81. 题目: Carbon Isotope Fractionation of Dissolved Organic Matter Due to •OH-Based Oxidation 文章编号: N25050307 期刊: Environmental Science & Technology 作者: Yunsong Zheng, Yuxuan Tan, Zhenchen Wan, Peng Zhang, Xiuli Li, Songhu Yuan 更新时间: 2025-05-03 摘要: •OH-based oxidation plays a crucial role in dissolved organic matter (DOM) transformation and carbon flux, whereas quantifying the contribution of this pathway remains challenging. Here we combined the concentration with the carbon isotope analysis of DOM and its generated CO2 to quantify the contribution of •OH-based oxidation. Results showed that the 13C enrichment factors (ε values) were −8.1‰ to −8.9‰ for benzene ring oxidation in aromatic compounds, −4.2‰ to −28.9‰ for lower-molecular-weight organic acids, and −13.0‰ for DOM from sediment. The fractionation of sediment DOM reflects the average ε value of humic substances and organic acids. These ε values were more negative than those of the photochemical and microbial processes, enabling the identification of DOM transformation mechanisms. Using an end-member mix model, we found that the proportion of •OH-based mineralization in total CO2 emission ranged from 20.9% to 39.8% for 100 g/L sediment oxidation by 5–20 mM H2O2 under pH-neutral condition within 2 h and was only 2% for oxidation by air under the same conditions. We also found that inorganic carbon degassing contributed greatly to CO2 emission during sediment oxidation. This study presents a new isotope-based tool to quantitatively assess the contribution of •OH-based oxidation to the emission of CO2 from DOM.
82. 题目: Taxonomically distinct diatom viruses differentially impact microbial processing of organic matter 文章编号: N25050306 期刊: Science Advances 作者: Chana F Kranzler, Devin A Busono, Gweneth J Walsh, Alyssa C Carrillo, Kay D Bidle, Kimberlee Thamatrakoln 更新时间: 2025-05-03 摘要: Phytoplankton viruses facilitate the production of dissolved organic matter (DOM) through host lysis, shaping DOM composition, and subsequent regenerative processing. We explored how DOM generated from a bloom-forming, centric diatom, infected with taxonomically distinct viruses—a single-stranded (ss) DNA and a ssRNA virus—impacted microbial processing of organic matter. DOM derived from uninfected and ssDNA virus–infected cultures supported growth in bacterial isolates and a mixed assemblage. In contrast, DOM from ssRNA virus infection did not stimulate growth, but rather induced ectoproteolytic activity, suggesting this DOM was less bioavailable. Exoprotease activity was also substantially higher in ssRNA virus–infected cellular exudates compared to ssDNA virus–infected and uninfected cultures. This suggests that DOM produced through virus-mediated host lysis does not a priori support secondary production and implicate ssRNA virus infection as a source of proteolytic activity in the water column, highlighting a multifaceted role for viruses in altering microbial utilization and remineralization length scales of organic matter in the ocean.
83. 题目: Solid-State NMR Demonstrates Urea Entrapment in Biochar Composites for Slow-Release Nitrogen Fertilizers 文章编号: N25050305 期刊: ACS Sustainable Chemistry & Engineering 作者: Elisa Carignani, Silvia Pizzanelli, Lucia Calucci, Claudia Forte, Daniel P Rasse, Silvia Borsacchi 更新时间: 2025-05-03 摘要: In recent years, biochar loaded with urea has been proposed as a promising N-rich fertilizer with both high-N capacity and slow release. Understanding the interaction between urea and biochar at the molecular level is key to product design. Solid-state NMR (SSNMR) spectroscopy is a particularly powerful method to probe molecular composition and interactions within the bulk of materials. The objective of this work was to identify molecular structures and interactions when urea is loaded into and released from biochar. To do so, we carried out SSNMR investigations of biochar loaded with 13C and 15N isotopically enriched urea. Biochar-urea composites were prepared both with a saturated aqueous urea solution (BUs) and with molten urea (BUm). SSNMR analysis revealed that urea is predominantly in a paracrystalline form on the biochar surface or physically entrapped within biochar pores. In BUm, products of the thermal degradation of urea were also detected, mainly in the form of biuret. Water-immersion experiments showed that 78 and 64% of the urea contained in BUs and BUm is released, respectively, after 24 h, demonstrating substantial retention of urea. The residual urea is mainly physically confined in the biochar pores. In the case of BUm, urea thermal degradation species are also partially retained.
84. 题目: Biochar amendment mitigates negative effects of controlled irrigation on paddy soil structure: Insights from micro-pore network analysis 文章编号: N25050304 期刊: Agricultural Water Management 作者: Jiazhen Hu, Shihong Yang, Wim M Cornelis, Qian Huang, Suting Qi, Zewei Jiang, Haonan Qiu, Yi Xu 更新时间: 2025-05-03 摘要: With increasing rice production demands and water scarcity, developing water-saving irrigation techniques for paddy fields is a global priority. The impact of these techniques on soil structure remains unclear, especially under varying water-carbon conditions. From 2022–2023, field experiments examined four biochar rates and two irrigation methods (controlled irrigation (CI) and flooding irrigation (FI)), resulting in five treatments: CK (0t/ha+CI), CA (60t/ha+CI), CB (30t/ha+CI), CC (10t/ha+CI), and FK (0t/ha+FI). Compared to FK, CK decreased mean weight diameter (19.73–25.54 %), soil organic matter (4.64–9.79 %), total nitrogen (2.68–10.59 %), dissolved organic carbon (1.90–9.48 %), water content at saturation (0.23–15.83 %) and permanent wilting point (3.69–7.87 %), while it increased unstable aggregates index (6.29–15.11 %) and fractal dimension (1.59–1.88 %). Biochar treatments (CA, CB, CC) mitigated CK's adverse effects on soil aggregate stability, total nitrogen, and water retention capacity and significantly improved these indicators. CA increased porosity across various effective pore diameters, while CB and CC primarily increased the proportion of porosity for diameters > 250μm. Simulation results indicated that compared to CK (3.879μm²), the intrinsic permeability (K) of soil under CA, CB, and CC treatments increased by 106.69 %, 77.77 %, and 3.31 %, respectively, while FK showed a contrasting decrease of 3.58 %. K correlated well with > 250μm porosity and connected porosity representing microstructure, with correlation coefficients of 0.96 and 0.94. Overall, biochar improved chemical properties and micropore structure (porosity for diameters >250μm, connected porosity) of soil aggregates under CI, enhancing macroaggregate functions such as soil stability and hydraulic properties.
85. 题目: Integrating fractional-order derivatives of soil and leaf hyperspectral reflectance for improved estimation of mangrove soil organic carbon 文章编号: N25050303 期刊: Geoderma 作者: Yibo Luo, Chunlin Li, Jinhong Huang, Chengcheng Dong, Junjie Wang 更新时间: 2025-05-03 摘要: Mangrove ecosystems are vital for carbon sequestration and coastal protection, yet accurate estimation of soil organic carbon (SOC) using remote sensing remains challenging due to spectral interference caused by dynamic vegetation cover. This study presents a novel framework integrating fractional-order derivative (FOD) techniques with machine learning algorithms for SOC estimation in mangrove wetlands. A total of 201 soil samples were collected from five mangrove wetlands in southern China. FOD was applied to both soil and leaf hyperspectral reflectance to amplify subtle spectral variations typically overlooked by conventional approaches. SOC-sensitive wavelengths were identified using the SHAP-XGBoost (Shapley Additive Explanations-Extreme Gradient Boosting) method. A total of 363 modeling strategies were constructed using Random Forest, XGBoost, and CatBoost (Categorical Boosting) algorithms across 11 vegetation cover levels (0–100 %) and 11 fractional orders (0–2 at 0.2 intervals). Results indicate that fractional orders between 0.8 and 1.4 consistently yielded superior performance. The CatBoost model under 10 % vegetation cover and a fractional order of 1.2 achieved the highest accuracy (R2 = 0.730, RMSE = 0.858 %). Incorporating key soil and terrain variables (e.g. soil iron, clay content, pH, salinity, redox potential, and elevation) into the spectra-based SOC estimation model significantly enhanced prediction accuracy, highlighting the complementary roles of spectral signals, soil characteristics, and topographic features in SOC modeling. This framework holds the potential for advancing blue carbon accounting and supporting sustainable mangrove conservation and management under changing environmental conditions.
86. 题目: Unexpected responses of SOC decomposition and its temperature sensitivity to plant invasion across soil layers: Implications for plantation understory management 文章编号: N25050302 期刊: Catena 作者: Sailan Yang, Xia Xu, Fanxi Peng, Zhu Zhu, Chonghua Xu, Chenghui Ju, Caiqin Shen 更新时间: 2025-05-03 摘要: Soil organic carbon (SOC) decomposition is a key process in regulating carbon (C) sequestration in plantation ecosystems, and its sensitivity of temperature (Q10) is essential for predicting C-climate feedback. However, plantations exhibit heightened vulnerability to plant invasion due to resource fluctuations and frequent disturbances, which may significantly affect SOC decomposition. The mechanisms by which plant invasion influences SOC decomposition rate and its Q10 in plantations remain poorly understood, particularly in subsoil layers. To fill the knowledge gap, we sampled topsoil and subsoil in poplar plantations, both with and without Solidago canadensis invasion, and conducted a 28-day incubation experiment. The results indicated that S. canadensis invasion increased SOC decomposition rate and its Q10 in both soil layers. Notably, the primary drivers of SOC decomposition rate and its Q10 vary with soil depth. In the topsoil, increased enzyme activities were the dominant factors driving SOC decomposition rate and Q10. In contrast, in the subsoil, increased substrate availability played a more significant role. These findings challenge the assumption that plant effects are limited to surface soils and demonstrate that SOC dynamics in subsoil are as sensitive to plant invasion as those in topsoil, due to increased substrate availability. This emphasizes the importance of considering subsoil processes when evaluating the impacts of plant invasions. Additionally, the results suggest that we should pay attention to plantation understory vegetation management to prevent the harmful effects of plant invasions on SOC dynamics under future climate warming scenarios, effects that enhance carbon dioxide (CO2) emissions and exacerbate regional C-climate feedbacks.
87. 题目: Co-utilization of green manure with straw return enhances the stability of soil organic carbon by regulating iron-mediated stabilization of aggregate-associated organic carbon in paddy soil 文章编号: N25050301 期刊: Soil and Tillage Research 作者: Muhammad Mehran, Li Huang, Mingjian Geng, Yafen Gan, Jinyun Cheng, Qiang Zhu, Iftikhar Ali Ahmad, Sharjeel Haider, Adnan Mustafa 更新时间: 2025-05-03 摘要: Despite increasing interest in sustainable soil management, the mechanisms by which long-term green manure and straw return impact Fe-organic associations and soil organic carbon (SOC) stabilization in paddy soils are unclear. This study examines their effects on SOC stability, aggregate fractionation, Fe oxides, aggregate stability, and SOC composition in macro- and micro-aggregates. A well-established 8 year field experiment with four treatments, i.e., Chinese milk vetch without straw incorporation and fertilizer (CK), winter fallow without straw incorporation and with NPK (WF+NSR+NPK), winter fallow with straw incorporation and NPK (WF+SR+NPK), and Chinese milk vetch with straw incorporation and with NPK (MV+SR+NPK), were selected. The results demonstrated that the MV+SR+NPK treatment significantly (p < 0.05) increased SOC storage in macroaggregates by 18.2 % compared to CK, while reducing SOC in microaggregates and non-aggregated fractions by 1.14 % and 21.54 %, respectively. Additionally, this treatment enhanced soil aggregation, as evidenced by a 26.33 % increase in mean weight diameter (MWD) and a 54.62 % increase in geometric mean diameter (GMD), alongside a 21.5 % rise in macroaggregate formation. Further, SOC stability was reinforced by a 16.8 % increase in aromatic-C content and a 19.4 % rise in the aromatic-C/aliphatic-C ratio depicting enhanced chemical stability and resistance to degradation. Amorphous (Feo) and complex Fe oxides (Fep) in macroaggregates were 13.5 % and 17.9 % higher than in CK. In comparison, the WF+SR+NPK treatment improved MWD by 25.94 %, GMD by 31.93 %, and SOC in macroaggregates by 1.69 %, with significant increases in Feo and Fep contents by 39.92 % and 102.08 %, respectively. Furthermore, the aromatic-C/aliphatic-C ratio increased by 33.9 %, indicating enhanced SOC stability. Conversely, the WF+NSR+NPK treatment decreased MWD by 12.97 %, with only a slight increase in SOC and Fed in finer aggregates by 0.80 % and 3.12 %, respectively. These results demonstrate that the co-utilization of green manure and straw return, in combination with NPK fertilization, significantly (p < 0.05) enhances SOC stabilization and aggregate stability by promoting Fe-organic associations, thereby contributing to long-term carbon sequestration in paddy soils.
88. 题目: A mechanistic study on removal efficiency of neonicotinoids by biochars with various fabrication methods 文章编号: N25050209 期刊: Journal of Environmental Chemical Engineering 作者: Xian Yuan, Wei Jiang, Haiyun Zhang, Xiaofang Shen 更新时间: 2025-05-02 摘要: Neonicotinoid insecticides (NNIs) are widely detected in the environment, and their removal has garnered significant attention. Biochar is an efficient sorbent, but various fabrication processes affect its adsorption efficiency, and the role of N-containing functional groups in NNI adsorption on biochar remains underexplored. In this study, 48 biochars were synthesized using various raw materials (rice straws, Cinnamomum camphora branches, or shrimp shells), pyrolysis temperature (300, 450, 600, or 750℃), and modification methods (pristine, NaOH, H3PO4, or urea). Adsorption results indicate that these three factors significantly influence the removal efficiency of four NNIs (clothianidin, imidacloprid, nitenpyram, and thiamethoxam). Moreover, biochars derived from rice straw and camphora branches at 750℃ exhibited significantly higher adsorption capacity than the others. Therefore, five biochars pyrolyzed at 750℃ were further analyzed, including four rice straw-based biochars (one pristine and three modified with NaOH, H3PO4 and urea), and one camphora branch-based biochar modified with urea. Although various modification methods significantly enhanced the biochars’ specific surface area and pore volume, these properties were not the dominant mechanisms governing NNI adsorption enhancement. However, the NNIs adsorption capacity was significantly correlated with the pyrrolic N content of the five biochars, with urea-modified rice straw biochar (7-r-U) exhibiting the highest adsorption capacity and pyrrolic N content. DFT calculations revealed that pyrrolic N carried a significant higher negative charge than graphitic or pyridinic N, leading to a stronger hydrogen bonding and electrostatic interaction with NNIs. These findings are crucial for developing highly efficient sorbents for NNI removal.
89. 题目: Hyperaccumulator biochar prepared via hydrothermal pretreatment for azo dye degradation: peroxymonosulfate activation and life cycle assessment 文章编号: N25050208 期刊: Journal of Environmental Chemical Engineering 作者: Minghui Pan, Yasir Hamid, Bożena Czech, Zhenli He, Xiaoe Yang 更新时间: 2025-05-02 摘要: Converting waste into catalysts is a sustainable approach for wastewater treatment and resource management. Here, heavy metals-enriched hyperaccumulator (Sedum alfredii) residues were utilized to prepare various functional biochars through hydrothermal carbonization (HTC) pretreatment followed by pyrolysis. The catalytic performance of these biochars for the removal of azo dye acid orange 7 (AO7) was evaluated in conjunction with activated peroxymonosulfate (PMS). The results depicted that functionalized biochar (SAHC200-8)/PMS system achieved 99.7% removal of AO7 (50 mg L-1) within 30 min, compared to the pristine biochar (SABC-8)/PMS system (10%), depicting the apparent rate constant (Kobs) of 0.1333 min-1. Despite the presence of multiple reactive oxygen species (ROSs) in the reaction solution, the relative contribution of nonradical electron transfer was quantified to be the largest (=86.56%). In addition, the quantitative evaluation using the life cycle assessment (LCA) revealed that the SAHC200-8/PMS system exhibits superior environmental performance compared to the conventional biochar/PMS system. This study highlights that HTC, as a pretreatment method, significantly enhances the electron transfer capacity of biochar by promoting the development of graphitic structures. This approach not only boosts catalyst performance but also offers a sustainable method for waste utilization, contributing to effective environmental remediation and pollution reduction.
90. 题目: Highly selective recovery of lanthanum and cerium from wastewater by amidoxime-modified biochar 文章编号: N25050207 期刊: Separation and Purification Technology 作者: Jiaying Li, Xu Zhu, Yiying Zhao, Min Yang, Xiaolei Zhang, Huihui Chen, Qiang Liu 更新时间: 2025-05-02 摘要: Efficient recovery of rare earth elements (REEs) is crucial for resource utilisation and environmental protection. In this study, we developed novel biochar adsorbents (AOBC300, AOBC500, and AOBC700) by grafting amidoxime groups onto corn stover biochar prepared at temperatures ranging from 300 to 700 °C. The adsorption and selective removal efficiency of these adsorbents for La(III) and Ce(III) from water were investigated. The results showed that, despite a significant reduction in specific surface area from 125.75 to 13.15 m2/g after modification, AOBC700 demonstrated superior adsorption capacity: 60.24 mg/g for La(III) (at a biochar dosage of 1.6 g/L, and pH 6) and 45.20 mg/g for Ce(III) (at a biochar dosage 2.0 g/L and pH 6). These values are 5.0 and 3.2 times higher than the unmodified biochar, respectively. Notably, AOBC700 exhibited remarkable selective removal ability for REEs in the complex leaching solutions of fly ash and red mud. It also retained over 75 % of its adsorption capacity after five adsorption–desorption cycles. Density functional theory (DFT) calculations provided insights into the adsorption mechanism of different REEs onto AOBC700. Additionally, machine learning (ML) models were employed to evaluate adsorbent performance, with the eXtreme Gradient Boosting (XGB) model showing the highest prediction accuracy. A Shapley addition explanation highlighted the key factors influencing REEs adsorption as follows: time > initial concentration > dosage > pH > electronegativity. These findings confirm the significant potential of AOBC700 for selectively recovering REEs from waste streams.
91. 题目: Design of functional groups on biochar for sulfamethoxazole adsorption from adsorption efficiency and adsorption mechanism 文章编号: N25050206 期刊: Journal of Environmental Chemical Engineering 作者: Yinxue Li, Zebin Cheng, Hongru Shang, Yanan Chen, Shengyuan Li, Xiao Wei, Tengfei Wang, Weixing Zhou, Yanling Yu 更新时间: 2025-05-02 摘要: Sulfonamide antibiotics (SAs) as persistent pollutants exist in urban and agricultural water environments, and biochar has a certain adsorption effect on SAs. The influence of surface functional groups of biochar on sulfamethoxazole adsorption from the quantitative relation of adsorption efficiency and adsorption mechanism was discussed in detail. Among the seven functionalized biochars, the highest adsorption of sulfamethoxazole (SMX) in the acidic and neutral environments was observed for phosphoric acid activated-biochar PB600, which reached 195 and 174 mg·g–1, respectively, and in the alkaline environment, which reached 155 mg·g–1 for amino-biochar NHB600. Phosphoric acid activation introduced –COOH-dominated oxygen-containing functional groups into PB600, increasing the total number of surface functional groups to 211% of the pre-functionalization level, and the adsorption contribution degree of π+−π electron donor-acceptor interaction (EDA) increased from 35% pre-functionalization to 48% post-functionalization at pH=2 in the meantime. Amination introduced a large amount of –NH2 to NHB600, increasing the total number of surface functional groups to 336% and the adsorption contribution degree of negative charge-assisted hydrogen bonds [(−)CAHB] from 14% to 37% at pH=10. In addition, PB600 showed good SMX continuous adsorption performance in the fixed bed reactor, especially when at low influent water concentration, the dynamic adsorption capacity reached up to 191 mg·g–1 (with the initial concentration of SMX of 50 mg·L–1). PB600 also performed well in real cattle manure effluent. Thus emphasizing the importance of the targeted functionalized design of biochar for the adsorption of sulfonamide antibiotics.
92. 题目: Enhanced fine soil aggregation and organic matter accumulation facilitated by Salix Psammophila sand barriers along desert highways 文章编号: N25050205 期刊: Frontiers in Environmental Science 作者: Chen Zhao, Yong Gao, Yanlong Han, Xiaojie Yang 更新时间: 2025-05-02 摘要: Desert ecosystems are inherently nutrient-limited and highly susceptible to disturbances. In such arid environments, sand barriers play a pivotal role in ecological restoration efforts. Despite their importance, the long-term effects of Salix Psammophila sand barriers on soil particle size distribution and organic matter content in the Hobq Desert, China, have received limited empirical investigation. To this end, the present study was conducted to investigate sand dunes along the Hobq Desert Sand Penetration Highway, where sand barriers had been established for 1, 3, and 5 years. Specifically, soil particle size distribution was analyzed using multifractal theory to assess spatiotemporal variations associated with varying durations of sand barriers installation. The following observations should be noted: Ⅰ. Significant differences were identified in soil particle size distribution between dunes with varying sand barrier ages and mobile dunes within the study area. As the duration of sand barriers presence increased, the proportions of clay (3.45%), silt (5.46%), and very fine sand (7.35%) increased correspondingly, whereas the fractions of medium and coarse sand decreased. Ⅱ. Multifractal spectral analysis of soil particle size distribution enabled the precise quantification of soil texture heterogeneity. Over time following the installation of sand barriers, soil particle size distribution exhibited enhanced heterogeneity, evidenced by an expanded spectrum and increased fine-grained material content. Ⅲ. Soil organic matter content increased substantially with the duration of sand barriers establishment. Notable spatial variations in organic matter content were detected across different dune slopes, following the trend: bottom slope (0.85 kg/kg) > middle slope (0.77 kg/kg) > top slope (0.62 kg/kg). Moreover, soil particle size distribution exhibited a strong correlation with soil organic matter content, suggesting the essential role of clay, silt, and very fine sand in organic matter stabilization. Collectively, the installation of Salix Psammophila sand barriers significantly enhances the accumulation of fine soil fractions (clay, silt, and extremely fine sand), thereby facilitating the sequestration of soil organic matter. This process improves soil physicochemical properties, fosters vegetation establishment, and ensures the long-term stabilization of aeolian landforms along desert highways.
93. 题目: Superior ammonia nitrogen adsorption capacity and reusability biochar microsphere applied in live fish transportation 文章编号: N25050204 期刊: Chemical Engineering Journal 作者: Ling Peng, Tao Yin, Zhiyong Song, Shanbai Xiong, Ru Liu, Juan You, Qiling Huang 更新时间: 2025-05-02 摘要: Ammonia nitrogen is a major stressor that negatively affects the welfare of fish during transportation, leading to considerable economic losses. However, there is a lack of effective materials to adsorb ammonia nitrogen in water during the transportation. In this study, we prepared a biochar microsphere, chitosan loaded magnesium biochar microsphere (CS-Mg-SB-M), which showed the superior ammonia–nitrogen adsorption efficiency and reusability compared to the materials prepared with either magnesium impregnation or chitosan modification alone. The removal rate of ammonia nitrogen reached 83.41 % in water containing 50 mg L−1 ammonia nitrogen. The Pseudo-second-order kinetics and Langmuir isotherm models fitted the adsorption process well, suggesting that chemical and monolayer adsorption play a dominant role in ammonia nitrogen adsorbed by CS-Mg-SB-M. The adsorption mechanism of ammonia nitrogen removal by CS-Mg-SB-M involved the synergistic effects of physical absorption (colossal surface area and pore size) and chemical absorption (including coordination bonds, hydrogen bonds, and ionic bonds) according to results of SEM, XRD, FTIR and molecular dynamic simulation. In practical applications, CS-Mg-SB-M demonstrated 33–53 % ammonia nitrogen absorption efficiency, elevating survival rates to 40–60 % alongside measurable enhancements in muscle quality (e.g., cellular structure, drip loss, whiteness, brightness, and redness) of fish after 24 h of transporting in high-density and individual packing modes. This study represents the first application of feasible material to remove ammonia nitrogen in the live fish transportation system, concurrently enhancing survival rate and muscle quality.
94. 题目: Transformation of dissolved organic matter and associated metals in boreal mire and river waters: Effects of biota and sunlight 文章编号: N25050203 期刊: Water Research 作者: Olga Yu. Drozdova, Alisa R Aleshina, Sergey A Lapitskiy, Oleg S Pokrovsky 更新时间: 2025-05-02 摘要: Despite the undeniable importance of bio- and photo-degradation of dissolved organic matter (DOM) in the carbon (C) cycle of natural waters, the combined effects of these processes on C and trace metal concentrations remain largely unexplored. In particular, a central question remains on the partitioning of major and trace metals and DOM in dissolved, colloidal, and particular fractions in the presence of sunlight and microorganism. In this study, we selected two contrasting yet representative water samples from a European boreal region: an acidic mire (pH = 4.3, DOC = 130 mg L−1) and a neutral boreal river (pH = 7.6, DOC = 39 mg L−1). By analyzing major and trace metal solutes in particulate (0.22–100 µm), colloidal (1 kDa–0.22 µm), and low molecular weight (LMW<1 kDa) fractions, we tracked changes in DOM quality and concentrations of major DOC (dissolved organic carbon) pools and trace metals during a 10-day exposure to sunlight and incubation with a native bacterial consortium (with and without sunlight). The susceptibility of organic and inorganic colloids to photo- and biodegradation was influenced by the pH of the aqueous solutions, with significant differences in the behavior of DOC, Fe, and trace metals between mire and river water. However, in both cases, photodegradation was the dominant process over biodegradation, with the most substantial solute concentration changes observed during combined sunlight and bacterial treatment Collectively, the experiments demonstrate the dominant effect of photolysis on the partitioning of DOM, Fe, and trace metals among particulate, colloidal, and low molecular weight (LMW) ‘truly’ dissolved fractions. Significant changes, ranging from 1.5 to 3 times in solute concentrations, can occur over relatively short exposure periods (< 1 week) and vary substantially between small water bodies with contrasting acidity and DOM concentrations. These findings highlight the need for further research into photolysis and biodegradation processes, with a focus on seasonal variations, residence times, and biotic activity.
An experiment of randomized block design, was conducted in a soil which was simulated to create equidistant levels between the desired characteristics of soil, such as clay, organic matter, pH, electrical conductivity, heavy metals and micro and macro nutrients, respectively. These simulated soil characteristics were attained by applying the appropriate quantities of the following substances on virgin soil: (i)- sterile fine particle sand of the type, (ii)- CaO, biosolids (iii)- mixtures of salts of heavy metals, for the enhancement of the equidistant levels between the soil characteristics, and (iv)- biosolids for the enhancement of the organic matter. The aim of the experiment was the investigation of the relation between soil toxicity as expressed by the soil toxicity indices and the interactive elemental contribution in heavy metals and the impact of incubation time over a period of 358 days. The studied interactions included heavy metals with pH, organic matter, clay, electrical conductivity, heavy metals and micro and macro nutrients. The regression analysis of the experimental soil data produced numerous statistically significant elemental interactions that ultimately contributed significant levels of heavy metals related to soil toxicity and was thus shown that these interactive activities constitute important regulatory factors of soil toxicity.
96. 题目: Physicochemical differences between wildfire pyrogenic carbon and slow-pyrolysis biochar suggest variations in elemental transport potential. 文章编号: N25050201 期刊: Environmental Science: Processes & Impacts 作者: Katherine N Snihur, Lingyi Tang, Kelly J Rozanitis, Daniela Gutierrez-Rueda, Cody N Lazowski, Daniels Kononovs, Logan R Swaren, Murray K Gingras, Janice P L Kenney, Shannon L Flynn, Kurt O Konhauser, Daniel S Alessi 更新时间: 2025-05-02 摘要: Wildfires play a crucial role in the carbon cycle. Their contribution to the global carbon cycle is expected to increase with climate change as fire activity, particularly in boreal forests, escalates. As 8-28% of annually produced pyrogenic carbon is transported through riverine systems, its impact on fluvial environmental conditions will likely increase in coming years. However, the impact of pyrogenic carbon on metal and nutrient transport remains poorly understood. Here, we compare the chemical composition of wildfire-derived pyrogenic carbon (F-PyC) with slow-pyrolysis biochar-derived pyrogenic carbon (B-PyC), both originating from the same mountainous boreal forest biomass, to determine if F-PyC shares physicochemical properties with artificial B-PyC. The results reveal notable differences in the physicochemical properties and bulk composition of F-PyC compared to B-PyC, even when both are produced under similarly high temperatures, due to the rapid heating and cooling during wildfires. These differences in pyrolysis conditions result in F-PyC having a smaller ash fraction (<2.7% vs. >5.0%), a more acidic pH (<7.0 vs. >7.8), and a less thermally mature mineral composition and surface functionality. Together these differences in properties result in markedly different leaching behaviors and suggest that F-PyC and slow pyrolysis B-PyC play different roles in elemental transport. Consequently, this work supports earlier claims that B-PyC is not a suitable proxy for the F-PyC, particularly with respect to elemental transport in fluvial environments. Our work highlights the necessity for research specifically focusing on F-PyC to accurately quantify the contribution of wildfires to global elemental cycling, presently and in the geologic past.
97. 题目: Ultrafast degradation of tetracycline via peroxymonosulfate activation using ZIF-8 modified biochar-supported MgAl/LDH 文章编号: N25050111 期刊: Journal of Environmental Chemical Engineering 作者: Hongbin Chen, Weikun Sun, Tao Li, Jian Zhang, Shengqin Liu, Yufang Liao, Mohammad Younas, Zumin Qiu 更新时间: 2025-05-01 摘要: Antibiotic contamination poses significant threats to ecosystems and human health, necessitating innovative and efficient treatment solutions. This study presents a novel catalyst system by synergistically combining biochar, layered double hydroxide (LDH), and zeolitic imidazolate framework (ZIF-8) for tetracycline (TC) degradation. LDH and ZIF-8 were co-precipitated onto corncob powder and pyrolyzed to obtain CoZn@LDO-BC2, a novel catalyst for the degradation of TC via peroxymonosulfate (PMS) activation. The CoZn@LDO-BC2 demonstrated a remarkable removal efficiency of 95.68% for TC within just 7 min, significantly surpassing other materials such as MgAl/LDH-BM (59.15%), ZIF-8 (75.73%), and ZIF-8@LDH-BM2 (78.31%). This excellent degradation performance is primarily attributed to the synergistic interactions between free radicals and non-free radicals, with 1O2 and SO4•- being the main reactive oxygen species. Moreover, CoZn@LDO-BC2 exhibited excellent performance in various real water environments and fixed-bed experiments, demonstrating its excellent anti-interference properties and broad practical applicability. Furthermore, detailed studies of TC degradation pathways and intermediate toxicity confirmed the reduced toxicity of by-products, as evidenced by wheat cultivation experiments. This work broadens the potential applications of biochar-based porous materials and provides an innovative approach to address antibiotic wastewater treatment.
98. 题目: Strong heterogeneity in laterally exchanged particulate organic matter across tidal marshes in a large river delta 文章编号: N25050110 期刊: Environmental Research 作者: Qi Wu, Hong-Sheng Cao, Youhei Yamashita, Christian Lønborg, Run Li, Jianzhong Ge, Hualei Yang, Bolin Liu, Jinzhou Du, Fang Cao 更新时间: 2025-05-01 摘要: Understanding the lateral exchange of particulate organic matter (POM) between wetlands and estuaries is essential for understanding coastal carbon budgets and dynamics. We studied tidal and seasonal changes in the concentration of POM ([POC]) and its optical properties in three marsh creek systems along a salinity gradient in one of the world’s largest river deltas — the Yangtze River Delta. Results reveal strong variability, with tides and among sites, in both [POC] and compositions of POM. The maximum tidal POC export occured in fall with brackish marshes exporting [POC] rich (9 times higher) with a lower chromophoric signal (i.e., lower light-absorbing capacity) compared to the freshwater marsh (avg. [POC] of 1708 (brackish) and 192 (freshwater) μmol L−1; avg. normalized POM absorption a*(350)p of 4.3 (brackish) and 16 (freshwater) L mol−1 cm−1). Creek POM in the brackish marshes were dominated by materials having visible fluorescence (avg. proportion of 54%), likely due to a higher contribution from suspended solids and wind-induced soil erosion. Contrary, in the freshwater marsh the tidal POM was consistently enriched in material strongly fluorescing in the UVA range (avg. proportion of 84%), likely caused by extreme droughts and higher aboveground biomass. The primary driver of the observed differences among the three marshes were differences in hydrodynamics, with the resulting high spatial heterogeneity complicating delta-wide assessments of carbon flows and stocks. This study highlights the importance of [POC] in carbon budgets and the necessities of integrating site-specific lateral POC monitoring to improve estimates on carbon budgets in large deltas.
Drought events are becoming more severe and recurrent over Europe. Changes in temperature and rain patterns can affect soil nutrient mobility and availability, modulating the biomass and activity of soil microbial communities. Here, we investigated the effects of drought on extracellular polymeric substances (EPS) and microbial biomass carbon (MBC) and nitrogen (MBN) in differently managed cropping systems. An on-field drought simulation experiment using rain-out shelters was conducted as part of a long-term field experiment cultivated with winter wheat, comparing cropping systems with contrasting fertilization strategies and crop protection measures: A biodynamic system and a mixed conventional system with no pesticide application, and a purely minerally fertilized conventional system, with conventional pesticide use. The implemented drought lasted for three months, starting at plant tillering stage and ending at ripening stage. No watering was performed on the drought treatment during that period. Soils were sampled at stem elongation, flowering, and ripening. EPS-carbohydrates and EPS-proteins significantly increased by approximately 20% due to induced drought but remained roughly constant from stem elongation to ripening under drought. Mean EPS-carbohydrates to EPS-proteins ratio was 1.9. MBC and MBN remained largely unaffected by drought. The ratio of both EPS fractions to microbial biomass was lowest in the biodynamic system and highest in the minerally fertilized conventional system, indicating that rhizodeposits and mucilage were predominantly diverted into microbial biomass, rather than into microbial EPS. This might be an important reason for the higher soil fertility of the biodynamic system.
100. 题目: Higher Remediation Efficiency of Cd and Lower CO2 Emissions in Phytoremediation Systems with Biochar Application 文章编号: N25050108 期刊: Environmental Pollution 作者: Yang Lei, Danlian Huang, Wei Zhou, Ruihao Xiao, Haojie Chen, Hai Huang, Wenbo Xu, Guangfu Wang, Ruijin Li 更新时间: 2025-05-01 摘要: Biochar has been considered a promising material for soil carbon sequestration. However, there are huge knowledge gaps regarding the carbon reduction effects of biochar-plant-polluted soil. Here, rice straw biochar (RB) was applied in ryegrass-cadmium (Cd)-contaminated soil to investigate the full-cycle carbon dioxide (CO2) emission and intrinsic mechanism. RB resulted in a 37.00%-115.64% reduction in accumulative CO2 emissions and a 31.61%-45.80% reduction in soil bioavailable Cd throughout the whole phytoremediation period. CO2 emission reduction triggered by RB can be attributed to the regulation of plant and rhizosphere ecological functions. RB could bolster photosynthetic carbon fixation by maintaining the stability of the structure of the chloroplasts and thylakoids, accelerating the consumption of terminal photosynthate, upregulating photosynthetic pigments, and mitigating oxidative damage. Besides, RB reduced the metabolism of readily mineralizable carbon sources while reinforcing the utilization of certain nutrient substrates. Besides, the composition of rhizosphere microbial communities was altered, especially those associated with carbon cycling (Chloroflexi, Actinobacteriota, and Acidobacteriota phyla) to orient soil microbial evolution to lower soil CO2 emission. This study aims to establish a win-win paradigm of “carbon reduction-pollution alleviation” to deepen the understanding of biochar in carbon neutrality and soil health and provide a theoretical basis for field pilot-scale studies.
