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161. 题目: Unveiling the Promoting Mechanism of Humic Acid in Photocatalysis via Bismuth Heavy-Atom Effect
文章编号: N26083116
期刊: Environmental Science & Technology
作者: Yansong Liu, Jingjing Jiang, Hongyu Liu, Jiage Li, Yanan Zhang, Yunhe Gong, Yutong Xie, Bowen Zhao, Di Sun, Zhenhao Zhao, Mingxin Huo, Dandan Zhou, Shuangshi Dong
更新时间: 2026-08-31
摘要: Humic acid (HA) can contribute to photochemical transformation of organic pollutants in natural waters via triplet-excited states (3HA*). However, in HA-containing water matrices for practical photocatalytic treatment (e.g., surface waters or wastewater effluents), HA is conventionally regarded as a persistent inhibitor; its rapid quenching of reactive species dominates the process, while the beneficial 3HA* pathway remains restricted by spin-forbidden singlet-to-triplet conversion. Herein, a heavy-atom-effect-driven molecular assembly with a bismuth catalyst was designed to overcome the spin-forbidden barrier limiting 3HA* formation. This strategy converted HA into an in situ promoter and increased antibiotic degradation by 4.24-fold. The catalyst formed a close-contact electron donor–acceptor (EDA) complex with HA, through which the bismuth heavy-atom effect enhanced spin–orbit coupling in attached HA, accelerated intersystem crossing, and raised 3HA* steady-state concentration by 12.1-fold. Explainable machine learning and multidimensional spectroscopy further revealed the molecular selectivity of this enhanced pathway, showing that higher-molecular-weight HA components rich in oxygenated groups and conjugated aromatic skeletons preferentially participated in the Bi3–P-enhanced photochemical process and were transformed into smaller products. The mechanism was validated in real water matrices, indicating that heavy-atom-enabled intersystem crossing can be leveraged to improve photocatalytic tolerance to organic backgrounds and guide photochemical design for water treatment.

162. 题目: Enhancing Global Cropland Soil Organic Carbon Stability Through Integrated Management Practices
文章编号: N26083115
期刊: Environmental Science & Technology
作者: Zhen Xu, Zihan Wang, Haiqing Gong, Zhong Chen, Ruichao Zhao, Chang Pan, Yulong Yin, Zhenling Cui
更新时间: 2026-08-31
摘要: The ratio of mineral-associated organic carbon to particulate organic carbon (MAOC:POC) can serve as an indicator for assessing relative soil organic carbon (SOC) stability, which is closely linked to climate change mitigation and sustainable agriculture. However, the potential for enhancing relative SOC stability in global croplands, and the corresponding optimized integrated management strategies, remain unclear. Here, we developed a machine learning model that captured the interactions among cropland management practices, soil, and climate factors using a compiled global data set of 2,029 field observations, enabling systematic geospatial analysis of MAOC:POC across croplands worldwide. We found that cropland management practices, including tillage, fertilization, and irrigation, exert strong control over the MAOC:POC, and identified grid-specific optimal integrated combinations that achieve the highest ratio without compromising total SOC. Compared with the current global mean MAOC:POC of 6.32, implementing these strategies could increase this ratio to 9.58, representing a 51.5% improvement. Our findings provide the first global spatial diagnosis of relative SOC stability and demonstrate the potential of context-adapted strategies, offering actionable insights for carbon-smart and climate-resilient agriculture.

163. 题目: Long‐Term Impact of Cropping System and Nitrogen Input Quality on Nitrogen Release and Organic Matter Chemistry
文章编号: N26083114
期刊: European Journal of Soil Science
作者: Sevendeep Kaur Chahal, BaoLuo Ma, John Lauzon, Joshua Nasielski, Adam W Gillespie
更新时间: 2026-08-31
摘要: Long‐term integrated soil management strategies are essential for enhancing soil organic matter (SOM) quality and promoting the availability of mineralizable nitrogen (N). This study employed a tripartite analytical framework to investigate how crop rotations and organic N amendments influence soil N availability and SOM chemistry. A twelve‐week incubation assay quantified potentially mineralizable nitrogen (Min N) across five cropping systems: continuous corn (CC), continuous soybean (Soy), continuous clover (Cl), corn‐soybean (CS), and corn‐clover (CCl), under four N fertility regimes: no N input (N0), synthetic N as Urea (NF), uncomposted manure (UCM), and composted manure (CM). To evaluate the chemical stability of soil N, pyrolysis was used to calculate NH 3 ‐T50 (the temperature at which 50% of ammonia is released), serving as an indicator of thermal N stability. In parallel, X‐ray Absorption Near Edge Structure (XANES) spectroscopy characterized the chemical speciation of carbon and N in SOM. The Min N assay revealed significantly enhanced N availability in legume‐inclusive systems, particularly Cl and CCl treatment amended with CM or UCM. The NH 3 ‐T50 exhibited a significant negative correlation with Min N, indicating that more labile, biologically accessible N forms are associated with lower thermal stability. The XANES spectroscopy suggested that CC systems were characterized by amide and pyrrole N structures: markers of proteinaceous residues and limited microbial decomposition. In contrast, CCl treatments were enriched with pyridinic, aromatic, and aliphatic compounds, indicative of advanced microbial processing and stabilization pathways. Notably, UCM and CM treatments clustered closely in multivariate space, suggesting comparable SOM transformation trajectories despite compost maturity differences. Divergence in SOM chemistry under NF and N0 treatments reflected shifts toward labile or recalcitrant N pools, modulated by rotation context and input type. These findings highlight that integrating legumes and organic N amendments fosters a more microbially accessible soil N pool while supporting the development of chemically complex and stable SOM. The combined use of Min N assays, thermal analysis, and molecular spectroscopy provides a robust framework for understanding the interactions between crop rotation, N management, and SOM quality in sustainable agroecosystems.

164. 题目: Soil Organic Carbon Stocks and Saturation Deficit in Mediterranean Olive Groves: Effects of Intensification and Management Practices
文章编号: N26083113
期刊: European Journal of Soil Science
作者: Víctor Valenzuela‐Polo, Victoria Ochoa, Julio Calero, María Caridad Peñafiel‐Suarez, Vasileios Gkisakis, Ioanna Michail, Emmanouil Kabourakis, Ioannis Zografakis, Thanasis Kizos, Giorgios Stavrianakis, Stratis Sentas, Rosolino Ingraffia, Alfonso S Fenda, Aadil Bajoub, Francesca de Luca, Antonio J Manzaneda
更新时间: 2026-08-31
摘要: Soil organic carbon (SOC) plays a critical role in climate regulation, particularly in agroecosystems where soil management practices significantly influence carbon sequestration. In the Mediterranean Basin, olive groves represent a major agricultural system whose carbon storage potential remains insufficiently characterized at large spatial scales. This study assessed SOC stocks and their saturation status in 52 olive orchards sampled across five Mediterranean countries (Spain, Greece, Italy, Portugal, and Morocco), with 39 orchards retained for stock calculations after quality control of bulk density and coarse fragment data. SOC was quantified by both dry combustion and the Nelson and Sommers wet oxidation method. Agreement between methods was formally tested, and a carbonate‐dependent positive bias of the dry combustion method ( r = +0.20 between ISO−NS difference and carbonate content, p < 0.0001) led us to retain Nelson & Sommers values for all stock calculations. Bulk density measured with Kopecky cylinders was retained over a Saxton & Rawls pedotransfer estimate after a paired comparison showed poor concordance (Lin's CCC = 0.08; 95% LoA = ±0.5 g cm −3 ). The maximum SOC saturation limit (SOC_max) was estimated from the silt + clay protective fraction, with consistent (1−FG) coarse‐fragment correction applied to both current and maximum stocks so that the saturation deficit (SOC_potential = SOC_max−SOC_current) is a directly comparable, physically meaningful gap. Multivariate analyses (PCA, LDA with Wilks' Λ, two‐way PERMANOVA) revealed that olive orchards are organized along a single dominant intensification gradient (PC1, 30.5% of variance; CD1, 91.7% of canonical variance, p 1000 trees ha −1 were not represented in the sample, and this is acknowledged as a limitation. These findings highlight that intensification, more than the organic‐versus‐conventional dichotomy, structures the multivariate variability of Mediterranean olive groves, and that current SOC stocks lie well below textural saturation in most systems, indicating substantial potential for additional carbon sequestration through soil‐conservation practices.

165. 题目: Mechanism of Combined Improvement of Saline‐Alkali Soil by Artificial Humic Acid and Microbial Inoculant
文章编号: N26083112
期刊: Land Degradation & Development
作者: Ying Zhao, Rui Zhang, Zeyu Zhang, Fan Yang, Zhuqing Liu
更新时间: 2026-08-31
摘要: To address the widespread constraints imposed by saline‐alkaline soils on agricultural production worldwide, the combined reclamation and carbon cycle regulation effects of artificial humic acid (AHA) and a multifunctional microbial inoculant were evaluated through pot experiments. Results demonstrated that co‐application of AHA (4 g·kg −1 ) and the inoculant (1 g·kg −1 ) significantly improved soil physicochemical properties: soil pH decreased by 11.0%, while EC and Na + content were reduced by 20.7% and 38.6%, respectively. Soil urease and catalase activities increased by 100% and 25%. This combined treatment increased crop yield by 64.2%. Microbial analysis indicated elevated bacterial alpha‐ and beta‐diversity in the treatment group, accompanied by significant community restructuring, characterized by the enrichment of functional taxa and a reduction in halotolerant groups. Furthermore, soil carbon metabolism was reconfigured: the Calvin cycle and reductive acetyl‐CoA pathway were suppressed, while anaerobic carbon fixation pathways, such as the reductive tricarboxylic acid cycle and the 3‐hydroxypropionate bicycle were promoted. In terms of carbon degradation, enzymatic systems for starch and lignin decomposition were preferentially activated, whereas cellulase activity was transiently inhibited. These findings elucidate the key mechanisms underlying the combined improvement of saline‐alkaline soils and carbon cycle regulation by AHA and microbial inoculant, providing a theoretical foundation for sustainable management of saline‐alkaline lands globally and advancing the understanding of nutrient‐microbe‐carbon cycle interactions in saline‐alkaline environments.

166. 题目: Biochar‐Induced Shifts in Resource Stoichiometry Shape Potential Nitrogen Limitation and Estimated Microbial Carbon Use Efficiency in Tropical Soils
文章编号: N26083111
期刊: Land Degradation & Development
作者: Mingwan Chen, Shoupeng Li, Pengyu Zhu, Xin Jin, Fulin Qin, Mengqi Li, Chen Li, Changjiang Li, Changzhen Li
更新时间: 2026-08-31
摘要: Biochar is widely recognized as a promising amendment for enhancing soil carbon sequestration and microbial functioning, yet how biochar properties and application levels jointly influence potential microbial nutrient limitation and estimated microbial carbon use efficiency (CUE) remains unclear, especially in tropical farmland soils. Here, a 2‐year field experiment was conducted to examine the effects of two types (RB, rice hull biochar and PB, peanut shell biochar) and four application levels (10, 20, 40, and 60 t/ha), with 0 t/ha serving as the control, on labile substrates, microbial biomass, extracellular enzyme activities (EEAs), stoichiometric imbalance, vector‐based indicators of potential nutrient limitation, and estimated microbial CUE. Increasing biochar application levels consistently enhanced substrate availability, with dissolved organic nitrogen (DON) showing a stronger response than dissolved organic carbon (DOC), particularly under PB, thereby decreasing the DOC:DON ratio. Biochar application also increased microbial biomass C, N, and P, and synchronously stimulated C‐, N‐, and P‐acquiring enzyme activities by 15.61%–159.88%, 9.73%–201.21%, and 9.98%–162.96%, respectively; thus, ecoenzymatic stoichiometry remained largely unchanged. Vector angles remained below 45° across all treatments, indicating persistent potential relative N rather than P limitation, but their responses to biochar showed no clear monotonic pattern. Biochar type had a stronger influence than application level on stoichiometric imbalance and estimated microbial CUE. PB increased DON availability and was associated with a lower DOC:DON ratio, reduced C:N imbalance, and higher estimated microbial CUE. Exploratory path analysis associated biochar type mainly with C:N imbalance and estimated microbial CUE, while application level was associated with labile substrates, EEA, and microbial biomass. Overall, our results provide new insights into how biochar quality and application level jointly shape microbial resource stoichiometry, microbial functioning, and soil C cycling in tropical farmlands.

167. 题目: Toward circular biochar systems from waste-derived precursors: multi-analytical and multivariate insights into adsorption and heterogeneous Fenton-like oxidation performance
文章编号: N26083110
期刊: Journal of Cleaner Production
作者: Antonio Faggiano, Andrea Bergomi, Marco Vitelli, Valeria Comite, Gianluca Carabelli, Oriana Motta, Maria Ricciardi, Antonio Proto, Antonino Fiorentino, Paola Fermo
更新时间: 2026-08-31
摘要: Understanding how waste-derived resources can be transformed into functional materials is essential for advancing circular economy strategies and sustainable water treatment technologies. In this work, a combined multi-analytical and multivariate framework is developed to elucidate how waste-derived precursor type, pyrolysis temperature, and iron functionalization collectively control adsorption and heterogeneous Fenton-like oxidation in biochar-based systems. Biochars were produced from 4 waste-derived precursors: spent coffee grounds, olive pomace, olive pomace stones, and sewage sludge, at three pyrolysis temperatures (450, 550, and 650 °C), generating 12 pristine materials and, after iron functionalization, a total of 24 materials. This design enables a systematic evaluation of waste-to-resource pathways and the decoupling of compositional and structural effects. Advanced characterization was combined with I-optimal response surface methodology (RSM) and principal component analysis (PCA) to provide complementary information: RSM was used to optimize material and process variables, whereas PCA was applied to interpret structure-property-performance relationships and identify the main descriptors controlling adsorption and heterogeneous Fenton-like oxidation. Equilibrium adsorption data were better described by the Freundlich model (R2 ≥ 0.97), indicating that surface heterogeneity was a dominant factor, while Langmuir-derived Qmax values were used only as comparative capacity indicators. Lignocellulosic biochars were governed by surface area and aromaticity, whereas sewage-sludge-derived biochars showed enhanced affinity due to their mineral-rich matrices and oxygenated functionalities. Iron functionalization significantly improved performance, with Fe-SSBC450 showing the highest Langmuir-derived adsorption capacity (Qmax = 6.57 mg g−1) and oxidation efficiency (∼76% phenol removal). Oxidation proceeded via •OH-driven mechanisms following pseudo-second-order kinetics. This work demonstrates how waste-derived precursors can be valorised into high-value materials for environmental remediation, supporting circular economy strategies through resource-efficient water purification.

168. 题目: Seasonal Dynamics of Geogenic Phosphorus in Alluvial-Lacustrine Aquifers: Coupling of Phosphorus-Containing Dissolved Organic Matter and Microbes as a Key Driver
文章编号: N26083109
期刊: Water Research
作者: Junna Ning, Yao Du, Baisong Deng, Mengze Li, Tianming Wu, Lijie Lin, Taiping Yu, Yiqun Gan, Dandan Si, Wen Zhang, Yanxin Wang
更新时间: 2026-08-31
摘要: Geogenic phosphorus (P) enrichment in groundwater driven by dissolved organic matter (DOM) degradation has been well documented worldwide but remains underexplored regarding temporal dynamics. As microbial metabolism regulates P-containing DOM mineralization, resolving seasonal shifts in microbial strategies is essential for clarifying geogenic P mobilization. In this study, seasonal field monitoring was integrated with molecular DOM characterization and metagenomic analyses to elucidate the coupling among geogenic P, P-containing DOM, and microbial functional pathways. Dissolved inorganic phosphorus (DIP) fluctuations were controlled by a degradation gradient of P-containing DOM and concurrent adjustments in microbial metabolism. The seasonal oxidant influx from dry to wet seasons modified redox conditions and promoted the transformation of high-molecular-weight humic substances into low-molecular-weight polar compounds, thereby weakening the microbial degradation of P-containing DOM and reducing DIP enrichment. Meanwhile, microbial P metabolism shifted from multi-pathway degradation involving dephosphorylation and C–P bond cleavage to a single dominant dephosphorylation pathway. These findings indicate that seasonal redox dynamics restructure microbial metabolic strategies and ultimately regulate temporal DIP enrichment in groundwater system.

169. 题目: Thermal stratification-mediated DOM transformation shapes the vertical coupling-to-decoupling of carbon and nitrogen in an oxic alpine reservoir
文章编号: N26083108
期刊: Water Research
作者: Chen Li, Wei Wu, Lei Ren, Sheng Xu, Yuxuan Shi, Hui Zhao, Baoying Cheng, Menghan Wang
更新时间: 2026-08-31
摘要: Owing to depth and distinctive geography, alpine reservoirs develop persistent seasonal thermal stratification that reshapes habitats and shapes carbon (C) and nitrogen (N) cycling, yet the fine-scale vertical mechanisms of C–N coupling remain unresolved. Combining FT-ICR MS, dual N-O isotopes, and multi-omic microbial analyses, we resolved biogeochemical dynamics across a full stratification cycle, targeting its stable phase to decipher C–N coupling and decoupling. In the epilimnion, intense radiation and full oxygenation sustained active dissolved organic matter (DOM) transformation; its high bioavailability, rather than hypoxia, appeared to relieve heterotrophic carbon limitation and accelerate mineralization, supporting ammonia-oxidizing archaea (AOA) nitrification. Incomplete denitrification potential and oxygen suppression of nosZ favored N2O accumulation via nitrification by-products, reflecting labile-carbon-associated C–N coupling. In the metalimnion, density barriers intercepted settling particulates and promoted reductive DOM transformation. Resulting substrate heterogeneity fostered niche differentiation between autotrophic (amoA) and heterotrophic (nirS) groups, co-enriching nitrification and denitrification potential and defining this layer as the biogeochemical hotspot. In the hypolimnion, prolonged isolation forged an oligotrophic, oxic habitat where carbon deprivation and oxygenation impeded denitrification while favoring chemolithoautotrophic AOA. Carbon-fixation potential co-occurred with autochthonous reduced lipids, implicating endogenous organic carbon via the microbial carbon pump (MCP). Largely independent of labile carbon, ammonia oxidation alongside stagnant denitrification coincided with nitrate accumulation, manifesting C–N decoupling. This study establishes a vertical framework of epilimnetic coupling, metalimnetic transition, and hypolimnetic decoupling, offering new insights into element cycling and greenhouse-gas management under global warming.

170. 题目: B–N Conjugated Biochar Enhances Peroxymonosulfate Activation for 1O2 Generation by Disrupting Extended π Conjugated System
文章编号: N26083107
期刊: Applied Catalysis B: Environment and Energy
作者: Jing Zhang, Yixuan Gao, Hongna Li, Sihui Zhan
更新时间: 2026-08-31
摘要: Selective activation of peroxymonosulfate (PMS) to produce singlet oxygen (1O2) is desirable for efficient water purification. Graphitized biochar is a promising catalyst, but its extended π-conjugated structure favors in-plane charge delocalization and hinders axial electron transfer, leading to low 1O2 selectivity. Herein, we fabricated a boron-nitrogen (B–N) conjugated doped carbon-vacancy biochar (BN-Cv-Biochar) to modulate the local π-electronic system. B–N doping breaks the extended π-conjugation, creating polarized active sites and localized electrons that strengthen axial electron transfer and selective PMS adsorption. The degradation rate constant of sulfamethoxazole (SMX) of BN-Cv-Biochar is 1.68 and 4.45 times higher than that of pristine (Biochar) and nitrogen-doped carbon-vacancy biochar (N-Cv-Biochar), respectively. Experimental and theoretical results reveal that B–N sites coupled with carbon vacancies optimize the electronic environment, reduce the energy barrier for 1O2 generation, and preferentially promote 1O2-dominated PMS activation. Product analysis clarifies the SMX degradation pathway, and toxicity assays using radish seedlings confirm the reduced toxicity of treated water. This work provides a novel strategy to tune the π-conjugated structure of biochar for high-performance carbon catalysts in advanced oxidation processes.

171. 题目: Warming potential of atmospheric black carbon modulated by particulate matter
文章编号: N26083106
期刊: Nature Geoscience
作者: Dantong Liu, Fei Jiang, Kang Hu, Shuo Ding, Xuan Wang, Huihui Wu, Yang Yang, Zhonghua Zheng, Chenjie Yu, James Allan, Dawei Hu, Yuan Sun, Ping Tian, Delong Zhao, Mengyu Huang, Siyuan Li, Yangzhou Wu, Sobhan Kumar Kompalli, S Suresh Babu, Weijun Li, Lei Bi, Shaofei Kong, Yuan Wang, Ying Chen, Pengfei Liu, Joshua P Schwarz, Hugh Coe
更新时间: 2026-08-31
摘要: The mixing state of atmospheric black carbon is a key determinant of its climate forcing. While higher concentrations of non-black-carbon components surrounding black-carbon particles (known as coatings) can enhance radiative effects, accurately representing and validating these effects at high spatiotemporal resolution remain computationally challenging. Here, we synthesize a decade (2012–2021) of intensive ground-based and aircraft-based global in situ observations of single-particle black carbon and its coatings to quantify how coating thickness varies across urban and wildfire biomass-burning sources and how this variability influences black-carbon radiative forcing. We find that coatings increase the global top-of-atmosphere radiative effect of black carbon from 0.20 ± 0.25 W m−2 to 0.30 ± 0.42 W m−2, with an additional 0.065 ± 0.15 W m−2 attributable to black carbon in cloud liquid water. Thicker coatings make the radiative effects of biomass-burning black carbon two to three times stronger than the radiative effects of urban black carbon. This enhanced forcing may persist into the future, as particulate-matter concentrations are projected to follow divergent trajectories over the next half century. Our results suggest that black carbon exerts stronger warming effects in more polluted environments, highlighting the importance of jointly controlling black-carbon and particulate-matter emissions.

172. 题目: Temporal effects of precommercial thinning on dissolved organic carbon leaching in pine–oak mixed forests
文章编号: N26083105
期刊: Catena
作者: Qian Wang, Menglin Su, Zi'’ao Liang, Xiangfu Wang, Shuiqiang Yu, Weifeng Wang
更新时间: 2026-08-31
摘要: As a critical process in hydrological and biogeochemical cycles, soil leaching transports dissolved organic carbon (DOC) from terrestrial to aquatic ecosystems. Precommercial thinning (PCT), an important silvicultural practice of forest management, affects forest biogeochemical cycling, particularly DOC leaching. However, the effects of PCT on DOC leaching dynamics over recovery time remain poorly understood. To clarify the temporal effects and mechanisms of PCT, we investigated DOC leaching across a PCT recovery sequence namely, PCT in 2010 (T2010), PCT in 2018 (T2018), and the unthinned control (CK) in a pine–oak secondary forest. The results revealed that soil DOC leaching fluxes increased initially (T2018: 18.64 ± 0.43 kg C ha−1 yr−1) but recovered to non-PCT levels (CK: 16.54 ± 0.57; T2010: 17.86 ± 0.32 kg C ha−1 yr−1), with a similar intensifying effect observed for the litter DOC leaching flux (T2018: 248.08 ± 4.62; CK: 200.40 ± 4.95; T2010: 198.77 ± 3.11 kg C ha−1 yr−1). Mechanistically, PCT reshaped the soil physical structure by modulating bulk density and capillary-to-noncapillary porosity ratio, thereby reducing water leaching flux. Simultaneously, the PCT recovery sequence promoted soil DOC concentrations by reducing soil sorption capacity and enhancing soil organic carbon accumulation driven by greater litter inputs and microbial biomass. These findings demonstrate that PCT alters forest hydrological and biogeochemical cycles, thereby affecting soil DOC export. This study enhances the understanding of PCT impacts on forest carbon and water dynamics, providing empirical evidence for optimizing PCT strategies to balance forest carbon sequestration and DOC inputs in aquatic ecosystems.

173. 题目: Blocking the “Trojan Horse” effect: Humic acid alleviates the combined toxicity of amino-modified nanoplastics and tetracycline to microalgae by inhibiting heteroaggregation and oxidative stress
文章编号: N26083104
期刊: Journal of Environmental Management
作者: Gopi Narayanan, Xiangyi Guo, Mohmmed Talib, Gopala Krishna Darbha, Saiyong Zhu, Daohui Lin, Jonathan Y S Leung
更新时间: 2026-08-31
摘要: Given the ever-increasing accumulation of nanoplastics in aquatic environments worldwide, there is concern that plastic pollution will lead to ecological disasters due to the transfer of man-made pollutants, such as antibiotics, into aquatic life by nanoplastics. However, the intensity of this “Trojan Horse” effect may be influenced by natural organic matter that can interact with nanoplastics and antibiotics, possibly affecting their biological impacts. Thus, this study assessed how humic acid (HA, 10 mg L−1) modulates the combined effects of amino-modified polystyrene nanoplastics (NH2PS, 25 mg L−1) and tetracycline (TC, 5–15 mg L−1) on microalga Chlorella vulgaris following 96 h exposure. Results showed that exposure to TC and NH2PS, especially in combination, elicited various adverse effects on microalgae (e.g., membrane disintegration, mitochondrial dysfunction, growth retardation and impaired synthesis of photosynthetic pigments) due to elevated oxidative stress resulting from heteroaggregation between pollutants and algal cells. This adsorption of TC onto NH2PS created a carrier-enhanced delivery system that amplified cellular internalization of both pollutants, leading to persistent disruption of cellular homeostasis. Importantly, HA could ameliorate these toxic effects on microalgae as physicochemical characterization revealed that HA competitively reduced TC adsorption onto NH2PS surfaces and enhanced pollutant dispersion stability, thereby reducing the oxidative and membrane damage caused by direct contacts with pollutants. Overall, this study provides a mechanistic understanding of how natural organic matter mitigates the “Trojan Horse” effect of nanoplastics with antibiotics, suggesting that the ecological impacts of nanoplastics may be less severe than anticipated under realistic conditions. Such insights are crucial for refining ecological risk assessment and guiding nanoplastic pollution management.

174. 题目: Machine learning reveals reservoir regulation of riverine sedimentary organic matter and its climatic implications
文章编号: N26083103
期刊: Water Research
作者: Sibo Kang, Lei Huang, Hongzhu Wang, Yongde Cui, Wenjuan Gao, Chen He, Quan Shi, Chen Zhao, Ding He, Kai Wang
更新时间: 2026-08-31
摘要: Reservoirs play a pivotal role in riverine water resource management, while their influence on the cycling processes of riverine carbon remains to be further explored, constraining our comprehension of ecological impacts of reservoirs on terrestrial ecosystems. Here, we developed a machine learning (ML) model to characterize the dynamic of sedimentary organic matter (SOM) in the Yangtze River, one of the world’s largest rivers under the influence of the Three Gorges Reservoir (TGR), one of the world’s largest reservoirs. The TGR exhibited lower organic carbon (OC) and dissolved organic carbon (DOC) concentrations than the midstream of the Yangtze River (MYR), with mean values of 0.90 ± 0.20% and 1.58 ± 0.37 mg L-1, respectively, compared with 1.34 ± 0.45% and 2.60 ± 0.58 mg L-1 in the MYR. These differences suggested enhanced microbial processing and carbon elimination within the reservoir. Our ML model further revealed that the TGR promoted the in situ burial of heteroatom-poor, low-aromaticity organic matter (OM), while facilitating the downstream transport and subsequent deposition of microbially reworked, highly recalcitrant OM in the MYR. Combining with greenhouse gas (GHG) emission data from TGR to MYR, we found that this dynamic of SOM is involved severely in the decline of CO2 (∼60%) and CH4 (∼24%) emissions in the middle and lower reaches of the Yangtze River. This study highlights the potential of ML in the assessment of ecological impacts of reservoirs, and suggests that reservoirs contribute to GHG mitigation in downstream river systems.

175. 题目: Molecular evidence for algal bloom decay as a critical window for bacteria-mediated DOM transformation toward more refractory forms
文章编号: N26083102
期刊: Water Research
作者: Ziwei Zhang, Huanjun Zhang, Yi Li, Wangkai Fang
更新时间: 2026-08-31
摘要: Algal blooms profoundly alter the sources and composition of dissolved organic matter (DOM) in eutrophic lakes, with bacterial processes playing a central role in DOM transformation. However, how algal bloom succession reshapes bacteria-mediated DOM transformation and further influences the molecular fate of DOM remains unclear. Here, we integrated Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS), paired mass distance (PMD)-based reactomics, and high-throughput sequencing to characterize DOM transformations and their microbial driving mechanisms across the pre-outbreak, outbreak, and decay stages of a natural algal bloom in a eutrophic lake. Across bloom succession, DOM molecular richness peaked during the outbreak stage, whereas molecular phylogenetic dispersion, aromaticity, and recalcitrance increased toward the decay stage, alongside reduced potential bioavailability. Relative to other stages, bacterially active DOM during the decay stage showed the highest relative intensity of biologically refractory DOM (i.e., tannin-like, condensed aromatic-like, and lignin-like compounds), along with higher aromaticity and unsaturation. PMD-based reactomics revealed the strongest reaction signatures during the outbreak stage, dominated by categories annotated as oxygenases acting on paired donors and acyltransferases, consistent with rapid DOM turnover. By contrast, decay-enriched reaction signatures, including categories annotated as intramolecular oxidoreductases, carbon–nitrogen lyases, and racemases/epimerases, suggested selective molecular transformation of DOM, potentially favoring molecular persistence. These findings highlight the algal decay stage as a critical window for bacteria-mediated DOM transformation toward more refractory forms, providing molecular-level evidence for microbial regulation of organic carbon persistence in eutrophic lakes.

176. 题目: Plastic-derived Dissolved Organic Matter Release from Agricultural Mulch Films: Impacts of Solar UV Weathering
文章编号: N26083101
期刊: Water Research
作者: Shahin Ahmed Sujon, Emma M Payne, Kyle J Moor
更新时间: 2026-08-31
摘要: Plastic mulch film coverings are increasingly used in sustainable agriculture production to better use water resources. As mulches weather in fields in contact with rainfall or irrigation water, they have potential to release a complex mixture of organic chemicals, often called plastic-derived dissolved organic matter (plastic-DOM). Photodegradation is a potentially important pathway for plastic-DOM generation, yet little is known about the quantities of plastic-DOM released from commercial biodegradable mulches during use. To address this unknown, we investigated the release of plastic-DOM from agricultural mulch films during ultraviolet (UV) weathering over growing season relevant timescales (months). We quantified the amount of plastic-DOM released from polyethylene (PE) and biodegradable mulches as a function of weathering conditions (in air or water) and time. We further assessed the composition of the mulch film plastic-DOM generated during weathering using fluorescence excitation-emission matrices (EEMs), which revealed formation of humic-like fluorescence signals in plastic-DOM from biodegradable mulch films with UV weathering. Results advance understanding on the quantities and composition of plastic-DOM released from mulches throughout the growing season, as a first step to estimate plastic-DOM’s impact on receiving soils, groundwaters, and surface waters.

177. 题目: Spectral preprocessing and machine learning models for prediction of subarctic climate woodland soil organic carbon and total nitrogen using Vis-NIR spectroscopy
文章编号: N26083009
期刊: Journal of Soils and Sediments
作者: Zhengxiang Xu, Qikai Lu
更新时间: 2026-08-30
摘要: Purpose Woodlands in subarctic climates are important for global carbon storage and sequestration, contributing significantly to climate stabilization. Accurate estimation of soil organic carbon (SOC) and total nitrogen (TN) is essential for managing these ecosystems. Methods This study applied visible and near-infrared (Vis-NIR) spectroscopy to predict subarctic climate woodland SOC and TN, where the performance of different spectral preprocessing and machine learning models were evaluated. To preprocess the spectrum, standard normal variates (SNV), normalization (NOR), multiplicative scatter correction (MSC), Savitzky-Golay smoothing with first derivative (SG1), and Savitzky-Golay smoothing with second derivative (SG2) were adopted. Meanwhile, partial least squares regression (PLSR), random forest (RF), support vector regression (SVR), extreme gradient boosting (XGBoost), light gradient boosting machine (LightGBM) and one-dimensional convolutional neural network (1D-CNN) were employed to model the relationship between Vis-NIR spectra and soil properties. A total of 1,368 soil samples collected from subarctic woodland of Finland and Sweden were used in the study. Results Experimental results demonstrated that Vis-NIR exhibits strong potential for estimating SOC and TN. Different spectral preprocessing approaches produced diverse results, with SG1 and SG2 outperforming the others. All machine learning models achieved satisfactory predictions, while the highest validation accuracies for both SOC (R2 = 0.949) and TN (R2 = 0.950) were achieved by the combination of SG1 and SVR. Conclusions This study offers both a theoretical reference and a practical framework for applying Vis-NIR spectroscopy combined with machine learning to support the monitoring and management of soil carbon and nitrogen in subarctic woodlands.

178. 题目: Vertical stratification of microbial necromass carbon and soil organic carbon fractions during natural secondary succession in temperate forests
文章编号: N26083008
期刊: Plant and Soil
作者: Gaoqiang Zhu, Guancheng Liu, Miao Wang, Xiaochun Wang, Liming Yin, Chao Liang, Yajuan Xing, Qinggui Wang
更新时间: 2026-08-30
摘要: Background and aims Natural secondary succession after clear-cutting is an important pathway for restoring forest soil organic carbon (SOC). However, how SOC fractions and microbial necromass carbon (MNC) vary among soil layers during succession remains unclear. Methods We investigated four natural secondary forests representing 20, 32, 47, and 61 years after clear-cutting and an undisturbed primary forest (> 200 years). Soil samples were collected from 0–10, 10–20, and 20–30 cm depths to quantify SOC, particulate organic carbon (POC), mineral-associated organic carbon (MAOC), MNC, and its contribution to SOC. Results SOC, POC, and MAOC increased significantly with succession across soil layers. POC contributed more to SOC at 0–10 cm, whereas MAOC contributed more at 10–30 cm. Fungal necromass carbon (FNC), bacterial necromass carbon (BNC), and MNC contents were significantly higher at 0–10 cm than at 20–30 cm across successional stages. The relationship between MNC and POC tended to weaken with depth, whereas the MNC–MAOC relationship varied among soil layers. The regulation of SOC fractions exhibited soil depth-dependence. At 0–10 cm, forest succession indirectly influenced SOC fractions by altering soil abiotic properties and thereby regulating microbial biomass and MNC accumulation. In contrast, at 10–30 cm, SOC fractions were directly regulated by soil abiotic properties. Conclusions MNC stratification was closely associated with depth-dependent SOC accumulation during secondary succession. These findings suggest that forest management should prioritize natural secondary succession and consider depth-specific necromass accumulation and SOC stabilization when enhancing forest soil carbon sequestration.

179. 题目: Biochar and hydrochar for saline soil amelioration and rice seedling growth promotion
文章编号: N26083007
期刊: Journal of Soils and Sediments
作者: Shuoding Xiao, Yu Xie, Jingru Yi, Yumei Huang, Weijie Yan, Sile Liu, Cheng Yi, Zongnan Li, Zhichao Xiang, Zhi Zhou, Wei Luo
更新时间: 2026-08-30
摘要: Purpose This study aimed to evaluate the effectiveness of biochar (BC), KOH/ Fe2(SO4)3-modified biochar (MBC), hydrochar (HTC), and modified hydrochar (MHTC) in ameliorating coastal saline-alkali soil properties and promoting rice seedling growth, and to explore the underlying mechanisms. Methods A pot experiment was conducted under simulated saline conditions. Treatments included a control (CK), BC, MBC, HTC, and MHTC, each applied at 2% (w/w). Rice seedlings were cultivated for 30 days. Soil physicochemical properties, enzyme activities, plant growth parameters, nutrient uptake, and ion homeostasis were analyzed. Results Compared with CK, all amendments significantly reduced soil electrical conductivity and sodium (Na⁺) content, while increasing soil organic carbon, cation exchange capacity, and the proportion of water-stable aggregates. Soil enzyme activities (urease, sucrase, catalase) were markedly enhanced. The amendments decreased Na⁺ accumulation and the Na⁺/K⁺ ratio in plants, improved nutrient (N, P, K) uptake, and increased seedling biomass. The synergistically modified material, MHTC, demonstrated the most comprehensive improvements across all measured parameters. Conclusions The synergistic KOH/Fe2(SO4)3 modification strategy significantly enhanced the functionality of carbon-based materials. MHTC effectively alleviated salt stress, improved soil properties, activated soil enzymes through integrated physicochemical and biochemical mechanisms, thereby substantially enhancing rice seedling growth. This study provides a promising novel material and strategy for the sustainable amelioration of saline-alkali soils.

180. 题目: Decrease of soil total and organic phosphorus with ectomycorrhizal tree dominance in a subtropical mountainous forest
文章编号: N26083006
期刊: Journal of Soils and Sediments
作者: Mi Yang, Mengzhen Lu, Long Chen, Qiuxiang Tian, Xiaorong Wang, Zhiyang Feng, Zhongfeng Sun, Feng Liu
更新时间: 2026-08-30
摘要: Aims Arbuscular mycorrhizal (AM) and ectomycorrhizal (ECM) plants differ in phosphorus (P) uptake strategies and litter quality, but the covariant relationship between tree mycorrhizal dominance and soil total phosphorus (TP) and its fractions along the natural gradient remains unclear. This study aims to elucidate the association between tree mycorrhizal symbiosis and soil P dynamics. Methods We established 35 plots across an AM and ECM tree dominance gradient. Soil P fractions were determined using the modified Hedley method. Plant traits, litter quality, soil properties, and microbial communities were analyzed to identify driving mechanisms. Results Soil TP, organic P (Po), and primary mineral P (HCl-Pi) decreased significantly with increasing ECM tree dominance. TP content was negatively related to the basal area of trees and the thickness of forest floor, and positively correlated with community-weighted-mean litter P content. Reduced TP was mainly driven by stronger aboveground P translocation and lower litter P input. Declines in Po and HCl-Pi were attributed to covaried with elevated mineralization and dissolution potential linked to soil enzymes, phosphorus-solubilizing microorganisms (PSM), and low pH. Conclusions Increasing ECM dominance was associated with decreased TP and Po pools in the soil, accompanied by increased acid phosphatase activity and increased abundance of PSMs recruited by ECM fungi. This study elucidates how mycorrhizal tree dominance synergistically changes with soil P fractions transformation and microbial P-activating functional groups in weathered subtropical forest soils.