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161. 题目: Fe-MOFs-derived Fe3O4-doped biochar from waste chopsticks: a novel catalyst for tetrabromobisphenol a degradation via peroxymonosulfate activation
文章编号: N25042407
期刊: Environmental Research
作者: Van-Anh Thai, Thanh-Binh Nguyen, Wei-Hsin Chen, Chiu-Wen Chen, Ruey-an Doong, Cheng-Di Dong
更新时间: 2025-04-24
摘要: Biochar production has emerged as a highly effective strategy for waste-to-resource conversion. In this study, biochar derived from waste chopsticks was doped with Fe₃O₄ using MIL-100 (Fe)—a metal-organic framework (MOF)—was synthesized at various pyrolysis temperatures and designated as Fe₃O₄@BC. The catalyst was employed to activate peroxymonosulfate (PMS) for the removal of tetrabromobisphenol A (TBBPA), a widely used brominated flame retardant (BFR). Remarkably, the Fe₃O₄@BC/PMS system achieved 98% TBBPA removal within 30 min. The exceptional catalytic performance of Fe₃O₄@BC was attributed to the uniform dispersion of iron oxides and the abundance of oxygen-containing functional groups on the biochar surface. The underlying mechanism of TBBPA degradation was systematically investigated, revealing two distinct degradation pathways and identifying 18 by-products using liquid chromatography-mass spectrometry (LC-MS) and density functional theory (DFT) analysis. Furthermore, scavenger tests and electron paramagnetic resonance (EPR) spectra demonstrated that superoxide radicals ($$) played a critical role in TBBPA degradation within the catalyst/PMS system. This study highlights the immense potential of biochar derived from waste chopsticks as an eco-friendly and efficient catalyst. Key advantages include the utilization of solid waste, reduced toxicity of degradation intermediates, and effective PMS activation for the degradation of BFRs.

162. 题目: Fast Pyrolysis-Driven Recycling of Spent LiCoO2 Batteries: Synergistic Reduction Effects of Biochar and Pyrolysis Gas
文章编号: N25042406
期刊: Journal of Environmental Chemical Engineering
作者: Zhenfei Mei, Fuyan Gao, Shuai Liu, Jinbo Chen, Shu Tian, Changxing Hu
更新时间: 2025-04-24
摘要: Utilizing biomass as a reducing agent to assist in the pyrolysis-reduction of spent lithium-ion batteries represents an emerging strategy that combines high efficiency with sustainability. To investigate the potential of biomass as a reducing agent for cathode material recovery, this study compared the reduction performance of pyrolysis products from key biomass components and employed a separated reduction roasting strategy combined with fast pyrolysis technology to reveal the high efficiency of gas-char synergistic reduction. The results showed that lignin exhibited stronger reducing capability than cellulose and hemicellulose, primarily due to the high concentration of amorphous carbon in its pyrolytic char. Furthermore, compared to the two-step gas-char reduction, gas-char synergistic reduction could significantly enhance reduction efficiency. Therefore, under fast pyrolysis conditions, cellulose-rich biomass demonstrated stronger reducing capabilities, benefiting from high-quality reducing gases produced by cellulose that intensified the carbothermal reduction reaction. Analysis of the reduction mechanism indicated that the release of reducing gases in high-temperature zones induced by rapid pyrolysis helped collapse the oxygen framework in cathode materials, promoting coupling reactions and thereby enhancing carbothermal reduction reactions. Additionally, the fast pyrolysis process could facilitate the conversion of biomass into a pyrolysis product system with high reducing activity composed of gas and char. This research provides scientific guidance for the development and optimization of biomass-assisted roasting processes for recycling spent lithium-ion batteries.

163. 题目: Functionalized biochar for enhancing the removal of antibiotics and resistance genes in swine manure composting: A review
文章编号: N25042405
期刊: Journal of Environmental Chemical Engineering
作者: Dong Wang, Yulong Shi, Li Zheng, Yu Liu, Xinyuan Wei, Qingwen Zhang
更新时间: 2025-04-24
摘要: Since the antibiotics typically employed for growth promotion and disease treatment in animals, a considerable quantity of antibiotics is retained in swine manure (SM). The inappropriate handling of SM may lead to the release of antibiotics into the natural environment, resulting in the development of antibiotic resistance genes (ARGs), posing significant risks to both the ecological system and human health. Biochar (BC), a carbon-rich, porous material derived from biomass pyrolysis, has emerged as a promising solution for mitigating ARGs risks during SM composting. To enhance the adsorption performance of BC, functional BC (physical, chemical, biological or composite material modification) has attracted widespread attention. This work presented a review of the various modification methods and performance improvement mechanisms of BC, especially the environmentally friendly earthworm-modified BC. The differences in adsorption mechanisms of antibiotics and ARGs by modified BC were compared and analyzed, revealing that biodegradation played a crucial role in the removal of these substances during the SM composting. Finally, the review identified current challenges and outlines prospective avenues for further investigation to achieve a greater role for functionalized BC in the treatment of antibiotics in SM compost, thereby contributing to more sustainable and environmentally responsible waste management strategies.

164. 题目: Prediction of Heavy Metal Uptake in Red Radish (Raphanus sativus var. sativus) in Relation to Soil Characteristics and Sewage Sludge Amendments
文章编号: N25042404
期刊: Water, Air, & Soil Pollution
作者: Mohamed T Ahmed, Sulaiman A Alrumman, Pankaj Kumar, Ebrahem M Eid
更新时间: 2025-04-24
摘要:

This study developed predictive models to assess the uptake of nine heavy metals (Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb, Zn) in red radish (Raphanus sativus var. sativus) shoots and roots under increasing sewage sludge amendments (0–50 g/kg soil). Sewage sludge application significantly altered soil properties, including pH, EC, and organic matter content. Cd, Co, Pb, and Zn were enriched in sewage sludge, whereas Cr, Cu, Fe, Mn, and Ni were more abundant in soil. Post-cultivation analysis showed significant changes in soil properties and heavy metal levels with increasing sewage sludge amendments. Red radish preferentially accumulated heavy metals in roots, though Zn showed the highest translocation to shoots. Bioaccumulation factors (BAFs) and translocation factors (TFs) indicated metal-specific uptake patterns influenced by soil pH, electrical conductivity (EC), organic matter (OM), and initial heavy metal contents. Also, multiple linear regression predicted heavy metal accumulation based on soil parameters with high model efficiency and low prediction errors. Thus, excessive sewage sludge application poses contamination risks, necessitating regulated application to safeguard agricultural systems.

165. 题目: Variability of the optical signatures of dissolved organic matter in soils of different mangrove stands (Ouvéa, New Caledonia)
文章编号: N25042403
期刊: Environmental Science and Pollution Research
作者: Naïna Mouras, Hugues Lemonnier, Thomas Crossay, Kapeliele Gututauava, Maximilien Mathian, Sarah Louise Robin, Océane Tardivel, Cyril Marchand
更新时间: 2025-04-24
摘要:

Mangrove ecosystems are known to play a key role in the global carbon cycle, due to their productivity and their ability for carbon sequestration both in the biomass and in the soil. In the latter, various geochemical processes lead to the production of dissolved organic matter (DOM) that can be exported through tidal pumping and then constitute an important source of organic carbon for adjacent ecosystems. DOM characteristics, and their variabilities, within mangrove soils depend on several factors, including the mangrove species, yet these variations and their origin still need to be precisely constrained. This study examined DOM sources in soils of a carbonate atoll mangrove (Ouvéa, New Caledonia), focusing on two tree species, Rhizophora apiculata and Bruguiera gymnorhiza, at different growth stages. We analysed porewater properties and DOM optical characteristics through spectroscopic and EEM-PARAFAC methods. Our results indicate distinct TOC and DOC concentrations across species, with mature B. gymnorhiza soils showing the highest TOC content (~ 30%) but the lowest DOC content (32 mg L⁻¹). These differences seem not to be directly related to site physicochemical conditions (redox, pH, salinity) but may rather reflect differences in DOM sources and production, notably due to different symbiotic relationships with mycorrhizal fungi, which influence microbial activity and organic matter diagenesis. DOM absorbance patterns also varied significantly between species: Beneath R. apiculata, DOM had higher protein-like and fulvic-like fluorescence, indicating fresher organic matter, while beneath B. gymnorhiza, especially in mature stands, DOM was more humified, suggesting older OM because of a possible long-term accumulation due to the basin-like morphology of this site.

166. 题目: Bulk density calculation methods systematically alter estimates of soil organic carbon stocks in United States forests
文章编号: N25042402
期刊: Biogeochemistry
作者: Ashley K Lang, Melissa A Pastore, Brian F Walters, Grant M Domke
更新时间: 2025-04-24
摘要:

Soils are the largest terrestrial carbon sink on Earth, yet substantial uncertainty in the size and stability of this pool remains. Much of this uncertainty stems from the characterization of bulk density, which is the mass of a soil sample divided by its volume, a key property in the calculation of soil organic carbon (SOC) stocks. We used data from nearly 2900 plots in the United States (U.S.) Nationwide Forest Inventory to quantify SOC stocks in forests with three common methods of calculating soil bulk density. Mean SOC stocks calculated with these methods varied by up to 13 Mg ha⁻¹, a difference equivalent to more than 70 percent of the 2022 economy-wide carbon dioxide emissions in the U.S. when scaled across all forest area. These differences were primarily driven by inconsistent treatment of coarse materials (i.e. rocks and roots) in soil bulk density calculations, which led to an overestimation of SOC content by 32 percent of the mean SOC stock across all U.S. forests. The largest discrepancies were found in soils with high coarse fragment content, which are more common in ecologically sensitive ecosystems like alpine zones and drylands, and in commercially important softwood forest types. Quantifying the size and stability of SOC in the land sector is essential to understanding how this carbon pool may serve as a nature-based solution to climate change. Consistent and transparent methods are necessary when estimating and reporting SOC content and when comparing SOC dynamics across ecological gradients, with disturbance, and over time.

167. 题目: Efficient Removal of Aqueous Cr(VI) Using Sulfur-Modified Biochar Derived from Anaerobic Digestate: Synergistic Mechanism for Reduction and Sorption
文章编号: N25042401
期刊: Environmental Science: Water Research & Technology
作者: Kunlun Yang, Yimei Wang, Dengyang Wang, Zengshuai Zhang, Peng Gu, Xueli Ren, Hengfeng Miao
更新时间: 2025-04-24
摘要: Combined with the separation and dehydration treatment of digestate from anaerobic digestion and acidification of food waste, sulfur-modified digestate biochar was facilely prepared for efficient Cr(VI) removal to realize anaerobic digestate recycling and waste control by waste. Characterization indicated the increased surface area and mesopores and the decreased aggregation degree for biochar under optimized S doping and pyrolysis temperature (900-2S@DBC), resulting in more functional groups with high reducibility (e.g., phenolic -OH, C-S-C, S species with low valency) and improved electron transfer ability. The forms transformation analysis confirmed the reduction of sulfate source via carbon under high pyrolysis temperature. Under the conditions of an initial Cr(VI) concentration of 10 mg/L, a pH of 3, and a dosage of 0.5 g/L, the removal efficiency of Cr(VI) by 900-2S@DBC approaches 100%. 900-2S@DBC showed apparent higher Cr(VI) removal performance than other biochar. Its quasi-second-order kinetic constant was tens of times than pristine biochar. Quenching and control experiments confirmed the S species with low valency played a more important role in Cr(VI) reduction than traditional carbon and oxygen based reductive groups on carbon structure. Direct surface electron reduction made more contribution than indirect solution •O2- reduction pathway, further confirming the synergistic effect between Cr(VI) sorption and reduction. Complexation, precipitation, and ion exchange processes participated in the final immobilization of Cr by 900-2S@DBC. Additionally, 900-2S@DBC exhibited excellent Cr(VI) removal capacity in real electroplating wastewater. This study offered a feasible approach for resource utilization of anaerobic digestate and deep insights for Cr(VI) removal mechanism via sulfur-modified biochar.

168. 题目: Regulatory effects of nano-carbon on poplar growth and rhizosphere soil organic carbon accumulation
文章编号: N25042310
期刊: Environmental Research
作者: Xiaomei Huo, Mengjie He, Jun Qiao, Jianguo Zhao, Bin Yang
更新时间: 2025-04-23
摘要: The positive effects of nano-carbon on plant growth and soil C sequestration within the rhizosphere have been widely recognized. Nevertheless, information is seriously deficient in understanding the underlying mechanisms based on microbial communities and carbon cycle functional genes. Here, metagenomic sequencing was employed to explore different responses of poplar seedling growth and organic carbon fractions to nano-carbon fertilizers at concentrations of 0 ml/kg (CK), 5 ml/kg (NC-5), 10 ml/kg (NC-10) and 20 ml/kg (NC-20). We observed that, after 120 days of nano-carbon fertilizers treatments, the growth indexes (height and biomass) of poplar were significantly increased by 53-173 %, and C fractions in the rhizosphere soil were significantly increased by 1.6-8.2 % with the NC-5 treatment having a greater impact on organic carbon components than the NC-10 and NC-20 treatments. Compared to CK, the additions of nano-carbon fertilizers significantly increased the content of total nitrogen (TN), nitrate nitrogen (NN), and available potassium (AK) in the rhizosphere soil and decreased the pH, and improved stochastic processes in microbial communities, which elevates the abundance of microbes involved in carbon fixation (e.g., Proteobacteria, Actinobacteria) and carbon-cycling genes. In addition, network complexity and stability of microbes were significantly enhanced by nano-carbon treatments. Structural equation model indicated that microbial community assembly processes directly alter rhizosphere SOC accumulation. Carbon functional genes influenced by microbial structure have positive effects on biomass of poplar and SOC contents. Our observations provide key evidence for evaluating how nano-carbon fertilizers may influence functional changes in C cycle that are mediated by microbial synergy.

169. 题目: Silicon-enriched rice straw biochar and silicon fertilizer mitigate rice straighthead disease by reducing dimethylarsinic acid accumulation
文章编号: N25042309
期刊: Plant and Soil
作者: Yang Yang, Zhong Tang, AXiang Gao, Chuan Chen, Peng Wang, Fang-Jie Zhao
更新时间: 2025-04-23
摘要:

Background and aims

Rice is prone to accumulating both inorganic arsenic (iAs) and organic arsenic species, such as dimethylarsinic acid (DMA). DMA is the primary causative agent of rice straighthead disease, a physiological disorder that leads to substantial yield losses. In this study, we investigated whether rice straw-derived biochar with different silicon (Si) contents and Si fertilizer can alleviate rice straighthead disease and decrease DMA accumulation in rice grains.

Methods

Low- and high-Si biochars were produced from straw of a low-silica rice mutant lsi2 and its wild type (WT), respectively, by carbonization at a temperature of 450 °C. Pot experiments were conducted to investigate the effects of rice straw-derived biochar and a powdered Si fertilizer on As speciation in soil porewater at different rice growth stages and DMA accumulation in rice grains.

Results

The Si content of the high- and low-Si biochars differed substantially (127.4 g kg⁻¹ for WT and 47.8 g kg⁻¹ for lsi2 biochar), with approximately 18% Si bioavailability following biochar application. Both biochar and Si fertilizer application alleviated straighthead disease and decreased DMA levels in grain by 24–58.2%, with the high-Si biochar outperforming other treatments.

Conclusions

The beneficial effects of the biochar on mitigating straighthead disease were primarily attributed to their Si content and the capacity to maintain prolonged Si availability in soil porewater. Additionally, supplementation with Si during the booting stage of rice proved particularly effective in maintaining Si availability, reducing DMA uptake, and alleviating straighthead disease.

170. 题目: Formation Mechanisms of Carcinogenic N-nitrosamines from Dissolved Organic Matter Derived from Nitrogen-containing Microplastics During Chloramine Disinfection
文章编号: N25042308
期刊: Water Research
作者: Run Zhou, Kecheng Zhu, Zhuo Gao, Xuemin Feng, Qian Hu, Lingyan Zhu
更新时间: 2025-04-23
摘要: The high occurrence of microplastics (MPs) in water treatment facilities may complicate the source-control of disinfection by-products. Herein, we reported that the carcinogenic N-nitrosamines, such as N-nitrosodimethylamine (NDMA) and N-nitrosodiethylamine (NDEA), were generated during monochloramine disinfection of water in which nitrogen-containing microplastics (N-MPs, such as polyamide and polyacrylonitrile) were present. The precursors of NDMA and NDEA were mainly derived from the dissolved organic matter released from N-MPs (N-MP-DOM), which were characteristic of a significantly higher proportion of polar and non-cationic fractions, favouring the N-nitrosamine formation. The results of excitation-emission-matrix spectra and orbitrap-mass spectrometry indicated that the polar components were mainly CHON and highly hydrogen-saturated molecules (H/C ≥ 1.5) (such as protein-like substrates), which are potential precursors of N-nitrosamines. Further mass difference network analysis revealed that the reactions of amine and nitro/nitroso groups in the precursors made predominant contribution to the generation of N-nitrosamines. Two potent NDMA precursors bearing a (CH₃)₂N-R structure were identified based on the diagnostic fragments (e.g., 45.0578 Da and m/z 58.0651) and in silico fragmentation tool (MetFrag2.2) in MS² spectra. Our findings provide valuable insights into understanding the potential risks of N-MPs due to monochloramine disinfection in water treatment systems.

171. 题目: The photoactivity of complexation of DOM and Fe(Ⅱ)/Mn(Ⅱ) in aquatic system: Implication on the photodegradation of MCLR
文章编号: N25042307
期刊: Journal of Environmental Chemical Engineering
作者: Haishuo Wang, Xinke Tian, Zhichun Li, Jie Zhang, Shiyin Li, Heyong Huang
更新时间: 2025-04-23
摘要: Lake eutrophication leads to the excessive proliferation of cyanobacteria in aquatic environments, resulting in microcystin-LR (MCLR) concentrations exceeding regulatory limits. The associated environmental risks and health concerns attract widespread attention. As one of the most active chemical substances in aquatic environments, dissolved organic matter (DOM) plays a critical role in the phototransformation of MCLR. In environments where Fe(II) and Mn(II) coexist, the phototransformation process of MCLR may be influenced. Among fulvic acid (FA), humic acid (HA), cyanobacteria-derived DOM (CDOM), and reed leaf-derived DOM (RDOM), FA has the highest apparent reaction rate constant for MCLR at 0.03567 h^-1. Using isopropanol, furfuryl alcohol, and sorbic acid as quenchers, the contributions of different photochemically produced reactive intermediates(PPRIs) to MCLR photodegradation follow the order: ³DOM⁎ > ·OH > ¹O₂. As pH increases, changes in the conformation and charge distribution of DOM and MCLR suppress MCLR photodegradation. The addition of Fe(II) or Mn(II) enhances the photodegradation of MCLR by DOM. Electron paramagnetic resonance tests and radical quenching experiments indicate that the introduction of Fe(II)/Mn(II) increases ·OH production. The enhanced ·OH promotes MCLR photodegradation more effectively than the suppression caused by Fe(II)/Mn(II) quenching of ³DOM⁎. Product analysis reveals that demethylation, hydroxylation, decarbonylation, decarboxylation, denitration, and bond cleavage are the main pathways of MCLR photodegradation. These findings provide valuable insights into the migration and transformation of MCLR in complex environments, contributing to a deeper understanding of the fate of pollutants in natural water systems, particularly in the presence of metal ions.

172. 题目: Plant functional type control on soil microbial activity and carbon source utilization in permafrost peatland
文章编号: N25042306
期刊: Plant and Soil
作者: Jing Xue, Yifei Zhang, Shujie Wang, Yu Du, Dongxu Wang, Hao Zhang, Yanyu Song, Xianwei Wang, Xiaoxin Sun
更新时间: 2025-04-23
摘要:

Background and aims

Climate warming can lead to changes in plant functional types (PFTs) in permafrost peatlands, which can subsequently affect soil properties and microbial functional structures. Although the effects of PFTs changes on soil microorganisms in various ecosystems have been documented, these effects are not well understood in permafrost peatlands.

Methods

This study investigated the impact of removing different PFTs (sedges, evergreen shrubs, deciduous shrubs, and mosses) on soil properties and microbial functional structures (microbial activity, microbial diversity, and carbon source utilization) in a permafrost peatland.

Results

Variations in PFTs lead to changes in soil properties and microbial functional structures. Removal of shrubs and mosses increased soil dissolved organic carbon (DOC) content by 26% and inorganic nitrogen content by 28%, the soil microbial activity and diversity were significantly enhanced, and microbes preferred amino acids and carboxylic acids as carbon sources compared to the natural control (N). In contrast, the moss treatment (M) with shrubs and sedge removed had 30% lower soil DOC and 50% lower inorganic nitrogen content, as well as a significant reduction in microbial activity and diversity, with microorganisms preferring to utilize polymers as a carbon source.

Conclusion

These results indicate that peatland microorganisms are sensitive to changes in PFTs over short time scales, with a particularly rapid response to specific plant functional groups such as sedges. These findings highlight the critical role of PFTs as drivers of microbial functional structures and suggest that future vascular plant expansion may alter peatland microbial functional structures and carbon cycling in the context of climate change.

173. 题目: Molecular Insights into Dissolved Organic Matter Post Electrokinetic-Persulfate Treatment: Heteroatom Induced Resistance
文章编号: N25042305
期刊: Journal of Hazardous Materials
作者: Xinxu Niu, Jian Liu, Shaohua Chen, Bin Jiang, Jianzhi Huang
更新时间: 2025-04-23
摘要: The application of electrokinetic-enhanced in situ chemical oxidation remediation of contaminated sediments has attracted increasing attention. However, the molecular changes in dissolved organic matter (DOM) during these remediation processes remain unexplored. To address the gap, we explored the molecular transformation of DOM subjected to electrokinetic (EK)-persulfate treatment. The findings revealed that DOM transitioned from a reduced to an oxidized state, marked by the removal of low O/C molecules and the formation of high O/C molecules. Heteroatom-containing molecules accumulated and constituted the dominant fraction among the resistant molecules post-treatment. N-containing and Cl-containing molecules displayed elevated N/C and Cl/C ratios during the treatment, decomposing into smaller and nitrogen-rich or Cl-rich molecules, while S-containing molecules exhibited a decrease in S/O ratios. Oxygen addition reaction and dealkyl group reaction were identified as the two most common transformation pathways, contributing to the increased oxidation and resistance of DOM molecules. This study deepens our understanding of DOM transformation using EK-persulfate treatment and aids in assessing the potential risks associated with resistant molecules in its practical application.

174. 题目: Modified slow sand filter amended magnetic corncob biochar and zero-valent iron for arsenic removal from drinking water
文章编号: N25042303
期刊: Environmental Earth Sciences
作者: Taimoor Khan, Qasim Ali, Imdad Ullah, Shams Ali Baig, Dilawar Farhan Shams, Xinhua Xu, Muhammad Danish
更新时间: 2025-04-23
摘要:

The toxicity of arsenic (As) in drinking water poses a significant risk to public health, and its effective removal is essential to reduce the associated risks. Modified slow sand filter (SSF) has emerged as a promising decentralized water treatment method in developing countries due to its user friendliness, economic viability, and environment-friendly properties. The present study investigated the total arsenic removal efficiency and turbidity reduction in laboratory-scale SSF columns designed for a 60-day filtration period. For this purpose, SSF columns were modified with magnetic corncob biochar (MCCB) and zero-valent iron (ZVI) layers in different ratios. The characterization tests, including Scanning Electron Microscopy (SEM), Energy Dispersive X-ray Spectroscopy (EDS), and X-ray Diffraction (XRD), were conducted before and after the filtration. Results revealed that the MCCB surface was porous with a honeycomb-like structure before adsorption, containing cave-like holes favourable for arsenic removal. Similarly, the ZVI surface exhibited a tabular and thread structure. The EDS results confirmed the presence of Fe in the MCCB and ZVI, indicating the magnetic properties of both adsorbents. Notably, maximum As removal efficiency of 80% was observed in SSF(b) with a 10 cm MCCB layer after 60 days, whereas SSF(d) with a 10 cm ZVI layer achieved 99% within just 10 days of filtration. In addition, SSF columns containing ZVI layers achieved a maximum turbidity removal of 98% and 99% after 10 days of filtration, while SSF(b) with a 10 cm MCCB layer reached a turbidity removal of 99.9% after 60 days. Statistical analyses indicated that these differences were significant (p < 0.05), demonstrating the superior efficacy of the ZVI-based SSF for arsenic removal and the strong performance of MCCB in turbidity reduction. Overall, SSF-amended MCCB and ZVI demonstrated effective removal of As and turbidity. The study suggests that the designed SSFs are durable and user-friendly filter made of locally avaible low-cost materials for water filtration.

175. 题目: Cropping History and Cropland Abandonment Period Influenced Levels of Soil Organic Carbon, Distribution of Aggregates and Aggregate Associated Carbon
文章编号: N25042302
期刊: Land Degradation & Development
作者: Sinesihle Mcengwa, Siphamandla Nyambo, Vusi Erick Mbanjwa, Dimpho Elvis Elephant
更新时间: 2025-04-23
摘要: Knowledge gaps remain regarding soil organic carbon (SOC) storage and aggregate dynamics under varying cropland abandonment periods, particularly within the context of degraded and low-SOC soils. This study aimed to assess the influence of cropping history and the period of cropland abandonment period on SOC, aggregate distribution, and aggregate associated carbon in the Eastern Cape, South Africa. Two abandoned cropland sites, namely 2 LUC (abandoned since 2021) and 6 LUC (abandoned since 2017), were examined. Soil samples were collected at depth intervals of 0–10 cm, 10–20 cm, and 20–30 cm. The samples were analyzed for soil texture, pH, organic carbon, humic and fulvic acids, exchangeable Ca, Mg, and K, wet and dry aggregate distribution, mean weight diameter (MWD), and aggregate associated organic carbon. Dry and water stable microaggregates plus individual particles dominated in 2 LUC, while 6 LUC showed an even distribution of large and small macroaggregates, along with microaggregates plus individual particles. Wet and dry MWD were significantly higher in 6 LUC across all depths. Macroaggregate associated organic carbon did not differ significantly between the sites and depths, whereas microaggregate associated organic carbon was consistent between sites but decreased with depth from 0–10 cm to 10–20 cm. The results highlight the complex interaction between soil structure, aggregate stability, and carbon content, suggesting that a combination of factors such as cropping history, soil disturbance, and biological activity shape aggregate characteristics, in addition to the effects of SOC. Additionally, the duration of cropland abandonment plays a key role in overcoming the legacy effects of prior land use.

176. 题目: Improved identification of chlorinated disinfection byproducts by the sequential elution and absorption mode
文章编号: N25042301
期刊: Journal of Hazardous Materials
作者: Rong Qin, Yiming Feng, Shasha Zhuo, Qing-Long Fu
更新时间: 2025-04-23
摘要: Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) has been extensively employed to characterize the chemodiversty of dissolved organic matter (DOM) including chlorinated disinfection byproducts (Cl_n-DBPs). However, little is known about the combined effects of the sequential solid phase extraction (SPE) and absorption mode of Fourier transform data processing on the identification of Cl_n-DBPs. In this study, the identification of Cl_n-DBPs by the sequential SPE extraction and absorption mode were systematically compared using a typical swimming pool water. The sequential SPE extraction was more effective in extracting DOM molecules including Cl_n-DBPs than the traditional extraction, yielding 48.2 % ± 2.1 % and 87.3 % ± 3.8 % more DOM molecules and Cl_n-DBPs molecules, respectively. Moreover, a total of 274 nitrogenous Cl_n-DBPs were identified by the sequential SPE extraction with 80 more than that by the traditional SPE. The absorption mode improved the resolution and the signal-to-noise values of DOM peaks by factors of 1.87–1.98 and 1.52–1.60, respectively. The number of resolved Cl-related mass doublets within 2 mDa mass difference in the absorption mode was 537 more than that in the magnitude mode. Overall, the combination of sequential elution and absorption modes facilitated the detection of more molecules of DOM and Cl_n-DBPs compared to traditional SPE in magnitude mode, with an increase of 92.7 % ± 2.1 % and 121.7 % ± 5.6 %, respectively. These results have highlighted the great potential of the sequential elution combined with absorption mode in improving the identification of Cl_n-DBPs and their precursors, facilitating the application of FT-ICR MS in the nontargeted analysis of emerging contaminants including Cl_n-DBPs at the molecular level.

177. 题目: Urbanization enhances soil nitrogen mineralization mainly by increasing particulate organic nitrogen fractions in urban park greenspaces: A case study in Hangzhou, China
文章编号: N25042219
期刊: Applied Soil Ecology
作者: Bo Fan, Yuye Shen, Yan Wang, Liming Yin, Kumuduni Niroshika Palansooriya, Yongfu Li, Bing Yu, Scott X Chang, Yanjiang Cai
更新时间: 2025-04-22
摘要: In addition to the direct input of inorganic nitrogen (N), the supply of plant-available N driven by soil organic N mineralization is crucial for the development of urban greenspaces, which are essential components of urban ecosystems. Soil N mineralization may vary with urbanization, but the responses of soil N mineralization to different urbanization intensities remain controversial. In this study, we investigated the responses of urban park soil (planted with trees, shrubs or grasses) N mineralization to different urbanization intensities (low, medium and high) in Hangzhou, China. To further evaluate the relative importance of soil organic N fractions in explaining variations in N mineralization, we analyzed the responses of soil particulate organic N (PON) and mineral-associated organic N (MAON) to different urbanization intensities, as well as their relationships with N mineralization. Our results indicated that soil N mineralization increased with increasing urbanization intensity, likely due to increases in soil organic carbon concentration, clay content, microbial biomass and activity under high urbanization intensity. Notably, compared to soil MAON, the increase in soil PON induced by urbanization was more pronounced, and its relationship with soil N mineralization was stronger. Furthermore, soil N mineralization and its relationships with soil organic N fractions varied substantially among different vegetation types. These findings suggest that researchers and urban planners should evaluate the N supply mineralized from soil organic N fractions, particularly PON fractions, to optimize N and vegetation management strategies in urban greenspaces under different urbanization intensities.

178. 题目: Microbial effect on soil organic carbon accumulation and stabilization is lithology-depend in subtropical coniferous forest
文章编号: N25042218
期刊: Applied Soil Ecology
作者: Tao Yang, Liang Dong, Haoran Zhang, Chenghao Zheng, Jinxing Zhou, Xiawei Peng
更新时间: 2025-04-22
摘要: Lithology plays a crucial role in controlling the soil carbon (C) pool in forest ecosystems. The dynamics of soil organic C (SOC) are significantly influenced by the composition and function of the soil microbial community. However, the mechanisms by which lithology influences SOC and the involvement of microbes in this process remain unclear. To assess both the accrual and stability of SOC, we analyzed its content and physical composition by fractionating it into labile particulate organic C (POC) and stable mineral-associated organic C (MAOC). The study was conducted in two representative plantation coniferous forests developed on karst (limestone) and non-karst (shale) soils, with the aim of elucidating potential microbial regulatory mechanisms underlying lithology-mediated differences in SOC dynamics. Our findings revealed that SOC concentration was significantly higher in karst soils compared to non-karst soils at both depths, primarily due to the greater accumulation of MAOC, while lithology had a different effect on POC between topsoil and subsoil. Interestingly, the ratio of MAOC to POC was higher in karst soils compared to non-karst forests only in subsoils. These results imply the crucial role of lithology on SOC accrual and stability in coniferous forests. Soil nutrients stoichiometry, pH and exchangeable calcium ions (Ca2+) have exerted influence over microbial community composition, whereas microbial biodiversity and life history strategies only affected by soil nutrients. Additionally, structural equation modeling analyses revealed that lithology exerts a stronger influence on SOC than tree species, as lithology affects soil nutrient availability, thereby indirectly regulating the microbial impact on SOC accumulation. Nonetheless, both tree species and lithology significantly influence Ca2+, which indirectly promote SOC accumulation by enhancing the stability of SOC pool. Collectively, our study highlights the key role of lithology in SOC stability and accrual, providing a lithology-dependent linkage between microbial communities and the soil C pool.

179. 题目: Distribution and Source Identification of Sediment Organic Carbon of the Coastal Wetlands Around Bohai Sea
文章编号: N25042217
期刊: Wetlands
作者: Xiaoyao Li, Mengyi Wang, Wanxin Tian, Gang Xu, Zhaona Ding
更新时间: 2025-04-22
摘要:

Coastal wetlands are significant global carbon (C) sinks, but the characteristics and sources of organic carbon (OC) are far from understood due to the difficulties in assessing the different sources of the OC. In this study, sediments from eight reed wetlands around the Bohai Sea were collected. Sediment organic carbon (SOC), total nitrogen (TN) and the stable carbon/nitrogen isotope compositions (δ¹³C, δ¹⁵N) were analyzed to quantify the contributions of different sources to SOC. The results indicated that the SOC content ranged from 0.15% to 4.90%, with an average of 1.16%. The δ¹³C ranged from - 27.10‰ to - 21.70‰ (mean: - 24.76‰) and the δ¹⁵N varied from 1.19‰ to 6.58‰ (mean: 3.16‰), suggesting that the SOC were predominantly derived from reed detritus. Three major sources of the SOC were identified: reed detritus, terrestrial and marine OC. Using the IsoSource model, the reed detritus contribution were calculated as 67.5%, 43.5%, and 51.8% to the SOC of the Liaodong Bay wetlands (LDBW), Bohai Bay wetland (BHBW) and Laizhou Bay wetland (LZBW), respectively. Terrestrial OC accounted for an average of 16.5%, 33.9%, and 40.2% of the SOC in LDBW, BHBW, and LZBW, respectively. In contrast, marine OC contributed 16.0%, 22.7%, and 8.1% to the SOC in the same regions. For LZBW and LDBW, the reed detritus was the main source of SOC of the restored wetland whereas the terrestrial or marine derived OC became increasingly significant in tidal wetlands. Our results suggested that vegetation played a crucial role in carbon sequestration of coastal wetlands, therefore the wetland restoration project for vegetation improvement management need to be strengthened in the future. These findings provide a scientific basis for future monitoring of the organic carbon of the coastal wetlands.

180. 题目: Multi-Phase mobilization and degradation pathway of natural organic matter within alluvial-lacustrine aquifer sediments
文章编号: N25042216
期刊: Journal of Hydrology
作者: Wenkai Qiu, Yao Du, Wenhui Liu, Xinyu Liu, Yamin Deng, Teng Ma, Yanxin Wang
更新时间: 2025-04-22
摘要: Alluvial-lacustrine sediments are crucial organic matter pools in the subsurface, fueling biogeochemical processes in aquifers through the release of dissolved organic matter (DOM). However, little is known about the detailed mobilization and degradation pathways of organic matter from sediments to groundwater. Here, we examined porewater bridging sediments and groundwater and characterized the fluorescence properties and molecular composition of DOM in porewater with varying binding strengths to sediments. Results showed that bound water DOM primarily contained polycyclic aromatics, polyphenols, and highly unsaturated compounds with high O/C ratios and humification indices. Free water DOM, by contrast, was rich in aliphatic compounds with high H/C ratios and biological indices. Unique molecular formulae analysis revealed that in bound water, CHO + nN polyphenolic compounds were consumed, and highly unsaturated CHO + 2 N compounds were produced; in free water, highly unsaturated CHO + 2 N compounds were consumed, and CHO + 1 N aliphatic compounds were produced. This molecular fractionation of organic matter is likely controlled by abiotic diffusion and adsorption as well as by biotic microbial activity, with the former dominating in bound water and the latter in free water. This may relate to the stable double-layer structure in bound water and the increased exposure to electron acceptors in free water. Together, these dual mechanisms produce a high proportion (>50 %) of biodegradable DOM in free water, potentially explaining the geogenic enrichment of ammonium in local aquifers. Our results highlight the strong influence of local mobilization and degradation processes on the molecular characteristics of DOM, bearing significant environmental implications for the evolution of groundwater quality.