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101. 题目: Exploring the co-occurrence of microplastics, DOM and DBPs inside PVC pipes undergoing chlorination by correlation analysis and unsupervised learning 文章编号: N25013112 期刊: Chemosphere 作者: Thitiwut Maliwan, Quyen Thi Thuy Do, Chi Mai Nguyen, Wan Kee Teo, Jiangyong Hu 更新时间: 2025-01-31 摘要: Drinking water distribution systems face a multifaceted emerging concern, including in situ microplastic (MP) generation, chemical leaching from plastic pipes, and the formation of disinfection by-products (DBPs). This study investigated the co-release of MPs and chemical leachates from polyvinyl chloride (PVC) pipes exposed to different chlorine concentrations on a lab scale, as well as the subsequent formation of DBP. Results highlighted significant evidence of PVC-derived dissolved organic matter (PVC-DOM) and microplastic (PVC-MP) leaching at higher chlorine concentrations. However, at chlorine residuals of 1 ppm, natural organic matter (NOM) retained its importance, with minimal release of PVC-DOM and PVC-MP from plastic pipes. Correlation analysis highlights the critical role of DOM, including both NOM and PVC-DOM, as a key intermediary between MPs and DBPs. This is evidenced by the strongest observed correlations within the DOM group and its significant associations with both MPs and DBPs. Conversely, the limited direct connections between MPs and DBPs further underscore the importance of DOM as the key link between these two targets. Using unsupervised learning techniques, including clustering and dimensionality reduction, further elucidated the influence of DOM in controlling the data patterns, enabling robust interpretation of complex datasets, and providing valuable insights. This study contributes to advancing understanding of the co-occurrence and behaviors of MP, DOM, and DBP within drinking water distribution systems, as well as propelling the associated risk in this intricate scenario. |
102. 题目: Biocrusts benefit soil carbon sequestration via increasing the stability of soil dissolved organic carbon in dryland ecosystem 文章编号: N25013111 期刊: Journal of Environmental Management 作者: Jia Shi, Jianguo Tao, Yumei Peng, Jie Wang, Xiang Wang 更新时间: 2025-01-31 摘要: Dissolved organic matter (DOM) is a bioavailable and complex carbon pool, which pool size and chemical composition fundamentally determine soil organic carbon (SOC) cycle and are strongly impacted by biocrusts. However, how the chemical compositions of DOM impact SOC sequestration in dryland ecosystems remains largely unknown. |
103. 题目: Humic Acid with Vertical Adsorption Conformation Enhanced the Transport of Petroleum Hydrocarbon-Contaminated Colloids 文章编号: N25013110 期刊: Environmental Science & Technology 作者: Jie Ma, Ping Zhou, Yong Liu, Wanli Lian, Bingcong Feng, Li Li, Yujie Zhao, Liping Weng, Gangxing Lei, Haiming Li 更新时间: 2025-01-31 摘要: Humic acid (HA) enhances colloidal transport in porous media, yet the mechanisms by which the HA adsorption conformation affects colloid transport remain unclear. This study investigated the influence of HA on the transport of petroleum-hydrocarbon-contaminated soil colloids (TPHs-SC) in saturated sand columns. The presence of TPHs on the colloidal surface occupied adsorption sites, hindering HA from forming a horizontal adsorption conformation, as observed on uncontaminated soil colloids (SC). Instead, a vertical adsorption conformation was formed, reducing the overall adsorption of HA. Vertically adsorbed HA increased the colloidal diffuse double-layer potential and extended the Derjaguin–Landau–Verwey–Overbeek energies between colloids and water-bearing media. This was evidenced by higher ζ potentials (−28.5 to −34.0 mV) and enhanced TPHs-SC transport compared to SC (ζ potentials ranging from −25.2 to −29.5 mV) in the presence of HA, particularly under alkaline conditions. Additionally, weak van der Waals and electrostatic interactions between TPHs near colloidal surfaces and free HA/TPHs formed a zonal distribution, facilitating the cotransport of colloids with TPHs. These findings underscore the significance of the HA adsorption conformation in TPHs-SC transport and provide insights into the critical mechanisms from an environmental structural chemistry perspective. |
104. 题目: Meta-metabolome ecology reveals that geochemistry and microbial functional potential are linked to organic matter development across seven rivers 文章编号: N25013109 期刊: Biogeosciences 作者: Robert E Danczak, Amy E Goldman, Mikayla A Borton, Rosalie K Chu, Jason G Toyoda, Vanessa A Garayburu-Caruso, Emily B Graham, Joseph W Morad, Lupita Renteria, Jacqueline R Hager, Shai Arnon, Scott Brooks, Edo Bar-Zeev, Michael Jones, Nikki Jones, Jorg Lewandowski, Christof Meile, Birgit M Muller, John Schalles, Hanna Schulz, Adam Ward, James C Stegen 更新时间: 2025-01-31 摘要: . Rivers receive substantial dissolved organic matter (DOM) input from the land and transport it to the ocean. As DOM travels through watersheds, it undergoes biotic and abiotic transformations that impact biogeochemical cycles and any subsequent CO2 release into the atmosphere. While recent research has increased our mechanistic knowledge of DOM composition within watersheds, DOM development across broad spatial distances and within divergent biomes is under investigated. Here, we combined DOM characterization, geochemical analyses, and shotgun metagenomics to analyze samples from seven rivers ranging from the U.S. Pacific Northwest to Berlin, Germany. Initial analyses revealed that many DOM properties were distinguished by river type (e.g., wastewater, headwater) and that geochemistry often explained variation across rivers. At a global scale, analyses rooted in meta-metabolome ecology indicated that DOM was structured overwhelmingly by deterministic selection. When controlling for scale, however, analyses indicated that ecological assembly dynamics were again partially structured by river type. Finally, microbial analyses revealed that many riverine microbes from our systems shared core metabolic functional potential while differing in peripheral capabilities in across the rivers. Further analysis of the carbon degradation potential for recovered metagenomically assembled genomes indicated that the sampled rivers had strong taxonomically conserved niche differentiation and that carbon degradation potential diversity was significantly related to organic matter diversity. Together, these results help us uncover interconnections between the development of DOM, riverine geochemistry, and microbial functional potential. |
105. 题目: Pyrolytic conversion of construction, renovation, and demolition (CRD) wood wastes in Québec to biochar: Production, characterization, and identifying relevant stability indices for carbon sequestration 文章编号: N25013108 期刊: Science of the Total Environment 作者: Aravind Ganesan, Olivier Rezazgui, Simon Langlois, Cyrine Boussabbeh, Simon Barnabé 更新时间: 2025-01-31 摘要: Management of heterogeneous construction, renovation, and demolition (CRD) wood residues in Québec brings into light, a widespread topic under discussion related to their current disposal methods in landfills, that may lead to environmental concerns. With rising forfeitures from a legal standpoint, alternative treatment methods for CRD wood wastes are being explored. Thermochemical biomass conversion techniques can be employed to depolymerize low-quality end-of-life CRD wood and valorize it to bio-based products. Biochar, a carbonaceous material obtained through heat treatment of wood under the absence of oxygen via slow pyrolysis, can be tailored for specific end-use applications in hard-to-abate industrial sectors pertinent to energy, composite materials, and environmental amendments. However, there is a scarcity of comprehensively understanding CRD wood pyrolysis and projecting the biochar product's stability due to a lack of relevant studies and frequent inconsistencies amidst currently available methods. Nevertheless, in the present study, CRD wood is pyrolyzed in a horizontal tube furnace of two scales under laboratory conditions. Temperatures ranging from 300 to 800 °C, biomass residence time (BRT) of 30–120 min, heating rates of 20–55 °C/min, and mass of feedstock between 100 and 500 g were the operational conditions chosen for experimentation. Evaluation of biochar stability was carried out by the proximate and ultimate analysis, Van-Krevelen plots, TGA/DTG profile, R50 recalcitrance, SEM-EDX, and Raman ID/IG methods. Data analysis indicated that carbon content (89–90 %), FC (70–74 %), TSF (73–75 %), R50 (0.64–0.65), and ID/IG (0.972) increased with an increase in BRT (120 min) and pyrolysis temperature (800 °C) rendering its utilization in metallurgical applications as a reductant. A surface area of 220–270 m2/g was also detected for these biochar at 800 °C recommending its implementation for adsorption applications. Biochar's cation exchange capacity (CEC), pH, and hydrophobicity also increased at high temperatures nurturing the ability to be used for soil pH adjustment as part of remediation activities. SEM-EDX proved that ash content predominantly harboring alkaline and alkaline earth metals (AAEM) like Ca and K also increased but to a certain point from where their devolatilization is implicit, thereby concentrating stable carbon. As for functionalities in biochar, they decreased from 500 to 800 °C verifying the rejection of oxychemicals groups. Noticeable striations associated to C-H/C-O/C=O vibration, stretching, and bending from FTIR spectral bands were linked to terminal dehydrogenation, condensation, and aromatization reactions highlighting the development of CC and CC linkages commonly assigned to aromatics. Evident from low Van-Krevelen H/C (0.51–0.09) and O/C (0.08–0.02) indices, it can be extrapolated that high-temperature biochars in PR:1 and PR:2 possess a high permeance that could bolster its utilization in carbon sequestration/draw-down and other CDR applications. |
106. 题目: Non-reactive biochar and Bacillus pumilus RSB17-based healing powder: A sustainable solution for enhanced bacterial viability in self-healing mortar 文章编号: N25013107 期刊: Science of the Total Environment 作者: P P Anoop, T Palanisamy 更新时间: 2025-01-31 摘要: Existing mortar uses self-healing powders that are based on mineral admixtures, whose reactive nature negatively impacts bacterial viability and diminishes their effectiveness over time. This study aims to develop non-reactive, sustainable biochar-based healing powders with extended bacterial viability to serve as self-healing admixture in bio-mortar. Biochar from coconut husk, coconut shell, and coconut leaf petiole was evaluated for compatibility with Bacillus pumilus RSB17, emphasizing bacterial growth and calcium carbonate precipitation. Coconut shell biochar demonstrated superior performance and was used to formulate a microbial biochar healing powder. Another healing powder was prepared by lyophilizing the bacterial spore solution without protectants. The shelf life was evaluated for 180 days at 4 °C and 25 °C, demonstrating that microbial biochar healing powder at 4 °C maintained bacterial viability above the 4.5 log CFU/g threshold necessary for effective calcium carbonate precipitation, while lyophilized spore powder stored at 25 °C dropped below the threshold at 90 days. Microbial biochar healing powder stored at 4 °C for 180 days was integrated into the mortar, which healed crack width up to 0.80 mm at 56 days under submerged rainwater maintained at 27 °C ± 2 °C and 85 % ± 5 % relative humidity. Electrical resistivity decreased from 28.16 Ω·m to 21.35 Ω·m, the permeability coefficient dropped from 153.90 mm/s to 0 mm/s, and compressive strength regained 90.53 %, which collectively indicated enhanced self-healing. Microstructural analysis confirmed the stable cuboid calcite crystals with a crystallite size of 86.62 nm. Thus, Microbial biochar healing powder produced from coconut shell biochar and Bacillus pumilus RSB17 and stored at 4 °C is an effective self-healing admixture for bio-mortar applications with a minimum storage period of 180 days. |
107. 题目: Machine learning unveils the role of biochar application in enhancing tea yield by mitigating soil acidification in tea plantations 文章编号: N25013106 期刊: Science of the Total Environment 作者: Rongxiu Yin, Xin Li, Yating Ning, Qiang Hu, Yihu Mao, Xiaoqin Zhang, Xinzhong Zhang 更新时间: 2025-01-31 摘要: Biochar, a widely utilized soil amendment in environmental applications, has been employed to enhance tea cultivation. This study utilized three machine learning models to investigate the effects of biochar on tea growth and yield, with the random forest (RF) model demonstrating superior performance (R2 = 0.8768, Root Mean Square Error = 6.1537). Feature importance analysis revealed that biochar characteristics and experimental conditions constitute critical factors exerting an impact on the output, accounting for 39.2 % and 38.6 %, respectively. Specifically, the Ca content of biochar (weight 0.274), the quantity of biochar applied (weight 0.206), and the calcium (Ca) content of soil (weight 0.120) emerged as the three most significant factors affecting tea yield. In conclusion, the machine learning models developed in this study elucidate the multifactorial impact of biochar application on tea yield, providing theoretical and methodological support for practical biochar application strategies in tea production. |
108. 题目: Sustainable removal of gaseous Hg0 using sulfur functionalized biochar: Adsorption experiment and life cycle assessment 文章编号: N25013105 期刊: Chemosphere 作者: Jung Ho Park, Ji Yeong Boo, Moon Hyeon Kim, Yong Sik Ok, Jaehak Jeong, Greg Thoma, Yongseok Hong 更新时间: 2025-01-31 摘要: Maximizing the sorption capacity of gaseous Hg0 by sulfur-functionalized biochar can lead to increased energy consumption and the production of secondary environmental pollutants such as greenhouse gases. This study evaluates the environmental impact of producing sulfurized biochar through a life cycle assessment (LCA), weighing these impacts against the benefits of enhanced Hg removal efficiencies. The biochar's Hg0 adsorption capacity, which ranges between 3 and 22 μg-Hg0/g-biochar, is influenced by several factors: it increases with higher sulfur loading (0−15 %), higher O2 levels (0−21 %), and longer pyrolysis times (1−5 h). However, it also decreases with increased pyrolysis temperature (100−500 °C). XPS and FT-IR analysis confirm that the sulfur in the biochar primarily exists as elemental sulfur, but each sulfurization condition also resulted in the formation of sulfate, organic sulfur, and sulfone. LCA results indicate that using biochar as a sorbent for Hg0 is carbon-negative when the biochar is disposed of in landfills. Sensitivity analysis showed that increasing mercury adsorption capacity through excessive investment in energy and resources does not necessarily reduce the overall environmental impact. Consequently, when selecting an adsorbent for mercury removal, it is crucial to consider both sorption capacity and environmental impact. |
109. 题目: Biochar promotes the dissolution of inorganic inactive phosphorus by mediating the bacterial community during corn stover and cattle manure composting 文章编号: N25013104 期刊: Chemosphere 作者: Linqin Zhao, Ying Li, Bowen Fan, Mengmeng Wang, Ning Sun, Fengjun Yang 更新时间: 2025-01-31 摘要: Phosphorus (P) is a macroelement primarily found in insoluble forms in nature. Enhancing the effectiveness of P is crucial for sustainable agricultural development and ecosystems. The research employed a combination of sequential extraction methods, high-throughput sequencing techniques, microbial culturing, and ecological network analysis of bacterial communities, along with module comparison, to explore the dynamics of different P fractions in calcareous soils. The objective of incorporating biochar into the composting of maize stover and cattle dung was to uncover potential microbial processes that could facilitate the activation of inorganic non-labile P. Findings revealed that during the composting process with biochar, bacterial populations played three distinct roles in the transformation of inorganic non-labile P compounds (such as occluded P and Ca10–P). Primarily, the introduction of biochar significantly increased both the diversity and abundance of bacterial communities. Additionally, it enhanced the ability of phosphate-solubilizing bacteria to maintain the structure of bacterial ecological networks by boosting their complexity, interconnectedness, and stability. Moreover, the incorporation of biochar stimulated the P-related metabolic activities within the bacterial community, significantly enriching key metabolic pathways such as the citrate (TCA) cycle, glycolysis/gluconeogenesis, the pentose phosphate pathway, galactose metabolism, starch, and sucrose metabolism, as well as the metabolism of amino and nucleotide sugars. Moreover, biochar addition intensified the connections between key operational taxonomic units (OTUs) and non-labile P while simultaneously increasing the total organic carbon concentration and enhancing alkaline phosphatase activity. This study provides valuable insights for enhancing P effectiveness in calcareous soils. |
110. 题目: Risk of increasing soil nitrous oxide emissions by chemical oxidation modification on biochar 文章编号: N25013103 期刊: Journal of Environmental Management 作者: Xiaolin Liao, Shuxia Mao, Wenran Gao, Shengsen Wang, Jing Hu, Saadatullah Malghani 更新时间: 2025-01-31 摘要: Biochar is widely recognized as a soil amendment capable of mitigating soil nitrous oxide (N2O) emissions. However, the effects of biochar modification, particularly through chemical oxidation, remain relatively unexplored. This study modified wood and corn straw biochars using H2O2 and acid (H2SO4/HNO3). Laboratory incubations were conducted to assess their effects on N2O emissions in agricultural and forest soils. The results revealed that acid modification significantly reduced biochar pH (<3) and introduced additional nitrogen, leading to substantial increases in N2O emissions by up to 181% and 7476% for wood and corn straw biochar, respectively. In contrast, H2O2-treated biochar caused limited changes in biochar properties and had minimal effects on soil N2O emissions. Correlation analyses suggest distinct pathways for N2O production, with forest soil emissions being negatively associated with potential denitrification enzyme activity, while agricultural soil emissions were positively linked to labile organic carbon and potential nitrification rates. While mild oxidation (e.g., H2O2) may better mimic natural aging process, stronger treatments (e.g., acid oxidation) pose risks of increased soil N2O emissions. This study provides valuable insights for optimizing biochar modifications to balance environmental and ecological benefits. |
111. 题目: Rice-crayfish farming enhances soil organic carbon by increasing labile organic carbon and altering microbial functions 文章编号: N25013102 期刊: Applied Soil Ecology 作者: Liang Peng, Liuliu Hao, Lili Dai, Ling Tao, Hui Zhang, Gu Li, Jianqiang Zhu 更新时间: 2025-01-31 摘要: In China, rice-crayfish farming (RCF) is a resource-efficient and eco-friendly agricultural model that demonstrates significant potential for soil organic carbon (SOC) storage. However, the impact of RCF on SOC accumulation and its associated microbial characteristics remains unclear. In this study, we conducted an experiment in rice fields with five years of RCF. We investigated surface SOC content and its components, as well as soil microbial community and its functions over two consecutive years. Compared to rice monoculture (RM), SOC in RCF increased by 24.13 % to 32.40 %. Labile organic carbon I (LOC I) and recalcitrant organic carbon (ROC) in RCF increased by 25.84 % to 39.07 % and 30.98 % to 60.87 %, respectively. While RCF reduced dissolved organic carbon (DOC) by 33.24 % to 45.83 %, it increased particulate organic carbon (POC) and easily oxidizable carbon (EOC) by 92.28 % to 132.61 % and 66.42 % to 69.76 %, respectively. The activities of β-xylanase (BX), β-glucosidase (BG) were significantly decreased and β-1,4-N-acetylglucosaminidase (NAG) was significantly increased in RCF. Additionally, RCF decreased the proportion of chemoheterotrophy and aerobic chemoheterotrophy of prokaryotic communities, while increased the proportion of dark sulfide oxidation and the dark oxidation of sulfur compounds. RCF also exhibited a high proportion of wood saprotroph functions of fungal communities. The structural equation models revealed that soil properties and prokaryotic communities were the main factors contributing the accumulation of SOC by enzyme activities in RCF. Overall, the practice of RCF increased the content of LOC I and ROC, altered soil prokaryotic community structure and predicted functions, led to a reduction of soil enzyme activities involved in the decomposition of organic matter, and consequently enhancing the accumulation of SOC. |
112. 题目: Impacts of the Ecosystem Transformation in Red Jujube Commercial Forests on the Soil Organic Carbon Sources and Stability in the Lvliang Mountains 文章编号: N25013101 期刊: Land Degradation & Development 作者: Hui Wang, Chunheng Mu, Jiaqi Li, Lin Sun, Gailing Wang 更新时间: 2025-01-31 摘要: Soil organic carbon (SOC) stabilization is vital for the mitigation of global climate change and retention of soil carbon stocks. The Loess Plateau is a crucial ecological zone in China and even worldwide for major ecosystem protection. However, in the Loess Plateau, there are knowledge gaps about the response of SOC sources and stabilization to different ecological transitions of jujube economic forests. Therefore, our study used clean‐cultivated jujube orchards as a control (CK) and selected five main ecosystem transformation models of abandoned jujube orchards on Lvliang Mountain: abandoned farmland (AF), replanted with Astragalus‐Bupleurum (AB), replanted with alfalfa (AL), replanted with Chinese pine (CP), and replanted with Chinese arborvitae (PO). The soil properties, sources and physical fractions of organic carbon and their correlations in the 0‐ to 20‐cm soil layer at each sample site were analyzed. The results show that the ecosystem transformation significantly increased the SOC by affecting plant‐ and microbe‐derived carbon and altering its components. Different treatments have varying impacts on the SOC content. The lignin phenol (VSC) content in the soils in the five ecosystem transformation models was greater than that in the CK and had the following ranking: CP > AL > PO > AF > AB (p < 0.05). The ecosystem transformation also significantly increased the soil total amino sugar (TAS) content, microbial residue carbon (MRC), and its contribution to organic carbon. Additionally, it promoted the accumulation of particulate organic carbon (POC) and mineral‐associated organic carbon (MAOC) and positively impacted the carbon stability. Among the five ecosystem transformation models, CP had the greatest impact on lignin phenols, amino sugars, SOC content, and stability, whereas AF and AB contributed the least to SOC. The results of this study provide a scientific basis to assess and select optimal transformation modes for the ecosystem transformation of commercial jujube forests. |
113. 题目: Limited degradability of dissolved organic carbon, nitrogen, and phosphorus during contrasting seasons in a tropical coastal environment 文章编号: N25013015 期刊: Limnology and Oceanography 作者: Jiangyong Chu, Christian Lønborg, Patrick Martin 更新时间: 2025-01-30 摘要: The biogeochemistry of dissolved organic matter (DOM) is poorly understood in tropical coastal waters. Here, we quantified the biological and photochemical lability of dissolved organic carbon, nitrogen, and phosphorus, in the tropical coastal waters of Singapore. We conducted experiments during the inter‐monsoon, the mid‐southwest monsoon, and the late southwest monsoon seasons, which span the greatest range of biogeochemical conditions found in the area. The DOM lability was quantified as concentration changes during 90‐d biodegradation and 7‐d photoreactor incubations. Overall, DOM showed low lability, even though dissolved organic nitrogen and dissolved organic phosphorus accounted for most of the dissolved nitrogen and phosphorus. In the biodegradation experiments, only 5–15% of dissolved organic carbon, 0–7% of dissolved organic nitrogen, and 8–21% of dissolved organic phosphorus were degraded. The addition of labile dissolved organic carbon, intended to test priming effects and to ensure the microbes were not carbon‐limited, had no measurable impact on the results. During our photochemical experiments only 2–10% of the dissolved organic carbon were degraded, while neither dissolved organic nitrogen nor dissolved organic phosphorus showed consistent photochemical losses. The DOM optical properties (absorbance and fluorescence spectra) showed limited or no changes during the biodegradation experiments but larger declines in the photochemical experiments. Overall, the biodegradation of DOM was highest during the inter‐monsoon, when autochthonous DOM was most dominant, while photolability was greater during the terrestrial DOM‐rich southwest monsoon. Our results illustrate that in some tropical coastal environments, DOM can be fairly resistant to biological and photochemical degradation, and thus does not represent a large stock of potentially available nutrients. |
114. 题目: Dilemmas in Linking Microbial Carbon Use Efficiency With Soil Organic Carbon Dynamics 文章编号: N25013014 期刊: Global Change Biology 作者: Jiacong Zhou, Yiqi Luo, Ji Chen 更新时间: 2025-01-30 摘要: There are still large uncertainties on the relationships between microbial carbon use efficiency and soil organic carbon across (1) different carbon use efficiency estimation methods, (2) various temporal, spatial and biological scales, and (3) multiple climate change scenarios. These uncertainties call for further efforts to re-examine the relationships between carbon use efficiency and soil organic carbon to better represent microbial processes in the current modelling frameworks. |
115. 题目: Microscopic mechanism of organic carbon sequestration and redox properties influenced by iron (Oxyhydr)oxides 文章编号: N25013013 期刊: Water Research 作者: Chuanjin Lin, Bin Dong, Zuxin Xu 更新时间: 2025-01-30 摘要: Iron and organic carbon (OC) biogeochemical cycling is highly correlated, and dissolved organic matter (DOM), a highly reactive component of soil and water environments, is the main OC source. However, the micro-mechanism of the molecular fractionation of DOM, the spatial OC distribution on iron (oxyhydr)oxides, and how these factors further affect their redox properties remain to be fully understood. Therefore, this study investigated the DOM adsorption properties of iron (oxyhydr)oxides with different crystallinities at the molecular level through the Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) and transmission electron microscopy/electron energy loss spectroscopy (TEM–EELS) analyses of the liquid-solid phases. Owing to the limited number of adsorption sites, OC sequestration on goethite and hematite surfaces generally followed an “onion” model, in the order of preference of aromatic, aliphatic, and carboxylic acid-rich compounds. Combined with dielectric electrochemical tests and charge differential density calculations, the results revealed that the complexation effect produced by iron ions increased the electron-accepting capacity (EAC) of the DOM remaining in the aqueous solution. In contrast, molecular selective adsorption and oxidative polymerization significantly enhanced the EAC of DOM adsorbed on the surface fraction of iron (oxyhydr)oxides. These findings help elucidate the mechanism of OC sequestration by iron (oxyhydr)oxides. The increased EAC may affect various biogeochemical processes, such as methane production and microbial Fe(III) reduction, facilitating the prediction of OC cycling in natural environments. |
116. 题目: Electroactive biofilms alter the EPS structure and metabolic pathways to sense potential and tetracycline 文章编号: N25013012 期刊: Journal of Hazardous Materials 作者: Fenglin Li, Lean Zhou, Shu Wang, Yongliang Wu, Tian Li, Shiquan Sun, Jinting Wang 更新时间: 2025-01-30 摘要: The extracellular polymeric substances (EPS) secretion decides the efficiency of microbial electron transfer and the resistance to toxic challenges. Electrode potential is a critical factor affecting both the rate and direction of electron transfer. However, the mechanism through which potential regulates EPS structure and toxic substance removal remains unclear. This research suggested that more positive potential stimulated increased extracellular protein and polysaccharides (PS) secretion. Nonetheless, excessive PS secretion restricted the current output, with the limiting current at −0.1 V being 1.39 times that of 0.3 V. A positive potential resulted in a more compact protein structure, but tetracycline (TC) addition has disrupted the polypeptide structure of EAB, while the α-helix and α-helix/β-sheet at −0.1 V was superior to other potentials. Under −0.1 V, the EABs maintained more abundant Geobacter (86 %) and cellular activity when sensing to the toxic of TC. The degradation rates observed at this potential was 1.5 times that of high potential, largely due to the upregulation of amino acid metabolic pathways. This study demonstrates the potential of using electrode potential to regulate the balance of EPS for electron transfer and self-protection, providing theoretical support for manipulating extracellular polymer secretion through electrode potential to enhance bioremediation of pollutants. |
117. 题目: Electro-oxidation mechanism profiling of humic acid by typical reactive substances 文章编号: N25013011 期刊: Separation and Purification Technology 作者: Zhenhui Song, Tianyu Gao, Huifeng Lu, Qi Zhang, Jingyu Liu, Tingting Kang, Xing Wu, Fubing Yao, Xiaobo Min, Chong-Jian Tang 更新时间: 2025-01-30 摘要: Electro-oxidation (EO) represents a promising and efficient technology for the disposal of humic acid (HA), leveraging the generation of radicals to degrade pollutants, ultimately achieving their removal or even complete mineralization. However, the detailed mechanistic profiling of the interaction between radical species (e.g. ·OH, active chlorine) and HA in the overall degradation remains significantly unclear, resulting in challenges in tuning and optimizing the treatment of HA-containing wastewater. Herein, a flow-through EO system using a Ti4O7 reactive electrochemical membrane (REM) as a model electrode was constructed to investigate the degradation mechanisms of HA under ·OH or active chlorine. Under optimal conditions (HA 100 mg L−1, current density 30 mA cm−2, pH 7), active chlorine achieved a higher HA oxidation efficiency (76.59 %) compared to ·OH (56.60 %) at 1 h, the HA mineralization efficiency of former (53.03 %) over 3 h was lower than that of latter (67.41 %). Meanwhile, multiple techniques (UV–Vis, FTIR, etc.) revealed that ·OH degraded HA’s macromolecular polycyclic structures into aliphatic products, while active chlorine produced mainly small molecular chlorinated aromatics. Furthermore, LC-MS analysis showed that hydroxylation by ·OH is crucial for promoting ring-opening reactions of aromatic compounds, while chlorination by active chlorine proves less effective for this purpose. Adjusting the electrolyte in EO controlled reactive species generation, allowing regulation of HA degradation rates or product distribution, making EO suitable as a pretreatment or advanced treatment in other processes. This work paves a new avenue for the rational design and construction of subprocesses aimed at HA-containing wastewater treatment. |
118. 题目: Export fluxes of dissolved, colloidal and particulate organic carbon, major and trace elements from the Ob River and its tributaries across seasons 文章编号: N25013010 期刊: Water Research 作者: Ivan V Krickov, Sergey N Vorobyev, Larisa G Kolesnichenko, Yuri Kolesnichenko, Dmitri Zinchenko, Liudmila S Shirokova, Oleg S Pokrovsky 更新时间: 2025-01-30 摘要: Riverine export fluxes of organic carbon (OC), major and trace elements remain at the forefront of environmental research in Arctic and subarctic regions, due mostly to high sensitivity of river hydrochemical parameters to climate warming and, at the same time, global importance of OC, nutrients and toxicants delivered by rivers to the Arctic Ocean. In contrast to reliable information on export fluxes of carbon and metals from the mainland to the Arctic Ocean by large and mid-size Arctic rivers, the majority of these studies quantify either dissolved (< 0.45 µm) or particulate suspended matter (PSM) fluxes, without mechanistic analyses of element speciation in most labile, low molecular weight (LMW) or colloidal form. Here we assessed colloidal versus LMW (< 3 kDa) and suspended (> 0.45 µm) export of OC, major and trace elements in a large Siberian river (Ob) and its smaller tributaries, situated within a boreal taiga / wetland zone. The main differences between Ob and its small tributaries are (i) higher dissolved OC and dissolved and particulate Fe concentrations in tributaries, due to input from surrounding bogs, (ii) much higher PSM load (clays) in the large river (Ob) compared to smaller tributaries; and (iii) strong underground water input for the Ob River, especially during baseflow, which is less pronounced for its tributaries. These major environmental factors were largely responsible for specific features of colloidal vs particulate export for the Ob River and its tributaries.Annual export fluxes normalized to the watershed area (yields) were similar for most elements in dissolved (< 0.45 µm) fraction between the Ob and the tributaries, exempting Fe, Mn, Co and Zn which were higher in tributaries essentially due to input from wetlands. Export of Mo, V, W and U was higher in the Ob River due to pronounced groundwater influence. Colloidal (3 kDa – 0.45 µm) yields were also generally higher in the tributary compared to Ob, except for those soluble elements of groundwater input (Sr, Mo, W, U). The particulate suspended (> 0.45 µm) yield of all elements, except Mn, was much higher in the Ob River when compared to its smaller tributaries. Overall, elemental fluxes of small wetland-draining tributaries of the Ob River can be considered analogous to the small rivers of the permafrost-free portion of the Arctic coast. Such small rivers are more sensitive to processes occurring at the watershed level, hence being an efficient potential sentinel for environmental changes. Fluxes in large Arctic coast rivers are more conservative and are strongly controlled by the effects of PSM interaction with river water at high flow and groundwater loading at base flow. Global significance of our findings is that elemental dissolved (< 0.45 µm) yields of small Artic rivers draining coastal wetlands and boreal forests can be adequately (within a factor of 2 to 3, comparable to inter-annul variations and uncertainties) approximated by those currently available for mid-sized and large rivers. |
119. 题目: Effect of simultaneously addition of Fe3+ and reed straw biochar on nitrogen removal efficiency and GWP for Anammox 文章编号: N25013009 期刊: Chemical Engineering Journal 作者: Jingran Fu, Huan Liao, Zelong Wang, Yaxuan Xiao, Yi Zhang, Guoliang Bai, Jing Zhang, Hongyu Wang, Haijun Lu, Yiqie Dong, Xinghua He 更新时间: 2025-01-30 摘要: Anammox is a new type of autotrophic nitrogen removal technology with high efficiency and low consumption. However, the long start-up time and poor running stability of Anammox seriously restrict its large-scale application. In this study, simultaneously addition strategy of Fe3+ and reed straw biochar was developed to improve the nitrogen removal performance of Anammox. The nitrogen removal was highest in Anammox system with simultaneously addition of Fe3+ and reed straw biochar prepared at 600 °C for 2 h. And continuous addition of Fe3+ in the Anammox system with reed straw biochar not only exhibit high nitrogen removal efficiency and excellent resistance to nitrogen shock loading, but also had low global warming potential (GWP). Genus Candidatus Brocadia as dominant AnAOB had the highest relative abundance with the simultaneously addition of Fe3+ and reed straw biochar. Besides, enrichment of iron oxidation–reduction microorganisms through enhancing extracellular electron transfer with reed straw biochar achieved the coupling of Anammox, Feammox and NDFO, which was significantly facilitated the nitrogen removal performance of Anammox. |
120. 题目: Unraveling the interaction of dissolved organic matter and microorganisms with internal phosphorus cycling in the floodplain lake ecosystem 文章编号: N25013008 期刊: Environmental Research 作者: Lan Lu, Ning Tang, Ziqian Zhu, Ronghan Wang, Xiang Gao, Min Yan, Tingting Hu, Han Ma, Guoyu Li, Weixiang Li, Jingyi Zhang, Xiaodong Li, Jie Liang 更新时间: 2025-01-30 摘要: Internal nutrient cycling, especially phosphorus (P), is of great influence in lake eutrophication. Dissolved organic matter (DOM) and microorganisms are ubiquitous in the sediments and closely associated with P-cycling. However, the underlying interactions of DOM, microorganisms and P in floodplain lake area with different hydrological characteristics remain scarce. This study evaluated the P and DOM properties, P functional genes and microbial community ranging from channel to stagnant to grass area (CA, SA, GA) in a floodplain lake, respectively. The results showed that sediments dissolved organic carbon (DOC) and total P (TP) gradually decreased from GA to SA to CA. Organic P (64.44%) and Fe-bound P (34.86%) were primary bioavailable P fractions in three areas. Water Chl-a, DO, DOC and fulvic-like C1 component were essential driving factors affecting the distribution of P in sediments (p < 0.05). Microbial diversity, community structure and P-cycling function were significantly different in three areas and closely associated with sediment P and DOM (p < 0.05). The co-occurrence network analysis revealed that the interconnection of microbial communities, DOM components and P fractions decreased from CA (node: 123, edge: 1399) to SA (node: 122, edge: 667) to GA (node: 119, edge: 521). Sediment microbial communities enhanced P cycling via mineralizing organic P and dissolving inorganic P (Ca-P) in CA and coupling DOM mineralization and Fe-P dissolution in SA, while sediment in GA owned the significant potential of P and DOM storage and the abundant P-cycling genes. This finding provides further understanding that underlying mechanisms of internal P-cycling in floodplain lake ecosystem. |
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