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Photochemical fate of nonionic polyacrylamide induced by hydroxyl radicals in the natural water: Mineralization mechanism exploration and half-life time evaluation

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science of the Total Environment 2024年 947卷 174485页

作者： Jia, Daqing Therias, Sandrine Voelker, François Kieffer, Johann Favero, Cédrick Mailhot, Gilles Université Clermont Auvergne CNRS Institut de Chimie de Clermont-Ferrand Clermont-FerrandF-63000 France SNF ZAC de milieux 42160 SA Andrézieux-Bouthéon France National Engineering Laboratory for Industrial Wastewater Treatment School of Resources and Environmental Engineering East China University of Science and Technology Shanghai200237 China State Environmental Protection Key Laboratory of Environmental Risk Assessment and Control on Chemical Process East China University of Science and Technology Shanghai200237 China Université Clermont Auvergne CNRS Laboratoire de Météorologie Physique Clermont-FerrandF-63000 France

Water-soluble polyacrylamide (PAM) compounds have been used extensively in various sectors. The abundance of PAM in the environment raises concerns about its environmental impact. However, the mineralization of PAM in water under natural light irradiation remains insufficiently explored. This study utilizes nonionic PAM (nPAM) as a representative model to investigate both the mechanism and efficiency of nPAM degradation in water when exposed to ultraviolet (UV) light with hydrogen peroxide (H2O2) as the hydroxyl radical source. In the dark or with only UVA irradiation, negligible mineralization of nPAM occurred. In contrast, the presence of hydroxyl radicals (produced by the UVA/H2O2 system) produced 50 % nPAM mineralization over 7 days under our experimental conditions. The corresponding molecular weight (MW) of the nPAM was swiftly reduced from 1.58 ×106 Da to 1.59 ×103 Da in 3 days. Moreover, five carboxylic acids and nitrate ions were identified as the photodegradation intermediates of nPAM. The efficiencies of nPAM photodegradation by the UVA/H2O2 system in different natural waters and environmental conditions were assessed. The rate constant for the reaction between the hydroxyl radical and nPAM was 2.17 ×109 M-unit−1 s−1. The half-lives of nPAM in the sea and continental surface waters were determined to be several years and dozens of days, respectively. The application of UVB obviously accelerated the mineralization of nPAM in ultrapure water (71 % degradation in 7 days). Moreover, mineralization of concentrated nPAM (200 mg/L) in sea water was more efficient when both UVA- and UVB-activated H2O2 were used. Additionally, toxic acrylamide was not generated during nPAM photodegradation. Moreover, the photodegradation intermediates from nPAM were found to be neither acutely nor chronically toxic to aquatic organisms. This comprehensive study sheds light on the photochemical fate of nPAM in natural waters and provides essential insight for practical treatment of

关键词： Rate constants

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Reduced Graphene Oxide as an Effective Promoter to the Layered Manganese Oxide-Supported Ag Catalysts for the Oxidation of Ethyl Acetate and Carbon Monoxide

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SSRN 2022年

作者： Dong, Ning Ye, Qing Zhang, Dan Xiao, Yang Dai, Hongxing Key Laboratory of Beijing on Regional Air Pollution Control Department of Environmental Science School of Environmental and Chemical Engineering Faculty of Environment and Life Beijing University of Technology Beijing100124 China Beijing Key Laboratory for Green Catalysis and Separation Key Laboratory of Beijing on Regional Air Pollution Control Key Laboratory of Advanced Functional Materials Education Ministry of China Laboratory of Catalysis Chemistry and Nanoscience Department of Environmental Chemical Engineering School of Environmental and Chemical Engineering Faculty of Environment and Life Beijing University of Technology Beijing100124 China

The layered manganese oxide ( δ -MnO 2 )-supported reduced graphene oxide (rGO)-promoted silver catalysts ( x Ag− y rGO/ δ -MnO 2;x and y are the Ag and rGO contents, respectively) were prepared via a polyvinyl alcohol-protected reduction route. Physicochemical properties of these materials were determined using the numerous techniques, and their catalytic activities were evaluated for the oxidation of CO and ethyl acetate. It is found that the doping of rGO as an electron transfer promoter could significantly strengthen the metal−support interaction (SMSI) between Ag and δ -MnO 2 , hence improving catalytic performance of the sample. Activity evaluation reveals that 1Ag−1.0rGO/ δ -MnO 2 performed the best, giving the T 90% of 140 o C for CO oxidation and 160 o C for ethyl acetate oxidation at space velocity (SV) = 60,000 mL/(g h). The doping of rGO led to an increase in Mn3+/Mn4+ or O ads /O latt molar ratio, thus giving rise to the enhancement in catalytic activity of Ag/δ -MnO2 . The good performance of 1Ag−1.0rGO/ δ -MnO 2 was associated with its high Oads /O latt molar ratio, good low-temperature reducibility, and strong SMSI between Ag and δ -MnO2 . © 2022, The Authors. All rights reserved.

关键词： Manganese oxide

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High Temperature Carbothermal Synthesis of Activated Carbon-Supported Nano Zero-Valent Iron and Nanosilver Composite and its Performance for Removal of As(Iii)

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SSRN 2023年

作者： Zhang, Lizhao Zhou, Zijian Chen, Zhili Li, Wenbin Huang, Mingming College of Environmental Science and Engineering Guilin University of Technology Guilin541004 China Guangxi Key Laboratory of Environmental Pollution Control Theory and Technology Guilin University of Technology Guilin541004 China Guangxi Collaborative Innovation Center for Water Pollution Control and Water Safety in Karst Areas Guilin University of Technology Guilin541004 China

Activated carbon-supported nano zero-valent iron and nanosilver composite (Ag/Fe/AC) is prepared by using simultaneous carbothermal reduction methods. The technical characterization reveals that the modification process results in a reduction of the specific surface area of the activated carbon to 586.752 m2·g -1 compared to its original value (914.637 m2·g -1), and the supported nano zero-valent iron and nanosilver particles exhibit particle sizes ranging from 15 to 30 nm, the co-doping of silver leads to a notable reduction in the particle size of the zero-valent iron. Batch equilibration studies show that the adsorption performance of Ag/Fe/AC is significantly superior to that of the single-supported modified activated carbon (activated carbon-supported nano zero-valent iron and activated carbon-supported nanosilver) prepared by the same method. The maximum adsorption capacity of Ag/Fe/AC calculated from the Langmuir adsorption isotherm is found to be 94.314 mg·g-1, which is approximately 10.0 and 1.4 times higher than activated carbon-supported nanosilver and activated carbon-supported nano zero-valent, respectively. Based on the comparison of surface materials of Ag/Fe/AC before and after adsorption, it has been concluded that under the synergistic effect of silver and iron nanoparticles, the majority of the adsorbed As(III) on the Ag/Fe/AC surface is converted into As(V) and forms complexes such as FexAsy(OOH)z and FexAsy(OH)z, which are firmly attached to the material surface. The experiments on silver-loss demonstrate that the presence of zero-valent iron significantly reduce the rate of silver loss, thereby ensuring the safety and reliability of water purification. © 2023, The Authors. All rights reserved.

关键词： Activated carbon

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Water Reducer: A Highly Dispersing Binder for High-Performance Lithium-Sulfur Batteries

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Chinese Journal of Chemistry 2021年第6期39卷 1523-1530页

作者： Xin Geng Ruihao Lin Xingxing Gu Zhi Su Chao Lai College of Chemistry and Chemical Engineering Xinjiang Normal UniversityUrumqiXinjiang 830054China School of Chemistry and Materials Science Jiangsu Normal UniversityXuzhouJiangsu 221116China Chongqing Key Laboratory of Catalysis and New Environmental Materials College of Environment and ResourcesChongqing Technology and Business UniversityChongqing 400065China

Sulfur has been paid close attention by the research and manufacturing as a cathode material for lithium-sulfur batteries(LSB)in recent decade because it has high specific capacity and low *** the low utilization of active materials and serious shuttle phenomenon inhibit its commercialization *** this work,for the first time,water reducers are reported as multifunctional binders to address the above problems to enhance the performance of *** to the synthetic actions of the water reducer binder,such as highly dispersing effect and good chemical trapping function,commercial sulfur powders are directly used as cathodes,and much better electrochemical performance compared to using the conventional binder polyvinylidene fluoride(PVDF)was obtained,among which the sulfur cathode with sulfonated melamine formaldehyde(SMF)water reducer binder exhibits a high reversible capacity of 625.5 mA·h·g^(-1) after 200 cycles at 1 C and the cathode with polycarboxylic acid(PC)water reducer binder even demonstrates a high area specific capacity of 5 mA·h·cm^(-2) at high sulfur loading of 5 mg·cm^(-2).These low-cost water reducers are a promising binder for LSB in the future.

关键词： Energy conversion Polymers Binder Polyanions Adsorption

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Effects of land use and dissolved organic matter on pCO2 are dependent on stream orders and hydrological seasonality in a low-order karst river

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science of the Total Environment 2024年 957卷 177502页

作者： Ma, Yongmei Ni, Maofei Gu, Shijie Zhang, Liuqing Sun, Huaiwei Tang, Wei Li, Siyue Key Laboratory of Reservoir Aquatic Environment Chongqing Institute of Green and Intelligent Technology Chinese Academy of Sciences Chongqing400714 China College of Eco-Environmental Engineering Guizhou Minzu University Guiyang550025 China Institute of Environment and Ecology Shenzhen International Graduate School Tsinghua University Shenzhen China School of Civil and Hydraulic Engineering Huazhong University of Science and technology Wuhan430074 China Administration office for Wu Shan Dachang lake national wetland park Chongqing404700 China School of Environmental Ecology and Biological Engineering Institute of Changjiang Water Environment and Ecological Security Hubei Key Laboratory of Novel Reactor and Green Chemical Technology Wuhan Institute of Technology Wuhan430205 China

Human activities and stream accumulation influence carbon loadings, altering the distributions and characteristics of dissolved inorganic and organic carbon in rivers. It is widely recognized that such alterations affect dissolved organic matter (DOM) components, water environment and river carbon dioxide (CO2) degassing, however, the control factors by which land use/land cover (LULC) and DOM components regulate the partial pressure of CO2 (pCO2) are unclear. Here, in the Daning karst river system, an extensive investigation was presented to investigate the role of LULC and DOM components in influencing the spatial and temporal variability of pCO2, as well as to investigate the regulating effect of stream order and hydrological rhythm on this influence. DOM quality and pCO2 levels exhibited significant spatial and temporal variations. In the 3rd – 4th order streams, pCO2 was correlated with protein and lignin compounds in the wet period and with DOM molecular weight in the dry period. Relatively high protein-like components (54.83 % ∼ 71.84 %, on average) and biological index (0.86–0.90, on average) indicated notable autochthonous processes. Significant relationships between pCO2 and water quality parameters were observed in the 3rd – 4th order streams in the wet period, demonstrating the role of runoff and upstream accumulation. Farmland increased pCO2 levels in the 3rd – 4th order streams, whereas forests could potentially mitigate river CO2 saturation. River pCO2 was well predicted by LULC under extended circular buffers (1000 and 2000 m in diameter). This study demonstrated that DOM and LULC directly or indirectly affect pCO2 and that the influences are largely regulated by hydrological seasonality and stream orders, which is better for understanding aquatic CO2 drivers. © 2024 Elsevier B.V.

关键词： Carbon sequestration

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Multiple metal exposure and metabolic syndrome in elderly individuals: A case-control study in an active mining district, Northwest China

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Chemosphere 2023年第1期326卷 138494页

作者： Guo, Sai Hua, Liting Liu, Wu Liu, Hongxiu Chen, Qiusheng Li, Yongcheng Li, Xiaoxiao Zhao, Leicheng Li, Ruoqi Zhang, Zining Zhang, Chong Zhu, Lin Sun, Hongwen Zhao, Hongzhi MOE Key Laboratory of Pollution Processes and Environmental Criteria College of Environmental Science and Engineering Nankai University Tianjin300350 China Jingyuan County Center for Disease Control and Prevention Gansu Baiyin730699 China Key Laboratory of Environment and Health Ministry of Education & Ministry of Environmental Protection School of Public Health Tongji Medical College Huazhong University of Science and Technology Hubei Wuhan430000 China Institute of Agro-product Safety and Nutrition Tianjin Academy of Agricultural Sciences Tianjin300381 China State Key Laboratory of Environmental and Biological Analysis Department of Chemistry Hong Kong Baptist University Hong Kong Hong Kong

The prevalence of metabolic syndrome (MetS) is increasing at an alarming rate worldwide, particularly among elderly individuals. Exposure to various metals has been linked to the development of MetS. However, limited studies have focused attention on the elderly population living in active mining districts. Participants with MetS (N = 292) were matched for age (±2 years old) and sex with a healthy subject (N = 292). We measured the serum levels of 14 metals in older people aged 65–85 years. Conditional logistic regression, restricted cubic spline model, multiple linear regression, and Bayesian Kernel Machine Regression (BKMR) were applied to estimate potential associations between multiple metals and the risk of MetS. Serum levels of Sb and Fe were significantly higher than the controls (0.58 μg/L vs 0.46 μg/L, 2167 μg/L vs 2042 μg/L, p © 2023

关键词： Risk perception

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Aggregation-Induced Emission for Monitoring Interfacial Polymerization and Membrane Fouling

SSRN

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SSRN 2022年

作者： Zhang, Qiang Li, Die Luo, Xinzhao Wang, Yan Xu, Xiaoling Yang, Tao Key Laboratory of New Membrane Materials Ministry of Industry and Information Technology School of Environmental and Biological Engineering Nanjing University of Science and Technology Nanjing210094 China Institute of Polymer Ecomaterials School of Environmental and Biological Engineering Nanjing University of Science and Technology Nanjing210094 China

It is of great significance to understand the matter evolution of membrane surface. The in-situ and real-time monitoring of membrane surface will not only favor the investigation of interfacial polymerization, but can also track the membrane fouling to reduce the operation cost. Herein, an aggregation-induced emission (AIE)-active membrane is prepared by interfacial polymerization of the cyclodextrin-based glycocluster (CD@Glucose) and the fluorescent agent (TPEDB) on the surface of polyacrylonitrile (PAN) ultrafiltration membrane with boronate ester as ligation. This interfacial polymerization method can be stacked layer-by-layer, and can regulate the hydrophilicity and pore structure of the membrane. With the increase of the polymer layers, the separation and antifouling properties of the membrane can gradually improve. Thanks to the AIE property of the crosslinking agent TPEDB, the occurrence of interfacial polymerization and the fouling degree during membrane operation can be monitored by fluorescence distribution and intensity. With the aggravation of membrane fouling, the fluorescence decreases gradually but can recover after cleaning. Therefore, this AIE effect can be used for real-time monitoring of interfacial polymerization as well as membrane fouling and performance recovery under UV light. (Image Presented) © 2022, The Authors. All rights reserved.

关键词： Fluorescence

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Simultaneous Mitigating the Bioavailability of Cadmium and Arsenic in Paddy Soil by Two Carbon-Iron Composites: A Field-Scale Evaluation

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SSRN 2023年

作者： Chen, Gongning Lu, Yuxi Feng, Mi Lin, Hua Liang, Yanpeng Zhou, Zijian Liang, Zihao Li, Huawei Zeng, Honghu College of Environmental Science and Engineering Guilin University of Technology Guilin541004 China Guangxi Key Laboratory of Environmental Pollution Control Theory and Technology Guilin University of Technology Guilin541004 China Guangxi Collaborative Innovation Center for Water Pollution Control and Water Safety in Karst Areas Guilin University of Technology Guilin541004 China

Cadmium and arsenic have become the difficulty of soil inorganic pollution control due to their opposite chemical properties. Field experiments were performed to evaluate the performance and mechanism of the carbon-iron composites in mitigating the bioavailability of soil Cd and As. The mitigating performance for Cd bioavailability decreased as follows: ZVI-biochar > ZVI-peat > biochar > wood peat > ZVI, and the mitigating performance for As bioavailability was in the order of ZVI-peat > ZVI-biochar > ZVI;Biochar and wood peat enhanced the bioavailability of soil As. Both ZVI-biochar and ZVI-peat composites showed superior immobilization performance due to its higher soil pH, formation of soil amorphous Fe oxyhydroxides and roots iron plaque. The increased Fe nutrition inhibited the transportation of Cd and As from roots to grains. Both ZVI-biochar and ZVI-peat resulted in a more than 42% reduction for grain Cd and 33.8% reduction for grain As. © 2023, The Authors. All rights reserved.

关键词： Peat

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Changing on the Concentrations of Neonicotinoids in Rice and Drinking Water Through Heating Treatment Process: An Unusual Increase in Imidacloprid

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SSRN 2023年

作者： Wei, Ziyang Zhang, Bo Li, Xu Gao, Yanxia He, Yuan Xue, Jingchuan Zhang, Tao School of Environmental Science and Engineering Sun Yat-Sen University Guangzhou510275 China Key Laboratory for City Cluster Environmental Safety and Green Development The Ministry of Education School of Ecology Environment and Resources Guangdong University of Technology Guangzhou510006 China

Neonicotinoids (NEOs) have become the most widely used insecticides in the world since the mid-1990s. According to Chinese dietary habits, rice and water are usually heated before being consumed, but the information about the alteration of NEOs before and after the heat treatment process is very limited. In this study, the parents of NEOs (p-NEOs) accounted for >99% of ∑NEOs in both uncooked (median: 66.8 ng/g) and cooked (median: 41.4 ng/g) rice samples, while the metabolites of NEOs (m-NEOs) accounted for less than 1%. Significant reductions in acetamiprid, imidacloprid (IMI), thiacloprid, and thiamethoxam (THM) have been observed after the heat treatment of the rice samples, while the reductions in the water samples were insignificant, except for those of THM and dinotefuran. These results indicate the degradation of p-NEOs and m-NEOs in the rice samples during the heat treatment process. However, the concentrations of IMI increased in the high-concentration-spiked water samples after boiling, suggesting the presence of potential IMI precursors. The concentrations of NEOs in rice and water can be shifted by the heating treatment process, so this process should be considered in relevant human exposure studies. © 2023, The Authors. All rights reserved.

关键词： Metabolites

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Single-Cell Raman Spectra Reveals the Cytochrome C-Mediated Electron Transfer in the Nanoscale Zero-Valent Iron Coupled Denitrification Process

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SSRN 2022年

作者： Liu, Chunlei Guo, Zhongrui Zhang, Hanrui Li, Jianfei Zhu, Chao Zhu, Guibing Key Laboratory of Drinking Water Science and Technology Research Center for Eco-Environmental Sciences Chinese Academy of Sciences Beijing100085 China School of Environmental Science and Engineering Shaanxi University of Science & Technology Xi′an710021 China School of Environmental and Municipal Engineering Tianjin Chengjian University Tianjin300384 China

Nanoscale zero-valent iron (nZVI) coupled denitrification is considered the typical abiotic-biotic synergistic process, but its underlying electron transfer mechanism remains unclear. Herein, we performed a heavy water labeling single-cell Raman spectroscopy (D 2 O-SCRS) for in-situ and dynamic characterization of the Cytochrome c-mediated electron transfer process with coexisting nZVI and a model denitrifying bacterium. Interestingly, the nZVI resulted in a strong synergistic effect with a high denitrification efficiency of 99.8% (~100 mg L -1 NO 3 -N), approximately 18 and 12-fold than those of pure nZVI (5.4%) and model bacterium (8.3%), respectively. The D 2 O-SCRS approach revealed the reduced Cytochrome c (Cyt c) facilitated electron transfer to enzymes and is responsible for NO 2 - →NO, NO→N 2 O, and N 2 O→N 2 reactions in the denitrification respiratory chain, thus accelerating the occurrence of synergistic effects. Furthermore, the decreased metabolic activity contributed to higher ATP availability for nitrate reduction, thereby favoring denitrification. The metatranscriptomic analysis confirmed that both up-regulated genes encoding Cyt c reductase and the down-regulated Cyt c oxidase promoted the generation of reduced Cyt c, corresponding well with the D 2 O-SCRS results. Additionally, the elevated complex I, complex III, and excess NAD+ ensured a large number of electrons participated in the respiratory chain. This study deepened the understanding of the biotic-abiotic synergistic mechanism and provided a new method to in-situ characterize the electron transfer process at a single-cell level. © 2022, The Authors. All rights reserved.

关键词： Raman spectroscopy

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