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41. 题目: 3D-EEMs reveals differential DOM contributions of two dominant diatoms in the South-to-North Water Diversion Project and ozone-mediated CODMn control
文章编号: N26030908
期刊: Journal of Hydrology
作者: Qiong Wang, Lei Bi, Jingzhang Liu, Yue Li, Wenzhong Tang, Hong Zhang, Maoyong Song
更新时间: 2026-03-09
摘要: South-to-North Water Diversion (SNWD) Project, the world’s largest water transfer project, has recently detected excessive permanganate index (CODMn > 2 mg/L), raising serious concerns. Previous studies have shown a significant correlation between diatom blooms and elevated CODMn. However, the impact of different dominant diatom species on the dissolved organic matter (DOM) remains unknown, and urgent research is needed to find safe and effective measures to address the issue of elevated CODMn. This study investigated the differential contributions of Cyclotella meneghiniana and Fragilaria nanana to DOM in SNWD Project using a novel three-dimensional fluorescence excitation-emission matrix spectroscopy (3D-EEMs) data analysis method. It demonstrated that both species significantly contribute to protein-like and microbial byproduct-like components of DOM, collectively accounting for over 90% of these fractions across all growth phases. Notably, F. nanana produced more DOM than C. meneghiniana across all growth phases (e.g., 13.25 times higher during the log phase) at equivalent cell densities. This finding reveals the importance of species-specific control strategies for monitoring, managing dominant algae in the SNWD main canal to ensure water quality. Moreover, we demonstrated that ozone treatment not only reduces diatom-derived DOM and CODMn to standard level within 1.5 min, but also effectively eliminates algal and prevents resurgence of CODMn. This study reveals the differences in the contributions of two dominant diatoms in SNWD Project, while simultaneously demonstrating the efficacy of ozone treatment for CODMn regulation.

42. 题目: Earthworms promote soil organic carbon formation across management histories without stimulating the mineralization of native carbon
文章编号: N26030907
期刊: Biology and Fertility of Soils
作者: Janus den Toonder, Šárka Angst, Jan Frouz, Veronika Jílková, Jaroslav Kukla, Travis B Meador, Stefan Scheu, Karel Tajovský, Gerrit Angst
更新时间: 2026-03-09
摘要: Earthworms promote litter incorporation into soil, potentially increasing soil organic carbon (SOC) stocks. However, they may also stimulate native SOC mineralization through priming, complicating assessments of their net impact on carbon sequestration. To disentangle these opposing pathways, we conducted an incubation experiment in soils with contrasting management histories using dual-isotope labeled litter, which allowed us to distinguish litter-derived carbon from native SOC in both soil and CO2 emissions. We show that earthworms consistently enhanced litter incorporation into the soil while increasing total soil CO2 emissions. However, the earthworm-induced increase in respired CO2 was entirely derived from the added litter, not native SOC, and the formation efficiency of new SOC was up to ninefold higher in the presence vs. absence of earthworms. Therefore, increased heterotrophic respiration in the presence of earthworms does not translate into lower SOC contents in mineral soil. Given that these effects were consistent across contrasting management systems, fostering earthworm activity may support SOC sequestration across agroecosystems and help mitigate climate change.

43. 题目: Twelve-year high manure input enhances soil organic carbon stability and ecosystem multifunctionality in a karst agroecosystem
文章编号: N26030906
期刊: Plant and Soil
作者: Zihong Zhu, Shuangshuang Chen, Qingquan Xie, Li Wen, Kelin Wang, Dejun Li
更新时间: 2026-03-09
摘要: Background and Aims Long-term fertilization profoundly influences soil health and agricultural sustainability, but its effects on ecosystem multifunctionality (EMF) in fragile karst agroecosystems remain poorly understood. In the karst regions of southwest China, inappropriate tillage and fertilization measures have triggered severe land degradation issues. We therefore conducted a 12-year experiment based on a maize-soybean rotation system in southwest China’s karst areas to identify effective fertilization strategies applicable in fragile karst agroecosystems. Methods The experimental treatments comprised an unfertilized control (CK), mineral fertilizer (NPK) alone, and NPK combined with straw or cattle manure at low (LSNPK, LMNPK) and high (HSNPK, HMNPK) rates. We assessed the effect of constrasting fertilization strategies on crop productivity, soil organic carbon stability, microbial community structure, and EMF. Results All fertilization treatments increased combined maize and soybean productivity relative to CK, but their effects on soil health diverged markedly. Among the five fertilization treatments, HMNPK maximized the proportion of large macroaggregates (> 2000 µm) and the organic carbon concentration within them. HMNPK also elevated the chemical stability of soil organic carbon compared to CK and HSNPK. Phospholipid fatty acid and biomarker analyses revealed the highest microbial biomass and necromass carbon under HMNPK. Consequently, HMNPK yielded the highest EMF index, outperforming HSNPK and NPK. Conclusions A nutrient management regime with high-rate manure input is an effective strategy for enhancing karst agroecosystem multifunctionality. This approach sustains high crop productivity while simultaneously improving soil structure, SOC stability, and microbial community abundance, thereby benefiting long-term agricultural sustainability.

44. 题目: Co NPs@N-Doped Peanut Shell-derived Biochar As an Efficient Catalyst for Peroxymonosulfate Activation in Acetaminophen Degradation
文章编号: N26030905
期刊: Water, Air, & Soil Pollution
作者: Xiaoxin Chen, Xingzi Zhu, Caiyan Ge, Jinxin Wang, Manli Guo, Yujuan Cao, Bixia Lin
更新时间: 2026-03-09
摘要: Valorizing organic waste to yield high-end products should be a key waste management approach in the future. Herein, a series of nitrogen-doped peanut shell derived-biochars loaded with Co nanoparticles (C-Nx-Coy) were successfully synthesized at different pyrolysis temperatures. In particular, the C-N3-Co0.5(800) material prepared under certain conditions demonstrated high efficiency in activating peroxymonosulfate (PMS) to degrade acetaminophen (ACE), achieving complete removal of 20 mg/L ACE within 5 min. The catalyst exhibited broad operational pH adaptability (pH = 3 ~ 11) and maintained robust performance in the presence of inorganic ions and complex water matrices. Furthermore, minimal cobalt leaching ensured environmental safety by preventing secondary contamination. Mechanistic investigations via quenching experiments, electron paramagnetic resonance (EPR) spectroscopy and electrochemical experiences identified a synergistic degradation mechanism involving radical pathways (•OH and SO4•−), non-radical pathway (1O2-mediated oxidation), and electron transfer pathway. Combining eco-friendly biomass precursors with efficient catalytic performance, this work provides a feasible strategy for designing practical wastewater treatment systems.

45. 题目: Enhancing soil carbon in arid regions: key role of dissolved organic matter in straw-amended systems
文章编号: N26030904
期刊: Biology and Fertility of Soils
作者: Jun Zhang, Anna Gunina, Lei Yang, Fenghua Zhang
更新时间: 2026-03-09
摘要: The return of straw to agroecosystems can promote the turnover, production, and sequestration of soil organic C (SOC). To elucidate the mechanisms by which straw-derived dissolved organic matter (DOM) regulates SOС sequestration and stability, hydrophilic (Hi-DOM) and hydrophobic (Ho-DOM) fractions, derived in a laboratory setting, were separated from cotton stalks and independently incorporated into sandy loam soils subjected to continuous straw return for 5 (Straw-5y) and 15 years (Straw-15y). Compared with the control and Hi-DOM treatments, Ho-DOM increased SOC content by 119–150% in both soils. Hi-DOM reduced the proportion of total lignin phenols, particularly syringyl units in the Straw-15y soil, whereas Ho-DOM demonstrated a stronger capacity to accumulate total lignin phenols, especially vanillyl units, than Hi-DOM in both soils. This indicated that the characteristics of straw-derived DOM and soil physicochemical properties are important factors regulating the preservation of plant-derived C in soil. Moreover, Ho-DOM promoted the accumulation of fungal necromass C more effectively than Hi-DOM, suggesting that Ho-DOM is more conductive to the formation and retention of fungal necromass. The contribution of Ho-DOM to enhancing recalcitrant SOC fractions, including alkyl C and aromatic-C, exceeded that of Hi-DOM, derived in a superior alkyl C/O-alkyl-C ratio and greater hydrophobicity. Overall, straw-derived DOM enhanced both plant- and microbial-derived C pools, facilitating the transformation of straw-derived DOM into microbial necromass in sandy loam soils of the arid zone of Northwest China under long-term straw return. Ho-DOM was more effective than Hi-DOM in promoting SOC sequestration and stability through increased lignin accumulation and fungal necromass formation.

46. 题目: Sequestration of antimony(V) and carbon by secondary iron (oxyhydr)oxides during ferrihydrite organominerals transformation: A nanoscale study and molecular mechanisms
文章编号: N26030903
期刊: Chemical Geology
作者: Yiqing Wang, Mengchang He, Chenfei Zhang, Chunye Lin, Wei Ouyang, Xitao Liu
更新时间: 2026-03-09
摘要: Ferrihydrite and its transformation to crystalline Fe (oxyhydr)oxides play important roles in controlling the mobility of antimony (Sb) and organic matter (OM) in natural environments, but the underlying molecular mechanisms for coupled sequestration of Sb(V) and carbon (C) and the interactions among Sb(V), Fe (oxyhydr)oxides, and OM remain unclear. This study comprehensively investigated the immobilization and distribution of Sb(V) and fulvic acid (FA) and their impacts on secondary Fe (oxyhydr)oxides formation during ferrihydrite organominerals transformation at the nanoscale level using Sb K-edge X-ray absorption spectroscopy (XAS) and spherical aberration corrected scanning transmission electron microscopy (Cs-STEM). X-ray diffraction (XRD) results indicated that the coprecipitated Sb(V) promoted the ferrihydrite transformation to goethite, whereas the adsorbed FA hindered both the rates and extents of ferrihydrite transformation but favored hematite formation. Chemical analysis indicated that Sb(V) dominated as nonextractable phase during the ferrihydrite and ferrihydrite organominerals transformation. XAS and Cs-STEM analysis verified that Sb(V) was incorporated into the lattice structure of newly-formed goethite and hematite by substituting Fe(III) octahedral sites and showed different spatial distribution within secondary Fe (oxyhydr)oxides. Additionally, FA molecules were either adsorbed on the hematite surface or occluded in the nanopores and/or structural defects of goethite and hematite. Our findings provide deeper insights into the molecular mechanisms for Sb(V) and C sequestration coupled with secondary Fe (oxyhydr)oxides formation during ferrihydrite organominerals transformation, which contributes to understanding the geochemical cycling of Sb(V) and C associated with ferrihydrite, and developing a potential strategy for Sb(V) immobilization and C stabilization in Sb-contaminated soils and sediments.

47. 题目: Multispectral bare soil composites as a resource for SOC mapping rather than SOC monitoring: A case study in the Walloon region (Belgium)
文章编号: N26030902
期刊: Geoderma
作者: Dries De Bièvre, Pierre Defourny, Bas van Wesemael
更新时间: 2026-03-09
摘要: Soil organic carbon (SOC) is a key indicator of soil health on croplands, as well as a potential lever for carbon sequestration in agriculture. This requires tools for understanding spatial and temporal variations in SOC content. Multispectral satellites provide data on bare soil reflectance which is influenced by SOC content. In this study, an extensive database of 34,418 soil analyses on 22,850 fields is leveraged to train a Machine-Learning model for SOC content prediction. The predictive covariates are derived from a bare soil composite of Sentinel-2 images over the Walloon region (Belgium) obtained from March to June over a three-year period (2019–2021) as well as some environmental covariates. We observe that multispectral data is complementary to environmental covariates for explaining spatial variability in SOC content. Through feature elimination relevant spectral features were identified: the normalized difference of band 3 (Green) and 2 (Blue); band 5 (Red-Edge) and 11 (SWIR1); band 11 (SWIR1) and 12 (SWIR2) and the reflectance in band 4 (Red). These spectral indices were combined with three environmental covariates: elevation, the agro-ecological zone and the fine fraction (< 20μm) content. The resulting model predicts SOC content at field-level with an RMSE of 2.7 g C kg−1 and an R2 of 0.56. Given this uncertainty, we conclude that multispectral data is insufficient for SOC content monitoring at parcel-level but is a tool to consider for SOC content mapping. The SOC content map can be used for regional SOC content estimates, after modeling the autocorrelation of the model errors. This offers the possibility to compare groups with different management practices or assess the average SOC content of fields in a soil conservation program compared to a regional baseline.

48. 题目: Distinctive evolutions of specific surface area in CO2 activation of biochars from different biomasses
文章编号: N26030901
期刊: Chemical Engineering Journal
作者: Hong Zhang, Xin Jia, Jun Pan, Yuhui Zhang, Jiancheng Yang, Kaixuan Li, Xuejing Liu, Shurong Wang, Guangwen Xu
更新时间: 2026-03-09
摘要: Elucidating the underlying mechanisms on distinctive evolutions of specific surface area (SSA) in CO2 activation of biochars from different biomasses is essential for rational design and process optimization. Herein, the dynamic evolution of SSA during CO2 activation of biochars was systematically investigated in a micro fluidized bed reactor integrated with an online particle sampling facility. Low-ash biochars derived from three kinds of biomasses showed highly similar SSA evolution profiles and comparable peak values (1786–1896 m2/g) at a carbon conversion ratio of ∼85%, indicating a negligible influence of the organic matrix in SSA evolution. However, pronounced variations in SSA evolution were observed for ash-varying biochars: low-ash walnut shell biochar (WSB) consistently exhibited higher peak SSA than high-ash corn straw biochar (CSB) over 850–950 °C (1632–1903 m2/g for WSB versus 859–1015 m2/g for CSB). For each feedstock, the peak SSA occurred at an approximately invariant carbon conversion ratio (∼85% for WSB and ∼64% for CSB) irrespective of temperature. In addition, demineralization of CSB increased its peak SSA from 863 to 1073 m2/g and shifted the corresponding carbon conversion ratio from 64% to 75%, demonstrating the dominant role of inherent minerals in governing SSA evolution. SEM–EDS analysis revealed mineral accumulation within activated pores, and HCl-treated activated CSB further increased its peak SSA by ∼40%, confirming ash-induced pore blocking as the primary origin of reduced SSA in high-ash biochars. Finally, a mechanistic framework explaining distinctive evolutions of SSA from different biomasses during biochar activation was proposed.

49. 题目: Composite modified hierarchical porous biochar for enhanced flow electrode capacitive deionization
文章编号: N26030816
期刊: Separation and Purification Technology
作者: Shuyu Xue, Dongbao Song, Xue Yang, Wenhuai Wang, Junyang Xiao, Junfeng Li
更新时间: 2026-03-08
摘要: Flow electrode capacitive deionization (FCDI) is an environmentally friendly and efficient technology with significant potential for desalination applications. However, its widespread adoption is limited by the challenge of balancing high electronic conductivity with superior ion adsorption capacity in electrode materials. In this study, low-cost agricultural waste (corn stalks) was used as the raw material to fabricate hierarchical porous biochar (CBC) through a composite modification strategy involving phosphoric acid etching followed by secondary pyrolysis, aiming to enhance the desalination performance of FCDI. The results show that the CBC electrode achieved a specific capacitance of 469.27 F g−1, which is 7.44 times higher than that of the raw biochar (RBC). Under optimized conditions (1.2 V applied voltage, 5 wt% carbon loading, and a 15 mL min−1 flow rate), the CBC electrode exhibited an average salt adsorption rate of 30.90 μg cm−2 min−1, which is more than 2.93 times that of RBC, outperforming most previously reported biochar-based FCDI electrodes. Moreover, the CBC electrode exhibited a high charge efficiency of 115.06%, low energy consumption of 2.79 × 10−2 kWh m−3, and excellent long-term cycling stability. Microstructural analyses revealed that our composite modification strategy created an interconnected hierarchical pore network and a more graphitized carbon framework in CBC, which together enables efficient ion adsorption and rapid electron transfer, ultimately enhancing desalination performance. This work provides a new approach and theoretical foundation for developing low-cost, high-performance flow electrodes for FCDI.

50. 题目: Spatial variability and drivers of soil organic carbon burial in the tidal flats of the Yellow River Delta
文章编号: N26030815
期刊: Catena
作者: Yiqi Zhao, Tian Ma, Shendong Xu, Yuan Li, Mingliang Zhao, Weimin Song, Xiaojie Wang, Xiaojing Chu, Guangxuan Han
更新时间: 2026-03-08
摘要: Coastal tidal flats play a critical role in the global carbon cycle, yet the spatial patterns and controlling mechanisms of soil organic carbon (SOC) burial within estuarine wetlands remain poorly understood. Here, we investigated the lateral (seaward-landward) and vertical variability of SOC burial across low, middle, and high tidal flats in the Yellow River Delta. Based on 210Pb chronology and coupled with δ13C and biomarker (lignin phenols, amino sugars) analyses, soil cores were collected to quantify sediment accumulation rates (SAR), organic carbon burial rates (OCBR), SOC stocks (SOCstock), and sources. Results showed that SAR decreased progressively from the seaward to the landward flats, while OCBR showed no significant lateral variation. The mean OCBR was 37.44 ± 7.57, 32.71 ± 9.16, and 24.62 ± 4.09 g m−2 yr−1 at the low, middle, and high tidal flat, respectively. Both SAR and OCBR reached their lowest values at 60–100 cm layer. SOCstock were significantly higher in the high tidal flats, especially within the 0–30 cm layer. The ISOsource model revealed that marine phytoplankton-derived organic carbon decreased landward across all soil depths, whereas riverine particulate organic matter and local plant-derived contributions increased correspondingly. Although lignin phenols generally decreased from sea to land, their vertical variation remained limited. In contrast, microbial necromass carbon exhibited no significant lateral or vertical trends. Random forest analysis indicated that the C/N ratio played a significant role in controlling SOCstock throughout the soil profile. These results highlight pronounced spatial heterogeneity in SOC burial across tidal flats, necessitating the integration of both lateral and vertical variations in assessing carbon sequestration potential.

51. 题目: Impacts of Spartina alterniflora invasion on fractions and fungal communities of mineral-associated organic carbon in subtropical coastal wetlands of China
文章编号: N26030814
期刊: Catena
作者: Ziwei Wu, Yuan Li, Weiqi Wang, Xuyang Liu, Ning Hou, Jie Hei, Jiawei Gan, Zhaoliang Song, Yunying Fang, Jordi Sardans, Josep Peñuelas
更新时间: 2026-03-08
摘要: Understanding the stabilization pathways of mineral-associated organic carbon (MAOC) under plant invasion is critical for predicting soil carbon dynamics in coastal wetlands. Spartina alterniflora, a widespread invasive species, exerts substantial ecological impacts, yet its influence on MAOC stabilization remains poorly understood. This study investigated the shifts in MAOC fractions，specifically iron and aluminum oxide-associated (MAOCFe(Al)-OC), calcium-associated MAOC (MAOCCa-OC), and residual MAOC (MAOCResidual-OC), along with soil fungal communities before and after invasion at a subtropical estuarine wetland. Results show that invasion significantly increased MAOCFe(Al)-OC and MAOCCa-OC by 31% and 21%, respectively, while the chemically stable MAOCResidul-OC remained quantitatively dominant. FTIR analysis revealed an enrichment in MAOCaliphatic-OC functional groups, suggesting a shift toward more chemically diverse yet labile carbon inputs. Although fungal α-diversity remained unchanged, the invasion drove a distinct functional reconfiguration of the community, characterized by a transition from r- to K-strategies and the proliferation of Saprotroph. Random Forest and redundancy analyses (RDA) identified saprotrophs as pivotal biological regulators (explaining 55% of the variation), exhibiting an apparent ecological coupling with the responsive MAOCCa-OC. These findings suggest that Spartina alterniflora invasion enhances carbon sequestration not only by increasing organic inputs but also by orchestrating a Saprotroph heavy community that strengthens specific mineral-organic associations. This study highlights the synergy between fungal functional shifts and geochemical pathways as a fundamental mechanism governing blue carbon resilience under biological invasions.

52. 题目: Organic fertilization promotes soil organic carbon sequestration by offsetting gaseous losses in sloping purple soil croplands
文章编号: N26030813
期刊: Catena
作者: Xianglong Liu, Qiuhong Li, Fangfang Yan, Peng Xu, Dongyang Liu, Hongyang Dong, Shihang Zhang, Xiaoguo Wang, Bo Zhu
更新时间: 2026-03-08
摘要: Although considerable research has examined the effects of soil respiration and erosion on soil organic carbon (SOC) loss, understanding of SOC loss through both gaseous and runoff-related pathways remains limited in sloping agroecosystems. In this study, a two-year field experiment under a wheat–maize rotation was carried out on sloping purple soil croplands to assess the effects of different fertilization regimes on SOC losses. The experimental treatments consisted of a control (CK), mineral fertilizers (NPK), organic manure combined with NPK (OMNPK), and crop residues combined with NPK (RSDNPK). The results indicated that organic fertilization significantly increased SOC loss through gaseous emissions and dissolved organic carbon (DOC) leaching, while reducing losses through sediment runoff, reflecting contrasting responses among SOC loss pathways. The three fertilization treatments (NPK, OMNPK, and RSDNPK) showed total SOC losses ranging from 8280.79 to 12,516.77 kg ha−1, which were substantially higher than those observed in the control treatment (6068.51 kg ha−1). Across all treatments, more than 98% of SOC loss originated from soil heterotrophic respiration, whereas the control treatment exhibited the highest proportion of runoff-related carbon loss (1.1%). By jointly assessing gaseous and runoff-related SOC loss pathways within a single field experiment, this study reveals contrasting regulatory mechanisms for SOC losses in sloping purple soils, with soil factors directly influencing gaseous SOC losses and climatic factors—especially rainfall—mainly controlling SOC losses via runoff pathways. The combined influence of soil and climatic factors accounted for 42% of the variation in gaseous SOC losses. Overall, the results suggest that organic fertilization leads to trade-offs among different SOC loss pathways and may enhance net ecosystem carbon balance under suitable management, highlighting the need to consider soil properties together with climatic conditions when developing sustainable carbon management strategies for agricultural ecosystems.

53. 题目: Inundation increases wetland soil organic carbon through microbial necromass rather than plant lignin components
文章编号: N26030812
期刊: Catena
作者: Mingliang Zhao, Lianjing Wang, Leilei Xiao, Weimin Song, Xiaojie Wang, Xiaojing Chu, Xiaoshuai Zhang, Qingyun Zhao, Yangjian He, Siyu Wei, Guangxuan Han
更新时间: 2026-03-08
摘要: Although wetlands are known to be important carbon sinks, the mechanisms governing soil organic carbon (SOC) stabilisation under different hydrological regimes remain unclear. While microbial necromass carbon (MNC) and plant lignin phenols are key components of SOC, the effects of different inundation depths on their relative contributions to SOC remain poorly understood. Here, we conducted a 6-year field experiment in the Yellow River Delta wetland, China, with varying inundation depths (0, 5, 10, 20, 30 and 40cm). The results revealed that SOC stocks in surface soils (0–20 cm) increased by 38% (4.86 to 6.73 g·kg−1) with increasing inundation depth, primarily due to enhanced plant productivity and microbial turnover. The contribution of MNC to SOC increased significantly from 14.8% to 23.8%, exceeding increase in lignin phenol content (0.08–0.12 g kg−1) by an order of magnitude (10–16 times). Fungal necromass dominated MNC accumulation and was strongly associated with soil microbial biomass C and Fep + Alp levels. In contrast, lignin phenol dynamics were regulated by abiotic factors (pH and Fep + Alp level), showing no significant SOC contribution shifts. Structural equation modelling indicated that soil microbial activity and mineral associations were the primary drivers of MNC, collectively explaining 88% of its variation. These findings refine the existing understanding of wetland C dynamics, demonstrating that inundation depth increases SOC stocks and preferentially stabilises microbial-derived C through biotic–abiotic interactions. Incorporating hydrological gradients into Earth system models is essential for predicting wetland carbon-climate feedback under intensifying hydrological variability.

54. 题目: Vegetation restoration drives a shift from plant-derived to microbial-derived soil organic carbon accumulation in a semi-arid sandy land in China
文章编号: N26030811
期刊: Applied Soil Ecology
作者: Jiannan Lu, Yuqiang Li, Xuyang Wang, Chengzhuo Zheng, Jie Lian, Xueyong Zhao
更新时间: 2026-03-08
摘要: Vegetation restoration in desertified regions enhances soil organic carbon (SOC) sequestration, but the relative contributions of plant-derived (PDC) and microbial-derived carbon (MDC) to this accrual remain largely unquantified in sandy lands. We used lignin phenol and amino sugar biomarkers to investigate SOC component dynamics across a five-stage restoration gradient from mobile dunes to sparse forest-grassland (aboriginal vegetation) in Horqin Sandy Land of northeastern China. Analysis showed that vegetation restoration significantly promoted SOC, PDC, and MDC accumulation. Crucially, SOC composition shifted dramatically; the relative contribution of PDC decreased from 58% to 14%, while that of MDC increased from 3.85% to 33%, identifying MDC gains as the primary driver of SOC accrual in later successional stages. Although the microbial community shifted towards bacterial dominance, a lower fungal-to-bacterial (F:B) phospholipid fatty acid (PLFA) ratio, fungal necromass consistently outweighed bacterial necromass, underscoring the dominant role of fungi in forming persistent necromass carbon. Random Forest model identified total PLFAs, soil texture (silt and clay content), and aboveground biomass as key predictors of SOC composition. Furthermore, structural equation modeling revealed that the PDC contribution was directly governed by the microbial F:B ratio, whereas the MDC contribution was controlled by the soil C:N ratio, with plant biomass and soil texture as indirect drivers. Our findings reveal a functional shift towards an MDC-driven SOC accrual pathway during sandy land restoration. Thus, SOC sequestration strategies must move beyond maximizing plant inputs to foster soil conditions promoting the microbial conversion of plant C into stable necromass, particularly persistent fungal carbon.

55. 题目: Development and validation of untargeted screening approaches to determine the source and fate of organic matter in coastal sediments
文章编号: N26030810
期刊: Geochimica et Cosmochimica Acta
作者: Zhe-Xuan Zhang, Julian P Sachs, Chen Zhao, Arnaud Huguet, Zhao Liang Chen, Jiying Li, Ding He
更新时间: 2026-03-08
摘要: The identification of organic matter sources and their fate in aquatic ecosystems is crucial for understanding their role in food webs, contaminant transport, and carbon sequestration; yet, source tracking techniques often face challenges related to the overlapping signatures of bulk geochemical parameters and the representativeness of targeted analyses of source-specific compounds (e.g., lipids). Recent advances in high-resolution mass spectrometry, such as direct infusion Fourier transform ion cyclotron resonance mass spectrometry (DI-FT-ICR MS), allow for the detection of thousands of known and unknown organic-solvent-extractable molecular signatures, including lipids, in a single sample; however, untargeted screening analysis remains underutilized due to difficulties in linking organic-solvent-extractable formulae to specific sources and biogeochemical processes. Here, we integrate both targeted biomarkers and untargeted screening approaches to label a wide range of organic-solvent-extractable formulae in sediments and explore their potential to decipher the sources, transport, and fates of terrestrial, marine, and anthropogenic organic compounds in coastal environments. Using Xiangshan Bay as a model ecosystem, three diagnostic groups were identified (t’-Peaks, m-Peaks, and h-Peaks) representing terrestrial, marine, and anthropogenic contributions, respectively. Three novel indices (It’, Im, Ih) are then introduced to trace the spatial variability of terrestrial, marine, and anthropogenic organic matter contributions across the bay. These indices are further validated in the Pearl River Estuary, demonstrating their broader applicability in coastal ecosystems. This study highlights the potential of untargeted screening using DI-FT-ICR MS as a sensitive and scalable tool for tracing diverse organic matter sources, with applications in carbon cycle and paleoenvironmental studies, as well as in watershed management and pollution monitoring.

56. 题目: Where do wildfire-related emissions travel? Transport trajectories of black carbon, organic carbon, and PM2.5 from Italian forest fires (2008–2024)
文章编号: N26030809
期刊: Atmospheric Environment
作者: Liudmyla Malytska, Maria Vincenza Chiriacò
更新时间: 2026-03-08
摘要: Forest fires are a major source of atmospheric pollutants, including fine particulate matter and carbonaceous aerosols, which significantly impact air quality, human health, and the climate. During intense fire seasons, wildfire emissions can exceed those from other anthropogenic sources and be transported over long distances. To identify regions most vulnerable to long-range wildfire pollutant transport, we first characterized forest-related events in Italy between 2008–2024 using the MODIS/SENTINEL-2 Burnt Areas product from EFFIS. Emissions were quantified with GFAS, and atmospheric transport was simulated using the HYSPLIT model, computing 72-hour forward trajectories at three vertical levels (0.5, 1.5, 3 km). Fire sources and transport pathways were clustered using DBSCAN, and representative trajectories and density maps were derived to identify dominant air mass patterns, validated using AERONET daily observations of Aerosol Optical Depth (440 nm). Fire activity in Italy was highly localized, with hotspots in Calabria, Sicily, central-southern Sardinia, and the northern mountain regions. Annual PM2.5 emissions ranged from 0.3 to 2 kt and increased over time, with organic carbon (OC) contributing 60%–80% and black carbon (BC) less than 10%. However, GFAS detected only about 21% of observed fires, likely underestimating emissions. Southern Italy, although characterized by numerous low-intensity fires ( 300 kg BC/fire), contributes the highest cumulative emissions, with pollutants often transported southward over the sea, toward North Africa. Balkans are frequently affected by plumes from Campania. In northern Italy, pollutants from fewer but more intense fires ( 550 kg BC/fire) mostly remain local, though higher-altitude transport increases variability, potentially affecting up to 20 million people.

57. 题目: Controls of organic matter sources and hydrodynamic conditions on carbon and phosphorus contents in two karst reservoirs
文章编号: N26030808
期刊: Applied Geochemistry
作者: Wenhui Wang, Yan Zeng, Jia Yu, Zhenzhen Ma, Yaoting Lu, Zuxue Jin, Lin Shi, Shuyun Xie, Jingfu Wang, Jingan Chen
更新时间: 2026-03-08
摘要: Most reservoirs in the karst regions of Southwest China are sub-deepwater lakes, exhibiting greater ecosystem fragility than shallow lakes, with internal loading remaining a significant contributor to eutrophication. This study investigates the Puding and Hongfeng Reservoirs—two contrasting karst systems distinguished by marked differences in physicochemical properties and hydrodynamic regimes—to clarify the spatial distribution of sedimentary biogenic elements of carbon (C), nitrogen (N), phosphorus (P) and silicon(Si) and identify the key environmental drivers governing this distribution. The results showed that the sediment C/N ratios indicated a predominantly endogenous organic matter (OM) in Hongfeng Reservoir (mean 11.5), while terrigenous OM in Puding Reservoir (mean 18.8). In Hongfeng Reservoir, TOC/OP was negatively correlated with TOC/TN and positively correlated with biogenic silica (BSi). The endogenous OM and the corresponding high decomposition rates resulted in low burial efficiency, while seasonal anoxia enhanced organic P (OP) regeneration. In Puding Reservoir, the ratio showed the opposite trend. The exogenous OM and high sedimentation rates led to high burial efficiency, while the aerobic conditions limited OP regeneration. TP is significantly positively correlated with OP, TOC, and BSi in Hongfeng Reservoir, indicating that primary production is likely primarily influenced by P. Conversely, in Puding Reservoir with strong hydrodynamic conditions, the significant negative correlation among TP, OP, TOC, and BSi suggests P is not the primary factor influencing primary production. Instead, it appears to be predominantly governed by hydrodynamic conditions in Puding Reservoir. This study can provide scientific basis for managing eutrophication in sub-deepwater karst reservoirs.

58. 题目: Targeted metabolomics reveals varying impairments of 17α-ethinylestradiol exposure in the presence of dissolved organic matter to Daphnia magna.
文章编号: N26030807
期刊: Environmental Toxicology and Chemistry
作者: Sanam Yousifie, Salwa Hajir, Karl Jobst, Andre J Simpson, Myrna J Simpson
更新时间: 2026-03-08
摘要: 17α-ethinylestradiol (EE2) is a highly potent endocrine disrupting chemical (EDC) that pollutes aquatic ecosystems, leading to biological impairment in freshwater organisms such as Daphnia magna. Bioavailability of EE2 may be affected by the presence of dissolved organic matter (DOM), also found in aquatic ecosystems; however, these interactions are not fully understood. To address this, EE2 interactions with two DOM types with varying chemistry (Suwannee River [SR] DOM and Leonardite-derived DOM) are explored by examining molecular-level perturbations to the polar metabolic profile of D. magna. D. magna were acutely (48 hr) exposed to sublethal concentrations of EE2 (high = 1 mg/L and low = 0.1 mg/L) and mixtures of each DOM type. Targeted metabolomics using liquid chromatography-tandem mass spectrometry was used to measure 52 polar metabolites from individual adult daphnids. In the absence of DOM, EE2 exposure at both concentrations significantly affected key metabolites and pathways that are essential for growth and survival in D. magna. Exposure to the DOM-SR and EE2 mixture resulted in the highest number of significant metabolite and pathway perturbations, whereas exposure to the Leonardite DOM and EE2 mixture demonstrated the least disruptions. These results suggest that the Leonardite DOM likely lowered the bioavailability of EE2 through binding, whereas the DOM-SR enhanced metabolic disruptions. Thus, these findings affirm that different types of DOM can distinctively affect EE2 behavior and biological response at the molecular-level, highlighting the importance of considering DOM chemistry when examining its interactions with pollutants and subsequent impacts to aquatic organisms.

59. 题目: Metal complexation promotes solar-driven peroxymonosulfate activation by dissolved organic matter for wastewater self-purification: Synergistic mechanisms and molecular-level transformations
文章编号: N26030806
期刊: Chemical Engineering Journal
作者: Yujia Han, Xue Bai, Min Du, Xuerui Song, Xin Jin, Lu Xu, Xuan Shi, Pengkang Jin
更新时间: 2026-03-08
摘要: The co-existence of metal ions and dissolved organic matter (DOM) is a common characteristic of industrial wastewater. Considering this phenomenon, this study developed an advanced oxidation system that leveraged metal-DOM complexation to significantly enhance the activation of peroxymonosulfate (PMS) by photoexcited DOM under solar irradiation. Compared with the system without metal ions, the Fe3+/DOM/PMS/solar system exhibited substantial performance improvements, with the efficiencies of PMS decomposition, UV254 removal, and DOM mineralization increasing by factors of 4.72, 4.56, and 12.94, respectively, reaching final efficiencies of 91.3%, 87.9%, and 68.05%, respectively. Mechanistic investigations revealed that metastable triplet-state DOM (3DOM*) served as a key intermediate, transferring electrons to PMS to predominantly generate 1O2, along with smaller amounts of •OH and SO4•−. X-ray absorption fine structure analysis confirmed the formation of FeO coordination bonds, which broadened DOM light absorption, promoted photoinduced electron generation, and facilitated a Fe3+/Fe2+ redox cycle that provided an additional activation pathway for PMS. At the molecular level, FT-ICR MS analysis demonstrated that the Fe3+-enhanced system induced extensive transformations across diverse elemental compositions and redox states, effectively converting DOM into lower-molecular-weight, more saturated, and less oxidized fragments. Machine learning combined with SHAP analysis further identified m/z, the nominal oxidation state of carbon, and the S/C ratio as key molecular descriptors determining DOM reactivity under Fe3+-enhanced conditions. Chloride effects and real industrial wastewater validation show the process remains effective in complex water matrices. This work elucidates metal-DOM complexation-enhanced PMS activation and provides a waste-treats-waste strategy for wastewater purification.

60. 题目: Fabricating nano- and micro- pesticide delivery systems using environmentally friendly humic acid
文章编号: N26030805
期刊: Chemical Engineering Journal
作者: Kun Zhuang, Yue Xu, Zijun Wang, Xin Liu, Yunyu Tang, Xiangyang Li, Guang Wei, Hongyu Cao, Tingting Zhai, Feng Liu, Nan Zou, Peng Zhang, Beixing Li
更新时间: 2026-03-08
摘要: Micro-nano pesticide delivery systems using lignin and its derivatives as wall materials exhibit remarkable advantages in improving the efficacy and safety of pesticides. Humic acid (HA) is a commonly used fertilizer with similar molecular structure to lignin. This study aims to explore the feasibility of substituting HA for expensive lignin and its derivatives for pesticide delivery systems. The HA suffered ultrafiltration according to its molecular weight (MW). The fractions with MWs of <5 kDa, 100–300 kDa, and > 300 kDa accounted for 8.56%, 14.88%, and 67.63%, respectively. HA with larger MW contains more aromatic rings or high conjugated systems. The nanocapsules prepared from HA of >300 kDa have a smooth surface without pores (particle size of 0.835 μm), while those prepared from HA of <5 kDa have a surface covered with nanoscale pores (particle size of 8.879 μm). The zeta potential of the nanocapsule solution prepared from HA of >300 kDa is −35.91 mV, while that of <5 kDa is −10.87 mV, which indicated an unstable system. The electrostatic self-assembly had favorable universality for the encapsulation of abamectin, lambda-cyhalothrin, pyraclostrobin and other pesticides. It was confirmed that capsules fabricated with HA could significantly reduce ultraviolet-induced pesticide degradation (only 10% degradation in 90 min) for foliar application and enhance the soil mobility of pesticides to improve their control efficacy on pests and diseases. The lowcost, environmentally friendly and universalizable natures endow HA with tremendous potential as the wall material for pesticide delivery systems.