levels and mitigate climate change-driven carbon release.