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341. 题目: Effects of the combined use of lanthanum carbonate and activated carbon capping materials on phosphorus and dissolved organic matter in lake sediments
文章编号: N24110711
期刊: Environmental Research
作者: Chenjun Yang, Qi Li, Xiang Chen, Minjuan Li, Xiangyu He, Gaoxiang Li, Yichun Shao, Jingwei Wu
更新时间: 2024-11-07
摘要: Lanthanum carbonate (LC) represents a novel material for the immobilization of internal phosphorus (P) in sediments. Activated carbon (AC) is a traditional adsorbent that has been employed in the remediation of sediments on a wide scale. The objective of this study is to examine the mechanisms and effects of the combined use of LC and AC capping materials on the immobilization of P and dissolved organic matter (DOM) in sediments, through a 90-day incubation experiment. The results of isotherm experiments showed that the adsorption mechanism of P on LC and AC was mainly chemisorption. The XPS analyses showed the adsorption mechanism of P on LC was mainly ligand exchange and inner-sphere complexation; while the adsorption mechanism of P on AC was mainly ligand exchange and electrostatic adsorption. The results demonstrated that the concentrations of soluble reactive phosphorus (SRP) and DOM in the 0 to −100 mm sediment layer were reduced by 69.79% and 33.93%, respectively, in comparison to the control group with the LC + AC group. Moreover, the HCl-P and Res-P (stable P) in the 0–5 cm sediment layer were increased by 50.07% and 21.04%, respectively, in the LC + AC group. This indicates that the combined application of LC and AC has the potential to reduce the risk of P release. Furthermore, the formation of Fe(III)/Mn(IV) oxyhydroxides by LC + AC treatment resulted in an increased adsorption of SRP and DOM. Moreover, the effect of LC + AC capping on microbial community was smaller than that of LC/AC capping alone. The findings of this study indicated that the combined use of LC and AC represents a novel approach to the effective treatment of internal P and DOM in eutrophic lake sediments.

342. 题目: Remediation of biochar-supported effective microorganisms and microplastics on multiple forms of nitrogenous and phosphorous in eutrophic lake
文章编号: N24110710
期刊: Science of the Total Environment
作者: Siqun Tang, Jilai Gong, Biao Song, Juan Li, Weicheng Cao, Jun Zhao
更新时间: 2024-11-07
摘要: Lots of studies on eutrophication, but there is a lack of comprehensive research on the repair of multiple forms of nitrogen and phosphorus under combined heavy metals (HMs) pollution. This work investigated the various forms of nitrogen and phosphorus in the water-sediment systems of eutrophic lakes with the application of biochar, Effective Microorganisms (EMs) and microplastics, aiming to deliberate the repair behavior of multiple forms of nitrogen/phosphorus and the integrated repairment of these nutrients and HMs in different remediations. For amended-groups, the application of biochar-supported EMs (BE) achieved the most desirable remediation for removing nitrogen, phosphorus and HMs in water and improved their stability in sediment due to the improved microbial activity and the developed biofilm system created by biochar. The addition of aging microplastics (MP) obviously reduced the systematic levels of nitrogen, phosphorus and HMs due to the stimulation of microbial activity and the adsorption of biofilm/EPS, but its high movability also increased the Fe(II) and S(-II) levels and the pollutants' ecological risks in sediment. The co-application of BE and MP (MBE) destroyed the ecosystem and decreased the removal of nitrogen and phosphorus, while greatly removing HMs by the superfluous biofilms/EPS. The application of biochar (BC) preferentially adsorbed and degraded dissolved nitrogen and phosphorus, releasing HMs into water. From these amended-groups, it's also knew that the removal of nitrogen and phosphorus mainly came from the degradation/assimilation of NH₃-N, SRP and dissolved matters, particularly those molecular weight below 3 kDa; the higher removal of phosphorus than nitrogen was attributed to the coprecipitation of Fe-S-P hydroxides and the adsorption of particulates; however, the colloidal (3–100 kDa) nitrogen and phosphorus had low accessibility and bioavailability, and it also showed the competitive adsorption with colloidal HMs, causing their relatively low removal in water. This study provides insight into the comprehensive repair of nitrogen, phosphorus and HMs in various forms by biochar-immobilized microbes and the influence of microplastics on nutrients and HMs in eutrophic lakes.

343. 题目: Effects of nanoplastics on the growth, transcription, and metabolism of rice (Oryza sativa L.) and synergistic effects in the presence of iron plaque and humic acid
文章编号: N24110709
期刊: Environmental Pollution
作者: Xiaoxue Ouyang, Jie Ma, Bingcong Feng, Yong Liu, Ping Yin, Xiaoyu Zhang, Pan Li, Qiusheng Chen, Yujie Zhao, Liping Weng, Yongtao Li
更新时间: 2024-11-07
摘要: Nanoplastics (NPs) can adversely affect living organisms. However, the uptake of NPs by plants and the physiological and molecular mechanisms underlying NP-mediated plant growth remain unclear, particularly in the presence of iron minerals and humic acid (HA). In this study, we investigated NP accumulation in rice (Oryza sativa L.) and the physiological effects of exposure to polystyrene NPs (0, 20, and 100 mg L⁻¹) in the presence of iron plaque (IP) and HA. NPs were absorbed on the root surface and entered cells, and confocal laser scanning microscopy confirmed NP uptake by the roots. NP treatments decreased root superoxide dismutase (SOD) activity (28.9–44.0%) and protein contents (31.2–38.6%). IP and HA (5 and 20 mg L⁻¹) decreased the root protein content (20.44–58.3% and 44.2–45.2%, respectively) and increased the root lignin content (22.3–27.5% and 19.2–29.6%, respectively) under NP stress. IP inhibited the NP-induced decreasing trend of SOD activity (19.2–29.5%), while HA promoted this trend (48.7–50.3%). Transcriptomic and metabolomic analysis (Control, 100NPs, and IP-100NPs-20HA) showed that NPs inhibited arginine biosynthesis, and alanine, aspartate, and glutamate metabolism and activated phenylpropanoid biosynthesis related to lignin. The coexistence of IP and HA had positive effects on the amino acid metabolism and phenylpropanoid biosynthesis induced by NPs. Regulation of genes and metabolites involved in nitrogen metabolism and secondary metabolism significantly altered the levels of protein and lignin in rice roots. These findings provide a scientific basis for understanding the environmental risk of NPs under real environmental conditions.

344. 题目: Iron-bound organic carbon declined after estuarine wetland reclamation into paddy fields
文章编号: N24110708
期刊: Science of the Total Environment
作者: Xuyang Liu, Weiqi Wang, Elise Pendall, Yunying Fang
更新时间: 2024-11-07
摘要: Iron-bound organic carbon (Fe-OC) is a main pathway for the long-term maintenance of soil organic carbon (SOC), but research on its mechanism is still relatively weak. We investigated the coupling relationships among iron (Fe), carbon (C) and Fe-reducing bacteria (FeRB) in the soil of a reclaimed paddy field in comparison with natural Phragmites australis wetland in the Minjiang River estuary in southeastern China. The results showed that conversion of P. australis wetland to paddy cultivation changed the soil redox process. After reclamation, soil Fe(II), Fe(III), HCl-Fe_t, free iron oxide (Fe_d) and amorphous iron (Fe_o) contents and Fe(III)/Fe(II) decreased significantly (p < 0.05), while the content of complexed iron (Fe_p) increased. Nonmetric multidimensional scaling analysis (NMDS) demonstrated variability in FeRB across soil types (r = 0.900, p = 0.001). The lower Fe-OC concentration in soil after wetland reclamation may be the result of Fe reduction by dissimilatory FeRB (e.g., Bacillus, Anaeromyxobacter). On average, both Fe-OC and SOC contents decreased significantly (p < 0.05), while the contribution of Fe-OC to total SOC (f_Fe-OC) increased significantly (p < 0.05), after conversion to paddy cultivation. Structural equation modeling (SEM) showed that SOC, dissolved organic C, and Fe-OC were affected by FeRB and the speciation of Fe. In addition, Fe (III) concentration affected SOC concentration (r = 0.60, p < 0.05) and DOC concentration (r = 0.58, p < 0.05), and Fe_d affected DOC concentration (r = 0.69, p < 0.05). We conclude that after rice field reclamation in estuarine wetlands, Fe-reducing bacteria can mediate iron-bonded organic C decoupling, affecting SOC stabilization.

345. 题目: Dominant Production of Dissolved Inorganic Carbon by Organic Matter Degradation in a Coastal Lagoon: Evidence from Carbon Isotopes
文章编号: N24110707
期刊: ACS Earth and Space Chemistry
作者: Mohd Danish, Gyana Ranjan Tripathy
更新时间: 2024-11-07
摘要: Coastal oceanic settings are biogeochemically active zones and play a dominant role in the global carbon cycle. In this contribution, we have investigated the spatial distribution of dissolved inorganic carbon (DIC) and δ¹³C_DIC along the salinity gradient of a large tropical coastal lagoon (Chilika, India) and major source waters (river, groundwater) to the lagoon for three different (pre-monsoon, monsoon, and post-monsoon) seasons. These data were used to constrain internal cycling and DIC fluxes to the Bay of Bengal. The average [DIC] and δ¹³C_DIC values of the Chilika, although they exhibit significant variation within a season, are found comparable for the pre-monsoon (1.8 ± 0.6 mM; −5 ± 3 ‰), monsoon (1.7 ± 0.4 mM; −4 ± 2 ‰), and post-monsoon (1.9 ± 0.3 mM; −4 ± 3‰) samples. Co-variation between DIC (and δ¹³C_DIC) and salinity during all three seasons deviates from the theoretical mixing line (TML) between river and seawater, indicating nonconservative behavior of DIC in the lagoon. The magnitude of the DIC and δ¹³C_DIC deviations from their corresponding TML points to dominancy of organic matter degradation in causing this nonconservative trend. Additionally, the pre-monsoon samples also show a minor effect of calcite precipitation on the [DIC]. The LOICZ model estimates that the DIC flux from this lagoon to the ocean is higher than that reported for several peninsular Indian rivers, despite their high (378 km³/yr) freshwater influxes to the Bay of Bengal. This disproportionally higher DIC flux is linked to remineralization of organic matter, underscoring its importance in regulating the inorganic carbon cycle of this highly productive coastal system.

346. 题目: Nitrogen-Doped Porous Biochar via Azotobacter chroococcum-Based Nitrogen Fixation for Improved Volatile Organic Compound Adsorption
文章编号: N24110706
期刊: ACS ES&T Engineering
作者: Fan Yao, Xiaohong Wang, Guangyi Zhao, Weixiao Peng, Wenfu Zhu, Yuqin Wang, Yujun Jiao, Haomin Huang, Daiqi Ye
更新时间: 2024-11-07
摘要: Nitrogen doping has been widely used to prepare porous carbon materials for the adsorption of volatile organic compounds (VOCs). However, in the current research, the nitrogen doping process is limited by the raw materials, and it is difficult to achieve simultaneous and precise synergistic regulation of the pore structure, doping quantity, and doping morphology. Inspired by the carbon–nitrogen cycle in nature, the symbiotic community of nitrogen-fixing microorganisms is an important functional group to regulate the elemental cycle. In this study, a novel biological nitrogen fixation incorporation doped method was proposed, i.e., Azotobacter chroococcum (A. chroococcum) is cultivated on the surface of the biochar and catalyzes the conversion of atmospheric nitrogen (N₂) to fixed nitrogen (NH⁴⁺) by nitrogen-fixing enzymes in the body of A. chroococcum, which leads to the formation of bionitrogen and thereby increases the total nitrogen content (0.99%) in the biochar material. The results showed that the content of pyrrole nitrogen in the material was 73.3% and that it possessed a larger specific surface area (1338.21 m²/g) and mesopore (0.499 cm³/g), which greatly improved its adsorption capacity (182.88 mg/g) for ethyl acetate. In addition, in order to elucidate the microscopic adsorption mechanism for enhanced adsorption performance, systematic theoretical calculations of adsorption amount, adsorption energy, and adsorption isotherm were carried out by molecular simulation. This study innovatively achieved green and safe regulation of biomass precursors by nitrogen-fixing bacteria without increasing the nitrogen source and provided a theoretical basis and technical methods to improve the quality and efficiency of the VOC adsorption materials.

347. 题目: Mobility, Speciation and Bioavailability of Zn and Pb in Artificially Polluted Soils by Magnetic Biochars from Siraitia Grosvenorii Residues
文章编号: N24110705
期刊: Water, Air, & Soil Pollution
作者: Yaolan Niu, Wei Hu, Taiming Shen, Kun Dong
更新时间: 2024-11-07
摘要:

The effects of magnetic biochar (SMBC) prepared from Siraitia grosvenorii residues on the mobility, speciation and bioavailability of Pb and Zn in the soil were studied. SMBC was characterized by N₂ adsorption–desorption isotherm, Scanning electron microscope, Fourier infrared spectroscopy and X-ray diffraction. Three different extractions of Pb and Zn by TCLP, CaCl₂ and PBET were used to simulate mobility, availability and bioaccessibility, respectively. SMBC was incubated with contaminated soils at rates of 0, 1, 2.5, and 5.0% by weight for 5 days and 30 days. SMBC was effective for both Zn and Pb immobilization, and the immobilization effect increased with the increase of SMBC dosage. It was observed that there was a slight rebound of TCLP-extractable Pb and CaCl₂-extractable Pb in the SMBC-treated soils after 30 days of incubation. The chemical fractions of Pb and Zn from sequential extractions were used for evaluating mobility and availability. After 30 days of incubation, the chemical species of Pb in the control distributed in the decreasing order of OX (26.5%) > CB (20.99%) > OM (18.52%) > RS (18.02%) > EX (15.95%) and RS (27.35%) > OX (24.88%) > EX (19.95%) > OM (17.42%) > CB (10.38%) for Zn in the soil. Siraitia grosvenorii residues has a broad application prospect in the remediation of heavy metal polluted soil in the future.

348. 题目: Enhanced Carbon Sequestration of Sustainable Biochar via Metal Salt Regulation: Insight into Reaction Mechanism and Carbon Footprint
文章编号: N24110704
期刊: ACS Sustainable Chemistry & Engineering
作者: Shaojie Zhou, Qi Wang, Qian Wang, Xiangdong Zhu, Jiajun Fan, James H Clark, Bin Chen, Shurong Wang, Yutao Wang, Shicheng Zhang
更新时间: 2024-11-07
摘要: Sustainable biochar can sequester carbon and therefore, mitigate climate change. However, only a small fraction of biomass carbon is retained during biochar synthesis, greatly restricting its carbon-sequestration capacity. A significant boost of the carbon-sequestration potential of biochar has so far been a challenge. This study reveals that when biochar is modified by FeCl₃, its carbon-sequestration capacity is boosted to 247.73% of that of pristine biochar derived at 500 °C. Meanwhile, pristine biochar retains only 43.18% of its biomass carbon, while FeCl₃-modified biochar retains 75.20% of its carbon by forming complexes between the iron salts and the carboxyl- and hydroxyl-rich organic compounds derived from biomass pyrolysis. As react proceeds, the complexes are further converted into ferrites and organic carbon. The resulting minerals provide physical barriers against carbon decomposition, further enhancing the long-term stability of biochar. Life cycle assessment results further show that ferric salt can markedly enhance the greenhouse gas─reduction potential of biomass-to-biochar-to-soil systems. The more cycles from biomass to upgraded biochar, the more potent the carbon-negative effect is. Undoubtedly, such discoveries hold significant implications for accelerating carbon neutrality.

349. 题目: Anthropogenic land use impacts carbon dynamics in Kolli Hills, Eastern Ghats, India
文章编号: N24110703
期刊: Environmental Earth Sciences
作者: Perumal Deepana, Selvi Duraisamy, Thiyageshwari Subramanium, Rangasamy Anandham, Senthil Alagarswamy, Ramalingam Kumaraperumal, Manimaran Gajendiran, Shanmugam Aravindan, Kavinkumar Subramaniyam
更新时间: 2024-11-07
摘要:

Biological equilibrium has been disturbed by significant land use changes in recent years in the Eastern Ghats of India, which has worsened soil quality and compromised vital ecosystem services. To determine the effect of changes in land use on the balance of soil carbon, this study was carried out in Kolli hills, a portion of the Eastern Ghats that includes six distinct ecosystems: evergreen forest (EF), deciduous forest (DF), thorn forest (TF), agricultural system (AS), horticultural system (HS), and plantation system (PS). Soil from 40 sites each within six ecosystems at two depths were collected to give a total of 480 soil samples, and the samples were analyzed. The results showed that soil organic carbon, carbon stock, microbial biomass carbon, and microbial biomass nitrogen were more significant in EF > DF > TF and lower in AS. The observed carbon stocks in EF, DF, and TF were 179.96, 146.80 and 128.99 t ha⁻¹, respectively, at 15 cm and decreased at 30 cm. Among the carbon pools, the water-soluble, less labile, very labile, non-labile, labile, and particulate organic carbon were greater in EF and lower in AS. The EF had higher soil microbial biomass, carbon, nitrogen, and dehydrogenase enzyme activity levels than the DF and TF. Finally, it is determined that AS, HS, and PS must immediately implement carbon management measure to restore productivity and ecosystem function.

350. 题目: Molecular mechanisms of iron nanominerals formation in fungal extracellular polymeric substances (EPS) layers during fungus-mineral interactions
文章编号: N24110702
期刊: Chemosphere
作者: Jian Xiao, ZhiLai Chi, XiaoDan Huang, GuangHui Yu
更新时间: 2024-11-07
摘要: Extracellular polymeric substances (EPS), which envelop on fungal hyphae surface, interact strongly with minerals and play a crucial role in the formation of nanoscale minerals during biomineralization in nature environments. However, it remains poorly understood about the molecular mechanisms of nanominerals (i.e., iron nanominerals) formation in fungal EPS halos during fungus-mineral interactions. This process is vital because fungi typically grow attached to various mineral surfaces in nature. According to the changes of thickness of the fungal cell and EPS layers during the Trichoderma guizhouense NJAU 4742 and hematite cultivation experiments, we found that fungal biomineralization could trigger the formation of EPS layers. Fe-dominated nanominerals, aromatic C (283-286.1 eV), alkyl C (287.6-288.3 eV), and carboxylic C (288.4-289.1 eV) were the dominant chemical groups on the EPS layers, as determined by nanoscale secondary ion mass spectrometry (NanoSIMS), high-resolution transmission electron microscope (HRTEM), and carbon 1s near-edge X-ray absorption fine structure (NEXAFS) spectroscopy. Further, evidence from Fe K-edge X-ray absorption near-edge structure (XANES) and X-ray photoelectron spectroscopy (XPS) spectra indicated that oxygen vacancy (O_V) was formed on the Fe-dominated nanomineral surface during fungus-mineral interactions, which played an important role in catalyzing H₂O₂ decomposition and HO∗ production. Taken together, the intrinsic peroxidase-like activity by reactive oxygen species (ROS) could modulate the Fe-dominated nanominerals formation in EPS layers to newly form a physical barrier between the cell and the external environments around hyphae, providing novel insights into the effects of ROS-mediated fungal-mineral interactions on fungal nutrient recycling, attenuation of contaminants, and biological control in nature environments.

351. 题目: Improved volatile fatty acid production in anaerobic digestion via simultaneous temperature regulation and persulfate activation by biochar: Chemical and biological response mechanisms
文章编号: N24110701
期刊: Environmental Research
作者: Zishuai Zhang, Ruijie Zhang, Yanwen Ma, Ying Sun
更新时间: 2024-11-07
摘要: Increasing volatile fatty acid (VFA) production via persulfate activation (i.e., chemical effect) in anaerobic digestion (AD) is an emerging resource utilization method. However, the reaction mechanisms responsible for improving VFA production in AD via simultaneous temperature regulation and persulfate activation by biochar remain unclear. In this study, three PB15 treatment systems of low temperature (15 °C), medium temperature (35 °C) and high temperature (55 °C) were set to explore the relationship between VFAs production and treatment temperature and the influence of temperature on the reaction mechanism. The results show that the improvement of hydrolysis and acidification efficiency of the system in the medium temperature system is the highest. The VFA yield and acid production rate in the treatment group at 35°C were 2.49 and 5.22 times higher than those in the control group, respectively. The chemical effect effectively initiated the anaerobic acid production process and maintained the dominant role of the biological effect. The activity of persulfate is too low at low temperature, and its decomposition is too fast at high temperature. Plenty of free radicals lead to enhanced oxidation of the system, which may kill the fermentation bacteria. The NCM model indicates that microbial stability is reduced in high temperature systems. The SEM model showed that temperature change mainly affected substrate degradation by hydrolytic bacteria and indirectly affected acid production by acid-producing bacteria. This study provides a new strategy for realizing pollutant recycling and increasing VFAs production in cold area.

352. 题目: Synergistic water quality and soil organic carbon sequestration benefits of winter cover crops.
文章编号: N24110513
期刊: Journal of Environmental Management
作者: Xuesong Zhang, Yiming Wang, Sangchul Lee, Kang Liang, Kaiguang Zhao, Gregory W McCarty, Joseph G Alfieri, Glenn E Moglen, W Dean Hively, Daniel T Myers, Diana Oviedo-Vargas, Tam V Nguyen, Audra L Hinson, Ling Du, Xiaobo Xue Romeiko
更新时间: 2024-11-05
摘要: Winter cover crops (WCCs) are promising best management practices for reducing nitrogen and sediment pollution and increasing soil organic carbon (SOC) sequestration in agricultural fields. Although previous watershed studies assessed water quality benefits of growing WCCs in the Chesapeake Bay watershed, the SOC sequestration impacts remain largely unknown. Here, we designed six WCC scenarios in the Tuckahoe Watershed (TW) to understand potential synergies or tradeoffs between multiple impacts of WCCs. Besides corroborating the nitrate reduction benefits of WCCs that have been reported in previous studies, our results also demonstrated comparable reduction in sediment. We also found that the six WCC scenarios can sequester 0.45-0.92 MgC ha-1 yr-1, with early-planted WCCs having more than 70% SOC sequestration benefits compared with their late-planted counterparts. With a linear extrapolation to all the cropland in Maryland, WCCs hold potential to contribute 2.1-4.4% toward Maryland's 2030 Greenhouse Gases reduction goal. Additionally, we showed that WCCs can noticeably increase evapotranspiration and decrease water yield and streamflow, potentially impacting aquatic ecosystem health and water supply. Overall, this study highlights the synergistic water quality and SOC sequestration benefits of WCCs in the Chesapeake Bay watershed. Meanwhile, sustainable adoption of WCCs into existing crop rotations will also require careful assessment of their impact on water availability.

353. 题目: Partitioning Ganoderma lucidum residue biochar differentially boosts anaerobic fermentation performance of cow manure via mediation of anaerobic microbiota assembly.
文章编号: N24110512
期刊: Journal of Environmental Management
作者: Yajing Wang, Yan Yang, Jiahui Sun, Yueqi Wang, Xiujie Liu, Jingyu Cao, Aiai Zhang, Chunfang Shi, Jiangang Pan
更新时间: 2024-11-05
摘要: Biochar is a promising strategy to solve the problem of low efficiency and ammonia inhibition during anaerobic digestion (AD). However, the correlation between biochar partitioning and its stimulatory effects on AD remains uncertain. Here, the effects of partitioned Ganoderma lucidum residue biochar (GLRB) on biogas and methane production were investigated. The GLRB produced at 450 °C, with richer functional groups on its surface, had the optimal enhancement effect on AD, resulting in a 20.59% increase in methane production compared with control. The doses of water-soluble GLRB (LZ450-W) and water-insoluble GLRB (LZ450-R) were not proportional to their enhancement effect on AD. However, the enhancement effect on AD by LZ450-R was better than that of LZ450-W. The optimal dosage of LZ450-W was 0.015 g, which increased methane production by 14.28%. Similarly, methane production increased by 26.91% with the addition of 0.603 g of LZ450-R. LZ450-R had more abundant functional groups on the surface and promoted the abundance of bacteria in the dominant phyla Bacteroidetes, Synergistetes, and Spirochaetes, increasing the rate of hydrolysis. Additionally, methanogens such as Methanobacterium and Methanospirillum were enriched, facilitating methane production by promoting the hydrogenotrophic pathway. Methanobacterium was also negatively correlated with most acid-producing bacteria, whereas Methanobrevibacter was positively correlated with Methanosphaera, Acetivibrio, and other acid-producing bacteria. These findings provide a basis for constructing synthetic microbial communities using biochar as a carrier of microbial inoculum.

354. 题目: Valorizing meat processing industry brines to produce added-value organic acids.
文章编号: N24110511
期刊: Journal of Environmental Management
作者: Miguel Martinez-Quintela, Gemma Casas, Manuel Carramal, Esther Vega, Laia Llenas, Lidia Paredes
更新时间: 2024-11-05
摘要: During the production of certain meat processed products, such as cured ham and cold meat, large amounts of wastewater with high organic matter and salt content are generated. In contrast with the conventional management processes, which involves high energy consumption, this study proposes the valorisation of such meat brines through anaerobic fermentation to produce added-value organic acids. Several brines coming from different meat processing processes were tested to evaluate their acidification potential as well as to establish the main operation parameters in the fermenter: pH and the substrate-to-inoculum ratio. The brine with the best acidification results in both experiments was selected to be fed into a fed-batch fermenter at pH close to neutrality (6.5-7.3) and with an HRT of 6 d. With such conditions, a 27% of acidification in average was observed under an electrical conductivity up to 155 mS cm-1. Acetic and propionic acid were the most produced volatile fatty acids (VFAs) (39% and 22.0%, respectively), being the rest (up to 40%) ≥ C4 (including butyric, valeric and their isomeric forms). Finally, a selective separation between the salt and the VFAs were achieved working at low current density (<100 A m-2) in an electrodialysis system (80% of recovery in the diluate). The technological approach proposed in this study can be considered as a starting point to valorize high-salinity industrial wastewater, aligning with the circular economy model principles.

355. 题目: Aridity-Driven Change in Microbial Carbon Use Efficiency and Its Linkage to Soil Carbon Storage
文章编号: N24110510
期刊: Global Change Biology
作者: Junmin Pei, Changming Fang, Bo Li, Ming Nie, Jinquan Li
更新时间: 2024-11-05
摘要: Global warming is generally predicted to increase aridity in drylands, while the effects of aridity changes on microbial carbon use efficiency (CUE) and its linkage to soil organic carbon (SOC) storage remain unresolved, limiting the accuracy of soil carbon dynamic predictions under changing climates. Here, by employing large-scale soil sampling from 50 sites along an ~6000 km aridity gradient in northern China, we report a significant decreasing trend in microbial CUE (ranging from approximately 0.07 to 0.59 across the aridity gradient) with increasing aridity. The negative effect of aridity on microbial CUE was further verified by an independent moisture manipulation experiment, which revealed that CUE was lower under lower moisture levels than under higher moisture levels. Aridity-induced increases in physicochemical protection or decreases in microbial diversity primarily mediated the decrease in CUE with increasing aridity. Moreover, we found a highly positive microbial CUE–SOC relationship, and incorporating CUE improved the explanatory power of SOC variations along the aridity gradient. Our findings provide empirical evidence for aridity-induced reductions in microbial CUE over a broad geographic scale and highlight that increasing aridity may be a crucial mechanism underlying SOC loss by suppressing the ability of soil microorganisms to sequester carbon.

356. 题目: Biochar-supported atomically dispersed copper as cost-effective and adaptable catalysts for heterogeneous activation of peroxymonosulfate towards the degradation of chlorophenol
文章编号: N24110509
期刊: Journal of Environmental Chemical Engineering
作者: Jiangling Mao, Hongzhi Chen, Ke Tian, Taiping Qing, Xiaoqing Liu, Shunfeng Jiang, Haijiao Xie
更新时间: 2024-11-05
摘要: It is highly desirable to design stable catalysts for efficient pollutants degradation in wastewater treatment. Biochar is a widely used catalyst for pollutant degradation, but the catalytic performance needs to further improve by increasing the active sites. Herein, a nitrogen-doped biochar-supported highly dispersed copper atom catalyst (Cu-NBC) was synthesized by a pyrolysis method, and used for peroxymonosulfate (PMS) activation to remove contaminants from wastewater. The low cost and environmental friendliness exhibited an excellent catalytic performance in permonosulfate activation. Under the ideal reaction conditions, the Cu-NBC/PMS system achieves a 100% removal rate of 4-chlorophenol (4-CP) and a 74.68% mineralization efficiency within 60 min. X-ray absorption near-edge structure (XANES) and density functional theory (DFT) calculations show that each single Cu atom is anchored by three N atoms in the form of CuN₃ active site. Singlet oxygen (¹O₂) has been demonstrated as the primary active component in the degradation of 4-CP. Based on the by-products detected by LC-MS and DFT calculations, a plausible degradation pathway for 4-CP was proposed, and the toxicity of these intermediates was assessed using the ECOSAR procedure. This study provides a new way to prepare atomically dispersed copper to activate PMS for wastewater treatment.

357. 题目: Differences in the regulation of soil carbon pool quality and stability by leaf-litter and root-litter decomposition
文章编号: N24110508
期刊: Environmental Research
作者: Jia Zeng, Xiangyang Li, Junnan Jian, Liheng Xing, Yu Li, Xing Wang, Qi Zhang, Chengjie Ren, Gaihe Yang, Xinhui Han
更新时间: 2024-11-05
摘要: Litter plays a crucial role in soil ecosystems. However, the differences in decomposition between leaf-litter and root-litter and their relative contributions to soil carbon pools and stability are not yet clear. Therefore, we conducted a 450-day in situ decomposition experiment in a semi-arid grassland to investigate the effects of soil biophysical and chemical properties on litter decomposition and to elucidate the dynamics of soil carbon pools during the decomposition process. The results showed that the decomposition rate (K) of leaf-litter was significantly higher than that of root-litter, and litter quality was the most important factor affecting the K of leaf-litter (58%) and root-litter (63%). Leaf-litter decomposition was more effective in promoting the increase in soil leucine aminopeptidase and β-1,4-glucosidase activities, as well as the accumulation of microbial biomass carbon (MBC), particulate organic carbon (POC), and dissolved organic carbon (DOC), compared to root-litter. However, the difference in the impact of leaf-litter and root-litter on soil organic carbon (SOC) was not significant. The decomposition of leaf-litter contributed more significantly to enhancing the soil carbon pool management index (CPMI) compared to root-litter, with increases of 39% and 25%, respectively. In contrast, leaf-litter decomposition significantly reduced the mineral-associated organic carbon (MAOC) and the MAOC/POC ratio, while root-litter decomposition significantly increased the MAOC and MAOC/POC. Random forest, partial correlation, and path analysis indicated that the effects of leaf-litter and root-litter decomposition on CPMI were mainly regulated by decomposition time and soil carbon components, while the effects on MAOC/POC were mainly controlled by litter quality. The results demonstrate that both leaf-litter and root-litter can enhance soil carbon storage and CPMI, but root-litter may be more beneficial for soil carbon pool stability. These results further contribute to the understanding of the continuous system of litter-soil carbon pools.

358. 题目: The effects of physical form, moisture, humic acids, and mixtures on the photolysis of insensitive munitions compounds.
文章编号: N24110507
期刊: Science of the Total Environment
作者: Warren M Kadoya, Samuel A Beal, Susan Taylor, Katerina Dontsova
更新时间: 2024-11-05
摘要: The explosive formulations IMX-101 and IMX-104 are replacing conventional explosives in munitions, making them safer to transport and handle. However, munitions manufacturing and military training can lead to the environmental release of constituent insensitive munitions compounds (IMCs) such as 2,4-dinitroanisole (DNAN), 3-nitro-1,2,4-triazol-5-one (NTO), and nitroguanidine (NQ). These IMCs absorb ultraviolet light and transform photochemically into products with potentially greater toxicity. This study explores the effects of physical form, moisture, humic acids, and compound mixtures on the photolysis of solid and dissolved IMCs under UV-A (350 nm) and UV-B (300 nm) light. Irradiation of dry vs. moist solid IMC crystals yielded few measured products, and while photolysis rates were not significantly different, they were orders of magnitude slower than for aqueous IMCs. There was no significant difference in photolysis rates for aqueous IMCs irradiated with 0, 0.4, and 4 mg L-1 humic acids, but 40 and 400 mg L-1 humic acids inhibited NTO and enhanced NQ photolysis. In two- and three-component aqueous mixtures, DNAN photolysis was enhanced by NQ (at 300 and 350 nm) and NTO (at 350 nm); NTO photolysis was inhibited by DNAN and enhanced by NQ (both at 300 nm); and NQ photolysis was inhibited by both DNAN and NTO (both at 300 and 350 nm). The average quantum yields of the IMCs irradiated alone in solution were: 8.29 × 10-5 (300 nm) and 6.26 × 10-5 (350 nm) for DNAN; 5.76 × 10-4 (300 nm) and 1.74 × 10-4 (350 nm) for NTO; and 1.01 × 10-2 (300 nm) and 1.14 × 10-4 (350 nm) for NQ. Although organic and inorganic products were detected in the mixtures, an average of 15-35 % of the theoretical starting IMC masses (as nitrogen) was not accounted for. Overall, aqueous IMCs transformed 4-48 times faster than the solid IMCs, but the environmentally-relevant conditions tested were found to play a minor role in IMC photolysis.

359. 题目: Stabilization of sulfidated nano zerovalent iron with biochar: Enhanced transport and application for hexavalent chromium removal from water.
文章编号: N24110506
期刊: Journal of Environmental Management
作者: Hao Cheng, Xiaoyu Zheng, Yi Zhu, Ping Wang, Jian Zhu, Jie Wei, Zili Liu, Chao Huang
更新时间: 2024-11-05
摘要: Nano zerovalent iron (nZVI) has been broadly used in the treatment of chromium (Cr) pollution. However, conventional nZVI particles are prone to surface oxidation and particle agglomeration, limiting their effectiveness in contaminant removal. To address these issues, sulfidated nZVI (S-nZVI) was synthesized on the corn stover biochar (BC) surface for rapid removal of Cr(VI) from water. Sedimentation and column transport experiments demonstrated that S-nZVI@BC exhibits excellent dispersion and transport properties, efficiently removing Cr(VI) in the pH range of 2.5-5.0 and showing minimal impact from dissolved oxygen. The Fe0, Fe(Ⅱ), and S2- components of the material, along with the leached Fe2+ ions, contributed to the Cr(VI) removal. A portion of the removed Cr(VI) was reduced to Cr(III) in solution, while another portion was adsorbed on the material's surface through precipitation, with 42.0% of Cr being adsorbed within 30 min. Cycling and water matrix interference experiments further demonstrated the material's excellent reusability and resistance to interference. Notably, the continuous Cr(VI) removal capability in column experiments and the reactivation potential of S-nZVI@BC highlight its promise for practical applications. Future studies are suggested to explore the ecotoxicological effects of the S-nZVI@BC and its capacity for the simultaneous removal of multiple contaminants.

360. 题目: Fungi present distinguishable isotopic signals when grown on glycolytic versus tricarboxylic acid cycle intermediates
文章编号: N24110505
期刊: Biogeosciences
作者: Stanislav Jabinski, Vítězslav Kučera, Marek Kopáček, Jan Jansa, Travis B Meador
更新时间: 2024-11-05
摘要: . Microbial activity in soils controls both the size and turnover rates of large carbon (C) inventories stored in the subsurface, having important consequences for the partitioning of C between terrestrial and atmospheric reservoirs as well as the recycling of mineral nutrients such as nitrogen or phosphorus, often bound to the C, that support plant growth. Fungi are major decomposers of soil organic matter (SOM); however, uncertainty in the predominant C substrates that fuel respiration confound models of fungal production and SOM turnover. To further define the signals of microbial heterotrophic activity, we applied a dual hydrogen (H) and C stable isotope probing (SIP) approach on pure fungal cultures representing the phyla Ascomycetes, Basidiomycetes, and Zygomycetes growing on monomeric (glucose, succinate) or complex substrates (tannic acid, β-cyclodextrin). Our findings demonstrate that the investigated species incorporated only minor amounts of inorganic C (provided as bicarbonate) into their membrane lipids, amounting to < 3 % of lipid-C, with no consistent patterns observed between species or growth substrates. The net incorporation of water-derived H (i.e., α_W) into lipids also did not differ significantly between incubations with monomeric versus complex substrates; however, growth on succinate solicited significantly higher α_W values than glucose or β-cyclodextrin. This finding suggests that ²H-SIP assays have the potential to distinguish between microbial communities supported predominantly by substrates that are catabolized by the tricarboxylic acid cycle versus glycolytic pathway. Furthermore, the average α_W value of heterotrophic fungal incubations [0.69 ± 0.03 (SEM)] is consistent with that observed for bacterial heterotrophs, and may be applied for upscaling lipid-based estimates of fungal production in environmental assays.