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21. 题目: Toward carbon-neutral wastewater treatment: Pharmaceutical mineralization via UV/H2O2/persulfate photolysis coupled with CO2 capture using ultrasonically activated olive pomace biochar
文章编号: N26051401
期刊: Chemical Engineering Journal
作者: J M Monteagudo, A Durán, J M Carrasco, P Castellanos, J Díaz, Jaime Monteagudo
更新时间: 2026-05-14
摘要: This study presents an integrated strategy toward carbon-neutral wastewater treatment by coupling Advanced Oxidation Processes with in situ CO2 capture in a closed-loop system using ultrasonically activated olive pomace biochar. The mineralization of a representative pharmaceutical mixture containing amoxicillin, sulfamethoxazole, and nimesulide was carried out using UV-C/H2O2 and UV-C/H2O2/S2O82− processes under mild conditions (natural pH ≈ 9, ambient temperature, low-power UV irradiation). The persulfate-assisted system significantly enhanced mineralization kinetics, achieving complete Total Organic Carbon (TOC) removal within 75 min under optimal conditions ([H2O2]o = 375 mg L−1, [S2O82−]o = 200 mg L−1). The CO2 generated during mineralization was continuously transferred from the aqueous phase to the gas phase and quantified in real time within a closed recirculation loop, enabling direct coupling between oxidation and carbon capture. The produced CO2 was subsequently captured in a fixed-bed column packed with biochar, demonstrating the feasibility of simultaneous pollutant removal and carbon mitigation. Radical scavenging experiments confirmed that hydroxyl (HO•) and sulfate (SO4•-) radicals were the predominant reactive species governing degradation. Ultrasonic activation markedly improved the biochar textural properties, increasing the CO2 adsorption capacity from 17.68 to 168 mg CO2 g−1. Regeneration experiments demonstrated high reversibility over five adsorption–desorption cycles. Comprehensive characterization (BET, SEM, Raman, FTIR, and XPS) revealed that ultrasonic cavitation enhances microporosity, removes mineral phases, and promotes surface carbon enrichment. XPS analysis further demonstrated reversible formation of carbonate-type surface species after CO2 capture and preservation of active sites after repeated cycles. Overall, the proposed system demonstrates that AOP-driven mineralization and CO2 capture can be effectively integrated within a single platform, providing a novel pathway toward carbon-aware wastewater treatment and circular valorization of agricultural residues.

22. 题目: Widespread Occurrence of Tire Wear p-Phenylenediamines and Their Quinones in Cloud Water
文章编号: N26051306
期刊: Environmental Science & Technology
作者: Runqi Zhang, Dongmei Cai, Jiangbin Shu, Xiaokang Wu, Xinke Wang, Yunqian Chen, Ling Li, Qing Li, Mingliang Fang, Lin Wang, Weijun Li, Abdelwahid Mellouki, Christian George, Jianmin Chen
更新时间: 2026-05-13
摘要: P-Phenylenediamines (PPDs), widely used tire antioxidants, undergo oxidation to form toxic quinones (PPD-Qs). Despite their detection in diverse environmental media, the role of cloud water in environmental fate remains unknown. This study employed ultrahigh-performance liquid chromatography-Orbitrap mass spectrometry to investigate ten PPDs and PPD-Qs in cloud water collected from Tianmu Mountain in China─a remote background site with minimal industrial/human activity. The concentrations of PPDs (3.0–43.7 ng/L) are markedly exceeding their transformation products (PPD-Qs, 0.2–11.5 ng/L), with IPPD and 6PPD dominating. PPDs exhibited greater accumulation in water-insoluble organic matter (WISOM) than in water-soluble organic matter (WSOM), with enrichment factors (concentration of PPDs in WISOM/concentration of PPDs in WSOM) ranging from 1.13 to 1.88, indicating a stronger tendency for particle-phase partitioning. Significant positive correlations linked PM_2.5 levels with the deposition fluxes of both PPDs and PPD-Qs in WSOM and WISOM, demonstrating cloud water’s key role in their atmospheric transport and wet deposition. This study presents the first characterization of PPDs and their quinone derivatives’ distribution and environmental behavior in cloud water, revealing clouds’ significant role in the fate of rubber-derived pollutants. The findings reveal clouds as pivotal reactors for tire-derived pollutants, driving oxidation and multiphase portioning, previously overlooked in global contaminant cycling.

23. 题目: Mechanistic insights into dissolved organic matter removal by magnesium-doped activated carbon: From model humic acid to real wastewater.
文章编号: N26051305
期刊: Journal of Environmental Management
作者: Tao Wang, Kean Zhu, Wenjing Zheng, Jianfeng Ye, Zuxin Xu, Wei Jin
更新时间: 2026-05-13
摘要: Dissolved organic matter (DOM) poses a major challenge for efficient water treatment. While traditional adsorbents are often developed using model compounds like humic acid (HA), their efficacy against complex DOM in real wastewater remains uncertain. This study aims to elucidate the mechanistic basis of this performance discrepancy by evaluating the adsorption behaviors of HA, salicylic acid (SA), and real wastewater DOM on magnesium-doped activated carbon. The results show that increasing magnesium doping enhanced HA removal, achieving up to 98% removal, whereas higher magnesium loading reduced adsorption capacity for real DOM. In contrast, unmodified activated carbon achieved only a 12% removal rate for HA but exhibited an 80% removal rate for SA, and demonstrated a higher capacity for adsorbing real DOM (with a maximum adsorption capacity of 54.77 mg C/g) and broad-spectrum DOM removal (achieving 95-97% removal for C1-C3 components identified by PARAFAC analysis). Mechanistic analysis revealed that magnesium doping enhances HA removal primarily through metal-organic complexation, as evidenced by zeta potential measurements showing neutralization of HA's negative surface charge from -44.5 mV to -10.7 mV, a 3.2-fold increase in the particle size of HA-Mg complexes, and potentiometric titration indicating that 94% of HA's carboxyl groups (which account for 89.2% of its acidic sites) were involved in magnesium binding. This study provides quantitative mechanistic evidence that the effectiveness of Mg-based strategies depends primarily on the carboxyl functional groups of DOM, highlighting that adsorbent development needs to move beyond HA benchmarks and consider the actual compositional features of real wastewater DOM.

24. 题目: Mechanistic insights into activation of periodate by sludge biogas residue biochar loaded with manganese for efficient sulfadiazine degradation in aqueous solutions.
文章编号: N26051304
期刊: Journal of Environmental Management
作者: Hao Xu, Xiaolong Chen, Jing Zhu, Yulong Li, Lie Yang
更新时间: 2026-05-13
摘要: The sewage sludge anaerobic digestion process produces a large amount of biogas residue. This study proposes a new path for the resource utilization of sludge biogas residue. Biogas residue biochar (BRBC) showed efficient periodate (PI) activation capability after hydrothermal loading of Mn. Under neutral conditions, the optimal removal rate of sulfadiazine (SDZ) could reach 100% within 5 min, and the pseudo-first-order kinetic reaction constant of the Mn-modified biogas residue biochar (Mn-BRBC) activating the PI system was 0.6942 min-1, which was 8.97 times that of the BRBC/PI system. It was confirmed that 1O2 plays a dominant role in the degradation process of SDZ. Characterization results showed that the hydrothermal process changes the vacancy structure of the BRBC surface, and the rearrangement of surface biomass during the process produces abundant oxygen-containing functional groups. Electrochemical experiments demonstrated that the ability of BRBC-mediated electron transfer was significantly enhanced after Mn loading. The biotoxicity of the sulfadiazine degradation products was greatly reduced compared with that of the parent pollutant. Moreover, the system achieved sulfadiazine degradation rates of 88.4% and 83.35% in tap water and lake water, respectively. This study offers a highly promising method for the resource utilization of sludge digestate.

25. 题目: Integration of tailored Co3O4@G with porous biochars for efficient degradation of tetracycline
文章编号: N26051303
期刊: Frontiers in Environmental Science
作者: Meiling Zhu, Yuejie Wang, Ruirui Li, Feng Liang
更新时间: 2026-05-13
摘要: Graphitic-carbon-coated metallic-catalyst-loaded porous carrier composites are widely used to degrade antibiotics by activating peroxymonosulfate (PMS). Integration of the defect sites within the graphitic shell, core–shell interface, and catalyst/carrier could enhance the “1 + 1 > 2” catalytic effect. In this work, graphitic-carbon-coated cobaltosic oxide (Co 3 O 4 @G) having a tailored nanostructure (23.3–29.7 nm for the core and 2.35–1.29 nm for the shell) was first synthesized by pulsed laser ablation. Then, porous Co 3 O 4 @G/biochars (Co 3 O 4 @G/Bs; 18.5–134.8 m 2 /g) were synthesized by crosslinking nitrogen-modified Co 3 O 4 @G with waste bamboo-pyrolyzed biochars. The degradation behaviors were evaluated as functions of the composite species, catalyst dosage, PMS concentration, tetracycline concentration, solution pH, and coexisting anions. The Co 3 O 4 @G/Bs presented high catalytic k values (0.159–0.449 min –1 ) that were 15.5–40.8 times higher than those of the individual biochars; furthermore, excellent recycling performance (92.5% remaining k value) and promising stability (8.31–2.77 μg/L of Co leakage) were observed after recycling 10 times. The favorable catalytic versatility of the Co 3 O 4 @G/Bs was verified by the efficient degradations of levofloxacin (88.6%), oxytetracycline (95.4%), and norfloxacin (92.5%). The degradation mechanism was governed by the radical-based degradation pathways involving •OH, SO 4 •– , and 1 O 2 via Co 3+ and Co 2+ recycling. The present study is expected to provide a valuable reference for degrading antibiotics by integrating tailored laser-ablated core/shell nanoparticles with biochars.

26. 题目: Soil Organic Carbon Improves Crop Yield and Yield Resilience
文章编号: N26051302
期刊: Global Change Biology
作者: Alison E King, Eunkyoung Choi, Jesse Burkhardt, Nathaniel D Mueller
更新时间: 2026-05-13
摘要: Increasing soil organic carbon (SOC) has been proposed as a strategy to promote crop yield resilience under extreme hydroclimatic stress, particularly drought, due to its positive effect on soil available water-holding capacity. We analyze how SOC mediates the relationship between US rainfed crop yields (1981–2020) and growing season hydroclimatic conditions—defined by soil water supply and atmospheric water demand—over 67,000 county-years across three major crops. We show that higher SOC is consistently associated with increased crop yields and yield resilience, evidenced through reduced interannual variability. Contrary to prevailing expectations, the largest yield gains from SOC occur during moderate water supply conditions—not drought. Under drought, water supply to crops may be more limited by water inputs to soil than by soil water-holding capacity, constraining the benefit provided by SOC regeneration. Furthermore, because moderate conditions are more frequent than drought or wet extremes, the largest production gains from SOC accumulate under moderate conditions. These findings indicate that SOC regeneration can enhance drought resilience to some degree but cannot compensate for extreme water scarcity; the services SOC provides to crops, including water storage, require water for their effective delivery.

27. 题目: Molecular-Level Exploration of Pyrogenic Dissolved Organic Matter in Charcoal and Soot Produced Simultaneously by the Combustion of Rice Straw
文章编号: N26051301
期刊: Environmental Science & Technology
作者: Xu Yan, Tao Cao, Hao Chen, Cuncun Xu, Jianzhong Song, Yin Zhong, Bin Jiang, Haiyan Song, Yingjun Chen, Guohua Zhang, Ping’an Peng
更新时间: 2026-05-13
摘要: Biomass burning is a substantial source of pyrogenic dissolved organic matter (PyDOM), yet the molecular-level differences between PyDOM derived from charcoal and soot remain poorly constrained. This study systematically compared the molecular characteristics of PyDOM from charcoal and soot coproduced by the combustion of rice straw under different temperatures and oxygen levels via ultrahigh-resolution mass spectrometry. The molecular composition of charcoal PyDOM showed significant temperature-dependent variations, whereas soot PyDOM exhibited negligible alterations with different temperatures. Moreover, common molecules shared by both PyDOM types were consistently dominated by lignin-like features, indicating a fuel-inherited emission profile that dominated overall composition. By contrast, unique molecules for each PyDOM type retained signatures related to their formation pathways and combustion conditions. PyDOM derived from charcoal showed a strong response to combustion temperature, with the enrichment of more condensed formulas under harsher conditions. PyDOM derived from soot remained relatively stable, featuring highly oxygenated CHO and CHON compounds and a strong presence of lignin- and carbohydrate-like groups. Furthermore, CHOS compounds were consistently more abundant in charcoal than in soot, suggesting charcoal preferentially retains sulfur. This study provides the first molecular-level features for distinguishing PyDOM in coproduced charcoal and soot, offering insights for assessing its environmental effect and behavior.

28. 题目: Two-Step pyrolysis enabled by bentonite catalysis for the co-production of bioactive humic acid and functional carbon-clay composites
文章编号: N26051218
期刊: Environmental Research
作者: Huanhuan Li, Jiarun Duan, Lijuan Zhang, Yong Wen, Yun Xiang, Chen Qiu, Junmei An, Zhiguo Guo, Yidong Cai, Changchun Ge, Xiaona Ren, Xinjiang Zhou, Bin Yuan, Bekchanov Davronbek, Xintai Su
更新时间: 2026-05-12
摘要: Converting biomass waste into artificial humic sustances (AHS) is critical for sustainable waste management and for mitigating soil organic matter depletion. However, conventional artificial humification routes typically couple depolymerization, condensation and oxidation, which limits yield, structural control and by-product utilization. Here we develop an atmosphere-programmed two-step pyrolysis strategy, assisted by bentonite catalysis, that decouples biomass depolymerization under an inert atmosphere from subsequent oxidative reconstruction under short-duration oxygen-limited conditions. The combined process affords 48.46% AHS, including 37.50% artificial humic acid (AHA) and 10.96% artificial fulvic acid (AFA). Structural characterization reveals controlled condensation with pronounced enrichment of acidic functional groups. Total acidity increases from 2.64 to 4.16 meq g-1, accompanied by enhanced aromaticity. The resulting AHA exhibits markedly improved bioactivity, increasing wheat root dry weight by more than 170%. Meanwhile, the post-extraction residue is valorized as a carbon-clay composite. This composite alleviates drought stress in chrysanthemum by enhancing antioxidant enzyme activities and scavenging reactive oxygen species. Overall, this work establishes an integrated pathway for the co-producing functional AHA and value-added composite materials from lignocellulosic biomass, with potential benefits for soil health improvement and plant stress tolerance.

29. 题目: Plant carbon fluxes govern soil organic carbon dynamics under climate change: Machine learning reveals critical GPP thresholds
文章编号: N26051217
期刊: Ecological Indicators
作者: Feini Huang, Yongkun Zhang, Xingjie Lu, Wei Shangguan, Qingliang Li, Zhangcai Qin, Zhongwang Wei, Huan Yuan, Lu Li, Yongjiu Dai
更新时间: 2026-05-12
摘要: Soil Organic Carbon (SOC) dynamics are profoundly influenced by climate change, yet the contributions of plant carbon fluxes, climatic forcing, and land-use changes remain poorly quantified. Here, we develop a machine learning framework to assess the drivers of SOC dynamics at both 0-20 and 20-100 cm depths across China from 1980 to 2100. The proposed model, validated via 10-fold cross-validation, achieved R2 values of 0.41 and 0.48 for the 100-cm and 20-cm soil profiles, respectively. Furthermore, independent temporal validation across two distinct periods yielded acceptable performance, demonstrating the model’s robust capacity to capture both the spatial distribution and temporal dynamics of SOC stocks. Future projections under four Shared Socioeconomic Pathway (SSP) scenarios indicate a national-scale SOC increase of 4.8 to 7.7 Pg C at 0-100 cm by 2100 compared to 2000-2015. Sensitivity analyses show that plant carbon fluxes are the dominant control on SOC variability. SHapley Additive exPlanations (SHAP) analysis further reveals a nonlinear Gross Primary Productivity (GPP)-SOC relationship that partially offsets warming-induced SOC losses. This relationship is characterized by two key thresholds. First, at GPP ≈ 4 gC m-2 d-1, the marginal contribution of GPP to SOC (SHAP value) transitions from negative to positive, indicating the ecosystem transitions from a net carbon deficit to a surplus, coinciding with the ecologically sensitive 400 mm isohyet of equivalent precipitation. Below this threshold, insufficient inputs stimulate existing SOC decomposition (likely priming effect). This zero-crossing indicates a regime shift where the GPP-driven carbon input overcomes historical deficit. Second, at GPP ≈ 7 gC m-2 d-1, the positive GPP-SOC sensitivity plateaus, indicating diminishing returns in carbon sequestration with further increases in productivity. Under high-emission scenarios, this transition zone expands northwestward into historically arid regions. These findings provide actionable insights for climate-resilient land management, highlighting targeted vegetation restoration, especially afforestation aligned with hydroclimatic thresholds, as a nature-based solution to safeguard SOC stocks in a warming world.

30. 题目: The binding effect of biochar with polycyclic aromatic hydrocarbons and their derivatives: Role in carbon sequestration and pollutant removal efficiency
文章编号: N26051216
期刊: Journal of Environmental Management
作者: Muhammad Fawad, Lingyu Zhang, Abdelrahman Ibrahim, Xinyi Xu, Tong Wu, Miao Han, Vishnu D Rajput, Chao Qin, Wanting Ling
更新时间: 2026-05-12
摘要: Polycyclic aromatic hydrocarbons (PAHs) and their toxic derivatives pose a significant threat to human health and the environment. Conventional remediations, such as chemical oxidation and hydrothermal treatments, are costly and generate secondary toxic byproducts, limiting their field applicability. This review aims to discuss the dual role of biochar as a cost-effective sorbent to remediate PAHs, and simultaneously provide an environment for PAH-degrading and carbon-sequestering microbial communities. Nonetheless, PAHs are released with pyrolysis gases during biochar production, which usually condense in the porous structure of biochar, having limited bioavailability. Furthermore, biochar engineering strategies such as wood ash amendments to feedstock and controlled pyrolysis conditions (350-550°C) in a vapor-solid separation chamber have been proposed to minimize PAHs contamination in biochar. This review elucidates hydrophobic interactions, pore-filling mechanisms, and π-π electron donor-acceptor interactions as dominant mechanisms for PAH sorption and long-term stabilization in soil. Quantitative evidence revealed that copper-modified Arundo donax and rice husk biochar exhibited high phenanthrene removal efficiencies (94.0-97.6%). Furthermore, rice husk biochar and immobilized bacteria removed 95.50% of phenanthrene and 73.78% of benzo[a]pyrene. Despite progress in safe biochar synthesis and PAHs removal from soil, limited research has addressed the remediation of PAH derivatives, which remains a critical knowledge gap. Therefore, future research should focus on designing multifunctional biochar, along with defined consortia of PAH-degrading and carbon-sequestration microbes to simultaneously enhance sorption and microbial degradation of PAH derivatives for long-term carbon stabilization in subsoil under field conditions.

31. 题目: Hydroxyapatite nanowires enhanced biochar hybrid aerogel for superior Ni(II) adsorption
文章编号: N26051215
期刊: Journal of Cleaner Production
作者: Ting Wang, Haiyan Wu, Yili Wang, Yuansong Wei, Dunqiu Wang, Haixiang Li, Yufeng Xu, Libing Zheng
更新时间: 2026-05-12
摘要: Industrial nickel pollution discharged into water bodies poses a serious threat to the environment and human health. Conventional biochar-based adsorbents suffer from poor mechanical strength, restricting large-scale application. Inspired by reinforced concrete, this study synthesized a high-strength hydroxyapatite nanowire (HANW) enhanced biochar hybrid aerogel (HBA). HANWs served as the reinforcing framework, while the MgCl2-modified biochar matrix provided abundant adsorption sites, synergistically boosting mechanical strength and adsorption capacity. The optimized HBA exhibited 47% higher compressive strength than conventional biochar aerogels and a notable Ni(II) adsorption capacity of 300.65 mg/g, which is 4 times more effective than conventional biochar. Comprehensive characterization confirmed Ni(II) adsorption on HBA follows a synergistic physicochemical process involving ion exchange, surface complexation, surface sedimentation, electrostatic interaction, and pore diffusion. The HANW-reinforced porous architecture not only sustains this multi-mechanistic pathway but also preserves high mass-transfer efficiency and structural stability during successive adsorption cycles. HBA further exhibited strong selectivity toward Ni(II) under competitive conditions, achieving 99.7% simultaneous removal of Ni in actual electroplating wastewater. The reinforced-concrete-like architecture offers new insights for the design of durable, recyclable, and scalable materials for heavy-metal-contaminated wastewater remediation.

32. 题目: Targeted sequestration of antimony via adsorption-induced topological transformation on supramolecular microcrystal-functionalized biochar
文章编号: N26051214
期刊: Journal of Hazardous Materials
作者: Xianke Wan, Zhixuan Yang, Bowei Chen, Ziyi Yu, Jun Nie, Zhiguo Wang, Chun Zhang, Jiajia Wang, Chunhui Li, Wei Huang
更新时间: 2026-05-12
摘要: The simultaneous and deep sequestration of multivalent antimony (Sb(III) and Sb(V)) from aquatic environments is strictly hindered by the “site-shielding effect”, where the random agglomeration of functional groups limits active site accessibility. To address this, a novel supramolecular microcrystal-functionalized biochar (CPPB) was engineered by anchoring L-cysteine and polyethyleneimine onto a lignin-derived biochar matrix. Structural analysis confirmed the in-situ growth of well-ordered hexagonal L-cystine microcrystals within the hierarchical pores. CPPB exhibited exceptional maximum adsorption capacities of 513.5 mg/g for Sb(III) and 500.9 mg/g for Sb(V), with >90% of the total capacity achieved within 10 minutes. The material maintained robust performance across a pH range of 3.0–8.0 and demonstrated high selectivity in complex wastewater matrices. Mechanistic investigations, integrating density functional theory calculations and multiscale spectroscopic analyses, unveiled a unique adsorption-induced topological transformation. Specifically, the intense coordination affinity between Sb species and active sites overcomes the lattice energy, triggering a transition of L-cystine from long-range ordered crystalline domains to short-range disordered open networks. This dynamic reconstruction effectively exposes previously shielded high-density sites (–SH, –NH, and –COO⁻) for multidentate coordination. Furthermore, the Sb-saturated CPPB was successfully upcycled into an SbPO4/C composite via in-situ carbonization; as a sodium-ion battery anode, this recovered material delivered a stable capacity of 261.0 mA h/g after 60 cycles. This work provides a transformative strategy to unlock the latent thermodynamic potential of biochar-based materials and establishes a sustainable “waste-to-resource” closed-loop for heavy metal remediation.

33. 题目: Microbially Driven Iron Redox Cycling Dominates Fe-Bound Organic Carbon Formation in Coastal Wetlands Under Sea Level Rise
文章编号: N26051213
期刊: Water Research
作者: Zhuang Huang, Shaoying Lin, Chun Wang, Jordi Sardans, Ning Hou, Yangyang Xie, Weiqi Wang, Josep Peñuelas, Ming Jiang
更新时间: 2026-05-12
摘要: Global sea level is projected to rise 0.28-1.02 m by 2100, exacerbating flooding and saltwater intrusion in estuarine wetlands. This threatens to alter soil iron (Fe) and organic carbon (C) pools, potentially affecting Fe-bound organic C (Fe-OC) formation. Given that Fe-OC represents a critically stable carbon reservoir-often referred to as the “rusty carbon sink”-its preservation is essential for the long-term carbon sequestration function of estuarine wetlands. Therefore, understanding how sea level rise influences Fe-OC dynamics is crucial for predicting future changes in coastal wetland carbon sink capacity. However, how enhanced flooding and salinity regulate Fe-OC via Fe/C pools and microbial processes remains unclear. We conducted a one-year in-situ experiment in a Phragmites australis wetland (Min River Estuary) with control (CK, natural tidal flooding) and two treatments receiving additional tidal water (TW) and saline water (SW) besides natural tidal flooding. Results showed that: (1) TW and SW increased soil free Fe oxide (Fed) by 70.7±5.6% and 94.8±8.3% (p < 0.05), while soil organic C remained unchanged (p > 0.05), indicating that the soil Fe pool is more responsive to sea level rise (enhanced flooding and salinity) than the soil organic C pool. (2) Soil Fe-OC content increased by 10% (TW) and 20% (SW), with its contribution to organic C rising by 5.3% and 9.2%. Concurrently, soil CO2 emission fluxes decreased significantly under both treatments and correlated negatively with Fe-OC content. Aggregated boosted tree (ABT) analysis confirmed Fed as the key driver of Fe-OC formation. (3) The diversity and abundance of the soil C-fixing microbial community (cbbL) remained unchanged (p > 0.05), but Fe-oxidizing bacteria (FeOB) and Fe-reducing bacteria (FeRB) increased with flooding-salinity (p < 0.05), especially FeRB. This microbial shift did not immediately alter soil Fe(II) or Fe(III), implying compensatory processes (e.g., root oxygen release). Mantel analysis revealed stronger FeOB/FeRB-Fe pool correlations than cbbL-C pool links. (4) Path analysis revealed that sea-level rise regulates FeOB/FeRB community structure to drive Fe redox cycling, transforming Fe minerals and dominating Fe-OC formation. This study reveals a “mineral-microorganism” synergistic mechanism underlying Fe-OC sequestration under sea-level rise: the coupled activities of FeRB (reductive dissolution) and FeOB (oxidative precipitation) drive Fe redox cycling, endowing estuarine wetland C pools with resilience to environmental stress. These findings offer new insights for coastal blue carbon management, suggesting that regulating Fe cycles could optimize Fe-OC stability and improve coastal C sink adaptability.

34. 题目: Enhanced vegetation activity leads to a significant increase in riverine particulate organic carbon concentrations in China
文章编号: N26051212
期刊: Catena
作者: Mengze Qin, Mingxu Li, Lingli Yu, Yinghua Zhang, Xiaoyan Kang, Boming Liang, Jiankun Chen, Youbin Deng, Xuanbo Wang, Xuyang Zhang, Yijia Li, Jie Li, Meng Wang, Qiuan Zhu, Huai Chen, Nianpeng He
更新时间: 2026-05-12
摘要: Particulate organic carbon (POC) is a key component of riverine carbon pools, influenced by hydrological and biogeochemical processes in rivers as well as changes in carbon and water cycling in upstream terrestrial ecosystems. However, large-scale assessments of riverine POC remain difficult due to sparse data and limited understanding of driving factors. In this study, we compiled a comprehensive observational database of POC concentrations (CRD-POC) across China and analyzed spatiotemporal patterns and drivers using a random forest model and variance decomposition method. Our results show that the mean POC concentration in Chinese rivers is 1.44 ± 0.007 mg L−1, with notable spatial and temporal variations. Higher concentrations were found in central and southwestern China, while lower values were observed in the northeast, southeast, and west. From 1982 to 2020, POC concentrations showed a significant upward trend (R2 = 0.74, p < 0.001), with most basins, except the Huai and Pearl Rivers, showing increases. Further analysis revealed that increases in vegetation indices such as the Leaf Area Index (LAI) and Normalized Difference Vegetation Index (NDVI), were the dominant drivers of rising POC concentrations. These findings highlight the relationship between terrestrial vegetation growth conditions and riverine POC concentrations. This study highlights the need to integrate land-ocean-aquatic continuum frameworks and long-term POC monitoring to improve regional carbon budget accuracy and inform ecosystem management.

35. 题目: Mechanisms of organic carbon sequestration in long-term tilled soils: The primacy of microbial over active mineral protection
文章编号: N26051211
期刊: Soil and Tillage Research
作者: Xiaolei Yin, Ming Jiang, Ji Chen, Chris Freeman, Xiaofei Yu, Xianguo Lu, Lei Qin, Yuanchun Zou
更新时间: 2026-05-12
摘要: In current models of the soil carbon cycle, microbially and mineral-driven organic matter dynamics are central to maintaining agri-environmental sustainability. However, there may be a large gap between the importance of minerals and microorganisms in regulating SOC accumulation in agricultural soils. Here, we analysed the C use efficiency (CUE), turnover time, microbial respiration rate (qCO2), microbial necromass carbon (MNC) and mineral drivers of carbon accumulation using a cropland cultivation chronosequence soil (soil organic carbon (SOC) content of 22.1–49.8 g kg−1). The results revealed that with the loss of SOC, the amount of active mineral-bound organic carbon (bound OC) also decreased significantly, and the molar ratio of bound OC: minerals was significantly reduced. Compared with C-poor soils, C-rich soils exhibited a significantly higher microbial carbon use efficiency (CUE, 0.47 vs. 0.28) and a lower microbial metabolic quotient (qCO₂). Microbial necromass carbon (MNC, 28.9–61.6% of SOC) showed a co-variation pattern with total SOC across the degradation gradient. There was no difference in microbial uptake efficiency among soils with different SOC concentrations, but qCO2 was significantly greater in low-carbon soils. These findings suggest that the decrease in soil CUE was due primarily to the increase in qCO2. We emphasise that the reactive mineral content (Fed, Ald) was not the limiting condition for bound OC accumulation during soil cultivation and that the reduced microbially derived carbon content was the underlying cause of the reduced soil bound OC content. Overall, microbial physiological traits (CUE, qCO2) and microbially-derived carbon showed a stronger association with soil carbon accumulation than reactive minerals. For future research on carbon sequestration in agricultural soils, the carbon turnover function of microbial communities should be further explored to identify potential improvements in the soil environment that could promote their carbon accumulation rates.

36. 题目: Molecular gatekeeping in sludge EPS: pH–thermal forcing reshapes biopolymer interactions and carbon release pathways
文章编号: N26051210
期刊: Water Research
作者: Ziqi Yang, Yu Hua, Yu Fu, Chong Chen, Yue Zhang, Xiaohu Dai
更新时间: 2026-05-12
摘要: The complex structure of extracellular polymeric substances (EPS) in waste activated sludge severely limits the recovery of endogenous carbon from sludge via thermal hydrolysis. In this study, a three-dimensional pH-time-layer framework was established to elucidate how pH and thermal effects jointly regulate EPS disintegration, molecular transformation, and carbon release pathways. Bulk measurements were combined with LC-MS/MS-based metabolomics analysis to reveal both macroscopic redistribution and molecular-level dynamic changes. The results showed that alkaline condition (pH 12) significantly promoted carbon release and generated a clear outward gradient (S-EPS > LB-EPS > TB-EPS). The Layer Distribution Index (LDI) indicated that the molecular gate was opened and the resistance to interlayer migration was reduced. In contrast, under acidic (pH 2) and neutral (pH 7) conditions, the EPS structure remained more compact, resulting in limited carbon release. The LDI further revealed that approximately 60 min was a critical transition point, corresponding to the initial loosening of the gatekeeping structure and the onset of outward migration. At the molecular level, proteins underwent sequential transformation from peptides to amino acids and amines, accompanied by rapid outward migration under alkaline conditions. In contrast, carbohydrates followed a staged pathway of “depolymerization-transient accumulation (60-90 min)-delayed migration,” reflecting stronger structural hysteresis. Humic-like substances exhibited relatively limited molecular-level variation (LDI ≈ 1.6-2.0) but substantial bulk release, indicating that their behavior was primarily driven by structural collapse rather than fragmentation-controlled migration. Under alkaline conditions, these components were transformed into more polar species, facilitating the co-solubilization of proteins and carbohydrates. Overall, these findings demonstrate that pH governs the opening of EPS gatekeeping pathways through distinct structural and molecular mechanisms. Under alkaline conditions, an optimal operational window (60-120 min) was identified to maximize the release of biodegradable carbon while limiting secondary reactions. This framework provides a mechanistic basis for achieving controllable and predictable carbon recovery from sludge.

37. 题目: Optimizing Sentinel-2 temporal composites for soil organic carbon mapping and cropland management insights
文章编号: N26051209
期刊: Environmental Technology & Innovation
作者: Xiande Ji, R Venkatesha Prasad, Binyuan Liu, Balamuralidhar Purushothaman, P V Aravind
更新时间: 2026-05-12
摘要: Accurate mapping of soil organic carbon (SOC) in intensive croplands is important for climate change mitigation and for guiding sustainable agricultural management. Despite the growing use of Sentinel-2 composites, evidence remains limited on how composite design affects SOC mapping accuracy in croplands and on whether satellite observations can capture management-relevant signals linked to SOC. This study compared four temporal Sentinel-2 spectral composites for SOC mapping using LUCAS 2015 and 2018 observations in Italy’s Po Plain. Three machine learning models, random forest, XGBoost, and CatBoost, were trained, and SHAP was used to interpret variable contributions. Across models, composites targeting the bare soil period, based on multispectral reflectance and non-photosynthetic vegetation indices, achieved the best performance. CatBoost performed best and produced a high-resolution SOC map for the Po Plain. In contrast, traditional vegetation indices such as NDVI and EVI showed limited relevance across all composites. Importantly, we found a robust negative association between SOC and bare soil frequency derived from multi-temporal Sentinel-2 observations, with lower bare soil frequency corresponding to higher SOC. This highlights bare soil exposure duration as a practical indicator for monitoring and suggests that management practices that shorten bare soil windows may help maintain or enhance SOC. Overall, this study optimized Sentinel-2 temporal composites with machine learning to improve SOC mapping in the Po Plain and provides actionable insights for cropland management in intensively cultivated regions.

38. 题目: Potential impacts of microplastic-derived dissolved organic matter in water and wastewater treatment systems: A critical review and future research needs
文章编号: N26051208
期刊: Critical Reviews in Environmental Science and Technology
作者: Rabia Zafar, Yun Kyung Lee, Mairaj Bibi, Jin Hur
更新时间: 2026-05-12
摘要: Microplastics (MPs) are widely recognized as particulate pollutants in water and wastewater treatment systems (WWTSs); however, their transformation into microplastic-derived dissolved organic matter (MP-DOM) and its potential impacts remain poorly understood. This review synthesizes current knowledge on the generation, composition, and treatment relevance of MP-DOM, an emerging fraction of dissolved organic matter (DOM) formed during photochemical, oxidative, mechanical, thermal, and biological aging of MPs within treatment processes. Available evidence suggests that WWTSs can act as active hotspots for MP-DOM formation, producing low-molecular-weight oligomers, oxidized fragments, and additive-derived compounds that persist beyond particulate removal. Compared with background DOM, MP-DOM exhibits distinct reactivity, bioavailability, and transformation pathways. We evaluate how these physicochemical properties may influence coagulation, adsorption, oxidation, membrane filtration, biological treatment, and sludge processing. Emerging studies indicate that MP-DOM can alter flocculation, compete for adsorptive and oxidative capacity, contribute to disinfection by-product formation, modulate microbial activity, and exacerbate membrane fouling. However, the magnitude and operational significance of these effects in full-scale systems remain poorly constrained due to limited field observations and reliance on simplified laboratory studies. We identify key knowledge gaps related to MP-DOM occurrence, polymer-specific generation pathways, microbial interactions, and differentiation from background DOM. Collectively, MPs should be considered not only as particulate contaminants but also as potential sources of reactive dissolved organic fractions that may influence treatment performance under increasing plastic inputs. Accordingly, monitoring strategies and process models may need to incorporate MP-DOM as a distinct compositional component of the DOM pool.

39. 题目: Multiscale spatial heterogeneity of sedimentary organic carbon in the intertidal zone of the Yellow River Estuary
文章编号: N26051207
期刊: Estuarine, Coastal and Shelf Science
作者: Jun Ma, Zihe Zang, Yinyin Feng, Xiao Liu, Ludan Zhao, Xuegang Li, Lilian Wen, Jiajia Dai, Jianwei Xing, Baoxiao Qu, Huamao Yuan, Liqin Duan, Fei Miao, Jinming Song
更新时间: 2026-05-12
摘要: The complex and dynamic nature of estuarine intertidal environments often leads to pronounced spatial heterogeneity in total organic carbon (TOC) in surface sediments, thereby affecting regional carbon pool estimation and the understanding of carbon cycling processes. In this study, surface sediment samples were collected from the low intertidal zone (LIZ), middle intertidal zone (MIZ), and upper intertidal zone (UIZ) across eight regions (A-H) of the Yellow River Estuary intertidal zone. It analyzed the multi-scale spatial distribution patterns of TOC, discussed the influencing mechanisms of regional and intertidal processes on TOC, and clarified the key driving factors of TOC. The results showed that TOC ranged from 0.065% to 0.530%, with an average of 0.179 ± 0.113% and a coefficient of variation of 63.1%, indicating strong spatial heterogeneity. At the regional scale, TOC exhibited clear spatial differentiation between the muddy southern bank and the sandy northern bank of the estuary, with relatively higher values in regions F, G, and H on the southern bank. At the intertidal zone scale, the distinct submergence and redox characteristics of the intertidal zones significantly affected TOC distribution, which generally followed the order LIZ > MIZ > UIZ. Clay content was the dominant factor controlling TOC spatial heterogeneity, largely because sediment grain size regulates the preservation efficiency of organic carbon. In addition, TN primarily reflected organic matter sources rather than acting as a direct control on TOC, whereas water content, TP, and petroleum hydrocarbons showed limited explanatory power for the long-term accumulation of TOC. These findings reveal the spatial heterogeneity of TOC and its underlying control mechanisms in the intertidal zone of the Yellow River Estuary, and provide a basis for assessing carbon pools in estuarine intertidal sediments.

40. 题目: Anthropogenic water and sediment regulation drives a refractory terrestrial carbon pulse to the Yellow River estuary
文章编号: N26051206
期刊: Marine Pollution Bulletin
作者: Yongsheng Hao, Meng Yu, Kexin Li, Lili Zhan, Honghai Zhang, Yang Ding, Li Li, Wanguan Wang, Yuping Zhou, Ding He, Meixun Zhao
更新时间: 2026-05-12
摘要: Rivers play an important role in land-to-ocean organic carbon (OC) transport, yet how intensifying human activities alter the composition and reactivity of riverine OC remains poorly understood, hindering predictions of terrestrial OC fate in marine environments. The Yellow River's Water and Sediment Regulation Scheme (WSRS) represents a major anthropogenic disturbance that dramatically alters carbon transport. Here, we characterized particulate and dissolved organic carbon (POC, DOC) contents, stable carbon isotope of POC, and optical properties of dissolved organic matter (DOM) and base-extracted particulate organic matter (POM) in the Yellow River under natural and anthropogenic hydrological variability, to explore the dynamic linkages between POC and DOC pools. Results show that sediment regulation triggered marked increases in POC and DOC contents, accompanied by enhanced aromaticity and humification of both carbon pools. Significant correlations between optical indices of POM and DOM revealed a tight compositional linkage between particulate and dissolved humic substances. The concurrent humic enrichment during sediment regulation could be primarily attributed to the resuspension and release of refractory OM that has previously accumulated within reservoir sediments, probably augmented by the subsequent transformation of resuspended POM into refractory DOM during transit. In 2024, the WSRS exported approximately 60% of the annual POC flux and 30% of the annual DOC flux to estuary and coastal seas. These findings highlight that the WSRS not only amplified short-term carbon export but fundamentally reshaped the composition and reactivity of riverine OC delivered to coastal systems, with important implications for carbon cycling along the estuary-coastal sea continuum.