论文检索

主页 | 软件工具 | 课题库 | 公众号
:



总访问量:2430060

总访客量:117353

关键词:
Organic Matter |
DOM |
POM |
Soil OM |
Sediment OM |
Organic Carbon |
Organic Nitrogen |
Biomarker |
Humic Substances |
Fulvic Substances |
Humins |
Biochar |
Black Carbon |
GDGT |
Lignin |
Free Radical |
...
最新文章  | 
昨日文章 | 
前日文章
期刊:
Agriculture, Ecosystems & Environment |
Agricultural Water Management |
Applied Geochemistry |
Applied Soil Ecology |
Aquatic Geochemistry |
Atmospheric Research |
Biogeochemistry |
Biogeosciences |
Biology and Fertility of Soils |
Bioresource Technology |
CATENA |
Chemical Engineering Journal |
Chemical Geology |
Chemosphere |
CLEAN - Soil, Air, Water |
Colloids and Surfaces A: Physicochemical and Engineering Aspects |
Deep Sea Research Part II: Topical Studies in Oceanography |
Earth-Science Reviews |
Ecological Engineering |
Ecology Letters |
Ecology |
Ecotoxicology and Environmental Safety |
Environment International |
Environmental Earth Sciences |
Environmental Geochemistry and Health |
Environmental Monitoring and Assessment |
Environmental Pollution |
Environmental Research |
Environmental Science & Technology |
Environmental Science and Pollution Research |
Environmental Science: Processes Impacts |
Environmental Science: Water Research & Technology |
Environmental Toxicology and Chemistry |
Estuarine, Coastal and Shelf Science |
European Journal of Soil Science |
Forest Ecology and Management |
Geochimica et Cosmochimica Acta |
Geoderma |
Geophysical Research Letters |
Global Change Biology |
Global Biogeochemical Cycles |
Groundwater |
Harmful Algae |
International Journal of Coal Geology |
Journal of Environmental Chemical Engineering |
Journal of Environmental Management |
Journal of Environmental Sciences |
Journal of Geophysical Research: Biogeosciences |
Journal of Geophysical Research: Oceans |
Journal of Hazardous Materials |
Journal of Membrane Science |
Journal of Soils and Sediments |
Land Degradation & Development |
Limnology and Oceanography |
Marine Chemistry |
Marine Pollution Bulletin |
Nature Communications |
Nature Geoscience |
Ocean Science Journal |
Oikos |
Organic Geochemistry |
Palaeogeography, Palaeoclimatology, Palaeoecology |
Plant and Soil |
Progress in Oceanography |
Quaternary International |
Science of The Total Environment |
Sedimentary Geology |
Separation and Purification Technology |
Soil and Tillage Research |
Soil Biology and Biochemistry |
Waste Management |
Water Research |
Water, Air, & Soil Pollution |
Wetlands |
...

所有论文

1. 题目: Carbon Emissions Through the Weathering of Petrogenic Organic Carbon and the Net Geological Carbon Budget of the Tibetan Plateau
文章编号: N25021308
期刊: Geophysical Research Letters
作者: Ye Wang, Yang Chen, Shilei Li, David William Hedding, Jun Chen
更新时间: 2025-02-13
摘要: Mountain building, alongside the associated erosion and weathering, plays a key role in mediating the long-term carbon cycle, thus impacting Earth’s climate. Certain processes, such as the weathering of petrogenic organic carbon (OCpetro), still lack comprehensive quantitative research owing to the interference of human activities, hindering a full understanding of the net budget and temporal changes of mountain building. This study explores OCpetro weathering within the Tibetan Plateau by utilizing rhenium as a tracer to quantify OCpetro weathering rates and elucidate carbon fluxes. The overall OCpetro weathering rate and net carbon budget of the Tibetan Plateau are 1.95(±0.60) tC km−2 yr−1 and 1.81+0.34/−0.49 tC km−2 yr−1, indicating the Tibetan Plateau currently serves as a carbon source. This study not only refines our understanding of the OCpetro weathering but also reveals a dynamic transformational impact on the geological carbon cycle from mountain building at different stages.

2. 题目: Enhanced visible light photocatalytic degradation of oxytetracycline through sugarcane bagasse biochar supported layered WS2 type-II staggered heterojunction: Towards performance, degradation pathway, toxicity, and life cycle assessment
文章编号: N25021307
期刊: Environmental Research
作者: Sahil Chauhan, Rajarshi Bhar, Koustuv Ray, Shamik Chowdhury, Makarand Madhao Ghangrekar, Brajesh Kumar Dubey
更新时间: 2025-02-13
摘要: This research presents the synthesis of sugarcane bagasse biochar (SCB) integrated with WS2 nanosheets via one step facile solid-phase reaction. The as-prepared SCBW composites were then evaluated for their photocatalytic efficacy in degrading the antibiotic oxytetracycline (OTC) from water. Among the tested conditions using a Taguchi L9 orthogonal array, SCBW-10 achieved a maximum OTC degradation efficiency of 92.7% under optimal conditions (pH = 7, dose = 0.5 g L⁻1, initial concentration = 5 mg L⁻1, reaction time = 180 min). The study also examined the impact of other environmental factors, identified the predominant reactive oxygen species (•O2⁻ and •OH) responsible for OTC degradation, and conducted toxicity assessment and prediction of degradation products using Vigna radiata seed germination and T.E.S.T software, respectively. Further, the SCBW-10 nanocomposites demonstrated reusability over four cycles with minimal loss in efficiency. Lastly, a life cycle assessment was performed to evaluate the environmental impact of the proposed remediation system from gate to gate viewpoint.

3. 题目: Pre‐aged organic matter dominates organic carbon burial in a major perialpine lake system
文章编号: N25021306
期刊: Limnology and Oceanography
作者: Benedict V A Mittelbach, Alexander S Brunmayr, Margot E White, Timo M Y Rhyner, Negar Haghipour, Thomas M Blattmann, Martin Wessels, Nathalie Dubois, Timothy I Eglinton
更新时间: 2025-02-13
摘要: Organic carbon (OC) burial in lake sediments is comparable to that in marine sediments globally. However, climatic and carbon cycle implications depend on the origin of buried OC. This study utilizes high‐resolution radiocarbon (14C) measurements in combination with stable carbon isotopes (13C) and total organic carbon/total nitrogen ratios to constrain sources and ages of OC deposited since the early 20th century in Lake Constance, the second‐largest lake in central Europe. We differentiate between aquatic, pre‐aged soil, and fossil rock‐derived (petrogenic) OC. The shape and magnitude of the 14C bomb spike recorded in the sediment profile indicate the sequestration of recently synthesized biospheric OC with a complex overlay from different OC sources. We find that soil‐derived OC is the dominant component of sedimentary OC, with a mean transit time in the catchment of around 110 yr. Additionally, we quantified the 14C dynamics of dissolved inorganic carbon in the lake, which can be modeled with a mean transit time of around 10 yr. An ordinary kriging spatial analysis revealed that the Alpine Rhine delta and the profundal areas are the primary loci for allochthonous OC deposition. Lake‐wide surface sediment OC fluxes were spatially heterogeneous but averaged 52.0 gC m−2 yr−1, where 26.7 gC m−2 yr−1 of mostly stable, allochthonous OC are buried long term. This study highlights the necessity of accounting for both pre‐aged and fossil OC sources, as well as spatial heterogeneity, when assessing the response of lakes and, more broadly, source‐to‐sink systems to ongoing climate and ecosystem change.

4. 题目: Changes in riverine dissolved organic matter caused by gypsum‐induced flocculation
文章编号: N25021305
期刊: Journal of Environmental Quality
作者: Samu Elovaara, Lingbin Zhao, Eero Asmala, Hermanni Kaartokallio, David N Thomas
更新时间: 2025-02-13
摘要: Gypsum (CaSO4·2H2O) is increasingly used to bind P to soil on agricultural fields, which mitigates eutrophication caused by runoff of excess PO43− fertilizers into adjacent aquatic environments. Gypsum also binds dissolved organic matter (DOM) to soil particles. Gypsum that gets into fresh water after field applications may result in enhanced particle formation by DOM flocculation and alter C transfer in rivers draining agricultural catchments. We tested the potential effects of gypsum additions on DOM cycling by adding concentrated gypsum solution into river water before subjecting it to controlled mixing to increase particle collisions and flocculation. Gypsum addition increased the amount of suspended particulate matter in river water three to four times higher than in controls without gypsum. The flocs contained a relatively high amount of minerogenic particles. Gypsum‐induced flocculation removed colored dissolved organic matter which, together with removal of minerogenic particles, may result in increased water clarity. Gypsum addition and the associated changes in the DOM pool did not affect microbial growth or DOM processing, suggesting that flocculation did not target the labile fraction of the DOM pool. While acknowledging that the responses detected in our study might depend on the region, we propose that the changes in riverine DOM cycling caused by gypsum application results in either no changes or slightly positive changes to the water quality of the rivers and should not be considered an obstacle for eutrophication prevention using gypsum applications.

5. 题目: Biochar reversed antibiotic resistance genes spread in biodegradable microplastics and Cu co-contaminated soil by lowering Cu bio-availability and regulating denitrification process
文章编号: N25021304
期刊: Journal of Environmental Chemical Engineering
作者: Zhenyu Wang, Ying Sun, Xuejiang Wang, Siqing Xia, Jianfu Zhao
更新时间: 2025-02-13
摘要: This study first revealed how biochar affected antibiotic resistance genes (ARGs) development in Cu-contaminated soil coexisting with biodegradable microplastics via microcosm experiments. Results indicated that biodegradable microplastics exacerbated ARGs spread in Cu-contaminated soil by increasing Cu bioavailability, which heightened selective pressure on microbes, and by accelerating the denitrification process, as denitrification genes were closely linked to ARGs. Fortunately, biochar amendment decreased the total ARGs abundance by 41.73% in co-contaminated soil. The passivation of biochar reduced the proportion of bioavailable Cu by 5.39%. The denitrification process was also diminished, with a 17.85% reduction in denitrification genes copies. Additionally, biochar altered the dominant denitrifying genera in soil, shifting from ARGs hosts (e.g., Acinetobacter and Bacillus) to non-hosts (Comamonas). Overall, these findings suggested that biochar adoption could promote Cu immobilization and regulate soil denitrification process, making it an effective strategy to mitigate the ARGs transmission in biodegradable microplastics and Cu co-contaminated soil.

6. 题目: Continued permafrost ecosystem carbon loss under net-zero and negative emissions
文章编号: N25021303
期刊: Science Advances
作者: So-Won Park, Jin-Hyuk Mun, Hanna Lee, Norman J Steinert, Soon-Il An, Jongsoo Shin, Jong-Seong Kug
更新时间: 2025-02-13
摘要: The loss of ecosystem carbon (the sum of vegetation, litter, and soil carbon) may occur in a permafrost region under mitigation pathways, which could reduce the efficiency of carbon dioxide removal. Here, we investigate changes in permafrost under net-zero and negative emissions, based on idealized emission-driven simulations using a state-of-the-art Earth system model. While acting as a net ecosystem carbon sink during most of the positive emission phase, permafrost becomes a net ecosystem carbon source just before reaching net-zero and negative emissions. Permafrost slowly recovers, especially in regions with high organic carbon content, and net ecosystem carbon loss persists until the end of simulations, resulting in a cumulative net ecosystem carbon loss of approximately 14 petagrams of carbon (PgC) in both scenarios. In addition, methane emissions increase under net-zero and negative emissions, due to the irreversibility of the inundated areas. We conclude that the permafrost ecosystem carbon loss may continue under net-zero and negative emissions, which could hinder climate change mitigation efforts.

7. 题目: Atmospheric black carbon (BC) in Hangzhou, China: Temporal variation, source apportionment, and case study of the 19th Asian Games
文章编号: N25021302
期刊: Environmental Pollution
作者: Jian Lin, Deming Han, Feng Chen, Xiaorong Zhang, Yang Yang, Lin Yang, Hua Guo, Zechen Yu, Liuyan Cao, Jianbo Shi, Guibin Jiang
更新时间: 2025-02-13
摘要: Black carbon (BC) is a refractory form of carbonaceous aerosol generated from fossil fuel and biomass incomplete combustion, which has adverse influence on global warming, air pollution, and human health. However, the relative importance of different sources and meteorology on atmospheric BC evolution was not well understood yet, especially during special periods when series of rigorous emission reduction measures were employed. Here, over one–year observation of BC concentration was conducted in urban of Hangzhou, China from Dec. 2022 to Jan. 2024. The annual mean BC concentration was 1.99±1.25 μg/m3, and displayed strong seasonal and diurnal variability. The BC aerosol in winter (–22.7±3.3‰) was 2.3‰ enriched in stable carbon isotope (δ13C) compared to BC in summer, this discrepancy indicated enhanced liquid fossil fuel combustion and C3 plant biomass combustion in cold season. Furthermore, Aethalometer model revealed that BC aerosols in Hangzhou were primarily derived from fossil fuel combustion (73.8±9.1%). Specifically, backward trajectory and potential source contribution factor (PSCF) results suggested that the relative high BC concentrations were mainly originated from local sources direct emission in Yangtze River Delta. The BC concentrations during the 19th Asian Games (1.40±0.87 μg/m3) decreased by 41.9% in comparison with that after Asian Games, which was attributed to the vehicle and industrial emissions reduction, and biomass burning prohibition in Hangzhou. These findings highlight the influence of anthropogenic sources emission on temporal variation of BC in urban agglomeration, which was of benefit to further developing effective emission reduction strategies to mitigate climate change and improve air quality.

8. 题目: Predicting the Kinetics of Cu and Cd Release from Diverse Soil Dissolved Organic Matter: A Novel Hybrid Model Integrating Machine Learning with Mechanistic Kinetics Model
文章编号: N25021301
期刊: Environmental Science & Technology
作者: Qianting Ye, Rong Li, Bin Liang, Lanlan Zhu, Jiang Xiao, Zhenqing Shi
更新时间: 2025-02-13
摘要: Kinetic release of trace metals from soil dissolved organic matter (DOM) to solution is the key process controlling the mobility and bioavailability of trace metals in soil environment. However, due to the complexity of soil DOM, predicting the reaction rates of trace metals with soil DOM from different sources remains challenging. In this study, we developed a novel hybrid model integrating machine learning with mechanistic kinetics model, which can quantitatively predict the release rates of Cu and Cd from diverse soil DOM based on their compositions and properties. Our model quantitatively demonstrated that the molecular compositions of DOM controlled metal release rates, which had more profound impact on Cu than Cd. Our modeling results also identified two key factors affecting metal release rates, in which high concentrations of Ca and Mg ions in DOM significantly decreased the release rates of Cu and Cd, and the reassociation reactions of metal ions with DOM became more significant with the release of metals from DOM. This work has provided a unified kinetic modeling framework combining both mechanistic and data-driven approaches, which offers a new perspective for developing predictive kinetics models and can be applied to different metals and DOM in dynamic environments.

9. 题目: Effects of extracellular organic matter from bacteria on the growth, physiology, photosynthesis, and transcriptome of the bloom-forming algal species
文章编号: N25021220
期刊: Journal of Hazardous Materials
作者: Jiao Ran, Rong Xiang, Binghui Zheng
更新时间: 2025-02-12
摘要: Cyanobacterial blooms pose one of the most severe ecological challenges in aquatic systems. However, the mechanism through which bacterial dissolved organic matter influences the formation of algal blooms remains unclear. In this study, extracellular organic matter (EOM) was extracted from Flavobacterium sp., a common bacterial group in bloom, and the impacts of this EOM on the growth, physiology, photosynthesis, and transcriptome of Anabaena sp. were investigated. The results indicated that flavobacterium-derived EOM (F-EOM) inhibited Anabaena sp. growth, physiological activity, and photosynthesis, with greater inhibition at higher concentrations. Meanwhile, transcriptome analysis showed that 803 genes in Anabaena sp. were differentially expressed after being exposed to 10 mg/L F-EOM, with simultaneously the majority being down-regulated. The down-regulation of genes in photochemical reactions, the synthesis of photosynthetic pigment, and light-trapping antenna protein inhibited photosynthesis. While ATP synthesis was reduced due to the genes related to oxidative phosphorylation and the tricarboxylic acid cycle was downregulated. Moreover, the down-regulated genes in amino acid synthesis affected the synthesis of proteins and metabolic regulatory factors. This may be the main reason why F-EOM could hinder the growth and metabolism of Anabaena sp. These results provide scientific insights into the formation and control of cyanobacteria blooms.

10. 题目: Regulation of organic matter Consumption, Nitrification, and iron reduction using magnetite nanoparticles in paddy Soil: Implications for anaerobic carbon sequestration
文章编号: N25021219
期刊: Chemical Engineering Journal
作者: Ruixiang Li, Yi Li, Yuxuan Wan, Xiaolin Zhang, Qixing Zhou, Tian Li
更新时间: 2025-02-12
摘要: The role of magnetite nanoparticles (MNPs) in regulating carbon transformation remains controversial, particularly with regard to its impact on carbon sequestration or emissions in paddy soils, which is of paramount importance for global climate change control. This study investigated the effects of MNPs on carbon cycling and geochemical element transformation under simulated rice rotation conditions. The results demonstrated that MNPs predominantly influenced the anaerobic zone, where increasing MNP content from 0.5 wt% to 1.5 wt% significantly inhibited organic matter decomposition and regulated electron transfer pathways. Organic matter depletion in the 1.5 wt% MNP group was only 17%–48% of that in the control group across different rotation stages. Furthermore, microbial community analyses demonstrated that the abundance of heterotrophic Fe-reducing and nitrogen-transforming microorganisms increased by 2-fold and 1.6-fold, respectively, resulting in a 2-fold increase in Fe2+ content and a 5–10-fold increase in NO3-N content. Detailed physicochemical analyses and calculations confirmed that MNPs regulated the Fe and nitrogen cycles, thereby suppressing carbon decomposition and enhancing carbon sequestration. This study offers new insights into paddy soil carbon sequestration, contributing to the global carbon balance and the climate change mitigation.

11. 题目: Compositions and concentrations of dissolved organic matter, selected elements and anions in German drinking waters
文章编号: N25021218
期刊: Journal of Environmental Management
作者: Muhammad Zeeshan, Vanessa Ingold, Leon Saal, Christian Höra, Alexander Kämpfe, Aki Sebastian Ruhl
更新时间: 2025-02-12
摘要: Dissolved organic matter (DOM) in water resources can lead to various drinking water quality issues, including undesirable color, taste, and odor, while also enhancing the mobility of heavy metals and promoting the formation of disinfection byproducts. This study investigated DOM concentrations and compositions in German drinking waters using fluorescence spectroscopy and size-exclusion chromatography coupled with organic carbon detection (LC-OCD). Additionally, the occurrence of selected elements and other inorganic ions were studied. Eighty-nine (89) drinking water samples were collected with the help of residents across Germany. The study revealed that DOM concentrations ranged from 0.3 to 5.7 mg/L, primarily due to humic substances. DOM fractions identified using LC-OCD and fluorescence spectroscopy showed a correlation, indicating that an increase in organic carbon resulted in an increase in fluorescent DOM, as expected due to the aromatic character of humic substances. Heavy metal concentrations in drinking waters were below the regulatory limits set by the German Drinking Water Ordinance (TrinkwV) for safe drinking water, except for one example of a lead concentration, which was 16.2 μg/L. No specific relation was found between the sources of drinking water (including surface water, groundwater, and bank filtrate) and the concentration and composition of DOM, as well as the occurrence of heavy metals. However, correlations between vanadium and chromium, nickel and lead, calcium and magnesium, and calcium and sulfate suggested that these components may share common sources or exhibit similar geochemical behaviors.

12. 题目: Potassium permanganate-hematite-modified biochar enhances cadmium and zinc passivation and nutrient availability and promotes soil microbial activity in heavy metal-contaminated soil
文章编号: N25021217
期刊: Journal of Environmental Management
作者: Xirui Kang, Na Geng, Xinyu Hou, Hui Wang, Hong Pan, Quangang Yang, Yanhong Lou, Yuping Zhuge
更新时间: 2025-02-12
摘要: Modified biochar has garnered considerable attention for its versatile applications in remediating soils contaminated with heavy metals. However, most existing studies have primarily focused on the stabilisation of heavy metals, with limited research exploring the broader environmental effects following the application of modified biochar. In this study, we developed a potassium permanganate (KMnO4)-hematite-modified biochar (MnFeB) as a passivating agent for heavy metals, specifically targeting cadmium (Cd) and zinc (Zn)-contaminated soils. We examined the effects of MnFeB on the biotoxicity of Cd and Zn, soil properties, enzyme activities, heavy metal resistance genes (czcA, czcC, and czcD), and the soil microbial community in contaminated soils. Treatment with MnFeB markedly reduced the soil diethylenetriaminepentaacetic acid (DTPA)-extractable Zn and Cd contents by 18.79% and 43.65%, respectively. Furthermore, soil organic carbon (SOC), cation exchange capacity (CEC), and the availability of nitrogen, phosphorus, and potassium were found to be increased. MnFeB application also enhanced the activities of catalase, urease, and alkaline phosphatase while reducing the expression of czcA by 23.63%. Moreover, changes in the composition and diversity of soil bacterial and fungal communities were observed. These findings highlight the effects of environmental changes induced by MnFeB application on Cd/Zn-contaminated soil and offer theoretical support for employing passivation strategies in the remediation of heavy metal-contaminated soils.

13. 题目: Humic acid inhibits hydroxyl radical generation during oxygenation of Fe(II) on goethite surface
文章编号: N25021216
期刊: Science of the Total Environment
作者: Meiru Yin, Wentao Yu, Siyu Nie, Kun Wang, Xin Xiao, Baoliang Chen
更新时间: 2025-02-12
摘要: The dark formation of hydroxyl radicals (•OH) by the oxidation of Fe(II) has been increasingly recognized at anoxic–oxic interface. Minerals play significant roles on oxidation of Fe(II) owing to the adsorption changed the reactivity of Fe(II). However, the impact of dissolved organic matter (DOM) on the oxidation of mineral adsorbed Fe(II) and •OH generation remains unknown. Herein, we examined the impact of humic acid (HA) on •OH accumulation during oxygenation of goethite surface-adsorbed Fe(II). We found the addition of 100–500 mg C•L−1 HA inhibited 3.7 % - 24.8 % •OH accumulation, compared to •OH generation facilitated by goethite-adsorbed Fe(II), and the electron utilization efficiency for •OH generation reduced from 15.4 % to 11.8 %. The adsorption experiment under anoxic condition showed that HA compete absorption with Fe(II) on goethite surface. XPS spectroscopy revealed that HA reduces the surface Fe-OH functional group by 4.8 %, thereby reducing the active sites on goethite. Voltammetric cycling curves demonstrated that HA decreased the reducing capacity and inhibited the electrical conductivity of the goethite-adsorbed Fe(II). This study elucidates the effects and mechanisms of HA adsorption on •OH generation during the oxygenation of Fe(II) on goethite surface.

14. 题目: Enhanced soil phosphorus availability via combined biochar and wood vinegar application
文章编号: N25021215
期刊: Journal of Soils and Sediments
作者: Deyu Fang, Yan Yue, Xi Lu, Hao Liu, Zhishuo Zheng, Zhibao Liu, Hongfang Ma
更新时间: 2025-02-12
摘要:

Purpose

To identify the optimal ratio for enhancing soil phosphorus availability, this study examined the effects of biochar and wood vinegar, applied individually and in combination at various ratios, on the phosphorus adsorption characteristics of soil.

Materials and methods

Biochar was incorporated into soil samples at mass ratios of 0%, 1%, 3%, and 5%. Each mixture was then divided into two portions, with wood vinegar evenly sprayed onto one portion. The effects on phosphorus adsorption were analyzed alongside changes in soil properties, including pH, electrical conductivity (EC), soil organic carbon (SOC), cation exchange capacity (CEC), and alkaline phosphatase (ALP) activity.

Results and discussion

Results demonstrated that biochar amendment reduced soil phosphorus adsorption by 2.93–26.65%, with the combined application of wood vinegar further decreasing adsorption by 4.43–28.02%, likely due to competitive adsorption of organic acid anions. The largest reduction in phosphorus adsorption was observed with the combination of wood vinegar and a medium dose of biochar (3% mass ratio). Negative correlations were observed between soil pH, EC, and SOC with the phosphorus adsorption coefficient Kl, while positive correlations were observed for CEC and ALP. The environmental factors influencing phosphorus adsorption were ranked in the order of EC > SOC > CEC > ALP > pH.

Conclusions

Combining 3% biochar with wood vinegar could effectively enhance soil phosphorus availability by reducing phosphorus adsorption, influenced by changes in environmental factors. 

15. 题目: Organic carbon and nitrogen accrual evidenced by the underpinning protection mechanisms in soil profile following contrasting 35-year fertilization regimes
文章编号: N25021214
期刊: Journal of Environmental Management
作者: Muhammad Mohsin Abrar, Muhammad Ahmed Waqas, Khalid Mehmood, Ruqin Fan, Baoku Zhou, Xingzhu Ma, Sun Nan, Jianjun Du, Minggang Xu
更新时间: 2025-02-12
摘要: Soil organic matter (SOM) is a highly complex variable and needs fractionation into distinct pools based on their differing behaviour to better elucidate and predict its dynamics. The present study aimed to quantify the soil organic carbon (SOC) and total nitrogen (TN) stocks and assess their sensitivity indices in fractions with contrasting functionality. Furthermore, the correlations were also evaluated between SOC and TN stocks of pools, system grain yield (SGY), soil physico-chemical properties, and climatic variables. The results demonstrated that C and N stocks in the combined application of organic manure (M), and nitrogen, phosphorus, and potassium (NPK) i.e., MNPK and sole application of M treatments significantly augmented at 0–40 cm and 40–100 cm soil layers, respectively. Also, the SGY was significantly higher under all fertilization treatments than control (no fertilization). Furthermore, SOC and TN stocks of major soil fractions were positively correlated with soil nutrients and mean annual precipitation. Thus, long-term manure application integrated with mineral fertilization (MNPK) in Black soil or Mollisol leads to enhanced crop yields and pool-associated SOC and TN stocks up to 40 cm depth. Whereas the manure-alone (M) is critical for enhancing pool-associated SOC and TN stocks at 40 to 100 cm soil profile. This study implicated how the SOC and TN stocks in different fractions respond to manure and mineral fertilization (35 years) which is pivotal for improving SOC and TN sequestration by modulating the response of SOM pools. The results provide insights into the accrual of C and N stocks underpinned by the stabilization mechanisms specifically implying the significance of microaggregation across the soil profile of cropland.

16. 题目: The effects of formation modes of ferrihydrite-low molecular weight organic matter composites on the adsorption of Cd(II).
文章编号: N25021213
期刊: Environmental Science: Processes & Impacts
作者: Xin Nie, Erping Bi, Shiyun Qiu
更新时间: 2025-02-12
摘要: The interactions between iron oxides and organic matter (OM) play vital roles in the geochemical cycle of cadmium (Cd). However, the effects of the formation modes of ferrihydrite (Fh)-low molecular weight OM (e.g., fulvic acid (FA)) composites on Cd(II) adsorption remain poorly understood. The immobilization mechanisms of Cd(II) on Fe-OM composites formed by adsorption and coprecipitation at varying C/Fe molar ratios were investigated by means of adsorption batch experiments, two-dimensional correlation spectroscopy, and surface complexation models (SCMs). The composites formed by adsorption or coprecipitation exhibited a crystal structure similar to that of Fh. Ligand exchange and hydrogen bonding were identified as the primary mechanisms between components in adsorption composites and coprecipitates, respectively. Compared to coprecipitates, the adsorption composites showed a higher adsorption capacity and formed ternary complexes (Fh-FA-Cd). In coprecipitates, Cd(II) primarily interacted with the carboxyl and hydroxyl groups of FA and the hydroxyl groups of Fh. With increasing C/Fe molar ratios, the FA functional group (R-COOH) in adsorption composites responded more quickly to Cd(II). However, the order of functional group reactions in coprecipitates was unaffected by C/Fe molar ratios, which is due to the irregular distribution of C and Fe elements. SCM calculation results indicated that Cd(II) distribution on Fh in adsorption composites was higher than that in coprecipitates. The molar ratios of C/Fe and Cd(II) concentrations influenced the distribution of Cd(II) on the composites, with the highest proportion of Cd(II) on Fh reaching about 70%. These findings contribute to understanding Cd behavior in environments with periodically fluctuating redox conditions.

17. 题目: Post-drought organic carbon mineralization leads to high productivity and nutrient uptake efficiency of perennial grassland after rewetting
文章编号: N25021212
期刊: Soil Biology and Biochemistry
作者: Marie-Louise Schärer, Lucia Fuchslueger, Alberto Canarini, Andreas Richter, Andreas Lüscher, Ansgar Kahmen
更新时间: 2025-02-12
摘要: Grasslands often recover well from drought, with some even surpassing non-drought-stressed controls in productivity long after drought release. However, the mechanisms responsible for such post-drought productivity outperformance remain unclear. In this study we examine how rewetting after drought influences important short- and longer-term soil microbial processes (i.e. nitrogen mineralization, potential enzyme activities) and consequent plant nutrient availability and uptake. For this, a field experiment was set up where an established perennial ryegrass sward under different N-fertilization levels was subjected to either a 2-month experimental summer drought followed by rewetting or to rainfed control conditions.Rewetting after drought led to an immediate pulse in gross N-mineralization and NH4-consumption rates. Both rates increased by >230% and >430% in formerly drought-stressed subplots compared to controls in plots not N-fertilized and N-fertilized during drought, respectively. Importantly, gross N mineralization rates correlated significantly with extractable soil organic carbon contents at the end of drought. Concurrently, drought and rewetting significantly increased NO3-N, P, K, S, Fe, Zn, and Mn availability during the 1st but not the 2nd month after rewetting, except for K. Aboveground productivity of perennial ryegrass responded positively to NO3-N availabilities during the 1st month after rewetting, leading to productivity outperformance of formerly drought-stressed plots compared to controls. These results suggest that short-term productivity outperformance of perennial grasslands in the 1st month after rewetting is driven by an increase in NO3-N availability caused by a rewetting-induced pulse in N-mineralization of organic substrates accumulated during drought. Although effects of drought and rewetting on nutrient availability were only observed in the 1st month after rewetting, grassland productivity outperformance persisted in the 2nd month after rewetting. This indicates that soil drought legacy increased plant nutrient uptake efficiency, explaining longer-term outperformance effects when effects of drought and rewetting on nutrient availability were no longer apparent.

18. 题目: Biochar affects the transformation and migration behavior of As and Cd in the rhizosphere-rice system at various growth stages
文章编号: N25021211
期刊: Journal of Soils and Sediments
作者: Fande Meng, Qiuxiang Huang, Wenzhe Chen, Yongbing Cai, Guodong Yuan
更新时间: 2025-02-12
摘要:

Purpose

Rhizosphere is the critical soil zone surrounding a plant root where the root influences soil biological and chemical processes. Biochar, a commonly used soil ameliorant, can affect soil properties and the and metal(loid)s transformation and migration behavior. We aimed to explore the metal(loid)s transformation and migration in rhizosphere-rice system and evaluate the biochar effects.

Materials and methods

A rice pot experiments and systematically determined the impact of biochar on key rhizosphere environmental factors, rice production, and fractions and translocation of arsenic (As) and cadmium (Cd) in the rhizosphere-rice system at four rice growth stages.

Results and conclusion

Biochar increased pH, DOM, and SOC in the rhizosphere and raised rice biomass but decreased Eh, thus affecting the redistribution of fractions of As and Cd. The bioavailable As increased, but bioavailable Cd decreased then increased with rice growth. Biochar increased bioavailable As by 11.27–80.95% but lowered bioavailable Cd by 44.72–99.25%. The higher bioconcentration factor (BCF) of As (0.31–2.40) than Cd (0.20–0.26) suggests As is much easier to move from the rhizosphere to rice root. The higher translocation factor (TF) of Cd (0.31–0.64) than As (0.08–0.44) indicates Cd is much easier to migrate from the root to shoot and grain. Biochar reduced the As and Cd migration from rhizosphere to root and shoot, lowered Cd but raised As accumulation in rice grain. This work underscores the potential risk of As to human health through the food chain when biochar is used to remediate As- and Cd-contaminated soils.

Graphical

19. 题目: Use of Copper in Evaluating the Role of Phenolic Moieties in the Photooxidation of Dissolved Organic Matter
文章编号: N25021210
期刊: Environmental Science & Technology
作者: Yanheng Pan, Shikha Garg, Jianglin Peng, Xin Yang, T David Waite
更新时间: 2025-02-12
摘要: In a recent study, copper was shown to act as a novel quencher for investigating the mechanism of the photooxidation and photobleaching of dissolved organic matter (DOM) by selectively quenching the one-electron oxidizing intermediates of DOM (DOMD•+). However, the capture of DOMD•+ by Cu is possibly partially due to strong competition from phenolic antioxidant moieties intrinsically present in DOM for DOMD•+ quenching. In this study, the extent of interaction between DOMD•+ and phenolic antioxidant moieties is quantified by measuring the inhibitory effect of Cu on DOM photooxidation and photobleaching under varying pH (5.2–10.0) conditions. The increase in pH facilitates formation of deprotonated phenolic moieties (pKa ∼ 9–10), increasing their quenching capacity of DOMD•+. Accordingly, our results indicate that the inhibitory effect of Cu on the DOM photobleaching and the loss of electron-donating moieties of DOM significantly decreased with an increase in pH, suggesting more pronounced competition for DOMD•+ from antioxidant phenolic moieties within DOM. Considering the precursors of DOMD•+ also originate from phenolic moieties of DOM, the findings of this study provide important insights into the long-distance charge transfer reactions occurring at different phenolic moiety sites during DOM photooxidation.

20. 题目: Biomarker signatures in host rocks and their co-occurring fossil plants from northern Scotland
文章编号: N25021209
期刊: Organic Geochemistry
作者: Olumuyiwa T Akinsanpe, Adebola O Akinsanpe, Solomon A Adekola, Oluwaseye P Oyetade, Waheed G Akande, Musa B Usman, Abdulwahab M Bello, Uzochukwu K Benjamin, Adeniyi O Olusanya, Chikezie Emele
更新时间: 2025-02-12
摘要: The Devonian Period paleogeographic setting fostered the growth of diverse terrestrial and marine organisms, enhancing organic matter production and preserving terrestrial organic matter (TOM). Northern Scotland shows rock sequences with well-preserved TOM, including distinctive fossil plant fragments. The biomarker record of host rock-fossil plant system is notably fragmented. Nonetheless, the exposed outcrops of Old Red Sandstone in northern Scotland allow detailed sampling and biomarker analysis of the Devonian rocks and their co-existing fossil plants. The biomarker record of the host rocks and the co-occurring plant fossils show that the organic matter of the Rhynie Chert, Newton of Kinkell and Kerrera siltstones were derived from vascular plants. The plant biomarkers detected in the Rhynie Chert includes tetracyclic diterpenoids (kaurane and beyerane), cadalene and methylnaphthalene. These biomarkers except cadalene were also present in Den of Morphie samples, Achanarras Quarry, Kerrera plant and Newton of Kinkell siltstone-plant samples. The similarity in biomarker signatures between fossil plants and host rocks in Achanarras suggested a shared origin of organic matter. Also, the sulfur-rich euxinic conditions in the studied areas, the hydrothermal permineralization and presence of pyrite framboids in the Rhynie Chert preserved the organic matter. This was indicated by low Pr/Ph ratios and high sulfur content, enhancing preservation and reducing organic matter degradation. The study concluded that the biomarker record of the host rock-plant fossil system in northern Scotland aids the understanding of terrestrialization process and higher plant evolution in the Devonian.

 共 25979 条记录  本页 20 条  本页从 1-20 条  1/1299页  1 2 3 4 5 6  下一页  末页   

本数据库数据来源自各期刊,所有权归属各期刊。数据仅供分享学习,不作商业用途,特此申明。