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61. 题目: A legume-grass cover crop builds mineral-associated organic matter across variable agricultural soils 文章编号: N25020310 期刊: Soil Biology and Biochemistry 作者: R Kent Connell, Timothy Y James, Jennifer Blesh 更新时间: 2025-02-03 摘要: Soil organic matter (SOM) fractions convey unique functions in agroecosystems, but the degree to which cover crops build multiple fractions of SOM and increase soil C storage is understudied. Particulate organic matter (POM) releases nutrients through microbial decomposition, whereas mineral-associated organic matter (MAOM) is associated with long-term C storage. We conducted a greenhouse experiment using 13C to trace the transfer of C from four cover crop treatments – cereal rye (Secale cereale), crimson clover (Trifolium incarnatum), a rye-clover mixture, and a no cover crop fallow – into these two SOM fractions in soils from 10 working farms that varied in texture, management history, and soil microbial communities. On average, MAOM C was 7.4% higher in the mixture treatment than in the fallow; however, this was not a significantly greater increase than in the cereal rye treatment. The amount of C transferred to MAOM and POM increased with cover crop biomass and soil C content, and was also moderated by fungal community composition. When compared to the rye treatment, the mixture provided a threefold greater transfer of C and a 2% greater transfer of nitrogen from POM to the more stable MAOM fraction, which is associated with long-term C sequestration. Overall, our results suggest that cover crop mixtures are a useful management strategy to increase agroecosystem multifunctionality. When grown in soils with high biological activity, mixtures can simultaneously stabilize C in soil while also increasing internal N cycling capacity of agroecosystems. |
62. 题目: Insight into enhanced tetracycline photodegradation by hematite/biochar composites: Roles of charge transfer, biochar-derived dissolved organic matter and persistent free radicals 文章编号: N25020309 期刊: Bioresource Technology 作者: Qian Liu, Zhuoyue Wang, Ting Chang, Tingxin Wang, Yafeng Wang, Zhilei Zhao, Meifeng Li, Jue Liu 更新时间: 2025-02-03 摘要: The combination of hematite and biochar significantly accelerated tetracycline (TC) removal under visible light irradiation. The kinit of TC removal with Hem/BC-5 reached 0.103 min−1, 3.8 and 6.1 times faster than those with hematite and biochar, attributed to boosting free radicals. The enhanced light absorption and charge transfer helped generate more H2O2 and •OH through 2e− oxygen reduction and direct valence band (VB) oxidation. Persistent free radicals (PFRs) on biochar helped generate H2O2. Biochar as electron shutter facilitated Fe3+/Fe2+ redox cycling and triggered more efficient photo-Fenton reaction. Biochar-derived dissolved organic matter (DOM) helped generate 3DOM*, a reactive intermediate to produce H2O2, •OH, and 1O2. Hem/BC composites have excellent photoactivity for the degradation of TC in different water matrixes under visible light irradiation. The degradation pathway was proposed based on theoretical calculation and detected degradation intermediates. These findings contribute to the development of biochar-based catalysts for organic pollutants removal. |
63. 题目: Synthesis of MnFe2O4-biochar with surficial grafting hydroxyl for the removal of Cd(II)-Pb(II)-Cu(II) pollutants: Competitive adsorption, application prospects and binding orders of functional groups 文章编号: N25020308 期刊: Journal of Environmental Management 作者: Yipeng Wang, Zetao Bing, Qingliang Zhao, Kun Wang, Liangliang Wei, Junqiu Jiang, Jing Ding, Miao Jiang, Ruiyuan Xue 更新时间: 2025-02-03 摘要: A novel biochar material with magnetic modification by MnFe2O4 and surficial hydroxyl grafting (h-MFO-BC) was synthesized for capturing HMs (Cd, Pb and Cu) and their competition in composite systems was investigated. The modification of hydroxyl considerably improved the adsorption capacity of HMs. Chemisorption and monolayer and homogeneous reaction dominated adsorption processes. Moreover, a pronounced competitive adsorption effect between HMs was observed in composite systems. The order of selectivity by h-MFO-BC was Pb > Cu ≫ Cd. The distinction in the adsorption of HMs was related to different adsorption pathways and binding sequences of functional groups. Two-dimensional correlation spectroscopy revealed that Pb and Cu preferred to bind to the active sites (Mn/Fe-OH) on h-MFO-BC surface. Moreover, they could generate hydroxide precipitation more easily, which prevented further adsorption of Cd due to the occupation or coverage of binding sites and electrostatic repulsion. Furthermore, h-MFO-BC could be effectively regenerated and recycled and possessed fascinating performance in HMs removal from real water, indicating its potential for widespread applicability. This work provided a novel composite material for the treatment of HMs in wastewater or selective recovery of Pb and Cu and gave a new perspective on understanding the competition mechanisms between HMs on adsorbents. |
64. 题目: Unraveling the origin of Pd nanoparticles supported N–doped biochar derived from spent coffee ground for enhanced Suzuki coupling reaction activity 文章编号: N25020307 期刊: Journal of Environmental Chemical Engineering 作者: Hongwei He, Shuya Zhang, Jiawen Wu, An Cai, Zhoulin Ma, Luping Shen, Xingjin Zhang, Xiaobin Fan, Wenchao Peng, Yang Li 更新时间: 2025-02-03 摘要: To convert spent coffee ground into high–value products, a N–doped biochar supported palladium nanoparticles catalyst (PdNP–NB) was prepared and utilized for the Suzuki coupling reaction. PdNP–NB with high electron density can efficiently catalyze the Suzuki coupling reaction between iodobenzene and phenylboronic acid, achieving a biphenyl yield of 99.24 % within 12 min. Palladium (Pd) nanoparticles decorated catalyst possesses better catalytic activity compared with its counterparts with palladium oxide nanoparticles or Pd single atoms embedded N–doped biochar (PdO–NB or Pd1–NB). Density functional theory calculation and X–ray photoelectron spectroscopy analysis reveal that the high electron density of active sites accelerates the Suzuki coupling reaction. PdNP–NB has a higher electron density than PdO–NB and Pd1–NB, which endows it better catalytic activity. The high electron density of Pd, smaller particle size of nanoparticles and rich porous structure of the materials are proven to be three crucial factors affecting the overall activity. This work not only illustrates the transformation of spent coffee ground into high–value catalyst, solving the issue of domestic waste, but also provides insights for designing new catalysts toward the Suzuki coupling reaction. |
65. 题目: Forest thinning effects on soil carbon stocks and dynamics: Perspective of soil organic carbon sequestration rates 文章编号: N25020306 期刊: Catena 作者: Qing Qu, Hongwei Xu, Lin Xu, Chengming You, Bo Tan, Han Li, Li Zhang, Lixia Wang, Sining Liu, Zhenfeng Xu, Sha Xue, Minggang Wang 更新时间: 2025-02-03 摘要: Forest thinning has significantly changed the forest community composition and structure and affected soil microbial activity and carbon (C) cycling. However, how thinning affects the soil C stocks and dynamics, especially the accumulation rate of soil C (RCC) and the driving mechanism of thinning affecting RCC globally, has not yet been revealed. Here, we analyze the effects of forest type (coniferous, broadleaf, and mixed), thinning intensity (light: <33.3 %, moderate: 33.3–66.6 %, and heavy: >66.6 %), and recovery time (0–5, 6–10, and > 10 years) on the RCC by the 1056 data points. Our results showed that thinning increased soil C accumulation; in particular, thinning significantly increased soil C stocks (average value) in the 0–30 and 0–60 cm layers from 70.5 to 76.5 Mg/ha, and from 115.6 to 125.8 Mg/ha, respectively, compared to the un-thinning treatments (control). Furthermore, the RCC in coniferous forests (2.3 Mg/ha yr−1) was higher than that in mixed forests (1.3 Mg/ha yr−1) in 0–60 cm layer. Additionally, the RCC decreased with thinning intensity and recovery time. Finally, the RCC had significant positive relationships with soil pH, whereas initial soil C stock, thinning intensity, and average annual temperature were important factors affecting the RCC. In conclusion, thinning increased the accumulation of soil C in global forest ecosystems, but RCC decreased with increasing thinning intensity and recovery time at the global scale. The results enhance our understanding of the carbon cycle in forest ecosystems during thinning processes. |
66. 题目: Plateau pika (Ochotona curzoniae) bioturbation triggers soil organic carbon loss by altering plant inputs and soil properties and their control on microbial composition 文章编号: N25020305 期刊: Catena 作者: Xiaozheng Wang, Jiena Li, Jie Li, Zhenggang Guo, Xiaopan Pang 更新时间: 2025-02-03 摘要: The loss of soil organic carbon (SOC) induced by plateau pika (Ochotona curzoniae) bioturbation has been widely reported. However, due to the complex composition of SOC and the combined impacts of pika bioturbation on above- and below-ground organisms, the underlying mechanisms driving SOC loss are not well understood. To better understand the mechanisms of SOC dynamics in response to pika bioturbation, this study measured SOC fractions, plant biomass, soil properties, microbial community composition, and SOC mineralization from three surface types: new bare patches (NP), old re-vegetated patches (OP), and original vegetation (OV) in an alpine meadow. The results showed that pika bioturbation decreased particulate organic carbon (POC) content while increasing the percentage of POC, which was attributed to increased exogenous carbon (C) input from vegetation capture despite a decrease in total plant biomass. However, both the content and percentage of mineral-associated organic carbon (MAOC) decreased, which can be explained by higher decomposition rates due to increased fungal abundance, a higher fungi:bacteria ratio, and greater activity of oligotrophic microorganisms. Moreover, higher SOC cumulative mineralization proportions (Cm/SOC) and POC:MAOC ratios were observed under pika bioturbation, indicating a lower stability of C pool. The higher Cm/SOC suggested the nutrients were released into the soil more quickly, which explained why pika bioturbation increased soil microbial activity, mainly alleviating P limitation. The structural equation model further confirmed these findings. Therefore, pika bioturbation enhanced the contribution of POC to the SOC pool and improved soil nutrient cycling, but it could not offset the negative effects of reduced SOC stability and increased CO2 emissions. Our findings provide insights into designing sound ecological management strategies for alpine meadows ecosystems. |
67. 题目: Predominant effects of soil organic carbon quality on phosphatase activity in upland Ultisols under long-term fertilizations 文章编号: N25020304 期刊: Geoderma 作者: Yunbin Jiang, Dexu Kuang, Wei Li, Cheng Han, Huan Deng, Kailou Liu, Shangshu Huang, Wenhui Zhong 更新时间: 2025-02-03 摘要: Understanding phosphorus (P) mobilization in “legacy P”-rich croplands is critical for sustainable agricultural P management. However, the role of soil organic carbon (SOC) quality (i.e., biochemical recalcitrance) in regulating the enzyme activity associated with microbial mineralization of organic P in such environments has not been extensively investigated. Therefore, in this study, upland Ultisols subjected to seven different fertilization regimens (i.e. no fertilizer, chemical N, P, NP, and NPK fertilizer, swine manure, and NPK plus swine manure) for 35 years were collected to clarify and quantify the effect of SOC quality on acid (ACP) and alkaline phosphatase (ALP) activities. The ratio between labile and recalcitrant C, an index of SOC quality, increased by 15.5 %– 22.9 % with manure application compared with the non-fertilized control, whereas it decreased by 1.94 %–18.5 % under chemical fertilizations. ACP activity was determined to be 3–6-fold greater than ALP activity in the same soil, and both were significantly greater under manure fertilization than the other regimens. A significant positive correlation was observed among SOC quality, phosphatase activities, the abundances of their encoding genes, and the compositional dissimilarities of corresponding functional bacterial communities. Soil nutrient content, SOC quality, and functional gene abundance were the predominant influencing factors regulating ACP activity rather than soil pH, nutrient stoichiometry, and the composition of functional bacterial community. This finding suggests that the increased ACP activity was strongly associated with the proliferation of functional taxa dominated by copiotrophs. In contrast, soil pH and the composition of functional bacterial community were the primary regulators of ALP activity, suggesting a mitigation of acidity-induced inhibition that promoted its enhancement. The findings of this study provide an empirical basis for manipulating microbial mineralization of organic P through the application of labile organic materials to maintain P bioavailability in fertilized croplands. |
68. 题目: A methodological study on the analysis of organic matter associated with iron oxides in marine sediments 文章编号: N25020303 期刊: Applied Geochemistry 作者: Milad Ezzati, Yves Gélinas 更新时间: 2025-02-03 摘要: Coastal shelves significantly contribute to the burial of natural organic matter (NOM) in marine sediments, with about 21.5 ± 8.6% of NOM associated with reactive iron oxides, which preserve NOM from biodegradation. Quantifying this preserved NOM requires a method to release bound carbonaceous molecules from iron minerals. The citrate-bicarbonate-dithionate (CBD) method is commonly used to liberate NOM from iron oxides through reductive dissolution. This method includes a control experiment using an NaCl solution to distinguish NOM associated with iron oxides from that leaching out from other minerals. This study aims to determine if desorbed NOM during the control experiment comes from other minerals or is loosely bound to iron oxides. We synthesized lepidocrocite (γ-FeOOH) in the presence and absence of plankton-extracted NOM to mimic sorption and conducted similar experiments on kaolinite, montmorillonite, and their mixture, representing common clay minerals in sediments. Quantifying the carbon content revealed that NOM associated with γ-FeOOH is 1.5–9.0 times greater than with other minerals. Post-treatment results indicate a 22.2%–42.7% loss of NOM associated with iron oxides, suggesting that deducting NOM lost during the control step underestimates the amount of carbon preserved by iron minerals in marine sediments. |
69. 题目: Soil nutrients and pH modulate carbon dynamics in particulate and mineral-associated organic matter during restoration of a Tibetan alpine grassland 文章编号: N25020302 期刊: Ecological Engineering 作者: Kaini Wang, Zhiwen Ma, Wenping Qin, Xiaoyan Li, Hongxiao Shi, Bagen Hasi, Xiang Liu 更新时间: 2025-02-03 摘要: Nature-based solutions have been proven effective in restoring soil organic carbon (SOC) levels within globally degraded grasslands. Nevertheless, the responses of C in particulate organic matter and mineral-associated organic matter to various grassland restoration strategies, especially in alpine grasslands, remain insufficiently addressed. In this study, we assessed the impacts of two nature-based solutions—grazing exclusion (natural restoration) and no-tillage reseeding (interventional restoration) on the dynamics of particulate organic C (POC) and mineral-associated organic C (MAOC) in an alpine grassland ecosystem on the eastern Tibetan Plateau. The results revealed that 12 years of restoration efforts significantly increased the content of soil total organic C (TOC) by 82.1–110.5 %. The SOC pool was primarily composed of MAOC, with its contribution varying from 52.3 % to 65.1 % across all experimental plots. After a 12-year restoration period, the contents of POC and MAOC in the bulk soil increased by 88.8–125.1 % and 46.8–51.8 %, respectively, indicating that POC is more responsive to restoration than MAOC. As a consequence, an enhanced proportion of POC within the TOC pool was observed at the reseeded plot. The accumulation of POC induced by the restoration process was primarily attributed to the enrichment of soil nutrient content, followed by the improved root quality. By comparison, the decline in soil pH emerged as a pivotal factor accounting for the increase in MAOC following restoration. The contents, stocks, and relative proportions of both POC and MAOC were generally comparable between the two restored plots. Nevertheless, the significantly higher contribution of MAOC to the TOC pool compared to POC at the naturally recovered plot implies that grazing exclusion favors the accumulation of stable C over labile C. Furthermore, we found that MAOC has not yet attained saturation levels at either of the restored plots. Notably, the naturally recovered plot exhibited a superior maximum capacity for MAOC compared to the reseeded plot. Our findings suggest that stratifying the SOC pool into POC and MAOC provides valuable insights into the dynamics, stability, saturation levels, and controlling factors of SOC in restored alpine grassland ecosystems. |
70. 题目: Chemodiversity of coastal seawater dissolved organic matter shaped by wastewater treatment plant effluent in Tokyo Bay, Japan 文章编号: N25020301 期刊: Applied Geochemistry 作者: Yanhui Cheng, Jibao Liu, Manabu Fujii, Qing-Long Fu 更新时间: 2025-02-03 摘要: The wastewater treatment plants (WWTPs) effluent can affect the chemodiversity of dissolved organic matter (DOM) in the aquatic systems. In this study, Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) was employed to reveal the effluence of WWTPs on the chemodiversity of coastal seawater DOM in Tokyo Bay, Japan. The average number of compounds identified in the background group with minor anthropogenic perturbation was 63.9% for the coastal seawater samples. Compared with the background samples, CHOS compounds were the predominant fraction of DOM in some coastal seawater receiving vast effluent from WWTPs. Additionally, the artificial sweetener sucralose was identified in coastal seawater samples. The intensity percentages of CHOS molecules in the coastal seawater linearly increased with the number of received WWTPs (R2 = 0.786, P < 0.05). These findings suggested that DOM molecular composition in Tokyo Bay coastal seawater had been highly influenced by upstream WWTPs effluents and highlighted the great potential of FT-ICR MS in tracing anthropogenically derived molecular signatures in the environments. |
71. 题目: Insights into the role of dissolved organic matter derived from paddy soils with different parent materials in the environmental behavior of heavy metal adsorbed by ferrihydrite 文章编号: N25020212 期刊: Environmental Pollution 作者: Tianming Wang, Bo Li, Leiye Sun, Wei Li, Meiqing Chen, Zhongbo Shang, Jiayan Wu, Linqing Liu, Jieyu Liu, Sheng Liu, Xuan Liu, Kejing Zhang, Pingxiao Wu, Nengwu Zhu, Zhi Dang 更新时间: 2025-02-02 摘要: The interaction between dissolved organic matter (DOM) and ferrihydrite (Fh) is a crucial process to control the environmental behavior of heavy metals (HMs) in soil environments, with DOM playing a particularly strong role in HMs fate. Since chemical properties of DOM vary based on different soil parent materials, the underlying impact of DOM-Fh associations on HMs binding remains unclear. This study systematically investigated the interactions between DOM from three soil parent materials (fluvial alluvium: FDOM, sand-shale: SDOM and granite: GDOM) and Fh, and meanwhile understand their effects on the environmental behavior of Cd and Pb under various environmental conditions. An increased Cd and Pb binding during DOM-Fh interactions was observed and attributed to the introduction of additional binding sites by the organic functional groups with a variety of metal affinities. Specifically, more aromatic carboxyl groups in FDOM and more aliphatic groups in SDOM strongly promoted the adsorption of Pb and Cd, respectively. Meanwhile, Higher pH and increased C/Fe also promoted HMs adsorption, particularly in the presence of DOM. Further characterization indicated that electrostatic attraction, ion exchange and surface complexation were primary mechanisms of HMs adsorption. These finding highlight the significant impact of DOM-Fh interactions, dependent on different soil parent materials, on the mobility and fate of HMs in soils, providing valuable insights into the role of DOM composition in influencing HMs contamination, which offer theoretical guidance for environmental management, especially in agricultural and contaminated soils. |
72. 题目: Mycorrhizal and nutrient controls of carbon sequestration in tropical rainforest soil 文章编号: N25020211 期刊: Geoderma 作者: Jie Chen, Xin Tang, Han Xu, Yanpeng Li, Adriana Corrales, Yide Li, Yakov Kuzyakov, Zhanfeng Liu, Shirong Liu 更新时间: 2025-02-02 摘要: Tree mycorrhizal associations have substantial consequences for soil organic carbon (SOC), but it remains unclear how nutrient availability will regulate the performance of arbuscular mycorrhizal (AM) and ectomycorrhizal (ECM) trees, and then consequently affect SOC sequestration in tropical forest soils. This study characterized the performances of AM and ECM trees, SOC content, and soil microbial functions under variable soil nitrogen (N) and phosphorus (P) content across an intact tropical rainforest based on the spatial dataset from a 60-ha dynamic plot and fitted statistical models to examine the mycorrhizal and nutrient controls on SOC stocks. ECM trees showed a better performance in soils containing higher N in total or in NH4+ forms and enhanced SOC content via increases in both species richness and basal area, which led to an increase in SOC as soil N content evaluated. AM trees had a greater basal area at N-richer (i.e., available N and NH4+) niches while a higher species richness under higher soil P levels (i.e., total and available P). The AM tree community patterns had inconsistent regulations on SOC, with basal area showing a positive while species richness exerting a negative effect on SOC content. Such counteracting effects from AM trees might attenuate SOC accumulation along the P gradient, resulting in a positive trend in SOC with soil total N:P ratios. As soil available P increased, species richness of AM trees increased, which was accompanied by a higher abundance of pathogens while a lower abundance of AM fungi. This indicated a decreased dependence of AM trees on mycorrhizal P acquisition, accompanied by the high susceptibility of roots to pathogen attacks, which may promote AM tree diversity. The performances of ECM trees were positively related to ECM fungi abundance, offering ECM trees a competitive P strategy and pathogen resistance. Summarily, our results suggest that both the basal area and species richness of mycorrhizal trees act as significant regulators for SOC sequestration along soil N or P gradient in tropical forests. Such findings provide a mechanistic understanding of soil C dynamics during vegetation changes under the rising global stoichiometric imbalance between N and P. |
73. 题目: Rhizodeposition stimulates soil carbon decomposition and promotes formation of mineral-associated carbon with increased clay content 文章编号: N25020210 期刊: Geoderma 作者: Md. Rumainul Islam, Bahareh Bicharanloo, Xing Yu, Balwant Singh, Feike A Dijkstra 更新时间: 2025-02-02 摘要: Rhizodeposition plays a key role in the formation and decomposition of soil organic carbon (SOC), but interactions with clay remain unclear. In this study, we examined how rhizodeposition contributes to SOC decomposition and the formation of particulate and mineral-associated organic C (POC and MAOC, respectively) in different soils with varying clay content. We collected soils from a grassland site covering three soil types and two depths, ranging in clay content from 15.6 to 66.4 %. We then grew ryegrass (Lolium perenne) in these soils in a glasshouse. After 76 days, plants were pulse-labelled with 13C-enriched CO2 to assess rhizodeposit C and SOC decomposition rates and the recovery of rhizodeposition in microbial biomass, POC and MAOC. The SOC decomposition showed no relationship with clay content, but a strong positive relationship with rhizodeposit C decomposition, indicating a positive rhizosphere priming effect. The rhizodeposition recovered in the MAOC was positively related to clay content and rhizodeposition recovered in microbial biomass. Our results suggest that microbial products from rhizodeposition are increasingly incorporated into MAOC with increased clay content. Our results further highlight the role of rhizodeposition for soil C decomposition and stabilisation and how both processes interact with clay content. |
74. 题目: Thermogravimetric data suggest synergy between different organic fractions and clay in soil structure formation 文章编号: N25020209 期刊: Geoderma 作者: Ivan Šimkovic, Andrej Hrabovský, Adela Joanna Hamerníková, Silvia Ihnačáková, Pavel Dlapa 更新时间: 2025-02-02 摘要: Although it has been recognized that soil structure formation affects soil organic carbon (SOC) sequestration, experimental data elucidating the relation between mechanical properties of soil structure and soil organic matter (SOM) stability are lacking. This study assesses the link between aggregate stability and SOM stability in lowland and hilly land soils of Central Europe. Overall, 39 topsoil samples were taken. Besides determining basic properties and nutrient availability, stability of soil aggregates was quantified using wet sieving (WS) and rainfall simulation (RS) procedures. The samples were analyzed by thermogravimetry and differential scanning calorimetry (TG-DSC). Besides significant correlations with basic soil properties and contents of selected nutrients, the aggregate stability data were linked to thermal processes, such as water desorption and SOM degradation. The RS values were significantly correlated (r > 0.7, p < 0.001) with the rate of water desorption (T < 200 °C) and SOM degradation (200 – 570 °C). Observed correlation pattern, with multiple maxima, suggests that aggregate stability is supported by clay and several SOM fractions, each showing different thermal stability. Significant correlations observed bellow 200 °C indicate that properties controlling soil specific surface area (SOM and clay) are important also for the aggregate stability. The 78 % of the variance observed in aggregate stability testing was explained by multilinear regression using weight loss rates recorded at selected temperatures (80, 130, 248, 401 and 455 °C) as predictors. We observed different relations between exothermic energy values, soil aggregate stability and thermal stability of SOM (SOC). Exothermic heat flux normalized with respect to SOC mass (energy density) indicates presence of stable organic fraction, as it showed correlation also with clay, which has positive effect on SOC stabilization. This is in line with the positive correlation between SOC energy density and aggregate stability. On contrary, normalizing the heat with respect to SOM mass indicates the content of labile organic components, as the correlations with clay or aggregate stability were insignificant. The TG-DSC data revealed that hilly land soils are depleted in fresh organic material, which is due to their genesis and the erosion intensified by tillage. |
75. 题目: Alkali extracts (humus-like substances) of straw have higher chemical activity than those of straw-derived biochar 文章编号: N25020208 期刊: Journal of Environmental Chemical Engineering 作者: Xinye Luo, Sen Dou, Nuo Jia, Song Guan, Dan Guo, Boyan Zhang, Dilimulati Yalihong 更新时间: 2025-02-02 摘要: Alkali extracts (AE), which are humus-like substances similar to natural humic substances (HS), can are derived from organic materials. These AE can be divided into acid-precipitable component (AP) and acid-soluble component (AS), both of which have the potential to improve soil quality. The differences among AEs from different materials, as well as those between AE and natural HS, influence their pathways for soil improvement. However, there are still debates regarding the specific differences. To address this issue, this study employed the traditional alkali - extraction method to obtain AE from straw, AE from biochar, and HS from soil, comparing their yields and compositions. The structural characteristics of soil humic acid (HA) and the AP were further analyzed using elemental composition, spectroscopic features, and thermogravimetric analysis. The results showed that the extraction rate of AE obtained from straw and biochar was significantly lower than that of soil HS. However, the structure of AP was simpler compared to that of soil HA. Among the two materials, the yield of AE from straw was 135.52 g kg−1, which was 35 times higher than that from biochar. Additionally, compared to biochar, the AP from straw exhibited a lower degree of condensation, higher carbonyl carbon content, and stronger alkyl carbon content and hydrophilicity, indicating higher chemical activity. These findings are critical for selecting and efficiently utilizing precursor materials for artificial HS, offering a novel strategy for enhancing the value of straw and biochar. |
76. 题目: Enhanced electron transfer for superior Cr(VI) removal in water using ball-milled aluminum/biochar composite with embedded structure: Efficiency and mechanism 文章编号: N25020207 期刊: Separation and Purification Technology 作者: Shiyu Zhang, Li Li, Zhiwei Zhao, Yu Li, Li Shen, Sai Zhang 更新时间: 2025-02-02 摘要: Biochar, being a cost-effective material, is widely used for water pollution control. However, the further degradation of most contaminants is limited due to the weak electron donor properties of raw biochar. Herein, we combined banana peel biochar with microscale zero-valent aluminum (mZVAl) using ball milling technology and demonstrated the effective chromium removal by the composite. Nearly complete removal of Cr(VI) could be achieved within 30 mins, alongside an impressive efficiency of 98.08% in total Cr elimination. Multiple parameters, including water matrices, composite ratio (mmZVAl/mbiochar), and initial solution pH, were explored. Additionally, detection of Cr species revealed that aqueous Cr(VI) was reduced to Cr(III) via chemisorption, followed by the formation of Cr(OH)3, which adhered to the surface of the composite. Structural analysis showed that the pristine mZVAl deformed into the plate-like structure under mechanical forces, with biochar distinctly embedded in the mZVAl matrix, increasing lattice spacings. Mechanistic studies suggested that mZVAl acted as the ‘electron donor’, while biochar functioned as the ‘electron shuttle’, accelerating electron transfer through galvanic cell structures. This study clarifies the electron-dominated mechanism in Cr(VI) removal and provides technical support for heavy metal elimination. |
77. 题目: Temperature seasonality regulates organic carbon burial in lake 文章编号: N25020206 期刊: Nature Communications 作者: Shengfang Zhou, Hao Long, Weizhe Chen, Chunjing Qiu, Can Zhang, Hang Xing, Jingran Zhang, Liangqing Cheng, Cheng Zhao, Jun Cheng, Philippe Ciais 更新时间: 2025-02-02 摘要: Organic carbon burial (OCB) in lakes, a critical component of the global carbon cycle, surpasses that in oceans, yet its response to global warming and associated feedbacks remains poorly understood. Using a well-dated biomarker sequence from the southern Tibetan Plateau and a comprehensive analysis of Holocene total organic carbon variations in lakes across the region, here we demonstrate that lake OCB significantly declined throughout the Holocene, closely linked to changes in temperature seasonality. Process-based land surface model simulations clarified the key impact of temperature seasonality on OCB in lakes: increased seasonality in the early Holocene saw warmer summers enhancing ecosystem productivity and organic matter deposition, while cooler winters improved organic matter preservation. The Tibetan Plateau’s heightened sensitivity to climate and ecosystem dynamics amplifies these effects. With declining temperature seasonality, we predict a significant slowdown or reduction in OCB across these lake sediments, leading to carbon emissions and amplified global warming. |
78. 题目: Enhanced adsorption for aqueous lead (II) by red mud-modified biochar via microwave-assisted hydrothermal carbonization and K2CO3 activation: Performance and mechanism 文章编号: N25020205 期刊: Separation and Purification Technology 作者: Baofeng Wang, Yaxin Guo, Yunxiao Chen, Mukun Xue, Xutao Song, Yanxia Guo, Fangqin Cheng 更新时间: 2025-02-02 摘要: In this study, red mud-modified biochar (AMHC) derived from low-cost corncob (CC) and red mud (RM) was successfully prepared by microwave-assisted hydrothermal carbonization (MHTC) and K2CO3 activation. The effect of RM and K2CO3 activation on the characteristics of AMHC for lead (Pb) (II) was innovatively investigated. The results showed that adding RM could promote the characteristics of AMHC obviously, and when the mass ratio of CC to RM was 8:2, AMHC exhibited the highest special surface area of 591.91 m2/g and the highest total pore volume of 0.49 cm3/g. And when the mass ratio of CC to RM was 5:5 (AMHC-C5R5), AMHC exhibited the highest magnetic strength of 30.85 emu/g, which was beneficial for separating of them from aqueous solutions by magnetic separation. Moreover, the results of batch adsorption experiment also showed that AMHC-C5R5 exhibited a maximum adsorption capacity of 350.28 mg/g at 45 °C, and this process was dominated by chemisorption. Interestingly, for AMHC without added RM, the adsorption process was non-spontaneous when the initial concentration of Pb (II) exceeded 200 mg/L, while for AMHC-C5R5, the adsorption was still spontaneous until the initial concentration of Pb (II) reach 500 mg/L. Furthermore, the results also indicated that –COOH, –OH, Fe3O4 and Fe2O3 on the surface of AMHC could promote electrostatic adsorption between Pb (II) and AMHC. And the adsorption mechanisms included not only ion exchange and electrostatic interaction, but also precipitation, complexation, and pore filling as well. |
79. 题目: Synergistic enhancement in ultra-trace thallium(I) removal using the titanium dioxide/biochar composite 文章编号: N25020204 期刊: Journal of Environmental Management 作者: Juanxi Huang, Jianying Mo, Ziyi Deng, Yirong Deng, Shenglin Mai, Yuan Xie, Canbin Zhong, Jianyou Long, Gaosheng Zhang, Ling Zhang, Tangfu Xiao, Huosheng Li 更新时间: 2025-02-02 摘要: Thallium (Tl), recognized for its high toxicity, is subject to stringent international regulations regarding its permissible concentrations at ultra-trace levels. In this study, titanium dioxide (TiO2) was integrated with potassium (K)-rich biochar to create TiO2/biochar (TiO2/BC) composites for synergistic enhancement in ultra-trace Tl(I) removal, focusing on achieving concentration below the rigorous local threshold of 0.1 μg/L for drinking water. The Tl(I) adsorption behavior of TiO2/BC was thoroughly investigated, along with characterizing the mechanisms behind Tl(I) removal. The material prepared at a TiO2/BC mass ratio of 1:2 demonstrated high efficiency in lowering Tl(I) concentrations, showing resilience against interference from coexisting ions at concentrations ranging from 1 to 100 mM. Actual wastewater from polluted river water containing Tl was successfully treated to meet regulatory limits, highlighting the practical applicability of the composites. The composites displayed a remarkable maximum adsorption capacity of 1152 mg/g at a material dosage of 0.1 g/L, surpassing most materials reported. The underlying Tl(I) removal mechanisms include inner-sphere surface complexation, cation exchange between K+ and Tl+, and electrostatic adsorption. Superior to individual components, the TiO2/BC composite benefits from an enlarged specific surface area and K⁺-based ion-exchange interactions. Tl capture was also found to have a linearly positive correlation with the K release from the composites. Overall, this study contributes to a better understanding of the interaction between titanium oxides and K-rich biochar, offering a promising approach for remediating water sources contaminated with ultra-trace levels of Tl. |
80. 题目: Air-filled porosity, its connectivity and relation to particulate organic matter in intact soil cores controls carbon emissions near saturation 文章编号: N25020203 期刊: Soil and Tillage Research 作者: Elsa Coucheney, Emilien Casali, Nicholas Jarvis, Johannes Koestel 更新时间: 2025-02-02 摘要: In wet soils, oxygen (O2) transport in large structural pores that drain close to saturation limits SOC mineralization and C emissions. However, these effects are still poorly understood because in standard incubation experiments soils are sieved and structural pore networks are destroyed. Our objective was to investigate the effects of soil structure on C mineralization rates under wet soil conditions. We measured CO2 emissions from intact soil cores of contrasting structure taken from conventional tillage vs. no-till treatments in laboratory incubations at pressure heads ranging from saturation to −30 cm. At each drainage step, we used X-ray CT to quantify various metrics of the geometry and topology of air, soil matrix and particulate organic matter (POM). We show that CO2 emissions are regulated by the air-filled porosity connected to the soil surface, as well as by the area of the interface between this connected air phase and the soil matrix and the volume of the matrix located within 2–3 millimetres of the interface and POM in this “active” zone. All four of these variables increase concomitantly with air-entry, although in the case of no-till soils, CO2 emissions increased most rapidly during initial drainage. We attributed this to the more heterogeneous “space-filling” pore structure and a larger fraction of bio-pores found in the no-till cores. These results should help to support the development of improved models of SOC turnover taking into account the effect of soil structure and soil management. |
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