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21. 题目: Engineering biochar from biomass pyrolysis for effective adsorption of heavy metal: An innovative machine learning approach
文章编号: N25011201
期刊: Separation and Purification Technology
作者: Lijian Leng, Huihui Zheng, Tian Shen, Zhibin Wu, Ting Xiong, Shengqiang Liu, Jianbing Cao, Haoyi Peng, Hao Zhan, Hailong Li
更新时间: 2025-01-12
摘要: The application of biochar in heavy metal removal has attracted significant attention due to its characteristics. However, engineering biochar materials through trial-and-error methods is traditionally applied, but it is time-consuming and labor-intensive. Applying machine learning (ML) promises to substantially enhance the efficiency of engineering biochar with desired properties. Here, ML was employed for the first time to predict multiple properties of biochar that are critical to heavy metal adsorption, such as cation exchange capacity (CEC). Previous studies have focused on correlations between the CEC and application performance of biochar, but no study has reported the direct prediction of heavy metal adsorption capacity (qe) from biomass. Therefore, a biomass—production—application hybrid ML model (test R² 0.996) was constructed by integrating the biomass—production—biochar-properties ML model (test R² 0.941) and the biochar-properties—application (heavy metal adsorption) ML model (test R² 0.960). This innovative hybrid model facilitated the screening of biomass feedstock and the optimization of pyrolysis conditions, using only elemental composition data of biomass. With nine biomass feedstocks in the lab, the hybrid ML model effectively provided the optimum solution for producing biochar with the highest q_e (e.g., predicted q_e of ∼0.60 mmol/g for Cd²⁺). Finally, the experimental verification of the optimum solution showed that the adsorption capacities of the as-produced optimum biochar were comparable with the hybrid model-predicted ones (validation R² 0.859), and the adsorption mechanism study echoed the dominant role of cation exchange, showing the great potential of such hybrid ML models to promote the production of designer biochar.

22. 题目: Unprecedented East Siberian wildfires intensify Arctic snow darkening through enhanced poleward transport of black carbon
文章编号: N25011107
期刊: Science of the Total Environment
作者: Yeonsoo Cho, Hyeonmin Kim, Rokjin J Park, Sang-Woo Kim
更新时间: 2025-01-11
摘要: Summer Arctic black carbon (BC) predominantly originates from boreal wildfires, significantly contributing to Arctic warming. This study examined the impact of MODIS-detected extensive East Siberian wildfires from 2019 to 2021 on Arctic BC and the associated radiative effects using GEOS-Chem and SNICAR simulations. During these years, Arctic surface BC aerosol concentrations rose to 46 ng m⁻³, 43 ng m⁻³, and 59 ng m⁻³, nearly doubling levels from the low-fire year of 2022. East Siberian wildfires accounted for 62 %, 75 %, and 79 % of elevated BC levels in 2019, 2020, and 2021, respectively. These wildfires also increased BC deposition on snow and sea ice, particularly in the Laptev and East Siberian Seas. The resulting snow contamination (30.6 ± 5.15 ng g⁻¹, 15.4 ± 1.29 ng g⁻¹, and 33.8 ± 5.24 ng g⁻¹) reduced surface snow albedo, increasing summer Arctic radiative forcing over snow and sea ice by +1.38 ± 0.65 W m⁻², +0.70 ± 0.20 W m⁻², and + 1.46 ± 0.73 W m⁻² in 2019, 2020, and 2021, respectively. As climate warming intensifies, more frequent extreme wildfires in East Siberia could further amplify Arctic snow darkening, potentially accelerating Arctic warming.

23. 题目: Dissolved organic carbon can alter coastal sediment phosphorus dynamic: Effects of different carbon forms and concentrations
文章编号: N25011106
期刊: Chemosphere
作者: Shuo-Nan Ma, Xu-Meng Dong, Ji-Lin Xu, Chun-Pu Zhao, Miao Liu, Hai-Jun Wang, Erik Jeppesen
更新时间: 2025-01-11
摘要: Coastal waters are receiving increasing loads of dissolved organic carbon (DOC), differing in structural complexity and molecular weights with potential different effects on the phosphorus (P) dynamics in these waters. This study conducted an in-situ investigation in Xiangshan Harbor, China, to explore the patterns of P release in response to DOC inputs. To further elucidate the underlying mechanisms behind the DOC-affected sediment P release, a two-month mesocosm experiment was undertaken with coastal sediment (Xiangshan Harbor) to which acetate, glucose, and humic acid (representing the fermentation product, the simple available carbon, and the refractory humic-like carbon sources, respectively) were separately added to the overlying water at dosages of 0, 5, 10, and 20 mg C L−1. We found that: i) sediment P release showed a non-linear increase with DOC input, a pattern likely due to the diverse forms of DOC in coastal zones, which had varying impacts on P release; ⅱ) significant P release for labile DOC (acetate- and glucose-amended) treatments but retention for humic acid treatments, and the magnitude of P changes mainly depended on the amount of DOC addition; ⅲ) acetate and glucose shared similar P-release-promotion mechanisms, i.e., decreased dissolved oxygen, increased ppk genes in water, and increased P bacteria and alkaline phosphatase activity were the dominant factors behind the P release for both carbon sources, as indicated by piecewise structural equation modelling; ⅳ) humic acid-inhibitory effects on sediment P release, which likely reflect increasing “P-humic acid” complexes that favor P adsorption and sedimentation and form stable “humic acid-enzyme” complexes that reduce the catalytic activity of alkaline phosphatase. Our findings provide new understanding of relationships between loading of DOC with different form/concentration and sediment P dynamics in coastal areas.

24. 题目: Changes in the composition of soil organic matter caused by organic and conventional management in the long term
文章编号: N25011105
期刊: Journal of Environmental Management
作者: Hugo Felipe da Silva, Paloma Viana Ferreira de Sousa, Maria Eugenia Ortiz Escobar, Teogenes Senna de Oliveira
更新时间: 2025-01-11
摘要: • Organic systems increase the variability of organic compounds in the topsoil. • Organic farming increases aromatic and aliphatic in the surface. • There is more organic functions in organic than in conventional in the topsoil. • Organic farming reduced carbon and suberin in the subsoil at mineral-associated.

25. 题目: Why the disinfection efficiency of ultraviolet radiation may become unsatisfactory at low suspended solid concentrations: the mechanism of extracellular polymeric substances secretion induced by different particles
文章编号: N25011104
期刊: Water Research
作者: Zhe Yu, Yicheng Xie, Xiqi Li, Wenzong Liu, Jing-Long Han, Chunyuan Zheng, Qun Zheng, Xuezhi Zhao, Aijie Wang
更新时间: 2025-01-11
摘要: Due to the global outbreaks caused by pathogens, disinfection has attracted widespread attention, especially as the final inactivation step in wastewater treatment plants (WWTPs). Ultraviolet (UV) radiation is regarded as one of low carbon disinfection methods without chemical agents, but in practice, the effects are sometimes unsatisfactory, e.g., Escherichia coli (E. coli) still stay alive excessively at low concentrations of suspended solids (SS) that meets the discharge standards (<10 mg L^-1). WWTPs focus on each process's efficiency, while the particle influence of different upstream processes on UV radiation is ignored. This study investigated the changes in extracellular polymeric substances (EPS) structure and biofilm from the perspective of single cell and cell-to-cell interactions at low SS concentrations before and after UV radiation. We disclosed that the effective characteristics of effluent SS particles were mainly related to some specific operation units, like coagulation sedimentation or sand filtration, which induced EPS secretion and biofilm formation, and subsequently caused the different responses of cells within the biofilm to UV radiation. Compared with filtrating sand particles, the magnetic coagulant induced more polysaccharide secretion and expanded the EPS structure, leading to a thicker and more effective protective layer to weaken UV intensity and reduce reactive oxygen species levels inside cells. The microbial community analysis of a real WWTP confirmed the survival of microorganisms with abilities of EPS secretion and sheltering others. Therefore, considering the potential positive effect of particles (such as metal particles) in the upstream process on the microbial aggregation in the subsequent process, it is recommended that the UV disinfection requires a lower SS concentration standard or a higher UV radiation dose. This study provides a basis for effective UV disinfection at the present application standards.

26. 题目: Adsorption and removal of pentavalent antimony from water by biochar prepared from modified rosa roxburghii residue
文章编号: N25011103
期刊: Frontiers in Environmental Science
作者: Yong Dai, Shengmao Zhao, Ruyi Zheng
更新时间: 2025-01-11
摘要: In order to investigate the adsorption properties of modified rosa roxburghii residue biochar to antimony (Sb) in water, the modified rosa roxburghii residue biochar (BC-FeOOH) was prepared from rosa roxburghii residue factory in Guizhou Processing plant. The adsorption characteristics of BC-FeOOH on Sb(V) in water were investigated by batch test experiments with different pH, biochar dosage and adsorption time. The results showed that the best adsorption effect of BC-FeOOH on antimony was achieved at the dosage of 0.05 g and pH 2.0, and the adsorption amount reached 5.7 mg/g. The results of adsorption kinetic modeling showed that the equilibrium time of the adsorption of BC-FeOOH on Sb(V) in water was in the range of 8–10 h, and the mechanism of adsorption was mainly chemical adsorption. Langmuir model can better describe the adsorption process of BC-FeOOH on Sb(V), and the surface adsorption process is monomolecular layer chemisorption. The experimental results showed that BC-FeOOH is a good adsorbent for Sb pollution remediation in water. This study provides n ew insights for the development of Sb contamination removal strategies in water and offers a new way for the resource utilization of prickly pear pomace.

27. 题目: Combination of anaerobic digestion and sludge biochar for bioenergy conversion: Estimation and evaluation of energy production, CO2 emission, and cost analysis
文章编号: N25011102
期刊: Journal of Environmental Management
作者: Matheus Antônio da Silva, Bruna Sampaio de Mello, Brenda Clara Gomes Rodrigues, Clovis Augusto Ribeiro, Ieda Aparecida Pastre Fertonani, Arnaldo Sarti
更新时间: 2025-01-11
摘要: Waste-to-energy technologies involve the conversion of several wastes to useful energy forms like biogas and biochar, which include biological and thermochemical processes, as well as the combination of both systems. Assessing the economic and environmental impacts is an important step to integrate sustainability and economic viability at anaerobic digestion systems and its waste management. Energy production, CO2 emissions, cost analysis, and an overall process evaluation were conducted, relying on findings from both laboratory and pilot-scale experiments. The digestate generated during anaerobic digestion proved to be an effective approach for mitigating some CO2 emissions while managing sludge waste within the anaerobic digestion and CHP system. Incorporating biochar production and application in soil into the process led to a 3.5 % reduction in CO2 emissions, which contributed to a more sustainable form of energy production while offering the potential for the generation of carbon credits through a carbon-negative process. The employment of digestate biochar for energy production seems a feasible way to reduce the amount of residue to final disposal in landfill with a minimal reduction of profit per GWh and a slight increase in the CO2 emissions by 2.7 %.

28. 题目: Sediment particle size distribution, source of organic matter and environmental implications in the Liao River, northeast China
文章编号: N25011101
期刊: Catena
作者: Panpan Cui, Haifu Li, Lijuan Cui, Fangli Su
更新时间: 2025-01-11
摘要: The Liao River Basin, one of China’s most severely affected coastal regions by soil erosion, necessitates a thorough quantitative evaluation of the sources of organic matter (OM) across sediment particle sizes to enhance understanding of carbon biogeochemical cycling. This study examined total organic carbon (TOC), total nitrogen (TN), the TOC/TN ratio (C/N ratio), and δ13C and δ15N isotope signatures in four distinct sediment particle size fractions from Liao River sediments, sampled during the summer and winter of 2023. The results demonstrated that the highest concentrations of TOC, TN, and C/N ratio were found in the <2 µm particle fraction (p <0.05), with summer values of 2.50 ± 0.43 %, 0.19 ± 0.06 %, and 13.89 ± 2.40, respectively, and winter values of 2.71 ± 0.42 %, 0.19 ± 0.05 %, and 14.66 ± 2.55. OM sources were characterized using δ13C and C/N ratio analysis, and the MixSIAR Bayesian model was employed to quantify their contributions. Aquatic plants were identified as the dominant OM source in the <2 µm fraction, whereas soil and sewage predominated in the >2 µm fractions. These results indicate that exogenous OM in the Liao River’s mainstem is primarily influenced by sewage discharge and soil erosion. This process facilitates the continuous release of nutrients from sediment particles into the water column, contributing to secondary pollution. Therefore, enhanced management of sewage discharge and erosion control is essential. Carbon and nitrogen isotope fingerprinting within sediment particle size fractions provides novel insights into biogeochemical processes within soil microenvironments.

29. 题目: Manganese Dioxides Induce the Transformation and Protection of Dissolved Organic Matter Simultaneously: A Significance of Crystallinity
文章编号: N25011008
期刊: Environmental Science & Technology
作者: Zhiqiang Wang, Haoran Zhao, Zihan Shi, Haokai Zhao, Shu Chen, Zhuoyan Chen, Yuntao Yuan, Chi Zhang, Bin Jia, Hanzhong Jia
更新时间: 2025-01-10
摘要: Interactions between manganese dioxides (MnO₂) and dissolved organic matter (DOM) have long been the subject of scientific inquiry. However, the effect of MnO₂ crystallinity on the DOM fate remains unclear. Herein, we comprehensively investigate the adsorption, protection, and mineralization of DOM by MnO₂ with various crystallinities (order of crystallinity: γ-30 < γ-90 < γ-120). The results show that DOM adsorption is positively correlated with the specific surface area (SSA) of MnO₂; γ-30 with the largest SSA adsorbs the highest amount of DOM, resulting in DOM protection. However, γ-90 and γ-120 with a smaller SSA could induce the Maillard reaction and thereby promote the formation of geopolymerized organic matter, leading to reduced bioavailability of DOM. Furthermore, the capability of MnO₂ to mineralize DOM decreases in the order γ-120 > γ-90 > γ-30, and it is determined by both Mn⁴⁺ and hydroxyl radical (^·OH) content. In particular, the contribution of radical-based oxidation of ^·OH to DOM mineralization is 64.8, 47.4, and 23.7% for γ-30, γ-90, and γ-120, respectively. We propose that crystallinity of MnO₂ may have a significant but hitherto unexplored influence on the global carbon cycle over geological time.

30. 题目: Network-Based Methods for Deciphering the Oxidizability of Complex Leachate DOM with •OH/O3 via Molecular Signatures
文章编号: N25011007
期刊: Environmental Science & Technology
作者: Hui Wang, Lan Wang, Thomas William Seviour, Changfu Yang, Yan Xiang, Ying Zhu, Michael Palocz-Andresen, Zongsu Wei, Ziyang Lou
更新时间: 2025-01-10
摘要: In landfill leachates containing complex dissolved organic matter (DOM), the link between individual DOM constituents and their inherent oxidizability is unclear. Here, we resolved the molecular signatures of DOM oxidized by ^•OH/O₃ using FT-ICR MS, thereby elucidating their oxidizability and resistance in concentrated leachates. The comprehensive gradual fragmentation of complex leachate DOM was then revealed through a modified machine-learning framework based on 43 key pathways during ozonation. Specifically, humic substances like humic acid (HA) and fulvic acid (FA) were measured to be the dominant DOM fractions in concentrated leachates, accounting for 35.9–51.7% of the total organic carbon, which was consistent with the observation by three-dimensional fluorescence spectroscopy. According to FT-ICR MS, carboxyl-rich alicyclic molecules (CRAMs) or lignin-like substances were the most abundant components, comprising 40.2–54.5% of all substances. The machine learning modeling showed that molecular weight was the most important structural factor for DOM resistance to ^•OH and O₃ degradation (SHAP value 0.84), followed by (DBE-O)/C (0.32), S/C (0.31), and H/C (0.08). During ^•OH and O₃ attacking, unsaturated and reduced compounds were the dominant precursors. For the molecular transformation of CRAMs-DOM, oxygen addition reactions were found to be the predominant O₃-attacking process, along with the dealkyl and carboxylic acid reactions during ^•OH oxidation that often resulted in more complete degradation of DOM. This study proposed a new framework integrating molecular signatures and machine learning for unraveling DOM’s inherent reactivity in complexity, which informs strategies for managing concentrated leachates.

31. 题目: Uranyl separation from wastewater on the porous Fe-BC synthesized through coupling carbothermal reduction and ZnCl2 activation
文章编号: N25011006
期刊: Separation and Purification Technology
作者: Yirou Bai, Yu Chen, Ping Xue, Lei Wang, Zenghui Diao, Gang Song, Diyun Chen, Lingjun Kong
更新时间: 2025-01-10
摘要: Nano zero-valent iron (nZVI) has been widely reported to attract uranium (U(VI)) from wastewater through surface adsorption and reduction. However, surface oxidation and agglomeration of nZVI significantly limited the application of nZVI in removing U(VI) from wastewater. In this study, a novel porous nZVI/BC composite (Fe₁Zn₃-BC(900)) was synthesized via a one-step process coupling carbothermal reduction and ZnCl₂ activation. In this process, ferric chloride and zinc chloride were employed as the Fe and Zn precursors, while starch was utilized as the biochar precursor. Zn and Fe were formed in the carbothermal reduction process. The Zn was sacrificed through evaporation to increase the porosity, providing sufficient inner space for well-dispersing the nZVI, what could be wrapped and protected by the porous carbon. Besides, the galvanic cell between the nZVI-C interface was formed, accelerating the electron transfer for reduction of U(VI) into U(IV). As expected, the Fe₁Zn₃-BC(900) performed a high efficiency of 94.3% for separating the U(VI) in an initial concentration of 10 mg/L within 30 min, confirming the positive effect of ZnCl₂ sacrifice on enhancing separation of U(VI) onto the Fe₁Zn₃-BC(900). The high uranium removal efficiency can be attributed to the fact that the enhanced porosity resulting from Zn evaporation facilitates U(VI) adsorption. The reduction of U(VI) is further facilitated by the high dispersion of nZVI and the formation of Fe/C galvanic cell. Therefore, this work has developed a promising method to address the agglomeration of nZVI in the separation of U(VI) from wastewater, which provides a new idea for the subsequent efficient uranium removal.

32. 题目: Unraveling the Edaphic Factors Driving Organic Material Decay: Insights from Long-Term Manure Application Studies
文章编号: N25011005
期刊: Soil Biology and Biochemistry
作者: Yuting Fu, Sabine Ravnskov, Marcos Paradelo, Lis W de Jonge, Emmanuel Arthur
更新时间: 2025-01-10
摘要: Organic material (OM) decomposition is crucial to soil fertility. We evaluated the hypothesis that long-term manure application induces changes in soil properties which affect the decomposition of OM in the first three months. We buried standardized plant litter with different C/N ratios, i.e., green tea (high-quality OM) and rooibos tea (low-quality OM), in five long-term organic fertilization experiments across different soil types in Europe. Intact 100 cm³ soil cores and bulk soil around the buried OM were analyzed for soil properties, including the physicochemical environment (nutrient contents, pore structure, etc) and microbiological properties (biomass of arbuscular mycorrhizal fungi, fungi, actinobacteria, Gram-positive and Gram-negative bacteria, and fluorescein diacetate [FDA] enzyme activity). Despite the difference in microbial growth and activity and soil pore structure between treatments and crops, the effect of manure on OM decomposition was inconsistent across the fields and varied with soil texture and standing crop species. Decomposition of high-quality OM was reduced by 5–7% in two sandy fields with manure treatment and that of low-quality OM was reduced by 22% in one silty manured field, while in the other fields, the decomposition was not affected by manure. The decomposition of both OM types was higher in the maize field than in the barley and grass fields in one sandy site. Soil texture and electrical conductivity were negatively linked to the mass loss of both OM types. For the high-quality OM, its decomposition was also negatively linked to soil organic carbon and nutrient content, but positively linked to FDA enzyme activity. In contrast, the decomposition of low-quality OM was positively impacted by the bacterial biomass and soil total porosity. In conclusion, the effect of long-term manure application on OM decomposition depends on the soil texture and the standing crop species, and the edaphic drivers for OM decomposition vary with OM quality.

33. 题目: Comparative study on the application of straw, biochar, dimethylpyrazole phosphate, and polyaspartic acid on nitrogen cycle, soil properties, and yield of potted rice
文章编号: N25011004
期刊: Plant and Soil
作者: Lexin Jia, Tai Liu, Yanxue Chen, Hongbin Liu, Chengyuan Wu, Hongyuan Wang, Ziyi Wang, Chaodan Niu, Jinhui Yang
更新时间: 2025-01-10
摘要:

Aims

Straw, biochar, dimethylpyrazole phosphate (DMPP), and polyaspartic acid (PASP) are promising materials to improve soil productivity and alleviate agricultural pollution. However, the comparison of these four materials in rice cultivation, in terms of fertilizer use efficiency and crop yield enhancement, remains limited. A pot experiment was therefore conducted to elucidate the comparative impacts of these materials on gaseous nitrogen loss, rice growth, nutrient uptake, soil properties, and soil nitrifying bacteria during different growth stages with the aim of identifying the optimal material facilitating rice production.

Methods

Six treatments were designed as follows: no nitrogen fertilizer (PK), conventional fertilization (NPK), partial substitution of nitrogen in NPK with straw (NPKS), partial substitution of nitrogen in NPK with biochar (NPKC), NPK plus DMPP application (NPKD), and NPK plus PASP application (NPKP).

Results

For the whole growth period, the inhibition of NH₃ volatilization only occurred in NPKP (17.22%) in comparison with NPK, while DMPP and PASP effectively reduced N₂O emissions by 40.54% and 25.29%, respectively. Moreover, all materials contributed to nitrogen fixation in soil while significantly decreasing the population of AOB bacteria, with PASP and straw demonstrating a significant inhibitory effect on AOA bacteria. Furthermore, straw was more favorable to nutrient uptake and utilization by rice, inducing additional accumulation of nitrogen (71.96%), phosphorus (21.03%), and potassium (14.97%). Lastly, straw, DMPP, and PASP increased the rice yield (> 6%), whereas the impact of biochar was less pronounced.

Conclusion

When considering factors such as environment, soil properties and crop yield, the application of biodegradable PASP demonstrates comprehensive advantages in rice cultivation.

34. 题目: Ultrahigh and rapid removal of Ni2+ using a novel polymer-zeolite-biochar tri-composite through one-pot synthesis route
文章编号: N25011003
期刊: Environmental Research
作者: Sadamanti Sireesha, Madivada Sumanth, Chetan M Patel, Inkollu Sreedhar
更新时间: 2025-01-10
摘要: In this work, a novel adsorbent from alginate, zeolite and biochar has been made through one-pot synthesis route with highly compatible Sodium Dodecyl Sulphate (SDS) modification. This gave ultra-high Ni²⁺ removal of 1205 mg/g in batch mode while treating almost 200 L of solution in column mode with 1171 mg/g capacity, which are the one of the highest reported values. The Point of Zero Charge (pH_zpc) for Ni²⁺ removal was determined to be 5, with optimal removal efficiency being observed at pH 7, indicating a negative surface charge of the ABPC beads, which aligns with the anionic charge provided by SDS enhancement. Mechanistic studies have been done to show the most prominent mechanisms of metal removal besides demonstrating stability upto 20 cylces with desorption efficiency as high as 97%. The adsorbent is found to be highly cost effective at 1.87USD per kg.

35. 题目: Biochar supporting and sulfidation synergistically affect reactivity of nanoscale zerovalent iron towards sulfamethoxazole
文章编号: N25011002
期刊: Chemical Engineering Journal
作者: Mi Li, Tiao Zhang, Jing Wang, Xiaoyu Xiao, Xinyi Zeng, Cui Hu, Xiaoming Zou, Wei Hui, Yuling Zheng
更新时间: 2025-01-10
摘要: Biochar supporting and sulfidation have been identified as promising methods for modifying nanoscale zerovalent iron (NZVI). However, their effects on the physicochemical properties and reactivity of NZVI as well as their relative importance remain unclear. Herein, a series of materials were synthesized to systematically explore the effects of biochar supporting and sulfidation on physicochemical properties (e.g., Fe crystalline structure, electron transfer tendency) and reactivity towards sulfamethoxazole (SMX). Results showed that biochar supporting and sulfidation could, individually and synergistically, expand lattice spacing of Fe crystalline (0.2026 ∼ 0.2045 nm), increase specific surface area (13.03 ∼ 100.76 m² g⁻¹), intensify water contact angle (29.7 ∼ 115.3°), enhance fraction of reduced Fe (30.73 ∼ 69.27 %), decrease corrosion potential (45.15 ∼ -0.850 V) and elevate pseudo-first-order kinetic rate constant (0.00036 ∼ 0.058 min⁻¹), in order of biochar supporting + sulfidation > biochar > sulfidation. Further, correlation analysis and partial least squares modeling revealed fraction of S_n^2-, corrosion potential, water contact angle and specific surface area mainly responsible for reactivity. Finally, for SNZVI-2/BC with best reactivity, influencing factors, mechanism and stability of SNZVI-2/BC’s reactivity towards SMX were further elucidated. This work advances to understand the effect of biochar supporting and sulfidation on physicochemical properties and reactivity with rational design of tailored NZVI for specific applications.

36. 题目: Study on stabilization of mercury in wastewater and soil by modified coal-based humic acid residue
文章编号: N25011001
期刊: Environmental Pollution
作者: Yingnan Wang, Hui Liu, Weike Wang, Bingtao Yin, Huang Wang, Fei Zhang, Jingru Wang, Zhanbin Huang
更新时间: 2025-01-10
摘要: Coal-based humic acid residue (HAS), as a waste generated during humic acid production, has been gaining attention in recent years due to its adsorption capacity and containing nutrients. In this study, to improve the adsorption capacity of HAS for and Hg, phosphate-modified materials (N−HAS) were prepared by a hydrothermal method and HAS and N-HAS were characterized by scanning electron microscopy (SEM), Fourier transforms infrared spectroscopy (FTIR), X−ray fluorescence (XRF); batch adsorption experiments investigated the adsorption capacity of N−HAS on Hg²⁺ under different pH, and isothermal adsorption model and kinetic model fitted the adsorption process to explore the adsorption mechanism; the effects of various amounts of N−HAS on the Hg content in maize and the effective Hg in the soil under Hg−contaminated soil were investigated by field trial. The results showed that the pseudo−second−order kinetic model (R²=0.9641) and Langmuir isothermal (R²=0.95) adsorption model could better describe the adsorption behavior of N−HAR on Hg²⁺, the maximum adsorption amount was 124.20 mg/g, and the time to reach adsorption equilibrium was shorter for N−HAS compared to HAS; after 5 times of adsorption−desorption, the removal rate of Hg²⁺ by N−HAS was still higher than 80%, with stable cyclic adsorption performance; the adsorption mechanism of Hg²⁺ by N−HAS included physical adsorption, precipitation, and surface complexation, and compared with HAS, the percentage of complexation for Hg²⁺ adsorption by N−HAS increased by 77.81%, and the percentage of precipitation increased by 7.68%; compared to the control group, it was shown that the addition of N−HAS significantly decreased (p < 0.05) the Hg content of maize kernels by 27.44% ∼ 72.09%, increased biomass by 4.34% ∼ 11.26%, and decreased the available Hg content in soil by 50.00% ∼ 82.80%. In addition, the addition of N−HAS at 0.4 kg/m² was optimal for the field trial. The study showed that N−HAS not only achieved resource utilization but also demonstrated great potential for treating Hg²⁺ in water and soil.

37. 题目: Unraveling the mechanisms underlying AOM-induced deterioration of the settling performance of algal floc
文章编号: N25010906
期刊: Water Research
作者: Ziqian Cheng, Zhe Lin, Xin Chen, Xuezhi Zhang, Haiyang Zhang
更新时间: 2025-01-09
摘要: The influence of algal organic matter (AOM) on the settling performance of algal flocs remains poorly understood. To address this, we employed fractionation techniques based on molecular weight to isolate different AOM fractions and analyzed their effects on floc structure and settling performance. This involved comparing the concentrations, compositions, potentials, and functional groups of organic matter before and after coagulation-sedimentation. The results demonstrated that AOM significantly impacts floc characteristics, including size and compactness, ultimately hindering floc settling performance. Specifically, AOM fractions smaller than 100 kDa, such as humic substances, preferentially consumed coagulants without directly participating in floc formation, leading to smaller and slower-settling algal flocs. This was particularly evident for fractions with a molecular weight below 5 kDa, where only 25% of the material participated in floc formation. In contrast, over 90% of the AOM with a molecular weight exceeding 100 kDa, such as proteins, exhibited negatively charged functional groups (e.g., carboxyl groups) that interacted with coagulants via electrostatic forces to form larger complexes. These complexes enhance the coagulant's ability to capture and bridge algal cells, directly binding to the flocs, resulting in an increase of 20.3% in the size and a 37.5% faster settling velocity of the flocs formed by >100kDa AOM compared to <5 kDa. This study elucidates the mechanisms by which AOM influences algal floc settling performance from the perspectives of AOM composition and its interactions with coagulants and algal cells. The findings provide a theoretical basis for a deeper understanding of algal flocculation mechanisms and for accelerating algal flocculation and sedimentation.

38. 题目: Nontargeted Screening Nitrogen-Containing Organic Compounds in Frost and Wet Deposition in Rural Northeast China
文章编号: N25010905
期刊: Environmental Science & Technology
作者: Runqi Zhang, Dongmei Cai, Lina Wang, Yunqian Chen, Chengze Li, Ling Li, Mingliang Fang, Lin Wang, Christian George, Jianmin Chen
更新时间: 2025-01-09
摘要: Nitrogen-containing organic compounds (NOCs) in frost serve as a critical pathway for atmospheric nitrogen deposition, significantly impacting the biogeochemical cycles of nitrogen. However, the molecular characteristics of NOCs in frost and their deposition fluxes are scarcely studied. In this work, frost samples, collected in rural Northeast China in the winter of 2023, were analyzed using nontargeted ultrahigh performance liquid chromatography-orbitrap mass spectrometry (UHPLC-Orbitrap MS) to reveal their content in nitrogen-containing organic compounds (NOCs) and explore their wet deposition fluxes. The average number of assigned molecular formulas were lager on hazy days compared to nonhazy days for both water-soluble (WSOM) and water-insoluble organic matter (WISOM) in frost (3114 vs. 1934 for WSOM and 3042 vs. 2224 for WISOM in electrospray ionization (ESI−); 6921 vs. 5954 for WSOM and 6629 vs. 5547 in ESI+). Specifically, the number proportions of CHON were 35.6–49.9% (724–1517) and 47–51.1% (2686–3388) in the ESI– and ESI+ modes, respectively. Nitrophenol (C₆H₅NO₃) and methyl nitrophenol (C₇H₇NO₄) were the most abundant NOCs, with wet deposition fluxes (at maximum average concentrations) of 22.2 and 21.2 μg m^–2·h^–1, respectively. On hazy days, the deposition fluxes of nitrophenol compounds reached up to 1.73 times that of nonhazy days, indicating significant ambient nitrogen deposition during the haze episode. This deposition flux positively correlated with PM_2.5 concentration, implying the important role of atmospheric particulates in influencing NOC deposition through frost. These findings highlight the susceptibility of frost to capturing NOCs from the atmosphere, potentially impacting nitrogen cycling in ecosystems.

39. 题目: Increased Mineral-Associated Organic Carbon and Persistent Molecules in Allochthonous Blue Carbon Ecosystems
文章编号: N25010904
期刊: Global Change Biology
作者: Yuan Li, Chuancheng Fu, Chenglong Ye, Zhaoliang Song, Yakov Kuzyakov, Tony Vancov, Laodong Guo, Zhongkui Luo, Lukas Van Zwieten, Yidong Wang, Yu Luo, Weiqi Wang, Lin Zeng, Guangxuan Han, Hailong Wang, Yongming Luo
更新时间: 2025-01-09
摘要: Coastal wetlands contain very large carbon (C) stocks—termed as blue C—and their management has emerged as a promising nature-based solution for climate adaptation and mitigation. The interactions among sources, pools, and molecular compositions of soil organic C (SOC) within blue C ecosystems (BCEs) remain elusive. Here, we explore these interactions along an 18,000 km long coastal line of salt marshes, mangroves, and seagrasses in China. We found that mineral-associated organic C (MAOC) is enriched in BCEs dominated by allochthonous inputs and abundant active minerals, leading to an increased proportion of persistent organic molecules. Specifically, soils with large allochthonous inputs (> 50%) are characterized by a substantial contribution of MAOC (> 70%) to total SOC with a notable preservation of lipids (36%) across salt marshes, mangroves, and seagrasses. The burial of allochthonous particles, derived from external sources such as rivers or tidal influxes, facilitates the formation of stable MAOC through binding to mineral surfaces or occlusion within microaggregates. The proportions of particulate organic C (POC) and MAOC are important predictors for molecular compositions of soil organic matter. Lipid proportions within molecular composition decrease as POC and autochthonous C proportions increase. These findings provide new insights into the coupled control over SOC sequestration in BCEs, emphasizing the role of allochthonous inputs, proportions of carbon pools, and persistent organic components.

40. 题目: Organic amendments with low C/N ratios enhanced the deposition of crop root exudates into stable soil organic carbon in a sodic soil
文章编号: N25010903
期刊: Plant and Soil
作者: Jingwang Li, Lin Chen, Congzhi Zhang, Changdong Han, Biao Feng, Donghao Ma, Guixiang Zhou, Jiabao Zhang
更新时间: 2025-01-09
摘要:

Background and aims

Numerous studies have demonstrated the enhancement effects of organic amendment additions on soil organic carbon (SOC) accumulation in agroecosystems. However, the effects of different organic amendment types on stable SOC formation through belowground inputs remain poorly understood, especially under stress conditions. This study aims to investigate the effects of three organic amendment types, namely lignin- (LDA), humus- (HDA), and vetch-derived (VDA) organic amendments, on the transformation process of ¹³C-rhizodeposits into SOC in sodic soil.

Methods

Sorghum bicolor L. was used in the experiments, and labelled using ¹³C-CO₂ for seven days after 75 days growing in a closed glass chamber.

Results

Our results showed that the nitrogen (N) compounds in the organic amendments accounted for 0%, 6.21%, and 11.37% of the LDA, HDA, and VDA, respectively. Organic amendments with low C/N ratios (HDA and VDA) enhanced the transformation of ¹³C-rhizodeposits into SOC, particularly into mineral-associated carbon (¹³C-MAOC). In addition, HDA and VDA substantially decreased the exchangeable sodium percentage (ESP) and increased the soil nutrient contents (e.g., total N and total phosphorus) compared with LDA, providing more favorable environmental conditions for both the crop and rhizosphere microbial growth. These effects, consequently, enhanced the deposition of the crop root exudates into ¹³C-MAOC in the sodic soil. Furthermore, compared with LDA, HDA and VDA enriched beneficial bacteria (e.g., Bacillaceae and Vermamoebidae) and inhibited pathogenic bacteria (Burkholderiaceae) through potential cross-trophic interactions, promoting crop growth and enhancing the production of root exudate deposition into ¹³C-MAOC.

Conclusion

Organic amendments with low C/N ratios enhanced the conversion of ¹³C-rhizodeposits into ¹³C-MAOC, by providing more favorable envrionmental conditions and enriching beneficial bacteria for plants. Our study provides a novel approach to selecting organic amendments with suitable and effective chemical structures to promote stable SOC formation through belowground inputs, especially under sodic conditions.