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21. 题目: Grazing in a megagrazer-dominated savanna does not reduce soil carbon stocks, even at high intensities
文章编号: N23060104
期刊: Oikos
作者: Olli Hyvarinen, Mariska te Beest, Elizabeth le Roux, Graham I H Kerley, Nicola Findlay, Walter D C Schenkeveld, Victor Trouw, Joris P G M Cromsigt
更新时间: 2023-06-01
摘要: Recent studies suggest that wild animals can promote ecosystem carbon sinks through their impacts on vegetation and soils. However, livestock studies show that intense levels of grazing reduce soil organic carbon (SOC), leading to concerns that rewilding with large grazers may compromise ecosystem carbon storage. Furthermore, wild grazers can both limit and promote woody plant recruitment and survival on savanna grasslands, with both positive and negative impacts on SOC, depending on the rainfall and soil texture contexts. We used grazing lawns in one of the few African protected savannas that are still dominated by megagrazers (> 1000 kg), namely white rhinoceros Ceratotherium simum, as a model to study the impact of prolonged and intense wild grazing on SOC stocks. We contrasted SOC stocks between patches of varying grazing intensity and woody plant encroachment in sites across different rhino habitat types. We found no differences in SOC stocks between the most- and least grazed plots in any of the habitats. Intermediately grazed plots, however, had higher SOC stocks in the top 5 cm compared to most and least grazed plots, but only in the closed-canopy woodland habitat and not in the open habitats. Importantly, we found no evidence to support the hypothesis that wild grazing reduces SOC, even at high grazing intensities by the world's largest megagrazer. Compared to the non-encroached reference plots, woody encroached plots had higher SOC stocks in soils with low clay content and lower SOC stocks in soils with high clay content, although only in the top 5 cm. Accordingly, our study highlights that wild grazers may influence SOC indirectly through their impact on tree-grass ratios in grassy ecosystems. Our study thus provides important insights for future natural climate solutions that focus on wild grazer conservation and restoration.
22. 题目: Synergistic improvement of carbon sequestration and crop yield by organic material addition in saline soil: A global meta-analysis
文章编号: N23060103
期刊: Science of the Total Environment
作者: Siping Li, Lei Zhao, Chong Wang, Huiying Huang, Minghao Zhuang
更新时间: 2023-06-01
摘要:
The improvement and utilization of saline soil is an important guarantee for cultivating healthy soil, ensuring global food security, and mitigating the negative impacts of climate change. Organic material addition plays a crucial role in soil improvement and remediation, soil carbon sequestration, and improving soil fertilizer and productivity. In order to explore the comprehensive impact of organic material addition on properties of saline soil (including the physical and chemical properties, nutrient fixation, crop yield, and carbon sink capacity), we conducted a global meta-analysis using data from 141 articles. We found that, soil salinization significantly reduced plant biomass (50.1 %), soil organic carbon (20.6 %), and microbial biomass carbon (36.5 %). Meanwhile, it also reduced CO2 flux (25.8 %) and CH4 flux (90.2 %) significantly. Adding organic materials to saline soil significantly increased crop yield (30.4 %), plant biomass (30.1 %), soil organic carbon (62.2 %), and microbial biomass carbon (78.2 %), but also increased CO2 flux (221.9 %) and CH4 flux (29.7 %). Considering the balance of both carbon sequestration and carbon emissions, organic material addition significantly increased the net carbon sequestration by about 5890.7 kg CO2-eq·hm−2·100 d−1 on average. Besides, the organic material addition reduced soil salinity, exchangeable sodium, and pH, and increased >0.25 mm aggregates and soil fertility. Our findings suggest that organic material addition can improve both carbon sequestration in saline soil and crop yield. Considering the huge area of saline soil around the world, this understanding is essential to reduce the saline obstacle, improve the soil carbon sink capacity, ensure food security, and increase farmland reserves.
23. 题目: Biochar enhances multifunctionality by increasing the uniformity of energy flow through a soil nematode food web
文章编号: N23060102
期刊: Soil Biology and Biochemistry
作者: Baijing Zhu, Bingbing Wan, Ting Liu, Chongzhe Zhang, Liuzhu Cheng, Yanhong Cheng, Shanyi Tian, Xiaoyun Chen, Feng Hu, Joann K Whalen, Manqiang Liu
更新时间: 2023-06-01
摘要:
Soil multifunctionality is the consequence of biotic interactions that drive decomposition, nutrient cycling and net primary production. Energy flux describes the energy consumed and transferred among multitrophic groups in the soil food web, which are logically linked to multifunctionality. In a subtropical agroecosystem with an annual sweet potato-oilseed rape rotation, we explored how biochar and synthetic fertilizer jointly affected agroecosystem multifunctionality (e.g., crop production, soil carbon storage and nutrient cycling) and the energetic structure of the nematode food web during two consecutive years. Results showed that biochar increased soil multifunctionality by 37–110% mainly by promoting a uniform energy flow through the soil nematode food web, which was largely due to increased energy fluxes of fungivores and omnivores-carnivores at the expense of decreased energy flux through herbivores. Applying a lower rate of synthetic fertilizer led to non-uniform energy flow in the soil nematode food web, suggesting that nitrogen limitation could offset the stimulatory effect of biochar on soil multifunctionality. This was because biochar induced oligotrophic conditions (a stoichiometry-induced nitrogen limitation), effectively warranting that continuous biochar application would aggravate nutrient limitations to crops, especially when low rates of synthetic fertilizer are applied. Notably, soil nutrient impoverishment could lead to resource reallocation from aboveground shoot to belowground root production, thereby fueling the energy flow through the herbivore channel. Our findings highlight the importance of balancing biochar and synthetic fertilizer applications to sustain a stable energetic structure in soil nematode food webs, which are associated with greater crop production and soil health in subtropical region.
24. 题目: Mechanistic investigation of direct photodegradation of chloroquine phosphate under simulated sunlight
文章编号: N23060101
期刊: Chemosphere
作者: Weiming Xiang, Fahao Xu, Dong Wan, Xing Wang, Fan Luo, Yong Chen
更新时间: 2023-06-01
摘要:
Chloroquine phosphate (CQ) is an antiviral drug for Coronavirus Disease 2019 and an old drug for treatment of malaria, which has been detected in natural waters. Despite its prevalence, the environmental fate of CQ remains unclear. In this study, the direct photodegradation of CQ under simulated sunlight was investigated. The effect of various parameters such as pH, initial concentration and environmental matrix were examined. The photodegradation quantum yield of CQ (4.5 × 10−5−0.025) increased with the increasing pH value in the range of 6.0–10.0. The electron spin resonance (ESR) spectrometry and quenching experiments verified that the direct photodegradation of CQ was primarily associated with excited triplet states of CQ (3CQ*). The common ions had negligible effect and humic substances exhibited a negative effect on CQ photodegradation. The photoproducts were identified using high-resolution mass spectrometry and the photodegradation pathway of CQ was proposed. The direct photodegradation of CQ involved the cleavage of the C–Cl bond and substitution of the hydroxyl group, followed by further oxidation to yield carboxylic products. The photodegradation processes were further confirmed by the density functional theory (DFT) computation for the energy barrier of CQ dichlorination. The findings contribute to the assessment of the ecological risk associated with the overuse of Coronavirus drugs during global public health emergencies.
25. 题目: Alkalization-induced disintegration increased redox activity of solid humic acids and its soil biogeochemical implications
文章编号: N23053113
期刊: Science of the Total Environment
作者: Caiqin Wang, Shuting Tang, Hangzhe Chen, Tingfeng Cheng, Daoyong Zhang, Xiangliang Pan
更新时间: 2023-05-31
摘要:
Solid humic acids (HAsolid) plays a significant role in maintaining soil ecosystem services, especially in alkaline soil. The unique chemical structures and electrochemical properties are the cores that HAsolid works. In this study, the alkalization-induced variations of particle morphology, functional groups and redox activity of HAsolid were investigated and its soil biogeochemical implications were discussed. Atomic force microscopy (AFM) deflection images and zeta potential results showed that alkalization induced disintegration of HAsolid, with particle size reducing to 200 nm when pH value reached 10.0. This result suggested that HAsolid could exist in alkaline soil. AFM-IR along with fluorescence intensity of HAsolid at different pH further proved that the supramolecular aggregation of HAsolid became loose and dispersive with more redox-active functional groups exposure after alkalization, which could lead to HAsolid susceptible to degradation in alkaline soil. Conductivity of HAsolid decreased 42.86 % when pH increased from 5.0 to 10.0, while electron exchange capacity (EEC) of HAsolid increased 45.30 %, indicating the increase of redox activity of HAsolid. Increase of redox activity of HAsolid by alkalization-induced disintegration not only can accelerate organic pollutant degradation via enhancing microbial co-metabolism, but also will speed the organic carbon loss. This study contributes to a better understanding of the role of HAsolid in organic carbon stocks and fluxes of alkaline soils and has great implications for soil biogeochemical process.
26. 题目: Effect of endogenetic dissolved organic matter on tetracycline adsorption by biochar
文章编号: N23053112
期刊: Environmental Science and Pollution Research
作者: Ying Xiong, Erping Bi
更新时间: 2023-05-31
摘要:
The endogenetic biochar–derived dissolved organic matter (BDOM) might interact with pollutants in the environment. In this study, tetracycline (TC) was selected as the representative pollutant, and corn straw biochar (pyrolyzed at 300 °C) was used as the adsorbent. Through batch experiments and microscopic characterization, the releasing kinetics of BDOM and its effect on TC adsorption on biochar were investigated. The results showed that BDOM with weaker aromaticity and higher molecular weight was preferentially released. BDOM release led to the decrease of specific surface area (from 4.02 to 1.83 m2/g), mesopore number, and aromaticity of biochar (H/C increased from 0.80 to 0.91) and consequently weakened the pore filling of TC on biochar, hydrophobic interaction, and π-π EDA (electron donor receptor) interaction between biochar and TC. In addition, the released BDOM could form a complex with TC in solution to prevent TC adsorption on biochar. Overall, the change in the structural properties of biochar caused by BDOM release had a greater impact on the inhibition of TC adsorption than that of BDOM and TC complexation in this study. Through EEM-PRARFAC, BDOM contained about 63% humic acid–like fluorescent component and 37% tryptophan-like fluorescent component; the former (logKb values were 7.31 and 6.48, respectively) had a stronger binding strength with TC than the latter (logKb was 6.45). The findings of this study could provide some useful evidence for the removal of organic pollutants in soil and water environments and biochar application in pollution remediation.
Graphical abstract
27. 题目: Impact Mechanisms of Humic Acid on the Transmembrane Transport of Per- and Polyfluoroalkyl Substances in Wheat at the Subcellular Level: The Important Role of Slow-Type Anion Channels
文章编号: N23053111
期刊: Environmental Science & Technology
作者: Siqian Liu, Jian Zhou, Jia Guo, Mengzhu Xue, Lina Shen, Sai Bai, Xiaoxue Liang, Tiecheng Wang, Lingyan Zhu
更新时间: 2023-05-31
摘要: Per- and polyfluoroalkyl substances (PFASs) have potential to accumulate in crops and pose health risks to humans, but it is unclear how the widely present organic matters in soil, such as humic acid (HA), affect their uptake and translocation in plants. In this study, hydroponic experiments were conducted to systematically disclose the impacts of HA on the uptake, translocation, and transmembrane transport at the subcellular level of four PFASs, including perfluorooctane sulfonic acid, perfluorooctanoic acid, perfluorohexane sulfonic acid, and 6:2 chlorinated polyfluoroalkyl ether sulfonate in wheat (Triticum aestivum L.). The results of the uptake and depuration experiments indicated that HA depressed the adsorption and absorption of PFASs in wheat roots by reducing the bioavailability of PFASs, and HA did not affect the long-range transport of PFASs to be eliminated via the phloem of wheat. However, HA facilitated their transmembrane transport in wheat roots, while the contrary effect was observed in the shoots. The inhibitor experiments coupled with transcriptomics analysis uncover that the increased transmembrane transport of PFASs stimulated by HA is mainly driven by the slow-type anion channel pathways interacting with Ca2+-dependent protein kinases (Ca2+-CDPK-SLAC1). The promoted transmembrane transport of PFASs might cause adverse effects on the plant cell wall, which causes further concerns.
28. 题目: Ambient Black Carbon reaches the Kidneys
文章编号: N23053110
期刊: Environment International
作者: Leen Rasking, Priyanka Koshy, Eva Bongaerts, Hannelore Bové, Marcel Ameloot, Michelle Plusquin, Katrien De Vusser, Tim S Nawrot
更新时间: 2023-05-31
摘要:
Background
Ultrafine particles, including black carbon (BC), can reach the systemic circulation and therefore may distribute to distant organs upon inhalation. The kidneys may be particularly vulnerable to the adverse effects of BC exposure due to their filtration function.
Objectives
We hypothesized that BC particles reach the kidneys via the systemic circulation, where the particles may reside in structural components of kidney tissue and impair kidney function.
Methods
In kidney biopsies from 25 transplant patients, we visualized BC particles using white light generation under femtosecond-pulsed illumination. The presence of urinary kidney injury molecule-1 (KIM-1) and cystatin c (CysC) were evaluated with ELISA. We assessed the association between internal and external exposure matrices and urinary biomarkers using Pearson correlation and linear regression models.
Results
BC particles could be identified in all biopsy samples with a geometric mean (5th, 95th percentile) of 1.80x103 (3.65x102, 7.50x103) particles/mm3 kidney tissue, predominantly observed in the interstitium (100%) and tubules (80%), followed by the blood vessels and capillaries (40%), and the glomerulus (24%). Independent from covariates and potential confounders, we found that each 10% higher tissue BC load resulted in 8.24% (p = 0.03) higher urinary KIM-1. In addition, residential proximity to a major road was inversely associated with urinary CysC (+10% distance: -4.68%; p = 0.01) and KIM-1 (+10% distance: -3.99%; p < 0.01). Other urinary biomarkers, e.g., the estimated glomerular filtration rate or creatinine clearance showed no significant associations.
Discussion
and Conclusion. Our findings that BC particles accumulate near different structural components of the kidney represent a potential mechanism explaining the detrimental effects of particle air pollution exposure on kidney function. Furthermore, urinary KIM-1 and CysC show potential as air pollution-induced kidney injury biomarkers for taking a first step in addressing the adverse effects BC might exert on kidney function.
29. 题目: The response mechanism of microorganisms to the organic carbon-driven formation of black and odorous water
文章编号: N23053109
期刊: Environmental Research
作者: Zhipeng Wei, Yaofei Xu, Yingying Shi, Xiaotian Zhou, Jie Lin, Aidong Ruan
更新时间: 2023-05-31
摘要:
The formation of black and odorous water is a complex process influenced by various factors such as organic matter and environmental conditions. However, there are limited studies on the role of microorganisms in water and sediment during the blackening and odorization process. In this study, we investigated the characteristics of black and odorous water formation by simulating organic carbon-driven black and odorous water through indoor experiments. The study revealed that the water turned black and odorous when DOC reached 50 mg/L and the microbial community structure in the water changed significantly during this process, with the relative abundance of Desulfobacterota increasing significantly and Desulfovibrio being the main dominant genus in Desulfobacterota. Additionally, we observed a notable decrease in the α-diversity of the microbial community in water and a considerable increase in microbial function of sulfur compounds respiration in water. In contrast, the sediment microbial community changed slightly, and the main functions of the sediment microbial community remained unchanged. The partial least squares path model (PLS-PM) suggested that organic carbon will drive the blackening and odorization process by affecting DO levels and microbial community structure and that the contribution of Desulfobacterota in water to the formation of black and odorous water was higher than that in sediment. Overall, our study provides insights into the characteristics of black and odorous water formation and suggests potential ways to prevent its formation by controlling DOC and inhibiting the growth of Desulfobacterota in water bodies.
30. 题目: Exploring the Complexities of Dissolved Organic Matter Photochemistry from the Molecular Level by Using Machine Learning Approaches
文章编号: N23053108
期刊: Environmental Science & Technology
作者: Chen Zhao, Xinyue Xu, Hongmei Chen, Fengwen Wang, Penghui Li, Chen He, Quan Shi, Yuanbi Yi, Xiaomeng Li, Siliang Li, Ding He
更新时间: 2023-05-31
摘要: Dissolved organic matter (DOM) sustains a substantial part of the organic matter transported seaward, where photochemical reactions significantly affect its transformation and fate. The irradiation experiments can provide valuable information on the photochemical reactivity (photolabile, photoresistant, and photoproduct) of molecules. However, the inconsistency of the fate of irradiated molecules among different experiments curtailed our understanding of the roles the photochemical reactions have played, which cannot be properly addressed by traditional approaches. Here, we conducted irradiation experiments for samples from two large estuaries in China. Molecules that occurred in irradiation experiments were characterized by the Fourier transform ion cyclotron resonance mass spectrometry and assigned probabilistic labels to define their photochemical reactivity. These molecules with probabilistic labels were used to construct a learning database for establishing a suitable machine learning (ML) model. We further applied our well-trained ML model to “un-matched” (i.e., not detected in our irradiation experiments) molecules from five estuaries worldwide, to predict their photochemical reactivity. Results showed that numerous molecules with strong photolability can be captured solely by the ML model. Moreover, comparing DOM photochemical reactivity in five estuaries revealed that the riverine DOM chemistry largely determines their subsequent photochemical transformation. We offer an expandable and renewable approach based on ML to compatibly integrate existing irradiation experiments and shed insight into DOM transformation and degradation processes.
31. 题目: Insights into the formation and stability of soil aggregates in relation to the structural properties of dissolved organic matter from various organic amendments
文章编号: N23053107
期刊: Soil and Tillage Research
作者: Kiattisak Sonsri, Akira Watanabe
更新时间: 2023-05-31
摘要:
Organic matter is an important determinant of soil aggregate formation and stability. However, the role of its structure, especially that of dissolved organic matter (DOM) from organic amendments (OAs), in the aggregation process remains imprecise. The purpose of this study was to understand the relationship between the chemical structure of water-extractable organic matter (WEOM), potential source of DOM from OAs, and their aggregate formation/stability functionality through model experiment. The WEOM samples were prepared from bark compost (BC), coffee residue compost (CRC), cattle manure compost (CMC), sewage sludge compost (SSC), fish cake (FC), and rapeseed oil cake (ROC) and characterized using high-performance size exclusion chromatography and 13C nuclear magnetic resonance and diffuse reflectance infrared Fourier transform (DRIFT) spectroscopies. An upland field soil was packed in glass columns and each WEOM solution or ultrapure water (Control) was applied repeatedly during a 30-day period. Aggregate size distribution (>2000, 500–2000, 250–500, 53–250, and <53 µm) was then measured and aggregate stability indices, mean weight diameter (MWD), and geometric mean diameter (GMD) were calculated. The addition of WEOM increased the distributions of soil mass and soil organic carbon (C) into the > 2000 µm aggregate fraction compared to Control treatment, and the ROC-, CRC-, and SSC-WEOM treatments resulted in greater MWD and GMD than Control and/or the other WEOM treatments. The % O-alkyl C (29–59% of total C) and the relative abundance of high-molecular-weight (HMW) fraction (>10 kDa; 2.3–7.1% of total) in WEOM correlated positively with the proportion of > 2000 µm aggregate fraction. The relative abundance of HMW fraction also correlated positively with MWD. These findings suggest that the high amounts of polysaccharides, suggested by % O-alkyl C and supported by DRIFT spectra, and/or other HMW components are desirable structural characteristics of WEOM for promoting macroaggregate formation and aggregate stability.
32. 题目: Construction of S-scheme Zn0.2Cd0.8S/biochar aerogel architectures for boosting photocatalytic hydrogen production under sunlight irradiation
文章编号: N23053106
期刊: Journal of Cleaner Production
作者: Chonghai Deng, Lulu Peng, Xiaohui Ling, Tao Wang, Rui Xu, Yibin Zhu, Chenchen Wang, Xuehui Qian, Lili Wang, Yiping Wu, Hanmei Hu, Yongsheng Han
更新时间: 2023-05-31
摘要:
Developing highly efficient, stable, and full-spectrum responsive non-precious photocatalyst is high desirable due to photocatalytic water splitting is a green technology for hydrogen evolution. In this work, a type of biochar-based composite photocatalysts is fabricated by a facile green microwave-assisted aqueous chemical deposition, which consists of monodispersed Zn0.2Cd0.8S nanoparticles (ZCS NPs) uniformly decorating on three-dimensional (3D) biochar aerogel (BA) derived from the biomass castoff tangerine peel. As-engineered ZCS/BA composite photocatalysts exhibit significantly strengthened photocatalytic activities under solar irradiation, in which the optimal 0.4ZCS/BA sample (0.4 represents the molar of ZCS) achieves the average photocatalytic hydrogen production efficiency of 10.52 mmol g−1∙h−1, being 24.5 folds higher than that of monolithic ZCS alloy. The boosted photocatalytic hydrogen evolution is ascribed to the synergistic effect on the heteroarchitecture with the closely interfacial interaction, which is beneficial for increasing the broad-spectrum sunlight absorption, promoting the photo-induced charge carriers separation efficiency, and accelerating the chemical reaction dynamic rate by the photothermal effect. The step-scheme (S-scheme) electron transfer mechanism for binary ZCS/BA heterojunction is proposed based on the experimental data and density functional theory (DFT) calculation. The study guides a practical approach to developing biochar-based composites for highly efficient utilization of agricultural biomass resources as well as conversion of solar energy to fuel in photocatalysis.
33. 题目: Preparation of P-doped biochar and its high-efficient removal of sulfamethoxazole from water: Adsorption mechanism, fixed-bed column and DFT study
文章编号: N23053105
期刊: Chemical Engineering Journal
作者: Yizhen Cheng, Jingrui Yang, Jimin Shen, Pengwei Yan, Shan Liu, Jing Kang, Lanbo Bi, Binyuan Wang, Shengxin Zhao, Zhonglin Chen
更新时间: 2023-05-31
摘要:
Heteroatom doping technology is of great significance for adsorption. However, the effect of P with relatively lower electronegativity (2.19) doped in the π-electron system and phosphorus-containing functional groups on the adsorption has always been neglected. Herein, P-doped biochar (PBC) was successfully synthesized via the in-situ activation method and applied in a bath experiment and a long-term fixed-bed dynamic adsorption for sulfamethoxazole (SMX) removal. Compared to pristine BC, the pHpzc, ash content and graphitization degree of PBC would be reduced significantly after phosphoric acid (H3PO4) was treated, but it gained a large specific surface area (SSA = 233 m2 g−1), as well as abundant surface functional groups. In the adsorption process, the behavior of SMX adsorbed onto PBC conformed to pseudo-second-order kinetic and Langmuir models in batch experiments. Its excellent adsorption capacity (148.62 mg g−1) benefited from a large number of functional groups. DFT calculation indicates that the C3-P-O configuration mainly promoted the adsorption of SMX. It is speculated that the hydrogen-bond interaction between SMX and C3-P-O was the main adsorption mechanism, and electrostatic and π-π EDA interaction also contributed. Various parameters during the dynamic process were thoroughly explored. The saturated adsorption capacity of the column would be promoted when influent SMX concentration and bed depth increased, but negatively correlated with solution pH and influent rate. Moreover, PBC fixed-bed column for SMX removal was well fitting Thomas, Yoon-Nelson and BDST models, which provided a predictable strategy for practical application.
34. 题目: Anthropogenic Activities Generate High-Refractory Black Carbon along the Yangtze River Continuum
文章编号: N23053104
期刊: Environmental Science & Technology
作者: Lize Meng, Weiyue Hao, Chu Zhao, Shuaidong Li, Jingya Xue, Jianhong Li, Luyao Tu, Tao Huang, Hao Yang, Zhaoyuan Yu, Linwang Yuan, Changchun Huang
更新时间: 2023-05-31
摘要: Combustion-driven particulate black carbon (PBC) is a crucial slow-cycling pool in the organic carbon flux from rivers to oceans. Since the refractoriness of PBC stems from the association of non-homologous char and soot, the composition and source of char and soot must be considered when investigating riverine PBC. Samples along the Yangtze River continuum during different hydrological periods were collected in this study to investigate the association and asynchronous combustion drive of char and soot in PBC. The results revealed that PBC in the Yangtze River, with higher refractory nature, accounts for 13.73 ± 6.89% of particulate organic carbon, and soot occupies 37.53 ± 11.00% of PBC. The preponderant contribution of fossil fuel combustion to soot (92.57 ± 3.20%) compared to char (27.55 ± 5.92%), suggested that fossil fuel combustion is a crucial driver for PBC with high soot percentage. Redundancy analysis and structural equation modeling confirmed that the fossil fuel energy used by anthropogenic activities promoting soot is the crucial reason for high-refractory PBC. We estimated that the Yangtze River transported 0.15–0.23 Tg of soot and 0.15–0.25 Tg of char to the ocean annually, and the export of large higher refractory PBC to the ocean can form a long-term sink and prolong the residence time of terrigenous carbon.
35. 题目: Unusual, hierarchically structured composite of sugarcane pulp bagasse biochar loaded with Cu/Ni bimetallic nanoparticles for dye removal
文章编号: N23053103
期刊: Environmental Research
作者: Mengqi Tang, Youssef Snoussi, Arvind K Bhakta, Mohamed El Garah, Ahmed M Khalil, Souad Ammar, Mohamed M Chehimi
更新时间: 2023-05-31
摘要:
Biochar-supported nanocatalysts emerged as unique materials for environmental remediation. Herein, sugarcane pulp bagasse (SCPB) was wet-impregnated with Cu(NO3)23H2O and Ni(NO3)26H2O, then pyrolyzed at 500 °C, under N2, for 1 h. We specifically focused on sugarcane pulp instead of SCB and biochar materials. The metal nitrate to biomass ratio was set at 0.5, 1, and 2 mmol/g, with Cu/Ni initial ratio = 1. The process provided hierarchically structured porous biochar, topped with evenly dispersed 40 nm-sized CuNi alloy nanoparticles (SCPBB@CuNi). The biochar exhibited an unusual fishing net-like structure induced by nickel, with slits having a length in the 3–12 μm range. Such a fishing net-like porous structure was obtained without any harsh acidic or basic treatment of the biomass. It was induced, during pyrolysis, by the nanocatalysts or their precursors. The CuNi nanoparticles form true alloy as proved by XRD, and are prone to agglomeration at high initial metal nitrate concentration (2 mmol/g). Stepwise metal loading was probed by XPS versus the initial metal nitrate concentration. This is also reflected in the thermal gravimetric analyses. The SCPBB@CuNi/H2O2 (catalyst dose: 0.25 g/L) system served for the catalyzed removal of Malachite Green (MG), Methylene Blue (MB), and Methyl Orange (MO) dyes (concentration = 0.01 mmol/L). Both single and mixed dye solutions were treated in this advanced oxidation process (AOP). The dyes were removed in less than 30 min for MG and 3 h for MB, respectively, but 8 h for MO, therefore showing selectivity for the degradation of MG, under optimized degradation conditions. The catalysts could be collected with a magnet and reused three times, without any significant loss of activity (∼85%). AOP conditions did not induce any nanocatalyst leaching.
To sum up, we provide a simple wet impregnation route that permitted to design highly active Fenton-like biochar@CuNi composite catalyst for the degradation of organic pollutants, under daylight conditions.
36. 题目: Soil organic carbon is a key determinant of CH4 sink in global forest soils
文章编号: N23053102
期刊: Nature Communications
作者: Jaehyun Lee, Youmi Oh, Sang Tae Lee, Yeon Ok Seo, Jeongeun Yun, Yerang Yang, Jinhyun Kim, Qianlai Zhuang, Hojeong Kang
更新时间: 2023-05-31
摘要:
Soil organic carbon (SOC) is a primary regulator of the forest–climate feedback. However, its indicative capability for the soil CH4 sink is poorly understood due to the incomplete knowledge of the underlying mechanisms. Therefore, SOC is not explicitly included in the current model estimation of the global forest CH4 sink. Here, using in-situ observations, global meta-analysis, and process-based modeling, we provide evidence that SOC constitutes an important variable that governs the forest CH4 sink. We find that a CH4 sink is enhanced with increasing SOC content on regional and global scales. The revised model with SOC function better reproduces the field observation and estimates a 39% larger global forest CH4 sink (24.27 Tg CH4 yr−1) than the model without considering SOC effects (17.46 Tg CH4 yr−1). This study highlights the role of SOC in the forest CH4 sink, which shall be factored into future global CH4 budget quantification.
37. 题目: Influence of natural organic matters on fate of polystyrene nanoplastics in porous media
文章编号: N23053101
期刊: Science of the Total Environment
作者: Mingzhi Zhang, Jun Hou, Jun Xia, Yuan Zeng, Lingzhan Miao
更新时间: 2023-05-31
摘要:
Natural organic matters (NOMs) are widely present in aqueous environments. The effect of NOMs on the fate of nanoplastics that are gradually receiving widespread attention in porous media needs to be noticed, but relevant research is lacking. To fill this gap, the present study focused on elucidating the influence of NOMs and metal cations with varying concentrations upon the transport, long-term release, and particle fracture of polystyrene nanoplastics (PS-NPs) in saturated porous media. The adsorption, transport, long-term release, and particle fracture tests were conducted. A mathematical model and the Derjaguin-Landau-Verwey-Overbeek (DLVO) theory were used in this research. NOMs could adsorb onto PS-NPs leading to a reduction in the PS-NPs' zeta potential and an increase in the energy barrier and steric hindrance between PS-NPs and quartz sand, ultimately facilitating the transport of PS-NPs through porous media. On the other hand, an increase in concentration and valence of metal ions enhanced the PS-NPs' zeta potential, resulting in PS-NPs' aggregation and increased size when NOMs were present. This reduced the energy barrier between porous media and PS-NPs, resulting in increased blocking and straining, allowing decreased PS-NPs' transport. Long-term release tests demonstrated release ability and mobilities of PS-NPs decreased as the enhanced NOM concentration, addition of metal cations, and decreased valence of metal ions, in agreement with the transport test findings. In the research about particle fracture, NOMs were found to inhibit the fracture of PS-NPs by adsorbing on their surface to protect them from fracture. Metal cations and increased metal cation valence promoted the fracture of released PS-NPs when NOMs were present by promoting NOM aggregation and thus hindering the protection of NOMs for the nanoplastics.
38. 题目: Long-term fertilization and plastic film mulching modify temporal incorporation of 13C/15N-labelled particulate organic matter
文章编号: N23053007
期刊: European Journal of Soil Science
作者: Xinxin Jin, Roland Bol, Tingting An, Lihong Zheng, Shuangyi Li, Jiubo Pei, Jingkuan Wang
更新时间: 2023-05-30
摘要: Plastic film mulching (PFM) is critical for agricultural planting and maximizing production in semiarid and arid areas. Particulate organic matter (POM) is assumed to be a sensitive indicator of evaluating the effects for different agricultural practices on soil fertility and the soil organic carbon (SOC) pool. Soil aggregates have the function of “wrap” and protect the POM stored in them. However, there is limited information regarding how PFM and fertilization jointly influence the dynamic changes of newly added stalk-derived POM in brown earth. Consequently, an in-depth study of the fate of carbon (C) and nitrogen (N) derived from maize stalk residues within the particulate organic carbon (POC) and particulate organic nitrogen (PON) fractions in soil aggregates was undertaken. Its outcome would contribute to better predictions on the active organic matter components sequestrated in the soil. The dynamics and accumulation of newly added maize stalk C and N as POC and PON in different soil aggregates (using the dry sieving method divided into >2, 1–2, 0.25–1 and <0.25 mm) were analyzed by an in-situ 13C15N-tracing technique under PFM and different fertilization treatments. Over 360 days of cultivation, the POC and PON contents were significantly (P < 0.05) higher in the nitrogen (N) and organic manure (M) treatments than in the MN (manure combined with nitrogen) and Control treatments. The PFM treatment accelerated the decomposition of maize stalk C in the N fertilizer treatment, with an increase of 64% in stalk-derived POC in the 1-day cultivation period. Stalk-derived POM tended to accumulate in <0.25 mm microaggregates in the early cultivation period, and then decreased rapidly with the extension of the cultivation period affected by PFM coupled with fertilization. However, stalk-derived POM accumulation in macroaggregates (>0.25 mm) fluctuated over the 360-day cultivation period. Accordingly, PFM application and fertilization practices had important effects on the accumulation of newly added stalk-derived POM in soil aggregates. We conclude that the accumulation of maize residue POM was primarily affected by soil fertilization type rather than by the presence or absence of PFM. These results provide new insights into agricultural management strategies for improving soil carbon sequestration capacity.
39. 题目: The fate of photoreduction of Hg(II) in aqueous solution by aged microplastic particles and their leached DOM
文章编号: N23053006
期刊: Science of the Total Environment
作者: Xu Yang, Chi Ma, Zihao Li, Tantan Wang, Xin Wen, Yubo He, Wenhao Chen, Xiaohong Shi, Chang Zhang
更新时间: 2023-05-30
摘要:
The transformation of Hg(II) and Hg(0) in aqueous systems governs the speciation and biogeochemical cycling of Hg. However, with the increasing amount of microplastics in the aqueous environment, little is known about the different effects of microplastic particles and their leached DOM on the photoreduction of Hg(II) to Hg(0) after long-term photoaging. In this study, we found that aged microplastic particles significantly inhibited the photoreduction efficiency (6.40–15.64 %) of Hg(II) compared to the control without any microplastic (31.02 %) and pristine microplastic particles (9.95–34.10 %). This inhibition was due to the adsorption of Hg by the microplastic particles, which decreased the amount of available Hg(II) (Hg(II)RED) that could participate in the photoreduction reaction. The characteristics of aged microplastic particles also indicated rougher surfaces and more oxygen-containing functional groups after photoaging, which may enhance their adsorption capacity compared to pristine microplastic. Interestingly, the photoreduction efficiency of Hg(II) was 11.58–53.28 % higher in the presence of microplastic leach DOM compared to the control. With increasing age, the microplastic leach DOM obviously promotes the photoreduction of Hg(II). Free radical inhibition and electron paramagnetic resonance spectra demonstrated that O2
− in microplastic leach DOM contributed to the photoreduction of Hg(II) under light irradiation. Moreover, X-ray absorption near edge structure analyses demonstrated that microplastic leach DOM produced Hg(I) as the primary photoproduct, accounting for 43.17 % of the total Hg in the photoreaction solution and likely reducing it to Hg(0). This study provides novel insights into forecasting the synthesized risks of microplastic aging in the biogeochemical cycle of Hg within aqueous environments.
40. 题目: Influences of peanut hull-derived biochar, Trichoderma harzianum and supplemental phosphorus on hairy vetch growth in Pb- and Zn-contaminated soil
文章编号: N23053005
期刊: Environmental Geochemistry and Health
作者: Elham Jam, Saeid Khomari, Ali Ebadi, Esmaiel Goli-Kalanpa, Akbar Ghavidel
更新时间: 2023-05-30
摘要:
In the present study, in order to improve the growth performance of hairy vetch (Vicia villosa Roth., Local landrace from Ardabil, Iran) seedlings grown in the soil contaminated with heavy metals Pb and Zn, our attention was directed toward the application of biochar, inoculation with conidial suspension of Trichoderma harzianum Rifai—T22 and management of phosphorus (P) nutrition. Heavy metal toxicity reduced leaf greenness, membrane stability index, maximum quantum yield of PSΙΙ (Fv/Fm), P concentration and uptake in plant tissues and root and shoot biomass, but increased Pb and Zn concentration and uptake in root and leaf, H2O2 and malondialdehyde content and CAT and POX activity in the leaves. The application of biochar, inoculation with Trichoderma fungus and P supplementation increased the shoot P content, which might contribute to the alleviation of P insufficiency and a subsequent elevation in P transfer to aboveground biomass, and eliminated the toxicity of heavy metal on hairy vetch plants, which was revealed in reducing oxidative stress and enhancing plant growth performance. The biochar considerably increased Zn immobilization, while being able to slightly stabilize Pb. Co-application of Trichoderma and 22 mg P/kg soil (22P) increased the concentration and uptake of Zn in the roots and decreased the translocation of this element to the shoots, especially when biochar was not amended. Although the biochar and P inputs could compensate the negative Trichoderma effects, the results suggested that biochar application in combination with fungal inoculation and 22-P supplementation could not only increase hairy vetch growth performance but also decline heavy metal uptake to ensure the production of a forage crop in soils polluted with heavy metals based on the nutritional standards of livestock.