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81. 题目: Mycorrhizal hyphae, but not fine roots modulate drought effects on soil organic matter accumulation in a temperate forest
文章编号: N25041201
期刊: Soil Biology and Biochemistry
作者: Xiang Li, Junwei Luan, Siyu Li, Pengsen Sun, Jinglei Zhang, Yi Wang, Shalom D Addo-Danso, Shaowen Mei, Baoliang Niu, Shirong Liu
更新时间: 2025-04-12
摘要: Extreme climatic events, such as drought, are projected to alter soil carbon (C) and nitrogen (N) cycling in forest ecosystems. However, how the effects of drought are modulated by tree roots and their associated mycorrhizal fungi remains poorly understood. Over 144 days of in-situ incubation, using mesocosms with different mesh sizes in an oak forest subjected to six consecutive years of throughfall rain reduction treatment, we distinguished the drought effects on soil organic C and N accumulations via root-pathway and mycorrhizal hypha-pathway. These effects were assessed within different stability fractions of soil organic matter, i.e., particulate organic matter (POM) and mineral-associated organic matter (MAOM). Drought led to greater accumulations of soil organic C and N via the hypha-pathway compared to the root-pathway. This outcome arose because the hypha-pathway drove greater accumulation in POM than losses in MAOM due to reduced decomposition rates, whereas the root-pathway led to greater POM losses relative to MAOM accumulation, primarily attributable to an enhanced root priming effect. Moreover, plants utilized more soil inorganic N relative to organic N through the hypha-pathway in response to drought, which may partly account for the inconsistent changes in C and N within different labile fractions. These findings emphasize the importance of distinguishing divergent roles of roots and mycorrhizal hyphae in modulating soil C and N processes in the context of future climate change scenarios.
82. 题目: Nitrogen-mediated engineering cobalt phosphide sites for enhanced peroxymonosulfate activation towards organic wastewater purification
文章编号: N25041107
期刊: Environmental Research
作者: Linqing Hou, Jiaying Zang, Siyu Liu, Pengyao You, Guangyin Fan
更新时间: 2025-04-11
摘要: Introducing heteroatoms into cobalt phosphide-based materials is expected to enhance their effectiveness in wastewater purification through peroxymonosulfate (PMS) activation by altering the electronic structure and reconfiguring the catalytic sites. In this study, we describe an efficient one-step calcination method for fabricating CoP@NC/NF, wherein simultaneous phosphorization and nitrogen nitridation occur during the calcination process. The CoP@NC/NF/PMS system effectively activates PMS and achieves a tetracycline (TC) removal rate of 92.3 % within 30 min. The calculated rate constant achieves 0.1615 min−1, representing a 1.85-fold increase compared to the CoP@C/NF/PMS system. Furthermore, the CoP@NC/NF/PMS system exhibits remarkable resistance to interference from various inorganic anions and humic acid. Mechanistic examinations reveal that non-radical pathways including 1O2 and electron transfer are the dominant mechanisms in the catalytic system. Additionally, potential catalytic sites for TC removal via PMS activation by CoP@NC/NF include Co2+, Co-Nx, graphitic N, and C=O. Finally, four potential degradation pathways were identified through the analysis of fourteen intermediates from TC decomposition. Toxicity assessments indicate a marked decrease in the toxicity of the degraded solution. Overall, this catalyst, characterized by multiple active sites and enhanced stability, presents a highly effective oxidation system for eliminating antibiotic pollutants from water.
83. 题目: Estimates of black carbon emissions from global biomass burning for the period 1997–2023
文章编号: N25041106
期刊: Journal of Environmental Quality
作者: Mingyu Yao, Junyu Fan, Xuexin Li, Yu Zhang, Qi Jing, Afeng Chen
更新时间: 2025-04-11
摘要: Estimating black carbon (BC) emissions from biomass burning is crucial for accurately assessing the climate impact of this pollutant. In this study, we have estimated BC emissions from biomass burning in different geographic regions worldwide at a resolution of 0.25° × 0.25° from 1997 to 2023. These findings are crucial for accurately modeling the impact of BC on global climatic forcing. Over the past 27 years, the emissions of BC from global biomass burning activities have remained stable. The high BC emissions between 2003 and 2008 were associated with increased precipitation. The Southern Hemisphere South America (SHSA) and Southern Hemisphere Africa (SHAF) regions have emerged as the primary contributors, accounting for approximately 40% of total BC emissions originating from global biomass burning sources and high BC emissions in the southern hemisphere's spring. This study also reveals that BC emissions in the SHAF region during 1997–2023 exhibit a granger causal relationship with Antarctic sea ice loss at a 2‐year lag, but the impact intensity demonstrates significant temporal heterogeneity. This study enhances our understanding of temporal and spatial variations in global BC release caused by biomass burning while providing fundamental data for international departments responsible for managing such activities.
84. 题目: Study on the Preparation of Biochar from Xinjiang Biomass Pyrolysis and Its Adsorption Characteristics for Water Pollutants
文章编号: N25041105
期刊: Water, Air, & Soil Pollution
作者: Yuze Su, Wen Fu, Xianxian Zhang, Xuefeng Wang, Xiaowei Bai
更新时间: 2025-04-11
摘要:
This study examines the adsorption capabilities of six types of biochars, prepared via pyrolysis of biomass materials sourced from Xinjiang, for removing pollutants from water. The results demonstrate that higher pyrolysis temperatures facilitate more complete decomposition of organic components within the feedstock, leading to increased pore size and specific surface area of the biochars. This enhancement significantly boosts the adsorption efficiency of methylene blue (MB) by the biochars. Efficient and well-structured porous biochars can be obtained at 700 °C; notably, biochars produced at 900 °C achieve MB removal efficiencies exceeding 99.5%. Furthermore, cyclic adsorption performance tests targeting MB indicate that, with the exception of corn cob biochar pyrolyzed at 900 °C, all other biochars maintain a removal rate of at least 71.4% after four cycles. The rich internal porous structure of the biochars and the presence of oxygen-containing functional groups on their surfaces enable those synthesized at 900 °C to achieve high equilibrium adsorption capacities for lead ions (Pb2⁺) in water within 30 min, averaging or surpassing 102.2 mg/g. Notably, cotton stalk biochar, which is abundant in oxygen-containing functional groups, exhibits a maximum equilibrium adsorption capacity for Pb2⁺ of up to 196.0 mg/g. Importantly, during the four cycles of reuse, both cotton stalk biochar and bamboo biochar pyrolyzed at 900 °C display relatively stable adsorption characteristics for Pb2⁺. Kinetic model analysis reveals that the adsorption processes of MB and Pb2⁺ by these biochars conform to both pseudo-first-order and pseudo-second-order kinetic models. These findings provide valuable guidance for the application of biochars in water treatment fields.
85. 题目: Critical role of biochar in the production and emission of greenhouse gas N2O in constructed wetlands: A comprehensive review
文章编号: N25041104
期刊: Journal of Cleaner Production
作者: Xin Wang, Zhiqiang Shen, Qin Zhang, Yijian Zhong, Mei Wang, Yang Zhang, Shaoyuan Bai, Ya-nan Zhang
更新时间: 2025-04-11
摘要: Biochar has been widely applied in constructed wetlands (CWs) where it positively affects pollutant purification and N2O reduction. However, the mechanism by which biochar affects N2O emissions during the nitrogen conversion process in CWs, despite its potential to improve simultaneous nitrogen removal and N2O emission reduction, remains unclear. This paper reviews nitrogen conversion and N2O production pathways, summarizes the response of N2O emissions to biochar addition, and analyses the mechanisms by which biochar influences N2O production and emission. The findings showed that biochar significantly regulated nitrogen conversion and N2O emissions. Specifically, biochar incorporation reduced average N2O emission fluxes by 47.94%, 18.74%, and 39.46% in horizontal subsurface flow, vertical flow , and surface flow CWs, respectively, in contrast, the total nitrogen removal efficiency of the three CW types increased by 27.94%, 27.37%, and 9.70%, respectively. The effect of biochar on N2O emissions in CWs is determined by its synergistic impact on oxygen diffusion, pH, microbial communities, adsorption capacity, electron transfer, and plant growth. Biochar creates a favourable microenvironment for functional microorganisms, especially those containing the nosZ gene. Efficient nitrogen removal and N2O reduction in CWs may be achieved by optimising the pyrolysis temperature, raw material, and addition ratio of biochar. This study offers valuable insights for optimising biochar use in CWs and provides new perspectives on enhancing its effectiveness.
86. 题目: Efficient and oriented oxidation of all n-alkanes in soil by direct passivation of soil organic matter
文章编号: N25041103
期刊: Journal of Environmental Chemical Engineering
作者: Jinlan Xu, Manman Wang, Huan Li, Mengzhen Gao, Chuanyu Liu, Jianan Dai, Zezhuang Cao, Huiwen Guan
更新时间: 2025-04-11
摘要: To explore the influence of soil organic matter on the degradation of all n-alkanes (C10-C30) in soil, it is proposed to regulate organic matter by kaolin and then perform Fenton oxidation to repair petroleum-contaminated soil. The results show that due to the protonation of functional groups, the content of protein and humus in soil is greatly reduced by the adsorption of kaolin. After the addition of kaolin, the total petroleum hydrocarbons (TPH) oxidation of the high-efficiency group was up to 7372 mg/kg, which was 1.93 times that of the unregulated group. Among them, the oriented oxidation amount of TPH in the high-efficiency group was 3555 mg/kg, and the remediation efficiency was 19.71% higher than that in the unregulated group, realizing the oriented oxidation of all n-alkanes in the soil. Further analysis found that the direct passivation of soil organic matter is mainly through the deprotonation of hydroxyl on the surface of kaolin minerals and combined with carboxyl groups, hydroxyl groups, and other functional groups of organic matter. Therefore, kaolin can absorb some small molecules in organic matter (protein II, humic acid, fulvic acid), which can directly passivate organic molecules and weaken the capture ability of organic matter to •OH. This greatly reduces the ineffective consumption of •OH by SOM（soil organic matter） and increases the utilization rate of H2O2, which provides a great reference value for practical engineering applications.
87. 题目: Coatings for protecting cellulosic ultrafiltration membranes from degradation during humic surface water purification
文章编号: N25041102
期刊: Separation and Purification Technology
作者: Joona Nieminen, Alma Liukkonen, Anni Valassaari, Arto Pihlajamäki, Mika Mänttäri
更新时间: 2025-04-11
摘要: Improvement of cellulosic ultrafiltration membrane durability was studied. With no protective modifications, the commercial regenerated cellulose membrane showed notable signs of degradation when in contact with lake water for several days. The most evident signs of degradation were increasing permeate fluxes and decreasing model substance retentions. TEMPO (2,2,6,6-tetramethylpiperidine-1-oxyl radical) −mediated oxidation of the membranes and charge-adhered coatings offered differing degrees of protection. Mere TEMPO-oxidation and consecutive coating with either poly(diallyldimethylammonium chloride)/poly(styrene sulfonate) (PDADMAC/PSS) or microfibrillar cellulose slightly improved the durability, whereas the poly(vinyl amine)/poly(acrylic acid) (PVAm/PAA) coating system made the membrane stable enough that any signs of degradation could not be observed during the testing period. The performed modifications did not alter the substrate membrane filtration properties significantly. The most notable changes were attributed to the [PVAm/PAA]1 coating that reduced both pure water permeance and molecular weight cut-off value by approximately 10%. It is suggested that the [PVAm/PAA]1 coating was sufficiently tight to block the cellulose-degrading substances that were present. Nevertheless, the structure was loose enough to sustain the desired properties of the substrate membrane. In concentrating filtrations, said coating mitigated flux decrease and the coated membrane had better filtration capacity than the non-coated alternatives
88. 题目: Physical Contact between Bacteria and Carbonaceous Materials: The Key Switch Triggering Activated Carbon and Biochar to Promote Microbial Iron Reduction
文章编号: N25041101
期刊: Environmental Science & Technology
作者: Lin Shen, Xiao Zhu, Haoze Jiang, Juntao Zhang, Chengyu Chen, John R Reinfelder, Andreas Kappler, Liping Fang, Tongxu Liu, Chuanping Liu, Yundang Wu, Fangbai Li
更新时间: 2025-04-11
摘要: Carbonaceous materials, including activated carbon and pyrolytic carbon, have been recognized for about over a decade as effective electron shuttles or conductive materials in promoting microbial Fe(III) mineral reduction. However, recent studies reveal inhibitory effects, sparking debates about their overall impact. We hypothesized that the physical contact between bacteria and carbon is an overlooked yet critical factor in determining whether carbon promotes or inhibits microbial Fe(III) reduction. Using systems containing Shewanella oneidensis MR-1, activated carbon, and ferrihydrite, we investigated how carbon–iron oxide aggregate structure affects Fe(III) reduction kinetics. At low activated carbon-to-iron oxide ratios (C/Fe = 5:7 by mass), ferrihydrite aggregated with carbon, forming carbon-encapsulated particles that suppressed Fe(III) reduction rates. Conversely, at higher ratios (C/Fe = 100:7), the ferrihydrite dispersed on the carbon surface, enhancing both the rate and extent of Fe(III) reduction. Tests with 11 different carbonaceous materials (activated carbon and biochar) all confirmed that the microstructure of iron oxides─whether encapsulating or dispersed─on carbon surfaces is critical for determining Fe(III) reduction rates. This insight resolves the debate on whether carbonaceous materials promote or inhibit Fe(III) mineral reduction and enhances our understanding of their roles in biogeochemical processes and environmental remediation.
89. 题目: Reduction of antimony bioavailability with the application of stable exogenous organic matter: a comparative study between rice straw and manure compost
文章编号: N25041013
期刊: Environmental Research
作者: Danxing Yang, Wen Fang
更新时间: 2025-04-10
摘要: Considering the widespread use of organic amendments to improve soil quality and enhance soil carbon sequestration, it is crucial to understand their impact on the bioavailability of metalloids in soils. Antimony (Sb), a priority pollutant, is particularly impacted by organic matter, yet the effects of different organic amendments—varying in stability and composition—on Sb bioavailability remain unclear. This study investigates the influence of different organic amendments, rice straw and compost, on Sb bioavailability in the rice-soil system, with rice ingestion being a major Sb exposure pathway in humans. Results show that while both amendments increased dissolved organic carbon in soil solution, their effects on Sb bioavailability differed markedly. Rice straw increased CDGT-SbIII by 13.24%–66.63%, whereas compost decreased CDGT-SbIII by 32.47%–43.51%. These differences were also reflected in Sb accumulation in rice shoots, where compost application resulted in lower Sb content. This reduction may be attributed to increased microbial genera such as Ramlibacter and Sphingomonas, which are associated with SbIII oxidation. Conversely, organic matter with low stability, prone to rapid degradation, could promote reducing soil conditions, thereby increasing SbIII concentrations. Our findings suggest that stable exogenous organic matter, such as pre-decomposed compost, is preferable for managing Sb-contaminated soils.
90. 题目: Characterization of magnetic chitosan-modified biochar and its adsorption of Zn2+ in electroplating rinsing wastewater
文章编号: N25041012
期刊: Journal of Environmental Chemical Engineering
作者: Changping Zhang, Mengwei Li, Xiaoou Wang
更新时间: 2025-04-10
摘要: This study introduced a novel chitosan-modified magnetic biochar (CMBC) for adsorbing Zn2+ from electroplating wastewater, aiming to enhance the adsorption capacity of biochar and facilitate its separation from aqueous phase. Results showed that the incorporation of Fe3O4 and chitosan into biochar reduced its specific surface area and pore volume by 93.8% and 79.6%, respectively, but increased the abundance of amino, carboxyl and hydroxyl groups on the carbon's surface. Zn2+ adsorption onto CMBC composites (up to 36.0 mg Zn2+/g at 125 mg/L Zn2+) tended to be monolayer and nonlinear, as well as spontaneous, endothermic and entropy-increasing, with chemisorption (surface complexation and ion exchange) being the predominant mechanism, in which negatively charged groups such as amino, hydroxyl, carboxyl and ester played key roles. pH affected Zn2+ adsorption onto CMBC by influencing its surface charge and degree of protonation/deprotonation of its functional groups, and 6.0 pH was most recommended. Balancing adsorption capacity and removal efficiencies, the economical CMBC dosage should be tailored to initial Zn2+ levels, e.g. it was 3.0 g CMBC/L for 100 mg/L Zn2+. Coexisting metal ions with smaller hydrated ionic radii and/or higher relative atomic masses competed with Zn2+ for CMBC adsorption. The desorption rate of Zn2+ from saturated CMBC was 73.7% when using 1.5% HCl over 60 minutes, and after five adsorption-desorption cycles, CMBC's adsorption capacity retained 74.8% of its initial value. Together with superparamagnetic properties and 15.73 emu/g saturation magnetization, CMBC offered satisfactory regeneration capabilities and recyclability. Overall, CMBC demonstrated substantial potential in removing Zn2+ from electroplating wastewater.
91. 题目: Effects of oleic acid on activated sludge systems: Performance, extracellular polymeric substances (EPS) and microbial communities
文章编号: N25041011
期刊: Journal of Environmental Chemical Engineering
作者: Zhuoni Chen, Chundi Gao, Xinyan Hu, Yunya Gao, Jiamin Zhou, Yongzhen Peng
更新时间: 2025-04-10
摘要: The presence of recalcitrant substances in wastewater poses challenges for water treatment, as together with other readily biodegradable substrates, they negatively affect the treatment of actual wastewater. In this study, the differential effects of a typical representative of recalcitrant substances (i.e., oleic acid) on the performance of activated sludge system and microbial community structure at different concentrations (0%, 50%, and 100%) were examined. According to the results, when the influent contained no oleic acid (0%), the best sludge settling performance was achieved with a sludge volume index (SVI) of 98 mL/g; this was superior to systems with oleic acid influents of 50% (SVI = 290 mL/g) and 100% (SVI = 146 mL/g). The addition of oleic acid significantly increased the content of extracellular polymeric substances, especially extracellular protein. This enhanced microbial activity but also led to poor sludge settling performance, particularly in the 50% oleic acid system, where the protein/polysaccharide ratio increased. Microbial community analysis revealed that 100% oleic acid promoted the growth of denitrifying bacteria, such as Hydrogenophaga and Rhodoferax, while inhibiting Candidatus_Accumulibacter and Dechloromonas. In the 50% oleic acid system, the filamentous bacterium Thiothrix spp. dominated, causing sludge bulking. In the 0% oleic acid system, the growth of Zoogloea facilitated floc formation and enhanced settling. These findings reveal that oleic acid alters microbial metabolism by shifting microbial carbon source utilization and increasing EPS production, which in turn alters microbial community dynamics and negatively impacts sludge settling. This study provides insights for optimizing the treatment of oleic acid-containing wastewater.
92. 题目: Ball milling-assisted synthesis of attapulgite-rice husk biochar composites for efficient formaldehyde removal: Experimental and computational insights
文章编号: N25041010
期刊: Separation and Purification Technology
作者: Wenchao Ji, Mingzhu Ren, Hefei Jin, Yu Lou, Shuzhen Wang, Xingjun Fan, Salma Tabassum
更新时间: 2025-04-10
摘要: This study explores the Ball milling-assisted synthesis of attapulgite-rice husk biochar composites (5 %ATP/BBC) to remove formaldehyde (HCHO) efficiently. The composite was fabricated to enhance surface area and increase exposure to functional groups, which are crucial for adsorption. The experimental findings showed that 5 %ATP/BBC effectively removes HCHO, with a maximum theoretical static adsorption capacity of 0.260 mg/g and a dynamic adsorption capacity of 141.048 mg/g, surpassing both BBC500 and BC500. Chemical adsorption was the predominant process, and the adsorption followed pseudo-second-order kinetics. Further X-ray photoelectron spectroscopy (XPS) analysis indicated that formaldehyde molecules were incorporated onto the biochar surface, as evidenced by changes in C=O and C–C bonds. Molecular-level investigations through density functional theory (DFT) and Bader charge analysis revealed that adsorption involves charge redistribution, with ATP playing a key role as an active site. These findings were confirmed by charge density difference (CDD) analysis, which demonstrated charge transfer during adsorption. The results show that 5 % ATP/BBC can be a sustainable and practical material for HCHO removal, offering valuable insights into developing advanced adsorbents for environmental applications.
93. 题目: Extracellular Polymeric Substances from Penicillium expansum reduce Lead (II) and Chromium (VI) Concentrations and other Physicochemical Parameters in Tannery Wastewater
文章编号: N25041009
期刊: Water, Air, & Soil Pollution
作者: Olufemi Adewale Adeniran, Aliyu Salihu, Abdullahi Balarabe Sallau, Sani Ibrahim, Muhammed Tijani Isa
更新时间: 2025-04-10
摘要:
Extracellular polymeric substances (EPS) are a collection of organic molecules from microbial metabolism, secreted outside the cell to counteract effects of harsh environment, a process that has enabled the application of the biopolymer for wastewater treatment. Reduction in concentration of lead II (Pb2+) and chromium VI (Cr6+) together with other physicochemical parameters from tannery wastewater by EPS from Penicillium expansum was studied. The maximum removal of Pb2+ and Cr6+ were 23.13% and 17.83% respectively under optimized removal conditions of 180 rpm agitation, 90 mg/L EPS concentration, 5.0 pH at 40 °C using a 2-h residence time. However, this low percentage removal of Pb2+ and Cr6+ in the tannery wastewater called for more batches of removal process under optimized conditions. After subjecting the EPS to four batches of removal process, 100% and 89.75% removal of Pb2+ and Cr6+ respectively were achieved in less than 8 h. Based on this, FTIR Analyses showed frequency shifts in alkenyl (C = C), hydroxyl (OH) and carbonyl (C = O) functional groups, and molecular overlapping in the EPS was observed on scanning electron micrograph. Physicochemical parameters in the tannery wastewater were significantly (p < 0.05) reduced by 50% or more with the exception of pH after the duration of the biosorption process. The findings in this study showed that EPS produced by P. expansum could significantly (p < 0.05) decrease the concentrations of Pb2+, Cr6+ and other heavy metals as well as other tannery wastewater physicochemical properties that contributed to its polluting effect.
94. 题目: Remediation strategy of biochar with different addition approaches on antibiotic resistance genes in riparian zones under dry wet alternation
文章编号: N25041008
期刊: Journal of Hazardous Materials
作者: Yufang Chen, Zhenhua Yan, Pengpeng Su, Shiqi Liu, Xi Chen, Runren Jiang, Guanghua Lu, Saiyu Yuan
更新时间: 2025-04-10
摘要: The global prevalence of antibiotic resistance genes (ARGs) has aroused increasing concern due to its threat to ecological security and human health. Although biochar has been widely used for pollution remediation including ARGs, little is known its regulation on antibiotics and ARGs propagation under riparian zones, where undergo frequent occurrence of dry and wet alternations (DWA) caused by water-level fluctuation. Therefore, this study investigated the regulative effects of biochar through different addition approaches on ARGs spread in riparian zone sediments. Under DWA, the presence of biochar (2% w/w) inhibited microbial diversity and function expression, especially for tiled biochar. In addition, compared with DWA, the tiled biochar decreased ARGs abundance by 45.36%, while the well-mixed increased that by 269.02%. The ARGs abundance in sediments was positively correlated with mobile genetic element abundance (R2=0.996, p<0.05), indicative of high horizontal gene transfer potential of ARGs. Metabolomics revealed that both DWA and biochar significantly altered microbial metabolism pathways in sediments, involving sulfur metabolism and histidine metabolism. Furthermore, ARGs propagation in riparian zones may be dominantly driven by MGEs, especially by transposases and integrase. These findings highlight the tiled biochar remediation effects on ARGs in riparian zones under DWA caused by global warming.
95. 题目: Impacts of chlorine disinfection of municipal sewage effluent on receiving rivers: changes in organic matter and microbial communities
文章编号: N25041007
期刊: Journal of Hazardous Materials
作者: Du Su, Weiwei Ben, Bjarne W Strobel, Zhimin Qiang
更新时间: 2025-04-10
摘要: Effluents from wastewater treatment plants (WWTPs) can impact various aspects of receiving aquatic ecosystems, yet the specific effects of chlorine disinfection of effluents on these ecosystems remain poorly understood. In this study, a simulated flow-through channel system was employed to evaluate the changes in water quality and microbial community in receiving rivers resulting from the discharge of WWTP effluent, with or without chlorination. Results showed that dissolved organic matter (DOM) in secondary effluent from WWTPs exhibited higher fluorescence intensity and elevated levels of biopolymers, humic acids, and low molecular weight compounds compared to river water. Microbial analysis revealed that the input of secondary effluent promoted the proliferation of diverse microbial communities in periphyton of the receiving water, while the chlorinated effluents selectively inhibited chlorine-sensitive taxa in periphyton and favored chlorine-tolerant ones. Chlorine disinfection effectively reduced most pathogens in effluents; however, certain genera, such as Neisseriaceae and Escherichia-Shigella, persisted. Moreover, exposure to chlorinated effluent significantly elevated the relative abundance of Pseudomonas in periphyton compared to other conditions, raising concerns about the persistence of chlorine-tolerant pathogens in aquatic environments. These findings highlight the critical need to further evaluate the impact of the disinfection process in WWTPs on the long-term health and stability of riverine ecosystems.
96. 题目: Responses of aggregate-associated carbon and their fractions to different positions in a karst valley of Southwest China
文章编号: N25041006
期刊: Environmental Monitoring and Assessment
作者: Lei Ma, Manyi Li, Cheng Li, Zheng Mao, Chen Wang, Mingze Xu, Dongxue Zhu, Hongtao Si, Shiwei Liu, Pujia Yu
更新时间: 2025-04-10
摘要:
Changes in aggregate-associated carbon and their fractions are vital for soil organic carbon (SOC) sequestration. However, changes in SOC contents and their fractions in different soil aggregates under different landform positions in karst regions remain unclear. Soil samples were collected from the valley bottom (VAFL), dip slope (DIPS), and anti-dip slope (ANTD) in a karst valley of Southwest China. These soil samples were then divided into three aggregates including macroaggregate (> 0.25 mm), microaggregate (0.053–0.25 mm), and silt and clay (< 0.053 mm) using wet sieving methods. Contents of total SOC and their three oxidized carbon fractions (F1: easily oxidized carbon fraction, F2: oxidized carbon fraction, and F3: stable carbon fraction) were measured. Compared with ANTD, total SOC contents, microaggregate-associated carbon contents, and SOC contents in silt and clay fraction decreased by 37.90%, 38.41%, and 40.07%, respectively, under VAFL, and by 12.95%, 11.65%, and 15.60%, respectively, under DIPS. Contents of F1 and F2 fraction under VAFL were significantly lower than those under ANTD and DIPS in bulk soil, microaggregate, and silt and clay. The mean percentages of F2 in total SOC in bulk soil, macroaggregate, microaggregate, and silt and clay were 43.66%, 43.81%, 45.67%, and 41.70%, respectively, while the percentages of F1 were 25.08%, 25.04%, 25.68%, and 24.86%, respectively. Compared with DIPS, SOC stability under ANTD and VAFL increased by 6.59% and 8.44%, respectively. These findings emphasized the influence of landform positions on the carbon contents in different soil aggregates, and deepened the understanding of SOC accumulation mechanisms in Southwest China.
97. 题目: Driving variables to explain soil organic carbon dynamics: páramo highlands of the Ecuadorian Real mountain range
文章编号: N25041005
期刊: Journal of Soils and Sediments
作者: Andrés A Beltrán-Dávalos, Johanna Elizabeth Ayala Izurieta, Magdy Echeverría, Carlos Arturo Jara Santillán, Jochem Verrelst, Jesús Delegido, Agustín Merino, X L Otero
更新时间: 2025-04-10
摘要:
Purpose
Large soil organic carbon (SOC) reserves and a high soil capacity for SOC storage within an ecosystem contribute to mitigating the release of carbon into the atmosphere. Developing new spatially-explicit SOC estimation methods at local and micro-watershed scales is essential for gaining landscape understanding of SOC variability.
Methods
This study provides new insights into the spatial variability of SOC in the Andean páramo soils. A range of variables from different sources (i.e., geophysical, meteorological, topographic, and spectral) were analyzed to identify driving variables to explain the SOC dynamic in the Andean páramo highlands of the Real range in the central region of Ecuador. This information was used to calibrate a SOC prediction model using Classification and Regression Trees (CART) and soil data samples from the 0–30 cm soil horizon.
Results
Eight key variables linking with the SOC storage were used to calibrate the model for SOC estimation with an accuracy of 67% with an RMSE value of 2.17%. Results reveal that sand content emerged as the most significant variable, while taxonomic suborder and protected area variables provided crucial supplementary information. This study improves the ability to detect changes in SOC, particularly in smaller areas where traditional predictors, often more suitable for regional or national assessments, may exhibit insufficient explanatory power.
Conclusion
The Andean páramo highlands of the Real range show high capacity for storing SOC, with values ranging from 3.5% to 19%. This variability highlights the ecosystem's importance as a globally relevant carbon reservoir.
98. 题目: An improved model for estimating soil organic matter content in salt-affected farmlands based on multi-source spectral data coupled with environmental variables
文章编号: N25041004
期刊: Journal of Soils and Sediments
作者: Qidong Ding, Huayu Huang, Junhua Zhang, Lingbin Yang, Keli Jia
更新时间: 2025-04-10
摘要:
Purpose
Accurate estimation of soil organic matter (SOM) content in a timely manner is crucial for soil management in salt-affected farmlands. The aim of the present study was to develop a machine learning model for SOM estimation in salt-affected farmlands using multi-source remote sensing data coupled with environmental variables.
Materials and methods
SOM content and ground hyperspectral reflectance (H) were measured in nine representative farmland sites of the Hetao Plain, northern China. Multi-source remote sensing images were acquired by Landsat 9 OLI (L), Sentinel- 2 MSI (S), and Sentinel- 1 SAR. In addition to single bands, 13 spectral indices (SI) were constructed and 11 environmental variables (EV) were introduced for SOM modeling. After variable selection by the gradient boosting machine, random forest models were developed based on different variable combination strategies.
Results
The SOM contents in the study area were generally low (2.24–23.70 g·kg−1) with moderate spatial heterogeneity. Temperature, precipitation, evapotranspiration, and combined radar polarimetric indices contributed substantially to SOM modeling. The model based on H + L + S + SI + EV showed the best performance, and its R2 value (0.893 in the validation set) was 0.249–0.318 greater than those of the models based on H + SI + EV, S + SI + EV, and L + SI + EV.
Conclusion
Shapley Additive exPlanations analysis identified mean annual precipitation as the overarching environmental variable influencing SOM estimation. Accurate mapping of SOM distribution across the study area was achieved using the optimal model with Sentinel- 2 images. This study presents a useful tool for rapid monitoring of SOM in salt-affected farmlands over large scales.
99. 题目: Role of biochar in enhancing the performance of low-carbon MSWI fly ash/bottom ash-based cementitious materials: Harmful component adsorption and mechanisms
文章编号: N25041003
期刊: Chemical Engineering Journal
作者: Tong Zhao, Siqi Zhang, Huifen Yang, Zeping Wu, Wen Ni, Anlin Shao
更新时间: 2025-04-10
摘要: Utilizing municipal solid waste incineration bottom ash (MSWI BA) to solidify MSWI fly ash (FA) and produce MSWI FA/BA-based cementitious materials (BFM) offers a promising approach for hazardous waste utilization. However, the low hydration activity of MSWI BA and the high concentrations of harmful substances in MSWI FA limit BFM’s potential. To address these challenges, biochar (BC) can be added to regulate harmful substance content and enhance performance, however Supporting Data are lacking. In this study, BC-enhanced BFM (BBFM) was prepared, and its hydration and immobilization mechanisms were investigated using TEM, NMR, XPS, and ion simulation. The results revealed that adding 10 % BC optimized the pore structure of BBFM (gel pores increased from 16.0 %/46.9 % to 46.1 %/78.3 % at 3d/28d), improved the initial water absorption rate (11.12 × 10−3 mm/s1/2, CK1-28d; 12.55 × 10−3 mm/s1/2, BC10-28d), CO2 capture (9.55 %/7.78 %, CK1-3d/28d; 10.94 %/9.12 %, BC10-3d/28d), and compressive strength (2.02/15.77 MPa, CK1-3d/28d; 4.87/28.79 MPa, BC10-3d/28d). BC’s porous structure regulated the Cl and S content through adsorption, promoting the generation of multiple hydration products and increasing crystallization nucleation sites. Pb/Zn immobilization occurred in two stages: first, the adsorption contact sites between PbOH+/ZnOH+ and OH– in C–(A)–S–H gel increased, facilitating the formation of ≡Si–O–Pb/Zn = and ≡Si–O–Si–Pb/Zn = bonds. Subsequently, the C–(A)–S–H gel encapsulated the surface-adsorbed Pb/Zn, generating low-solubility residuals. For As/Cr, BC incorporation enhanced chemical contact sites between Cr/As and hydration products, facilitating the oxidation of Cr3+/As(III) to Cr6+/As(V). Preliminary calculations indicated that adding 10 % BC reduced CO2 emissions by 12.94 % and increased the strength-benefit coefficient by 97.08 %. This work enhances understanding of BC-enhanced BBFM mechanisms, which is essential for carbon reduction, environmental protection, and waste utilization
100. 题目: Organic acid promoting the degradation of nonylphenol by persistent free radicals in biochar
文章编号: N25041002
期刊: Chemical Engineering Journal
作者: Jie Ji, He Zhang, Feichao Zhang, Yao Wu, Han Zhang, Ziwei Mei, Wenxuan Zhou, Liang Li, Hong Tao, Meicheng Wen
更新时间: 2025-04-10
摘要: The environmental and health impacts of nonylphenol (NP) have led to increased efforts in developing green and efficient treatment methods. This study prepared biochar (BC) from pine leaves and sludge at 300 °C and 400 °C, and added organic acid to regulate persistent free radicals (PFRs) for continuous reactive oxygen species (ROS) production to degrade NP. Low-temperature biochar contained more oxygen containing functional groups, enhancing redox reactions. Organic acid effectively regulated pH and provided electrons, promoting high-redox-potential ROS generation in the organic acid-biochar (OA-BC) PFRs system, significantly increasing NP degradation. Notably, 85.71 % of NP was removed using 0.2 g/L 300 °C sludge-derived biochar and 20 mM citric acid. Quenching experiments confirmed that hydroxyl radicals (
OH) played the most significant role in NP degradation. Electrochemical tests and DFT calculations showed that biochar-PFRs can mediate electron transfer from organic acid, maintaining stable ROS generation. This research offers valuable insights into ROS generation and a novel approach for NP degradation.