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1. 题目: Legume introduction increases soil organic carbon in grassland via regulation of microbial metabolism regardless of phosphorus fertilization
文章编号: N25032309
期刊: Geoderma
作者: Meiqi Guo, Tongtian Guo, Gaowen Yang, Nan Liu, Jiqiong Zhou, Yingjun Zhang
更新时间: 2025-03-23
摘要: Introducing legumes into grasslands can enhance soil organic carbon (SOC) storage, but high phosphorus (P) requirement of legume nitrogen (N) fixation may accelerate soil P depletion. As a result, P fertilizers are often applied to improve legume performance. However, the effects of legume introduction and P availability on SOC storage in grasslands remain poorly understood. In this study, we investigated how legume introduction and P fertilization influence SOC physical fractions and associated microbial metabolic activities, based on a ten-year field experiment. Our results showed that legume introduction increased mineral-associated organic carbon (MAOC) by 7.4 % and total SOC by 5.7 % compared to grasslands without legume introduction. This enhancement can be attributed to the improved soil substrate quality (lower carbon to nitrogen ratio) and enhanced microbial carbon (C) limitation (relative microbial nutrient limitation calculated using vector analysis based on ecoenzymatic stoichiometric theory models), which led to higher microbial carbon use efficiency (CUE) and lower microbial metabolic quotient (qCO2). Phosphorus fertilization reduced microbial biomass and qCO2 by increasing microbial C limitation, thereby leading to a 9.3 % increase in particulate organic carbon (POC); however, it did not affect SOC compared to no P fertilization. Moreover, the positive effect of P on POC was observed only when legume was not introduced, indicating legume introduction weakened this positive effect. In conclusion, introducing legumes to natural grasslands can enhance long-term SOC stabilization and storage by stimulating microbial metabolic activity, offering a sustainable strategy to improve soil fertility and agricultural productivity without the need for P fertilization.

2. 题目: Enhancement of dark fermentative hydrogen production using metal-modified biochar from sugarcane residues: Optimization, characterization, and metabolic analysis
文章编号: N25032308
期刊: Journal of Environmental Management
作者: Nantharat Wongfaed, Sureewan Sittijunda, Sompong O-Thong, Prawit Kongjan, Rattana Jariyaboon, Pensri Plangklang, Alissara Reungsang
更新时间: 2025-03-23
摘要: This study investigated the enhancement of dark fermentative hydrogen production (HP) using metal-modified biochars derived from sugarcane bagasse (SB) and sugarcane leaves (SL). The biochars were modified with Fe and Ni, with optimal conditions identified through Box-Behnken Design as 6.09 g/L biochar: SB, 5.38 g/L biochar: SL + Fe, and 7.66 g/L biochar: SL + Ni. This optimization achieved a maximum hydrogen yield of 108.77 mL-hydrogen (H2)/g-glucose, a 58.77 % increase over the control. Metal modification enhanced biochar surface properties and selectively enriched H2-producing bacteria, particularly Clostridium sensu stricto 1 and Paraclostridium sp. Metabolic pathway analysis showed enhanced glucose catabolism and increased H2-producing enzyme abundance. The study demonstrates that sugarcane-derived biochar can effectively enhance bio-HP, though careful optimization of metal concentrations is crucial to avoid inhibitory effects.

3. 题目: Application of bimetallic cerium-based biochar adsorbent for efficient removal of Cr(VI): Effective regulation of Fe doping and straw-based biochar incorporation
文章编号: N25032307
期刊: Separation and Purification Technology
作者: Bing Hou, Ling Wang, Xinyu Yang, Yuyou Li, Zhuohang Wu, Jingwen Pan, Lei Wang
更新时间: 2025-03-23
摘要: Cerium-based adsorbent with the merits of variable valence and ample oxygen vacancies was applied for the removal of highly toxic hexavalent chromium (Cr(VI)). However, its cost controllability and recycling stability in practical applications remain to be further explored. Herein, a varieties of bimetallic cerium-based biochar adsorbents (CeFe@BC) were prepared by doping iron (Fe) and loading onto straw-based biochar, and the effects of the introduced Fe and biochar on adsorption performance of cerium-based adsorbent for Cr(VI) were studied. In comparison to pure cerium-based adsorbent (Ce@C), CeFe@BC had a stronger Cr(VI) adsorbability with the maximum adsorption capacity of 57.05 mg/g (25°C). Meanwhile, CeFe@BC had good regeneration stability and environmental friendliness. The adsorption capacity only decreased by 16.11 % after 7 adsorption–desorption cycles, with almost no metal leaching in different pH. Results showed that Fe doping and loading onto straw-based biochar could effectively promote Ce(III) and oxygen vacancy content in Ce@C. Electrochemical and density function theoretical calculations proved that Fe doping and loading onto straw-based biochar could promote the reduction of Ce@C impedance and the increase of current density. In conclusion, Fe doping and loading onto straw-based biochar effectively regulated the intrinsic properties of cerium adsorbent and further accelerated the electron transfer in adsorption. This study shows that bimetallic cerium-based adsorbent is a promising, efficient and stable environmental friendly adsorbent for Cr(VI) removal from wastewater.

4. 题目: The predominance of root- and salt-marsh-derived soil organic carbon in a mangrove poleward range expansion front
文章编号: N25032306
期刊: Geoderma
作者: Prakhin Assavapanuvat, Joshua L Breithaupt, Ding He, Ralph N Mead, Thomas S Bianchi
更新时间: 2025-03-23
摘要: Due to global warming, temperate salt marshes (e.g., Spartina alterniflora and Juncus roemerianus) are being overtaken by poleward migrating mangroves (e.g., Avicennia germinans and Rhizophora mangle). While bulk soil organic carbon (SOC) stocks have been widely compared across mangrove and salt marsh habitats, differentiation of SOC derived from leaves and roots of each mangrove and salt marsh species remains a challenge. Hence, we used multiple biomarkers and proxies (stable isotopes, lignin oxidation products, n-alkanes, sterols, and triterpenoids) to quantify the relative contribution of leaves and roots of each plant taxon to bulk SOC in a mangrove-salt marsh ecotone in Apalachicola (Florida, USA). The shallow peaks of mangrove leaf biomarker (α-amyrin for A. germinans, taraxerol for R. mangle) suggested the deposition of mangrove leaf-OC over soil surface after the initial mangrove establishment, while the abundance of betulin and 3,5-dihydroxy benzoic acid in A. germinans and R. mangle deep soils, respectively, indicated subsurface contribution of mangrove root-OC, down to 45-cm depth. Based on mixing models, the principal source of SOC in mangrove habitats has shifted from S. alterniflora roots to mangrove roots. The total contribution of roots to the SOC pool in mangrove habitats was 69.0–86.1 %, highlighting that SOC was preferentially formed belowground. Interestingly, within ∼34 years after initial mangrove establishment, the majority (62.3–74.0 %) of SOC in mangrove habitats continues to be derived from pre-existing salt marshes. This emphasizes that comparing bulk SOC without considering their actual sources could result in an overestimation of the contribution of encroaching mangroves to SOC stocks.

5. 题目: Optimizing CO2 capture: Effects of chemical functionalization on woodchip biochar adsorption performance
文章编号: N25032305
期刊: Journal of Environmental Management
作者: Antonio Faggiano, Angela Cicatelli, Francesco Guarino, Stefano Castiglione, Antonio Proto, Antonino Fiorentino, Oriana Motta
更新时间: 2025-03-23
摘要: As atmospheric CO2 concentrations rise, primarily due to fossil fuel combustion and deforestation, the urgent need for effective carbon capture solutions becomes increasingly critical to mitigate global warming. This study investigates the enhancement of CO2 adsorption in woodchip biochar (WBC) through targeted chemical functionalization with potassium hydroxide (KOH), sodium hydroxide (NaOH), and ferrous sulfate (FeSO4). Using Central Composite Design (CCD) and Response Surface Methodology (RSM), it is systematically possible to identify optimal functionalization conditions to maximize the biochar's adsorption efficiency. The KOH-treated biochar exhibited the highest adsorption capacity (Qmax of 9.89 mmol/g), substantially improving over untreated biochar (Qmax of 4.54 mmol/g). Adsorption analysis through Langmuir and Freundlich isotherm models highlighted a strong alignment with the Langmuir model, suggesting a predominantly monolayer adsorption surface. Additionally, kinetic studies using pseudo-first-order (PFO) and pseudo-second-order (PSO) models indicated a favourable chemisorption process, with the PSO model showing a superior fit. These results demonstrate the potential of chemically functionalized biochar, especially when treated with KOH, as a viable material for CO2 capture, presenting an environmentally sustainable pathway for addressing the pressing issue of atmospheric CO2. Utilizing biochar derived from organic waste also promotes waste valorisation and supports a circular economy. Optimised biochar could mitigate CO2 emissions, potentially serving as a complementary solution in climate change mitigation strategies, especially in scenarios where biochar can be deployed at scale in industrial or agricultural settings.

6. 题目: Nonlinear microbial thermal response and its implications for abrupt soil organic carbon responses to warming
文章编号: N25032304
期刊: Nature Communications
作者: Kailiang Yu, Lei He, Shuli Niu, Jinsong Wang, Pablo Garcia-Palacios, Marina Dacal, Colin Averill, Katerina Georgiou, Jian-Sheng Ye, Fei Mo, Lu Yang, Thomas W Crowther
更新时间: 2025-03-23
摘要:

Microbial carbon use efficiency (CUE) is a key microbial trait affecting soil organic carbon (SOC) dynamics. However, we lack a unified and predictive understanding of the mechanisms underpinning the temperature response of microbial CUE, and, thus, its impacts on SOC storage in a warming world. Here, we leverage three independent soil datasets (n = 618 for microbial CUE; n = 591 and 660 for heterotrophic respiration) at broad spatial scales to investigate the microbial thermal response and its implications for SOC responses to warming. We show a nonlinear increase and decrease of CUE and heterotrophic respiration, respectively, in response to mean annual temperature (MAT), with a thermal threshold at ≈15 °C. These nonlinear relationships are mainly associated with changes in the fungal-to-bacterial biomass ratio. Our microbial-explicit SOC model predicts significant SOC losses at MAT above ≈15 °C due to increased CUE, total microbial biomass, and heterotrophic respiration, implying a potential abrupt transition to more vulnerable SOC under climate warming.

7. 题目: Field experiment reveals varied earthworm densities boost soil organic carbon more than they increase carbon dioxide emissions
文章编号: N25032303
期刊: Geoderma
作者: Yufeng Qiu, Ronggui Tang, Yihong Liu, Youchao Chen, Yuye Shen, Shoujia Zhuo, Yanjiang Cai, Scott X Chang
更新时间: 2025-03-23
摘要: Earthworms play crucial roles in regulating soil organic carbon (SOC) and greenhouse gas emissions in forest soils. Laboratory studies have proven that they promote soil carbon dioxide (CO2) emissions. However, the effects of earthworm activity on forest soil CO2 emissions and organic carbon (C) have not yet been quantified in situ, and the impact of different earthworm densities remain unclear. In this study, we investigated how earthworm (Pheretima guillelmi) activity at three densities (no earthworms, original density, and double the original density) affected SOC, its labile fractions, C-related enzyme activities, and soil CO2 emissions in a Moso bamboo (Phyllostachys edulis) forest ecosystem over a six-month field experiment. Our results showed that the original earthworm density resulted in a 23.4 % increase in soil CO2 emissions, while double the original earthworm density resulted in a 9.6 % reduction in emissions compared to the original density. Additionally, earthworms at both densities significantly increased the concentration of SOC and its labile fractions. Notably, the increase in SOC density (SOCD, SOC stock per unit land area, kg C ha−1) induced by earthworm activity far exceeded the increase in CO2-C emissions. Specifically, the earthworms at double the original density led to an 8.8-fold increase in SOCD, while the original density resulted in a 3.7-fold increase. Furthermore, our findings identified dissolved organic C (DOC) as the most critical labile organic C fraction influencing soil CO2 emissions associated with earthworm activity, while β-glucosidase (BG) was the most significant C-related enzyme affecting soil CO2 emissions driven by earthworm activity. These results provide important insights into the role of earthworms in both CO2 emissions and SOC accumulation in subtropical forests.

8. 题目: Microbial Community Metabolism of Coral Reef Exometabolomes Broadens the Chemodiversity of Labile Dissolved Organic Matter
文章编号: N25032302
期刊: Environmental Microbiology
作者: Zachary A Quinlan, Craig E Nelson, Irina Koester, Daniel Petras, Louis-Felix Nothias, Jacqueline Comstock, Brandie M White, Lihini I Aluwihare, Barbara A Bailey, Craig A Carlson, Pieter C Dorrestein, Andreas F Haas, Linda Wegley Kelly
更新时间: 2025-03-23
摘要: Dissolved organic matter (DOM) comprises diverse compounds with variable bioavailability across aquatic ecosystems. The sources and quantities of DOM can influence microbial growth and community structure with effects on biogeochemical processes. To investigate the chemodiversity of labile DOM in tropical reef waters, we tracked microbial utilisation of over 3000 untargeted mass spectrometry ion features exuded from two coral and three algal species. Roughly half of these features clustered into over 500 biologically labile spectral subnetworks annotated to diverse structural superclasses, including benzenoids, lipids, organic acids, heterocyclics and phenylpropanoids, comprising on average one‐third of the ion richness and abundance within each chemical class. Distinct subsets of these labile compounds were exuded by algae and corals during the day and night, driving differential microbial growth and substrate utilisation. This study expands the chemical diversity of labile marine DOM with implications for carbon cycling in coastal environments.

9. 题目: Grazing Affects Soil Organic Carbon Stocks Directly and Indirectly Through Herbaceous Species Diversity in Sahelian Savanna Ecosystems
文章编号: N25032301
期刊: Land Degradation & Development
作者: Haftay Hailu Gebremedhn, Simon Taugourdeau, Sylvanus Mensah, Lydie Chapuis‐Lardy, Torbern Tagesson, Patricia Moulin, Ousmane Ndiaye, Aleksander Wieckowski, Paulo Salgado
更新时间: 2025-03-23
摘要: The impact of livestock grazing on soil organic carbon (SOC) stocks in the Sahel has been poorly documented due to a lack of data from different grazing intensities. This study evaluated SOC stocks under four grazing intensities within 0–30 cm soil depth in dry savanna ecosystems of Senegal. It also examined possible indirect relationships between grazing and SOC through herbaceous species diversity, herbaceous biomass, and carbon–nitrogen ratio. Four sites representing high, moderate, light, and no grazing intensity levels were selected. Transect survey methods were used for sampling soil and vegetation data within each of the sites. Data were analyzed using mixed‐effects models and piecewise structural equation modeling (pSEM). SOC stocks were significantly different among the four grazing intensities, and higher stocks were observed with increased intensity. Furthermore, high‐intensity grazing was shown to reduce the carbon–nitrogen ratio by negatively affecting the diversity of herbaceous species, which indirectly promoted SOC stocks. In conclusion, this study found that increased grazing intensity promoted SOC stocks both directly and indirectly through herbaceous species diversity.

10. 题目: Effects of redox-modified biochar on mercury reduction and methylation on electron transfer in Geobacter sulfurreducens PCA
文章编号: N25032215
期刊: Bioresource Technology
作者: Zhenya Tang, Jie Yu, Fangling Fan, Suikai Wang, Dingyong Wang, Yizhong Huang
更新时间: 2025-03-22
摘要: Geobacterplays a key role in mercury (Hg) methylation and reduction in rice fields.Biochar boosts microbial electron transfer, but its impact on Hg reduction and methylation remains unclear. This study investigates how oxidative (OBC) and reductive (RBC) biochar influence Hg reduction and methylation by Geobacter sulfurreducens PCA. OBC increased electron donating capacity (EDC) but reduced electron accepting capacity (EAC), while RBC decreased electric resistance. Correlation analysis revealed biochar’s electron exchange capacity (EEC) positively correlated with –OH (r = 0.73*), O-CO (r = 0.81*), COO/CO (r = 0.73*), –NH (r = 0.67*), and electron transfer number (n) (r = 0.99**), but negatively with –CH (r = -0.70*) and –NH3 (r = -0.80**). Both total Hg (THg) and methylmercury (MeHg) negatively correlated with EEC (THg:r = -0.99**, MeHg: r = -0.92**), EDC (THg:r = -0.99**,MeHg:r = -1.00**), and n (THg:r = -1.00**,MeHg: r = -0.85**), but positively with ΔIp (THg:r = 1.00**,MeHg:r = 0.80**). These findings suggest biochar with higher EEC, EDC, and electron transfer capacity enhances Hg2+ reduction and inhibits methylation, highlighting its potential for Hg pollution control.

11. 题目: The effects of enriched biochar and zeolite and treated wastewater irrigation on soil fertility and tomato growth
文章编号: N25032214
期刊: Journal of Environmental Management
作者: Sara Paliaga, Sofia Maria Muscarella, Rosa Alduina, Luigi Badalucco, Pedro Tomás Bulacio Fischer, Ylenia Di Leto, Giuseppe Gallo, Giorgio Mannina, Vito Armando Laudicina
更新时间: 2025-03-22
摘要: Resource recovery from wastewater treatment is the key for sustainable environment management. Treated wastewater (TWW) represents a promising opportunity not only as irrigation water but also as a source of nutrients that can be recovered with adsorbent materials, such as biochar and zeolite. These materials efficiently adsorb phosphate and ammonium, respectively, from wastewater, and once enriched can act as soil fertilizer. This study investigated, the impact of PO43−-enriched biochar and NH4+-enriched zeolite, combined or not with treated wastewater (TWW) irrigation, on soil fertility and growth of tomato plants, through a pot experiment. Five treatments were tested: control soil irrigated with tap water, soil amended with enriched biochar and zeolite with tap water or TWW, and soil amended with natural biochar and zeolite with TWW. After 80 days, shoot dry weights of tomato plants showed no significant differences across treatments. However, root dry weights decreased in plants irrigated with TWW, whether unamended or amended with natural biochar and zeolite. The TWW irrigation, both with and without enriched amendments improved soil total N and available P by 22 and 15 %, respectively, but increased soil salinity, as evidenced by 27 % rise in electrical conductivity. However, enriched and natural biochar and zeolite effectively mitigated salinity effect, promoting a more salinity-tolerant microbial community, and increasing microbial biomass carbon. These results support the integrated use of TWW with nutrient-enriched amendments to support the transition to a circular economy in the water sector.

12. 题目: Investigating the efficiency and mechanism of biochar in-situ reaction zones for groundwater remediation: A case study of 1,2-dichloroethane in gravel column
文章编号: N25032213
期刊: Journal of Environmental Management
作者: Chongkai Zhao, Xueyu Lin, Xiaosi Su, Shengyu Zhang
更新时间: 2025-03-22
摘要: Dichloroethane (1,2-DCE), a common groundwater contaminant in petroleum extraction and refining areas, poses a threat to both the environment and nearby populations. To address this issue, a cost-effective and straightforward engineering approach is suitable for treating contaminated areas. In this study, nitrogen-doped biochar was prepared through an anoxic roasting modification method using sesame meal. At optimal dosage: 4.5 mM persulfate with 1.2 g/L N-SDB. The system achieved complete removal of 0.1 mM of 1,2-DCE within 90 min, with a total organic carbon (TOC) removal rate of 87.03 %. The biochar exhibited excellent stability, achieving 99.88 % removal of 0.1 mM 1,2-DCE and 76.13 % removal of TOC after six degradation cycles. The results indicated three main pathways for 1,2-DCE degradation, with hydroxyl radicals (·OH) and single-linear oxygen (1O2) as the main reactive species in the reaction system. Moreover, we developed a biochar in-situ reaction zone within a one-dimensional gravel column by optimizing particle size and injection concentration and conducted simulated remediation experiments on 1,2-DCE. The results revealed that all 1,2-DCE passing through the in-situ reaction zone was completely removed within 630 min.

13. 题目: Biochar and sodium carboxymethyl cellulose (CMC) improve the soil matrix for treating highway rainwater runoff
文章编号: N25032212
期刊: Environmental Geochemistry and Health
作者: Tianhong Zhou, Douhong Yang, Huidong Shen, Yumei Ou, Wenqing Han, Lixia Wang, Kai Ma
更新时间: 2025-03-22
摘要:

In view of the rainwater pollution problems in highway runoff on the Northwest Expressway, especially heavy metal pollution and poor soil water retention, this study focused on the sandy soils along the highway sides in Qilian Mountain National Park, Gansu Province. It investigated the removal of pollutants as well as water and fertilizer retention effects in simulated highway rainwater runoff using four amendments: carboxymethyl cellulose (CMC), corn straw biochar, corn cob biochar, and rice husk biochar, both individually and in combination. Through permeability tests, evaporation tests, and static adsorption experiments, the optimal soil treatment for runoff rainwater was determined. Experiments showed that mixing soil with quartz sand in a 4:6 ratio and adding 5% rice husk biochar and 0.1% CMC can significantly enhance the adsorption of various pollutants and improve soil moisture retention. We packed the initially selected improved soil matrix into columns, initiated operation, and set the influent flow rate to 9 mL/min. During stable operation, the average retention rates of nutrients—ammonia nitrogen (NH₄⁺-N), total phosphorus, and chemical oxygen demand—from highway runoff were 81.75%, 66.72%, and 77.97%, while the average removal rates of copper (II) (Cu²⁺) and chromium (VI) (Cr⁶⁺) were 91.94% and 84.18%, respectively. After operation, the residual forms of copper (Cu) and chromium (Cr) in the soil matrix accounted for 56.96% and 52.28%. The transformation of Cu and Cr into stable residual forms with low migration risk effectively reduced their environmental impact.

14. 题目: Microbial functional trait predicts soil organic carbon across soil aggregates in Northeastern China
文章编号: N25032211
期刊: Soil Biology and Biochemistry
作者: Lina Sun, Shun Han
更新时间: 2025-03-22
摘要: Soil aggregates offer diverse habitats for microorganisms, characterized by variations in microbial 16S rRNA gene operon (rrn) copy number, a valued functional trait indicative of microbial growth rates and organic matter availability, which is crucial for enhancing soil fertility, nutrient cycling, and ecosystem health. However, the impact of soil aggregate stratification on microbial functional traits, as reflected by rrn copy number, remains unclear. This study revealed that microbial taxonomic composition is significantly different in soil aggregate stratification, with microaggregates favoring higher community-level rrn copy numbers, potentially indicating the prevalence of microbial r-strategists compared to macroaggregates and silt+clay fractions. Additionally, strong positive correlations between soil organic carbon and community-level rrn copy number suggest that rrn copy number serves as a meaningful functional trait reflecting soil organic carbon availability. Overall, this finding provides new insights into how soil aggregate shapes the life-history strategies of microbial communities, soil organic matter content and promote soil health.

15. 题目: Recent gains in global terrestrial carbon stocks are mostly stored in nonliving pools
文章编号: N25032210
期刊: Science
作者: Yinon M Bar-On, Xiaojun Li, Michael O'Sullivan, Jean-Pierre Wigneron, Stephen Sitch, Philippe Ciais, Christian Frankenberg, Woodward W Fischer
更新时间: 2025-03-22
摘要: Terrestrial sequestration of carbon has mitigated ≈30% of anthropogenic carbon emissions. However, its distribution across different pools, live or dead biomass and soil and sedimentary organic carbon, remains uncertain. Analyzing global observational datasets of changes in terrestrial carbon pools, we found that ≈35 ± 14 gigatons of carbon (GtC) have been sequestered on land between 1992 and 2019, whereas live biomass changed by ≈1 ± 7 GtC. Global vegetation models instead imply that sequestration has been mostly in live biomass. We identify key processes not included in most models that can explain this discrepancy. Most terrestrial carbon gains are sequestered as nonliving matter and thus are more persistent than previously appreciated, with a substantial fraction linked to human activities such as river damming, wood harvest, and garbage disposal in landfills.

16. 题目: Arbor‒shrub mixed vegetation restoration strategies enhanced soil organic carbon storage and stability via fine root and fungal characteristics in limestone hills
文章编号: N25032209
期刊: Plant and Soil
作者: Longyan Shi, Yutian Zhang, Linjing Zhang, Tiandong Xu, Jiahao Zhao, Junjie Li, Chenyi Yu, Qingwei Guan
更新时间: 2025-03-22
摘要:

Backgound and aims

Afforestation and reforestation are essential for bolstering soil carbon stocks. Traditionally, vegetation restoration has relied on monoculture planting. However, mixed forests, with their relatively complex stand structures, are increasingly recognized as a more promising strategy. Owing to the resource limitations of limestone hills, the effects of arbor-shrub mixed vegetation restoration on soil organic carbon (SOC) storage and stability, as well as the mechanisms driving these effects, remain underexplored compared to monocultures.

Methods

We quantified biomass and chemical traits of litterfall and fine roots, soil physiochemical properties, SOC and its fractions, microbial necromass carbon (MNC), microbial traits, and enzyme activity. Pearson correlation analysis and structural equation modeling (SEM) were employed to explore the mechanisms influencing SOC storage and stability across vegetation restoration strategies.

Results

Arbor-shrub mixed vegetation restoration forests significantly enhanced SOC content, storage, and stability, primarily through a greater contribution of mineral-associated organic carbon (MAOC) to SOC and increased MNC content, compared to monoculture stands. These improvements were strongly associated with higher fine root biomass, reduced C/N and lignin/N ratios, enhanced fungal diversity, shifts in fungal phyla abundance, and elevated activities of peroxidase (POD) and sucrase (SC) enzymes. The quality of fine roots and fungal community dynamics accounted for most variations in SOC storage and stability, surpassing the influences of soil physicochemical properties, litterfall, or bacterial community dynamics.

Conclusions

Our findings highlight the effectiveness of arbor-shrub vegetation restoration strategies in enhancing soil carbon stocks in limestone hills, which contribute to optimizing afforestation strategies.

17. 题目: Can biochar fillers advance the properties of composites? Early-stage characterization and life cycle assessment of novel polyamide/biochar biocomposites
文章编号: N25032208
期刊: Environmental Research
作者: Hossein Baniasadi, Laura Äkräs, Zoe Paganelli, Nele Dammann, Roozbeh Abidnejad, Sami Lipponen, Frans Silvenius, Marjatta Vahvaselkä, Hannu Ilvesniemi, Jukka Seppälä, Jukka Niskanen
更新时间: 2025-03-22
摘要: In response to growing environmental concerns, this study explores the potential of polyamide 1010 (PA1010) and biochar biocomposites as a sustainable solution in polymer engineering. The research addresses the gap in reinforcing biocomposites with biochar, demonstrating enhanced physical properties and reduced environmental impact. Scanning electron microscopy (SEM) revealed excellent biochar dispersion and strong adhesion with the PA1010 matrix. Mechanical testing showed significant improvements, including a 44% increase in tensile strength and a 110% increase in tensile modulus. Thermal stability also improved, increasing decomposition temperature from 460 °C to 474 °C. Additionally, dynamic mechanical analysis (DMA) and rheology tests confirmed increased stiffness and flow resistance. Life cycle assessment (LCA) highlighted a 65% reduction in carbon footprint, indicating the environmental benefits of these biocomposites. These findings position PA1010/biochar biocomposites as promising materials for sustainable applications in engineering, particularly in industries seeking to reduce environmental impact while enhancing performance.

18. 题目: The role of Ca-bridged organic matter in an alkaline soil, as revealed by multimodal chemical imaging
文章编号: N25032207
期刊: Geoderma
作者: Tamas Varga, Ravi K Kukkadapu, Libor Kovarik, Alice C Dohnalkova, Qian Zhao, Mark H Engelhard, Swarup China, Nurun Nahar Lata, Anil K Battu, Rosalie K Chu, Matthew A Marcus, Thomas W Wietsma, Daniel E Perea, Lye Meng Markillie, Hugh D Mitchell, Rene M Boiteau, James J Moran, Kirsten S Hofmockel
更新时间: 2025-03-22
摘要: Mineral–organic matter (OM) studies have predominantly focused on acidic soils that are abundant in iron (Fe) oxides and aluminum (Al) oxides. We have probed mineral–OM interactions in an alkaline or calcareous soil of the Aridisols class. Unlike the role of Fe and Al, the role of Ca-minerals (particularly calcite), which are ubiquitous in alkaline soils, in OM sequestration is not well understood. Multiple recent model studies with aqueous Ca2+ or synthetic calcite and a suite of OM compounds have shown Ca-OM assemblages to be spatially correlated with calcite at the microscale. To study the chemical state of both Ca and Fe and their competing role in soil organic matter (SOM) stabilization, we performed laboratory characterization using x-ray diffraction, Mössbauer spectroscopy, x-ray photoelectron spectroscopy, scanning electron microscopy, and scanning transmission electron microscopy, alongside synchrotron-based microscale chemical imaging using scanning transmission x-ray microscopy combined with near-edge x-ray absorption fine structure. Ca mineral–organic associations were found to be ubiquitous in this system and are likely critical for understanding SOM stabilization/degradation in alkaline soils. From our findings on mineralogy, speciation, and the nature of Ca-OM bridging, we identified differences in C and Ca chemistry based on the relative location of OM to Ca minerals. The OM near the calcite crystal was enriched in lipid and protein moieties, Ca-OM next to Fe minerals displayed a strong contribution from aromatic compounds, while on the surface of microbes, the carbonate was believed to be of microbial in origin, as also suggested by preliminary works reporting on the formation of amorphous calcite or nano-calcite. In Ca-OM admixed with carbonate, it was difficult to distinguish Ca-associated OM from amorphous calcite or nano-calcite.

19. 题目: Microcystin-LR removal by powdered activated carbon: the influence of natural organic matter in non-bloom and bloom water
文章编号: N25032206
期刊: Environmental Science: Water Research & Technology
作者: Katarzyna Jaszczyszyn, Sigrid Peldszus, Peter M Huck
更新时间: 2025-03-22
摘要: This bench-scale study examined the impact of natural organic matter (NOM) on microcystin-LR (MC-LR) adsorption to powdered activated carbon (PAC) prior to and during a cyanobacterial bloom by quantifying NOM fractions including humic substances (HS) and biopolymers with liquid chromatography-organic carbon detection (LC-OCD). Three commercially available powdered activated carbons (wood-, coal-, and coconut-based PACs) were applied to the same reservoir water sampled prior to and during a bloom. Under bloom conditions, phytoplankton content was much higher, mainly cyanobacteria, the dissolved organic carbon increased by 57.4%, and the NOM composition changed. The content of biopolymers increased substantially, doubling compared to non-bloom conditions. The change in the amount of other NOM components, including HS, was less notable. For the cyanobacterial bloom water, MC-LR adsorption kinetics slowed for all PACs, while capacities decreased for the coal-based PAC at all contact times, and for the wood-based PAC only at 0.5 h contact time. The microporous coconut-based PAC performed poorly under all conditions studied. HS appear to be in direct competition with MC-LR for adsorption sites in the mesopore volume. In bloom water, the mass of HS adsorbed per unit mesopore volume was lower for wood-based PAC (45 mgC cm⁻³) than for coal-based PAC (106 mgC cm⁻³), indicating that more adsorption sites were available for MC-LR on the wood-based PAC, which was the least impacted by the bloom. Overall, this study provides new insights into the impact of different NOM fractions on MC-LR adsorption by PACs when treating surface water during a toxic cyanobacterial bloom.

20. 题目: Integrating Dual-Stage Gas Permeable Membranes and Humic Acid Recovery to Optimize Fenton Oxidation of Landfill Leachate: Insights into Full-Process Performance and DOM Molecular-Level Transformation
文章编号: N25032205
期刊: Water Research
作者: Linjun Wu, Huan Li, Yanyue Gu, Zhiqiang Shen, Yuexi Zhou, Jiane Zuo
更新时间: 2025-03-22
摘要: This research introduces an innovative full-process treatment technology that integrates dual-stage gas permeable membranes (GPM) and humic acid (HA) recovery to enhance Fenton oxidation of landfill leachate (LFL). In terms of full-process performance, this integrated approach (LFL-GPM-HA (Fenton)) synergistically combines LFL concentration, ammonia recovery, HA recovery, purified water reclamation, and efficient Fenton oxidation, thereby achieving holistic minimization, detoxification, and resource recovery of LFL. Specifically, under the conditions of low-intensity aeration and a temperature gradient of 65-55-25°C, the GPM achieved an ammonia recovery rate exceeding 96%, while the LFL was concentrated by a factor of 4.72 within 12 hours. During HA recovery at pH 2, the HA yield from the concentrated LFL reached 3.68 g/L, representing an 88.72% increase compared to the raw LFL. Due to the significant consumption of bicarbonate alkalinity during the GPM process, the required dosage of H₂SO₄ per gram of HA recovered was reduced by 86.72%. Under different dimensionless oxidant dosages, the LFL-GPM-HA (Fenton) demonstrated a significant improvement in COD removal efficiency compared to standalone Fenton oxidation. In terms of dissolved organic matter (DOM) molecular-level transformation, ESI FT-ICR-MS analysis showed a significant enhancement in the removal of CHOS and CHONS in LFL-GPM-HA (Fenton), with a concurrent reduction in the produced sulfurous byproducts. Additionally, the LFL-GPM-HA (Fenton) notably increased the frequency of decarboxylation, desulfurization, and dealkylation reactions. In terms of operational stability and economic feasibility, this integrated system demonstrates excellent long-term stability and robust membrane fouling-cleaning recovery properties, achieving LFL treatment at a cost of approximately 12.142 $/m³, which is significantly more cost-effective than conventional full-process advanced treatment technologies (20-30 $/m³). In conclusion, the findings offer a pathway for developing more efficient and cost-effective strategies for LFL management.