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141. 题目: Biochar modulates microbial carbon metabolism to mitigate global warming potential during composting
文章编号: N26071911
期刊: Environmental Pollution
作者: Wenqi Liang, Xu Ma, Yujuan Wang, Wenming Zhang, Chenxu Yu
更新时间: 2026-07-19
摘要: Carbon loss via CO2 and CH4 emissions reduces the organic carbon available for humification, which may negatively affect compost quality while exacerbating environmental pollution. Herein, this study investigated the impacts of biochar (e.g., rice husk biochar (RHB) and sawdust biochar (SDB) as composting additives on CO2 and CH4 emissions, as well as the underlying microbial mechanisms. The results demonstrated that, comparing to the control (CK), RHB and SDB reduced cumulative CO2 emissions by 11.38% and 16.30%, respectively (both P < 0.05), whereas they increased CH4 emissions by 45.35% (P < 0.05) and 81.04% (P < 0.01), respectively. Overall, the 100-year global warming potentials (GWP-100s) of the RHB and SDB treated groups were decreased by 15.91 g CO2e·kg-1 and 19.29 g CO2e·kg-1, respectively. Redundancy analysis (RDA) and partial least squares path modeling (PLS-PM) revealed the total organic carbon (TOC) to be the key environmental regulatory factor. Specifically, TOC was significantly negatively correlated with CO2-producing genes and aerobic methane oxidation genes, yet it exhibited a positive correlation with methanogenic genes which underlines the up-regulation of CH4 emissions from the biochar-treated composting systems. The addition of biochar increased the TOC of the compost systems, which induced microbial community shift from r-strategy to K-strategy, inhibited CO2 production, yet modulated methanogenesis. This cascade of effects reduces the net GWP of compost via microbial-mediated mechanisms. The findings of this study provided a critical theoretical foundation and a practical guideline for optimizing the biochar-manure co-composting process to reduce overall greenhouse gas emission from composting.

142. 题目: Synergistic effects of sugarcane biochar and glycine betaine foliar spray on lettuce (Lactuca sativa L.) physiological performance, biochemical markers, metabolites, and antioxidative features under wastewater irrigated soil
文章编号: N26071910
期刊: Environmental Technology & Innovation
作者: Hafiza Iqra Almas, Fasih Ullah Haider, Lili Nian, Muhammad Sajid, Aaliya Batool, Fahd Rasul, Usman Zulfiqar, Mashael Daghash Alqahtani, Mayank Anand Gururani
更新时间: 2026-07-19
摘要: Wastewater irrigation can alleviate freshwater shortages, but its continued use may impair soil quality and crop performance by accumulating salts and heavy metals (HMs). Biochar (BC) can reduce HM bioavailability in soil, whereas glycine betaine (GB) can enhance plant tolerance by improving osmotic adjustment and antioxidant defence. However, their combined role in mitigating HM stress induced by wastewater in lettuce (Lactuca sativa L.) remains insufficiently understood. Therefore, a pot experiment was conducted using two irrigation sources, canal water (CW) and Madhuana drain wastewater (MDWW), together with four amendment treatments: control, BC (3% w/w), foliar-applied GB (50 mM), and BC + GB. Morphological, physiological, biochemical, and antioxidant attributes were evaluated and analysed using analysis of variance at P < 0.05. Compared with CW, MDWW irrigation significantly reduced shoot length (11.0%), root length (63.5%), fresh weight (84.9%), dry weight (27.3%), and leaf number, while also decreasing photosynthetic pigments, gas-exchange traits, and membrane stability. Wastewater stress further increased oxidative damage and HM accumulation in lettuce tissues. Among all treatments, the combined application of BC + GB provided the strongest protection by improving growth, photosynthetic efficiency, metabolite accumulation, and antioxidant enzyme activity, while reducing oxidative stress indicators. Importantly, BC + GB also lowered cadmium, chromium, and lead accumulation by 68%, 46%, and 49%, respectively, compared with the untreated wastewater control. Overall, the integrated BC and GB application mitigated wastewater-induced stress in lettuce by improving physiological resilience, enhancing biochemical defense, and reducing HM uptake under contaminated irrigation, thereby promoting safer and more sustainable lettuce production.

143. 题目: Decoupled storm-phase source dynamics of dissolved and particulate organic matter in an agricultural watershed
文章编号: N26071909
期刊: Journal of Hydrology
作者: Yun Kyung Lee, Ho-Yeon Park, Haeseong Oh, Seung-Hee Kim, Kyung-Hoon Shin, Jae-In Kim, Byung Joon Lee, Jin Hur
更新时间: 2026-07-19
摘要: Storm events strongly regulate organic matter (OM) mobilization in agricultural watersheds, yet potential differences in the source evolution of dissolved and particulate OM (DOM and POM) across storm phases remain poorly constrained. Here, we conducted hydrograph phase-resolved storm sampling during two rainfall events and applied end-member mixing analysis (EMMA) to quantify phase-specific OM source dynamics. Source contributions were traced using δ13C–δ15N for POM and fluorescence indices for DOM. Bulk water-quality parameters and POM concentrations increased with discharge during the monitored events, closely tracking suspended solids and particulate nutrients, suggesting cumulative mobilization under event-specific hydrological conditions rather than a clear first-flush-like decline. EMMA results indicated highly dynamic POM source evolution, with leaf litter/riparian vegetation initially contributing 60–67% of POM during the early stage but declining to ∼29% near peak flow as soil-derived POM increased sharply to ∼51%, consistent with discharge-associated particulate mobilization and progressive source-area activation during storm progression. In contrast, DOM showed comparatively buffered dynamics and a strong manure/compost-like signature within the FI–BIX-based EMMA framework, contributing ∼37–58% across storm phases, suggesting persistent leaching and flushing from manure-amended areas once source areas became connected to active flow paths. Source-specific OC fluxes were concentrated in short high-flow windows, with sharp POC pulses near peak discharge and more persistent DOC export into recession. These findings indicate decoupled POM and DOM transport during the monitored storms and highlight the value of phase-resolved, OM-specific source apportionment for interpreting storm-driven carbon export and informing targeted watershed management.

144. 题目: Pre-monsoon flow-path switching regulates downstream dissolved organic carbon dynamics in a high-alpine river on the Qinghai–Tibet Plateau
文章编号: N26071908
期刊: Journal of Hydrology
作者: Dong Zhang, Yindong Tong, Xiaodong Li, Yanli Sun, Jiajun Han
更新时间: 2026-07-19
摘要: High-altitude semi-arid rivers undergo rapid hydrological reorganization during the pre-monsoon season, yet the respective roles of antecedent warming, initial thaw, and changes in hydrological connectivity in regulating the downstream export of dissolved organic carbon remain poorly understood. To clarify these controls, we conducted high-frequency monitoring at 3-day intervals in the Lhasa River Basin on the Qinghai-Tibet Plateau from March to early July 2024. Dissolved organic carbon (DOC), dissolved inorganic carbon (DIC), major ions, and stable isotopes (δ13C-DOC, δ13C-DIC, δD, and δ18O) were measured to trace water sources and carbon dynamics. Our results reveal a pronounced pre-monsoon hydrochemical turning point, driven primarily by seasonal flow-path switching rather than by direct glacier meltwater inputs. During the early pre-monsoon period (March–mid-May), river discharge was dominated by groundwater, and DIC and major ions increased gradually while DOC remained relatively low. Distinct hydrochemical and isotopic shifts occurred around mid-May, coinciding more closely with sharp increases in air temperature. After mid-May, the river transitioned to a more mixed hydrological regime, as indicated by marked shifts in water isotopes (δ18O: −17.0‰ to −14.5‰; d-excess: 9.3‰ to 13.5‰), declining DIC and major ion concentrations, increasing DOC concentrations (0.7–2.0 mg C·L−1), and progressively more depleted δ13C-DOC (−25.8‰ to −28.5‰) and δ13C-DIC values (−4.5‰ to −6.9‰). These coupled patterns suggest that antecedent warming and initial thaw preconditioned near-surface hydrological connectivity and reorganized flow paths, thereby increasing the DOC mobilization from shallow organic-rich source areas while diluting groundwater-derived DIC and major ions with low-solute near-surface waters, including thaw and snowmelt contributions. Comparisons with glacier-fed streams further indicate that glacier meltwater contributes only marginally to downstream DOC in the Lhasa River. Overall, our findings show that pre-monsoon carbon dynamics in this high-alpine river are controlled primarily by thermally driven hydrological switching superimposed on early-season thaw, highlighting the sensitivity of alpine carbon export to short-lived connectivity pulses on the Qinghai-Tibet Plateau.

145. 题目: Slope position regulates soil organic carbon sequestration across particulate and mineral-associated fractions in karst soils
文章编号: N26071907
期刊: Environmental Technology & Innovation
作者: Xiaoxiao Zou, Qin Tang, Yujia Li, Qiang Li
更新时间: 2026-07-19
摘要: The sources and stability of particulate organic matter (POM) and mineral-associated organic matter (MAOM) fundamentally regulate soil carbon dynamics, but their characteristics in karst ecosystems remain poorly understood. This study focused on the typical peakless basin system in Guangxi, and soil samples were collected across slope positions. Using physical fractionation, 13C nuclear magnetic resonance spectroscopy, and biomarker analysis, our study characterized the sources and stability of POM and MAOM. Our results showed that with slope position, the contents of dissolved organic carbon, exchangeable magnesium, and exchangeable sodium in both POM and MAOM decreased significantly, whereas exchangeable calcium and iron increased. The alkyl C/O-alkyl C ratio in POM generally decreased along downslope, whereas the ratio in MAOM significantly increased at depression. Biomarker analyses indicated that microbial necromass carbon (MNC), primarily of fungal origin, was the dominant source of soil organic carbon (SOC) in POM and MAOM, while total lignin phenols (TLP) was significantly higher in POM than that in MAOM. Random forest analysis and structural equation modeling revealed divergent accumulation pathways. Specifically, exchangeable iron was identified as the primary predictor for POM, with TLP directly driving SOC sequestration. Conversely, microbial richness indirectly promoted SOC sequestration by enhancing MNC formation, which served as the primary mediator. By differentiating soil carbon fractions, this study reveals the distinct mechanisms of organic matter accumulation in POM and MAOM across karst slope positions. Consequently, these findings advance the mechanistic understanding of the spatial heterogeneity of soil carbon sinks and their underlying biogeochemical drivers in karst ecosystems.

146. 题目: Boosting bioenergy recovery from corn stover and food waste via Fe/Ni-modified biochar in anaerobic co-digestion: Synergistic electron transfer and metabolic regulation
文章编号: N26071906
期刊: Journal of Environmental Chemical Engineering
作者: Minhao Wu, Minglei Tang, Yipeng Zhang, Li Chen, Jiyong Bian, Dapeng Li, Longyi Lv
更新时间: 2026-07-19
摘要: Anaerobic co-digestion (AcoD) of corn stover (CS) and food waste (FW) represents a promising synergistic technical pathway for energy recovery from biomass waste streams. However, the practical deployment of this AcoD technology faces challenges such as low lignocellulose hydrolysis efficiency, excessive accumulation of volatile fatty acids (VFA), and imbalanced microbial community structure. Herein, a novel mild-reduction strategy was innovatively employed to fabricate Fe/Ni-bimetallic modified biochar (Fe/Ni-BC) to overcome these issues. Comprehensive characterization confirmed that Fe/Ni-BC featured abundant surface-active sites, excellent electrical conductivity, and superior electrochemical stability. Batch fermentation tests revealed that Fe/Ni-BC amendment enhanced cumulative methane production by 126% compared with the control group, with total solid (TS) and volatile solid (VS) removal efficiencies reaching 44.36% and 67.78%, respectively. Meanwhile, Fe/Ni-BC effectively buffered pH, alleviated VFA accumulation, and accelerated acidogenic substrate degradation. Microbial analysis demonstrated that Fe/Ni-BC significantly enriched functional hydrolytic and fermentative bacteria (e.g., Clostridium, Bacteroides) and both hydrogenotrophic and acetotrophic methanogens, which suggests favorable conditions for direct interspecies electron transfer and optimizes methanogenic pathways based on microbial community variations. Metabolic profiling further indicated that Fe/Ni-BC upregulated the core carbohydrate metabolism module and boosted the activities of key lignocellulolytic enzymes, including β-glucosidase, cellulase, and α-glucosidase. This study provides a novel feasible strategy for efficient AcoD intensification, clarifies the synergistic mechanism of Fe/Ni bimetallic biochar for enhancing anaerobic digestion, and offers valuable guidance for sustainable biomass waste-to-energy conversion.

147. 题目: Pore regulation of chitosan biochar and its efficient adsorption of dyes in high-salty wastewater: Revealing the effect of NaOH distribution on pore shape
文章编号: N26071905
期刊: Journal of Environmental Chemical Engineering
作者: Tailin Guo, Shan Gao, Tengfei Ren, Jianxin Liu, Jiancheng Wang
更新时间: 2026-07-19
摘要: Porous biochar represents an important adsorbent for the adsorption removal of dyes, largely owing to its mesopores structure. Nevertheless, the treatment of dye-containing pollutants, particularly those in high-salty wastewater, still poses a persistent challenge in the environmental field. Herein, we report a facile strategy to fabricate hierarchical micro-mesoporous structure dominated by mesopores, by regulating the distribution of NaOH within chitosan beads (CB). It was found that when NaOH is distributed both inside and outside the CB, a novel hierarchical pore architecture with a proposed “funnel-like” morphological feature can be formed in the resulting biochar (denoted CBWn-T-t). When evaluated as an adsorbent, CBW2-800–2 showed adsorption capacities of 789.89 mg/g, 571.76 mg/g, and 376.08 mg/g for MB, NR, and MO, respectively. It can be attributed to the stacking of dye molecules within the proposed “funnel-like” pores during adsorption. Notably, CBW2-800–2 delivered an adsorption capacity as high as 939.97 mg/g in high-salinity MB solutions and reached adsorption equilibrium within 15 min, indicating both enhanced adsorption capacity and accelerated kinetics. The adsorption process was mainly governed by pore filling, π-π interactions, and hydrogen bonding. To the best of our knowledge, this work is the first to systematically elucidate how NaOH distribution during material preparation affects the porous topology of biochar. The adsorbent with the proposed novel “funnel-like” pore structure exhibited superior adsorption capacity for organic dyes, especially in high-salinity wastewater.

148. 题目: Effects of cellulase treatment on properties and functional performances of hardwood-like lignocellulose-based biochar and its modified derivatives
文章编号: N26071904
期刊: Bioresource Technology
作者: Kai Yang, Kang Wang, Wenyan Xie, Wenjuan Wang, Wen Tao Li, Jing Cao, Jing Wang, Han Tang, Min-tian Gao, Jiajun Hu, Jixiang Li
更新时间: 2026-07-19
摘要: Treating lignocellulosic agricultural wastes with cellulase generates monosaccharides for biofuel production and saccharification residues that can be converted into biochar with better performance than those from untreated materials. However, while cellulase pretreatment is highly effective for gramineous straws, its efficacy on hardwood-like lignocellulosic materials remains unknown. This study explored the applicability of cellulase pretreatment to tobacco stalks (hardwood-like) for biochar preparation. Results showed cellulase pretreatment enhanced biochar stability and subsequent optimization via thermal air oxidation and colloid modification further improved its performance, confirming it as a high-quality precursor biochar. Cellulase pretreatment primarily increased raw material crystallinity, which in turn improved biochar crystallinity and structural stability. Compared with untreated biochar (BC-O), colloid-modified biochar (BC-SAC) exhibited a rise in specific surface area from 4.9 to 344.1 m2/g, alongside rapid phenol adsorption reaching equilibrium within 12 h and enhanced removal performance toward various phenolic contaminants. Environmental and economic evaluations indicated that BC-SAC achieved a carbon emission reduction of 0.68 t CO2 per year per ton of feedstock. Additionally, its iodine value, a key pricing index for carbon-based adsorbents, rose from 503 mg/g to 881 mg/g. This study broadens the feedstock scope of cellulase pretreatment for biochar production and is of great significance for efficient multi-product utilization of lignocellulosic biomass resources.

149. 题目: Membrane and electric field co-assisted promotes the reduction of greenhouse gas emission coupled with humification of thermophilic composting
文章编号: N26071903
期刊: Environmental Research
作者: Dandan Liu, Kaipeng Zhai, Li Chen, Yuchen Liu, Jie Ye, Dayong Chen, Zhen Yu, Jian Lü, Hao Lin, Zhi Chen
更新时间: 2026-07-19
摘要: Electrical field-assisted thermophilic composting (eTC) is considered a promising technology for enhancing compost maturation, while membrane-covered composting is an effective strategy for reducing harmful gas emissions. However, the combined application of membrane and electric field to simultaneously enhance organic matter humification and mitigate greenhouse gas emissions during composting has rarely been explored. In this study, we constructed membrane and electric field co-assisted thermophilic composting (m-eTC) and confirmed its effect on promoting organic matter humification and greenhouse gas emissions reduction, respectively. The results showed that humic acid content in m-eTC was 1.22- and 1.15-fold higher than that in ordinary thermophilic composting (oTC) and eTC, respectively. Moreover, the global warming potential, expressed as CO2-equivalent emissions, was reduced by 11.9% and 9.8% compared with oTC and eTC. Microbial analyses revealed selective enrichment of humification-related bacteria (e.g., Nocardiopsis and Saccharomonospora) and regulation of key functional genes related to greenhouse gas emissions (e.g., pmoA and norB) in the m-eTC system. Interactive Mantel test and partial least-squares path modeling further demonstrated that m-eTC significantly enhanced the positive effects of composting properties and small-molecule organic acids on organic matter humification. In contrast, m-eTC attenuated the positive effects of composting properties and bacterial activity on greenhouse gas emissions. This study indicated that m-eTC is an effective strategy for simultaneously reducing greenhouse gas emissions and promoting organic matter humification, offering a promising pathway for efficient and sustainable organic solid waste management.

150. 题目: Organic Matter Removal in Microplastic Extraction from Environmental Samples: Challenges and Methodological Solutions
文章编号: N26071902
期刊: Journal of Hazardous Materials
作者: Hrithik Nath, Shiva Zolfaghari, Melissa A Maurer-Jones, Gopala Krishna Darbha, Maryam Salehi
更新时间: 2026-07-19
摘要: Accurate quantification and characterization of microplastics (MPs) in complex environmental samples is essential. Achieving this requires reliable protocols for extracting and isolating MPs from other matrix components that may interfere with analytical detection or hinder recovery. To address this need, this paper focuses on the removal of biogenic organic matter (OM), a major constituent of terrestrially derived environmental samples and water samples. We discussed how the interferences caused by OM, such as biofilms, algae, plankton, plant debris, and microbial residues, can reduce separation efficiency, clog filtration systems, overlap with MP signals in microscopy and spectroscopy, or introduce background noise in thermal analyses, ultimately leading to misidentification or false positives. To address these issues, a preparatory step involving the efficient removal of OM while minimizing alterations to the physicochemical properties of MP particles is essential. In this paper, we present a detailed discussion of various OM digestion methodologies and factors such as temperature and duration impacting their efficiencies. Moreover, the potential impacts of these methodologies on the MPs’ physicochemical properties, such as surface chemistry and size distribution, are discussed. The most common methods involve oxidative, acidic, alkaline, and enzymatic digestions showed varied levels of OM removal efficiency. Integrating these approaches has shown to enhance OM digestion while minimizing damage to MPs, thereby offering optimized performances for diverse environmental samples while preserving polymer stability.

151. 题目: Organic matter enrichment and warming synergistically drive sediment phosphorus release in macrophyte-dominated lakes: Geochemical and microbial mechanisms
文章编号: N26071901
期刊: Journal of Cleaner Production
作者: Fajian Li, Yaobin Lv, Chunmin Zhang, Xue Zhang, Hongbin Yin, Ming Kong
更新时间: 2026-07-19
摘要: Sediment phosphorus (P) release generally intensifies with warming; yet the synergistic effects of temperature and organic matter (OM) enrichment on P dynamics remain poorly understood. In this study, we conducted long-term microcosm incubations under ambient and elevated temperatures using sediments with equivalent total P but varying OM contents. The results showed that elevated OM expanded the sedimentary mobile P (Mobile-P) pool; high-OM sediments (M-10%) contained 1.5 times more Mobile-P than low-OM sediments (M-2%). Warming and high-OM loading synergistically increased the sediment oxygen uptake rate and compressed the interfacial oxidation layer (<2 mm). Consequently, the average soluble reactive phosphorus (SRP) release flux in the M-10% treatment on day 15 was 47 times that of the M-2% treatment. This intense P release was driven by the reductive dissolution of iron-bound P (BD-P), the enzymatic hydrolysis of organic P (Org-P), and the chemical dissolution of calcium-bound P (HCl-P). Microbial analysis further revealed that high OM enrichment upregulated genes involved in Org-P hydrolysis (phoD) and iron reduction (mtrC). However, warming reshaped the dissolved organic matter (DOM) pool in the M-10% treatment, where accumulated insoluble humic acids immobilized SRP via chemical complexation with metal cations, thereby reducing the SRP flux by day 50. Nevertheless, this flux remained 21 times that of the M-2% treatment. This study elucidates the key geochemical and microbial mechanisms by which macrophyte-derived OM enrichment promotes sediment P release under warming, providing critical insights for sediment management and eutrophication control in macrophyte-dominated ecosystems.

152. 题目: Regional-scale prediction and assessment of soil organic matter content in the Yuanmou Dry-Hot Valley, Southwest China, using satellite-derived phenological time series and deep learning.
文章编号: N26071719
期刊: Environmental Monitoring and Assessment
作者: Dengdeng Ding, Jida Yang, Sihe Deng, Hongye Zhu, Zhengbo Ma, Chengxiu Fu, Junlang Deng, Dingyun Zhao, Zhen Long, Xiaoyan Wang, Peiwen Yang, Qibin Chen, Qing Zhang
更新时间: 2026-07-17
摘要: The dry-hot valley region is characterized by pronounced topographic relief and a complex land-use mosaic, resulting in strong nonlinearity and fine-scale spatial heterogeneity in soil organic matter (SOM). These characteristics increase the difficulty and uncertainty of remote sensing-based digital soil mapping. Although Yuanmou County has been widely investigated, limited attention has been paid to regional-scale SOM prediction in dry-hot valley ecosystems using long-term satellite-derived phenological dynamics and deep learning approaches. To address this gap, this study integrated 475 topsoil samples, topographic factors, environmental covariates, and multi-year satellite-derived phenology time-series variables to develop a regional-scale SOM prediction and assessment framework in Yuanmou County, Yunnan Province, China. The predictive performance of four models was compared, including a convolutional neural network (CNN), a CNN-random forest hybrid model (CNN-RF), a CNN-long short-term memory model (CNN-LSTM), and an attention-augmented CNN-LSTM model (CNN-LSTM-Att). The results showed that model architecture had a substantial influence on SOM prediction accuracy, with overall performance ranked as CNN-LSTM-Att > CNN-LSTM > CNN-RF > CNN. Among the four models, CNN-LSTM-Att achieved the best performance on the independent test set, with R2 = 0.61, RMSE = 2.49 g kg⁻1, and MAE = 1.39 g kg⁻1. The incorporation of temporal modeling and the attention mechanism improved the extraction of dynamic phenological signals associated with SOM formation, resulting in a more refined spatial representation. The CNN-LSTM-Att prediction map clearly identified low-SOM areas along the northern valley corridor and high-SOM zones in the forest-dominated southern and eastern regions, while showing stronger sensitivity to local patches and transitional ecotones. Overall, coupling long-term phenological dynamics with an attention mechanism improved both the predictive accuracy and spatial expressiveness of SOM mapping in complex terrain, providing a useful methodological reference for SOM assessment and precision land management in dry-hot valley regions.

153. 题目: The influence of microplastic type on biochar efficacy in Cd-microplastic co-contaminated soils: divergent impacts of PLA versus PE in pepper
文章编号: N26071718
期刊: Journal of Soils and Sediments
作者: Yanhang Zhong, Yawen Shen, Jingwen Bi, Yuge He, Shushu Liu, Xin Feng, Liangmeng Ni, Zhijia Liu
更新时间: 2026-07-17
摘要: Purpose Microplastics (MPs) and cadmium (Cd) often co-occur in farmland soils, but it remains unclear whether microplastic type changes Cd mobility and the remediation efficacy of biochar. This study compared whether polyethylene (PE) and polylactic acid (PLA) differentially regulate Cd bioavailability, plant uptake, and biochar remediation effect in a soil-pepper system. Materials and methods A pot experiment with pepper (Capsicum annuum L.) was conducted using PE, PLA, Cd, and their combined treatments with or without biochar amendment. Soil properties, plant growth and microbial communities were analyzed. Results Responses were strongly dependent on microplastic type. PLA, especially under PLA + Cd co-contamination, acidified soil, increased exchangeable Cd, suppressed pepper growth, and reduced yield. PE caused much weaker disturbance, and PE + Cd behaved similarly to the Cd treatment. Biochar generally increased soil organic carbon and improved soil enzyme activities and microbial diversity, while reducing exchangeable Cd and plant Cd in Cd- and PE + Cd-treated soils, thereby promoting plant recovery. In contrast, biochar showed limited efficacy under PLA + Cd because persistent acidification maintained high Cd mobility and constrained biological recovery. Conclusions Microplastic type determined both Cd risk and the effectiveness of biochar in co-contaminated soils. PLA enhanced Cd bioavailability through acidification and narrowed the effective remediation window of biochar, whereas PE did not. These findings indicate that identifying microplastic type and managing soil pH are critical for successful remediation of Cd-microplastic co-contaminated soils.

154. 题目: Ambient black carbon and its dependence on in situ stubble burning.
文章编号: N26071717
期刊: Environmental Monitoring and Assessment
作者: Vikas Goel, Ajit Kumar, Anjanay Pandey, Mohd Faisal, Umer Ali, Rakesh Maity, Ravindra Khaiwal, Suman Mor, Vikram Singh, Mayank Kumar
更新时间: 2026-07-17
摘要: Crop residue burning (CRB) in Northern India is a serious concern that poses substantial health risks and deteriorates air quality in the Indo-Gangetic Plain (IGP) region via regional transport. Despite governmental regulations and various interventions, the practice remains prevalent. In this study, we investigate the influence of CRB on ambient black carbon (BC) level in rural areas of Punjab during the post-monsoon period. BC source contributors were quantified using Aethalometer model (AM) and positive matrix factorization (PMF) approaches. Interestingly, despite the distinct mathematical framework of these two models, their results showed good agreement. Although the measurements were conducted in the agricultural field, CRB contributed on average 48% to the total BC, periodically exceeding 90% during the active burning hours (1:00 PM-6:00 PM), resulting in strong diurnal variation. In addition to the CRB several other BC sources, e.g. traffic emissions (20.2%), power plant emissions (24.0%), waste incineration (2.0%), and a Pb-rich industrial factor (6.1%) were also quantified. The BC concentration measured during the study ranged from 1.45 to 85.0 µg/m3 with an average of 12.6 µg/m3. Absorption Ångström exponent (AAE) was also calculated and observed to be 1.7 ± 0.3, with hourly variations ranging from 1.1 to 2.4, suggesting a significant influence of CRB. Furthermore, spectral variation in absorption characteristics of BC and brown carbon (BrC) was also evaluated, providing insight into the optical properties of fresh biomass-burning carbonaceous aerosols. The study highlights the persistent dominance of CRB emissions in shaping rural aerosol composition. Moreover, when transported by prevailing winds, these aerosols substantially influence air quality across the IGP. Forward wind trajectory analysis further demonstrates that air masses originating in Punjab frequently move toward the IGP region, supporting the observed regional impact of CRB emissions. These findings provide quantitative evidence to support targeted policy interventions, including stricter enforcement of crop residue burning bans, wider adoption of sustainable residue management alternatives, and regionally coordinated air quality mitigation strategies across the IGP.

155. 题目: How does moisture content regulate EPS dynamics and microbial interactions to mediate erosion resistance in sewer sediments?
文章编号: N26071716
期刊: Environmental Research
作者: Bingchan Jia, Xinyu Zhao, Meili Zhang, Jian Wang, Xinyue Yuan, Zhaoxia Xue, Jingyang Luo, Xindi Chen, Qian Feng
更新时间: 2026-07-17
摘要: The erosion resistance of sewer sediments is a key determinant of hydraulic efficiency and flood risks in urban drainage systems. In real sewer networks, sediment moisture content fluctuates substantially due to intermittent drainage, seasonal variation, and storm inflow pulses, yet its influence on microbially mediated sediment stability remains poorly understood. This study systematically investigated how moisture content regulates extracellular polymeric substances (EPS) dynamics, microbial community structure, and microbial interactions in sewer sediments across a moisture range of 10.10-59.09%. Sediments at intermediate moisture levels (29.17-40.91%) exhibited the highest erosion resistance, with EPS content strongly positively correlated with critical shear stress (R2 = 0.92). Moderate moisture also enriched key EPS-producing taxa and promoted a more cooperative microbial interaction pattern, thereby enhancing the capacity of the community to withstand scouring disturbance. These findings introduce the concept of adaptive moisture window, representing the moisture range where microbial activity and EPS secretion are most favorable for sediment stability. This framework provides new insights into predicting sediment cohesion under variable sewer moisture regimes and offers new guidance for adaptive sediment management in urban drainage systems.

156. 题目: Improving monitoring of microplastics in soils and biosolids using near-infrared spectroscopy: the effect of organic matter.
文章编号: N26071715
期刊: Journal of Environmental Management
作者: Luana Circelli, Erika Di Iorio, Zhongqi Cheng, Ruggero Angelico, Martina Cusano, Claudio Colombo
更新时间: 2026-07-17
摘要: Microplastics (MPs) are emerging contaminants ubiquitously present in the environment, yet their rapid quantification in complex matrices such as soils and biosolids remains challenging because of spectral interference from organic matter (OM). This study investigates, for the first time, how high OM contents influence the spectral detectability and machine-learning-based quantification of high-density polyethylene (HDPE) and polystyrene (PS) polymers (at 0-8% v/v) in soils and biosolids. Pre-processed NIR spectra were analysed using partial least squares-discriminant analysis (PLS-DA) to identify MP- and OM-related wavelength regions via variable importance in projection (VIP), which were subsequently used as inputs for four regression algorithms (PLS, support vector machines, random forest and custom neural network). In soils with low OM (0.78-1.23%), HDPE and PS produced polymer-specific absorption features and were predicted with excellent accuracy (up to R2 = 0.96 and residual prediction deviation, RPD = 5.19), using a relatively small set of VIP-selected wavelengths. In biosolids with very high OM (64-72%), polymer bands were partially masked, and VIP scores shifted towards OM-dominated regions. However, prediction performance remained robust, especially for HDPE with neural network model (R2 = 0.98, RPD = 6.41). Overall, although the OM strongly influenced the spectral regions driving model predictions and partially reduced discrimination among MP concentration levels, it does not prevent accurate quantification of MPs when appropriate variable selection and machine-learning strategies were applied. These findings demonstrate that NIR spectroscopy coupled with targeted variable selection and advanced regression can provide robust, non-destructive estimation of MP contamination in OM-poor soils and OM-rich biosolids, highlighting key spectral features to prioritise in future studies targeting natural organic-rich samples with low-MP concentration.

157. 题目: Raman imaging of the phycosphere reveals sharp gradients of organic matter exuded by single phytoplankton cells
文章编号: N26071714
期刊: Proceedings of the National Academy of Sciences of the United States of America
作者: Zachary C Landry, Riccardo Foffi, Valerio Anelli, Paolo Arosio, Marcos Gil-Garcia, Richard J Henshaw, Oliver Müller, Giacomo Paccagnan, Timo N Schneider, Carsten J Schubert, Jonasz Słomka, Kang Soo Lee, Tomaso Zambelli, Sophie T. Zweifel, Roman Stocker
更新时间: 2026-07-17
摘要: Phytoplankton cells exude a wide array of chemicals in the water column, generating a localized microenvironment known as the phycosphere. Although it is now well accepted that the phycosphere mediates interactions between phytoplankton and bacteria, the chemical gradients around individual phytoplankton cells have never been explicitly measured, and their shape has been classically assumed to be set by ideal diffusion. Here we used Raman microspectroscopy to obtain micrometer-scale measurements of the concentration profile of a phytoplankton metabolite (fucoxanthin) around individual phytoplankton cells of different species, having radii between 2.5 and 60 μ m. We found that fucoxanthin concentration decreases more rapidly with distance from the cell than predicted by ideal diffusion, showing that the phycosphere includes compounds whose diffusion is characterized by nonideal effects. We explain this observation using a space-dependent diffusivity model where nonideality arises from viscosity and solubility gradients in the extracellular environment. Our results suggest an onion-structured model of the phycosphere, in which small hydrophilic solutes that obey ideal diffusion generate broad but weak gradients, whereas insoluble compounds are retained within 10 to 20 μ from the phytoplankton cell surface and yield steep gradients of organic matter. These observations, supported by evidence that fucoxanthin can act as an effective chemoattractant for marine bacteria, show the existence of strong and highly localized chemical cues with potentially far-reaching impacts on microbial interactions in aquatic environments. These findings highlight the importance of directly measuring the microscale chemical landscape experienced by marine microbes.

158. 题目: The Aridity Threshold of Soil Organic Carbon Density Along the Climate Aridity Gradient in the Alpine Ecosystem of the Qinghai‐Tibetan Plateau
文章编号: N26071713
期刊: Land Degradation & Development
作者: Qiao Cui, Zongxing Li, Xufeng Wang, Juan Gui, Baijuan Zhang, Yunying Wang
更新时间: 2026-07-17
摘要: Soil organic carbon density (SOCD) is a key indicator for evaluating the stability of soil carbon pools, especially in alpine ecosystems that are sensitive to climate change. However, research on the response of SOCD to different aridity gradients is still limited. Therefore, we conducted extensive sampling along different aridity gradients of the Qinghai‐Tibetan Plateau to study how SOCD varies with aridity gradients and how environmental factors drive changes in SOCD under different aridity gradients. The study has found that the SOCD at depths of 0–100 cm on the Qinghai‐Tibetan Plateau ranges from 0.39 to 78.12 kg C m −2 . Meanwhile, the SOCD is higher in the more humid southeastern region than in the more arid northwestern region. Topography, climate, and vegetation factors jointly regulate the distribution of SOCD. The SOCD shows a nonlinear variation trend and decreases with the increase of aridity; the key aridity threshold is 0.66. The altitude, aridity, mean annual temperature (MAT), and normalized vegetation index (NDVI) are the main drivers of SOCD below this threshold (low aridity gradient). Moreover, the SOCD is primarily affected by the NDVI and MAT above this threshold (high aridity gradient). The above research results emphasize the differences in SOCD across aridity gradients, suggesting that it may be possible to mitigate the negative impact of aridification on soil organic carbon by increasing vegetation coverage in areas with high and low aridity gradients.

159. 题目: Iron Oxide Types Determine the Regulatory Effects of Biochar on Carbon Emissions from Arsenic-Contaminated Soils
文章编号: N26071712
期刊: Water, Air, & Soil Pollution
作者: Qi Li, Wenjing Li, Yanyan Lu, Sada Tanzil, Wan Yang, Muhammad Mahroz Hussain, Shengsen Wang
更新时间: 2026-07-17
摘要: Arsenic (As) remediation in flooded paddy soils through iron (Fe) redox cycling can be influenced by carbon-based amendments, yet the CO2 emission in this process remain unclear. This study evaluated the effects of Fe oxides with contrasting crystallinity, goethite (Gt) and ferrihydrite (Fh), with or without biochar (BC) amendment, on As immobilization, geochemical fractionation and microbial-carbon dynamics from As-contaminated paddy soil under reduced conditions. The results showed that Fh and Gt, with BC addition, significantly (p < 0.05) reduced As bioavailability by 87.5% (0.39 mg kg−1) and 76.6% (0.73 mg kg−1), respectively, compared to control. Partial Least Squares Path Modeling revealed a strong negative direct effect of Fe-oxides on As (β = -3.86), confirming their role as the principal gatekeepers for As sequestration. Iron oxides application increased the CO₂ flux; however, a dramatic decrease was observed with BC application to Fe oxide-treated soils. This elucidates that the increased C emission from As-contaminated soil induced by Fh or Gt can be compromised by BC application, although the extent of reduction depends on the type of Fe oxide. Microbial community analysis revealed increased relative abundance of Pseudarthrobacter and Anaerolinea in Fh-amended soils, highlighting their potential role in carbon cycling processes. Fe oxides recruited Fe(III)-reducing bacterial guilds (Firmicutes, Proteobacteria) to drive CO₂ emissions, whereas BC addition suppressed reshaped functional potentials of these taxa, explaining the trade-off between reduced CO₂ and As immobilization. This study provides an insight towards the mitigation of As contamination and GHG emission through co-application of Fe oxides and BC as a sustainable approach.

160. 题目: Abiotic Pathways Bridge the Molecular Transformation from Terrestrial to Lacustrine Dissolved Organic Matter in Shallow Lakes.
文章编号: N26071711
期刊: Environmental Science & Technology
作者: Xueyan Liu, Kangping Cui, Yiling Yao, Hongjia Yao, Minshu Cui
更新时间: 2026-07-17
摘要: Terrestrial dissolved organic matter (DOM) is a dominant allochthonous input to shallow lakes but exhibits low bioavailability due to prior microbial degradation and complex aromatic structures. In contrast, lacustrine DOM is more saturated and structurally homogeneous, implying in-lake transformation. Herein, we investigated the abiotic transformation of terrestrial and lacustrine DOM using Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS), linkage reaction classification, and XGBoost-SHAP machine learning. Under coupled simulated sunlight and MnO2 exposure, terrestrial DOM is more prone to dearomatization and partial oxidation, with limited carbon backbone cleavage due to stable condensed aromatic frameworks. Conversely, while partial oxidation remains a primary pathway, aliphatic-rich lacustrine DOM readily undergoes carbon backbone fragmentation. Notably, MnO2 acts as an electron acceptor and reactive oxygen species regulator, mitigating direct photosensitized carbon backbone cleavage while enhancing oxidation and structural complexity. Machine learning confirms that, despite distinct origins, both DOM types exhibit consistent shifts toward higher oxygenation and aliphatic character. Furthermore, this analysis provides new insights, identifying the nitrogen content and DBE/O as universal indicators of DOM reactivity. Ultimately, abiotic processes impose common molecular constraints, guiding DOM transformation along partially convergent pathways and driving structurally distinct DOM pools toward a shared chemical fate.