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Liu X, Wang J, He Y, Li J, Tian Q, Xu H. The redistribution process of As(Ⅲ) and Fe(Ⅱ) caused by As/Fe ratio, organic matter, and co-existing ions: Co-precipitation and co-oxidation. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2024; 281:116631. [PMID: 38941658 DOI: 10.1016/j.ecoenv.2024.116631] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/22/2024] [Revised: 06/12/2024] [Accepted: 06/19/2024] [Indexed: 06/30/2024]
Abstract
The contamination of arsenic (As) in aqueous environments has drawn widespread attention, and iron compounds may largely alter the migration ability of As. However, the stability of As(III) in Fe-As system with the intervention of organic matter (OM) remains unclear. Herein, we had explored the co-precipitation and co-oxidation processes of As-Fe system by using batch experiments combined with Fourier Transform Infrared Spectroscopy (FTIR) and X-ray Photoelectron Spectroscopy (XPS) in this research. The precipitation quantity of As(III) increased (28.85-92.41 %) when the As/Fe ratio decreased, and increased (24.20-64.20 %) with pH increased. The main active substance for oxidizing As(III) was H2O2, which was produced in the As-Fe system. FTIR and XPS revealed that As(III) was first oxidized in neutral, and then absorbed and enteredthe interior of Fe(OH)3 colloids. But under alkaline conditions, As(III) was adsorbed by Fe (Oxyhydr) oxides firstly, and then oxidized. The intervention of OM would inhibit the redistribution process of As(III) in aqueous environments. Functional groups and unsaturation of the carbon chain were the dominant factors that affected the precipitation and oxidation processes of As(III), respectively. Co-existing ions (especially PO43-) also signally affected the precipitation quantity of As(Ⅲ) in the system and, when coexisting with OM, could exacerbate this process. The influence of co-existing ions on the redistributive process of As(III) in the As-Fe system with/without OM were as follows: PO43- > SO42- > mixed ions > SiO32-. Moreover, high concentration of OM and PO43- might lead to morphological alterations of As, acting as a threat to aqueous environments. In summary, the present findings were to further understand and appreciate the changes of As toxicity in the aqueous environments. Particularly, the coexistence of OM and As can potentially increase the risk to drinking water safety.
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Affiliation(s)
- Xin Liu
- College of Water Conservancy & Architectural Engineering, Shihezi University, Shihezi 832000, PR China
| | - Jiankang Wang
- College of Water Conservancy & Architectural Engineering, Shihezi University, Shihezi 832000, PR China; Key Laboratory of Water Resources Efficient Utilization in Arid Areas, Shihezi University, Shihezi 832000, PR China.
| | - Yongxian He
- College of Water Conservancy & Architectural Engineering, Shihezi University, Shihezi 832000, PR China
| | - Junfeng Li
- College of Water Conservancy & Architectural Engineering, Shihezi University, Shihezi 832000, PR China.
| | - Qingyuan Tian
- College of Water Conservancy & Architectural Engineering, Shihezi University, Shihezi 832000, PR China
| | - Hong Xu
- College of Water Conservancy & Architectural Engineering, Shihezi University, Shihezi 832000, PR China
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Zhou Z, Yang L, Qu X, Fu H. Dissolved black carbon mediated photo-oxidation of arsenic(III) to arsenic(V) in water: The key role of triplet states. CHEMOSPHERE 2024; 347:140718. [PMID: 37972870 DOI: 10.1016/j.chemosphere.2023.140718] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/19/2023] [Revised: 11/03/2023] [Accepted: 11/12/2023] [Indexed: 11/19/2023]
Abstract
Arsenic is a common contaminant found in natural waters, and has raised significant environmental concerns due to its toxicity and carcinogenicity. In this study, we investigated the mediated photo-oxidation of arsenite (As(III)) under simulated sunlight by dissolved black carbon (DBC), an important dissolved organic matter (DOM) constituent released from black carbon. Five DBC were collected from the water extracts of black carbons that were derived by pyrolyzing different biomass (i.e., bamboo, rice, peanuts, corn, and sorghum stalks), and four well-studied dissolved humic substances (DHS) were selected for benchmarking. The presence of DBC (i.e., 5 mg C-1) significantly accelerated the photo-oxidation of As(III) to arsenate (As(V)), with the observed pseudo-first-order rate constant of reaction increased by 5∼11 times. Quenching experiments of photochemically produced reactive intermediates suggested that As(III) was mainly oxidized by triplet-excited DBC (3DBC*, contribution of 48%), singlet oxygen (1O2, 18%) and superoxide anions (O2•-, 28%) in sunlight-irradiated DBC solutions. The average apparent quantum yield of As(III) photo-oxidation for DBC was found to be more than 4 times higher in comparison with DHS. Such a strong mediation efficiency of DBC was due to its smaller molecular size and higher aromaticity than DHS, which facilitated the non-charge-transfer process to produce triplet-excited states and their sensitized 1O2. Consistently, DBC exhibited a higher apparent quantum yield and a longer lifetime of triplet states as compared with DHS. The results imply that DBC may play a previously unrecognized important role in the fate of arsenic in aquatic environments.
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Affiliation(s)
- Zhicheng Zhou
- State Key Laboratory of Pollution Control and Resource Reuse/School of the Environment, Nanjing University, Jiangsu 210046, China
| | - Lanqing Yang
- State Key Laboratory of Pollution Control and Resource Reuse/School of the Environment, Nanjing University, Jiangsu 210046, China
| | - Xiaolei Qu
- State Key Laboratory of Pollution Control and Resource Reuse/School of the Environment, Nanjing University, Jiangsu 210046, China
| | - Heyun Fu
- State Key Laboratory of Pollution Control and Resource Reuse/School of the Environment, Nanjing University, Jiangsu 210046, China.
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Wang Y, Gong X, Dong X. Photo-oxidation of arsenite in acidic waters containing Suwannee River fulvic acid: roles of 3SRFA* and hydroxyl radical. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2021; 28:45144-45154. [PMID: 33864218 DOI: 10.1007/s11356-021-13900-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/29/2020] [Accepted: 04/07/2021] [Indexed: 06/12/2023]
Abstract
The photo-oxidation of arsenite (As(III)) in solution containing Suwannee River fulvic acid (SRFA) under the ultraviolet A (UVA) irradiation (λmax = 365 nm) was studied. In a solution containing 100.0 μg·L-1 As(III) and 10.0 mg·L-1 SRFA at pH 3.0, SRFA induced As(III) photo-oxidation by producing the triplet excited state of SRFA (3SRFA*) and hydroxyl radical(HO˙). Approximately 82% of As(III) oxidation was attributed to HO˙ which depended strongly on HO2˙/O2˙-. The remaining 18% of As(III) oxidation was attributed to the direct reaction between As(III) and 3SRFA*. The photo-oxidation of As(III) was significantly affected by solution pH. Excess SRFA inhibited As(III) photo-oxidation. The addition of a low concentration of ferric ions retarded the photo-oxidation of As(III) due to the poor photo-activity of Fe(III)-SRFA complexes. In contrast, the addition of ferric ions at high concentration greatly accelerated As(III) photo-oxidation because of the high photo-activity of Fe(III)-OH complexes. The fractions of SRFA with different molecular weight showed different oxidizing capacities under UV irradiation which was possibly related to the different contents of phenolic OH groups. The findings have important environmental implications for the photo-transformation behavior of As(III) in natural surface waters containing dissolved organic matter, especially acidic waters.
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Affiliation(s)
- Yajie Wang
- School of Eco-Environmental Engineering, Guizhou Minzu University, Guiyang, 550025, People's Republic of China.
| | - Xianhe Gong
- School of Eco-Environmental Engineering, Guizhou Minzu University, Guiyang, 550025, People's Republic of China
| | - Xin Dong
- School of Eco-Environmental Engineering, Guizhou Minzu University, Guiyang, 550025, People's Republic of China
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Wang Z, Fu Y, Wang L. Abiotic oxidation of arsenite in natural and engineered systems: Mechanisms and related controversies over the last two decades (1999-2020). JOURNAL OF HAZARDOUS MATERIALS 2021; 414:125488. [PMID: 33676246 DOI: 10.1016/j.jhazmat.2021.125488] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/22/2020] [Revised: 02/17/2021] [Accepted: 02/19/2021] [Indexed: 06/12/2023]
Abstract
Abiotic oxidation of toxic As(III) to As(V) is being deemed as a necessary step for the overall arsenic decontamination in both natural and engineered systems. Direct oxidation of As(III) by chemical oxidants, such as ozone, permanganate, ferrate, chlorine and chloramine, or naturally occurring minerals like Mn, Fe oxides, seems straightforward. Both O2 and H2O2 are ineffective for arsenite oxidation, but they can be activated by reducing substances like Fe2+, Fe0 to increase the oxidation rates. Photo-induced oxidation of As(III) has been demonstrated effective in Fe complexes or minerals, NO3-/NO2-, dissolved organic matter (DOM), peroxygens and TiO2 systems. Although a variety of oxidation methods have been developed over the past two decades, there remain many scientific and technical challenges that must be overcome before the rapid progress in basic knowledge can be translated into environmental benefits. To better understand the trends in the existing data and to identify the knowledge gaps, this review describes in detail the complicated mechanisms for As(III) oxidation by various methods and emphasizes on the conflicting data and explanation. Some prevailing concerns and challenges in the sphere of As(III) oxidation are also pointed out so as to appeal to researchers for further investigations.
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Affiliation(s)
- Zhaohui Wang
- Shanghai Key Lab for Urban Ecological Processes and Eco-Restoration, School of Ecological and Environmental Sciences, East China Normal University, Shanghai 200241, China; Shanghai Engineering Research Center of Biotransformation of Organic Solid Waste, Shanghai 200241, China; Technology Innovation Center for Land Spatial Eco-restoration in Metropolitan Area, Ministry of Natural Resources, 3663N. Zhongshan Road, Shanghai 200062, China.
| | - Yu Fu
- Shanghai Key Lab for Urban Ecological Processes and Eco-Restoration, School of Ecological and Environmental Sciences, East China Normal University, Shanghai 200241, China
| | - Lingli Wang
- Shanghai Key Lab for Urban Ecological Processes and Eco-Restoration, School of Ecological and Environmental Sciences, East China Normal University, Shanghai 200241, China
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Liu S, Tan M, Ge L, Zhu F, Wu S, Chen N, Zhu C, Zhou D. Photooxidation mechanism of As(III) by straw-derived dissolved organic matter. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 757:144049. [PMID: 33316532 DOI: 10.1016/j.scitotenv.2020.144049] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/15/2020] [Revised: 11/18/2020] [Accepted: 11/19/2020] [Indexed: 06/12/2023]
Abstract
Straw return-to-field is a common agronomic practice that would affect the physicochemical characteristics of the paddy soil and overlying water, but few studies have focused on the possible impacts of straw return on the conversion of pollutants. In this study, the photooxidation of As(III) in aqueous solution by straw-derived dissolved organic matter (S-DOM) was investigated. The results showed that dissolved organic matter derived from wheat straw (DOMws) and rape straw (DOMrs) exhibited good spectroscopic features and could efficiently oxidize As(III) under irradiation at pH 5.0, with the kobs values of As(III) oxidation being 0.15 h-1 and 0.17 h-1 for DOMws and DOMrs, respectively. Quenching studies indicated that hydroxyl radical (OH) dominated the oxidation of As(III) for both types of dissolved organic matter (DOM), though singlet oxygen (1O2) also played a role in the DOMrs system. Since acidic conditions are favorable for the formation of OH, As(III) oxidation decreased with an increase of pH value. Additionally, the oxidation efficiency of As(III) was inhibited in the presence of NO3- (0.2-2 mM) while enhanced in the presence of Fe(III) (5-50 μM). This study is of great significance for understanding the removal/transformation behavior of pollutants in paddy fields that receive straw return.
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Affiliation(s)
- Shaochong Liu
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, PR China
| | - Mengxi Tan
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, PR China
| | - Liqiang Ge
- Geological Survey of Jiangsu Province, Nanjing 210018, PR China
| | - Fengxiao Zhu
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, PR China
| | - Song Wu
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, PR China
| | - Ning Chen
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, PR China
| | - Changyin Zhu
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, PR China.
| | - Dongmei Zhou
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, PR China.
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Removal of As(III) from Water Using the Adsorptive and Photocatalytic Properties of Humic Acid-Coated Magnetite Nanoparticles. NANOMATERIALS 2020; 10:nano10081604. [PMID: 32824146 PMCID: PMC7466695 DOI: 10.3390/nano10081604] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Revised: 07/31/2020] [Accepted: 08/11/2020] [Indexed: 11/17/2022]
Abstract
The oxidation of highly toxic arsenite (As(III)) was studied using humic acid-coated magnetite nanoparticles (HA-MNP) as a photosensitizer. Detailed characterization of the HA-MNP was carried out before and after the photoinduced treatment of As(III) species. Upon irradiation of HA-MNP with 350 nm light, a portion of the As(III) species was oxidized to arsenate (As(V)) and was nearly quantitatively removed from the aqueous solution. The separation of As(III) from the aqueous solution is primarily driven by the strong adsorption of As(III) onto the HA-MNP. As(III) removals of 40–90% were achieved within 60 min depending on the amount of HA-MNP. The generation of reactive oxygen species (•OH and 1O2) and the triplet excited state of HA-MNP (3HA-MNP*) was monitored and quantified during HA-MNP photolysis. The results indicate 3HA-MNP* and/or singlet oxygen (1O2) depending on the reaction conditions are responsible for converting As(III) to less toxic As(V). The formation of 3HA-MNP* was quantified using the electron transfer probe 2,4,6-trimethylphenol (TMP). The formation rate of 3HA-MNP* was 8.0 ± 0.6 × 10−9 M s−1 at the TMP concentration of 50 µM and HA-MNP concentration of 1.0 g L−1. The easy preparation, capacity for triplet excited state and singlet oxygen production, and magnetic separation suggest HA-MNP has potential to be a photosensitizer for the remediation of arsenic (As) and other pollutants susceptible to advanced oxidation.
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Zhu N, Li Y, Jiao J, Yun Y, Ku T, Liang D, Sang N. Investigating photo-driven arsenics' behavior and their glucose metabolite toxicity by the typical metallic oxides in ambient PM 2.5. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2020; 191:110162. [PMID: 31935557 DOI: 10.1016/j.ecoenv.2020.110162] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/19/2019] [Revised: 12/29/2019] [Accepted: 01/01/2020] [Indexed: 06/10/2023]
Abstract
It is essential and challenged to understand the atmospheric arsenic pollution because it is much more complicated than in water and top-soil. Herein the different behavior of arsenic species firstly were discovered within the ambient PM2.5 collected during daytime and nighttime, winter and summer. The diurnal variation of arsenic species in PMs is significantly correlated with the presence of metallic oxides, specifically, ferrous, titanium and zinc oxides, which might play a key role in the process of the photo-oxidation of As(III) to As(V) with the meteorological parameters and regional factors excluded. Subsequently, the photo conversion of arsenite was detected on metal-loaded glass-fiber filters under visible light. The photo-generated superoxide radical was found to be predominantly responsible for the oxidation of As(III). In order to reveal toxicity differences induced by oxidation As(III), HepG2 cells were exposed to various arsenic mixture solution. We found that the antioxidant enzyme activities suppressed with increasing the As(III)/As(V) ratio in total, followed by the accumulation of intracellular ROS level. The glucose consumption and glycogen content also displayed an obvious reduction in insulin-stimulated cells. Compared to the expression levels of IRS-1, AKT and GLUT4, GLUT2 might be more vulnerable to arsenic exposure and lead to the abnormalities of glucose metabolism in HepG2 cells. Taken together, these findings clarify that the health risk posed by inhalation exposure to As-pollution air might be alleviated owing to the photo-driven conversion in presence of metal oxides.
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Affiliation(s)
- Na Zhu
- College of Environmental and Resource, Research Center of Environment and Health, Shanxi University, Taiyuan, 030006, PR China
| | - Ying Li
- College of Environmental and Resource, Research Center of Environment and Health, Shanxi University, Taiyuan, 030006, PR China
| | - Junheng Jiao
- College of Environmental and Resource, Research Center of Environment and Health, Shanxi University, Taiyuan, 030006, PR China
| | - Yang Yun
- College of Environmental and Resource, Research Center of Environment and Health, Shanxi University, Taiyuan, 030006, PR China
| | - Tingting Ku
- College of Environmental and Resource, Research Center of Environment and Health, Shanxi University, Taiyuan, 030006, PR China
| | - Dong Liang
- School of Chemical Engineering and Technology, North University of China, Taiyuan, 030051, PR China
| | - Nan Sang
- College of Environmental and Resource, Research Center of Environment and Health, Shanxi University, Taiyuan, 030006, PR China.
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Jin J, Chen Z, Song X, Wu B, Zhang G, Zhang S. Effects of acetylacetone on the thermal and photochemical conversion of benzoquinone in aqueous solution. CHEMOSPHERE 2019; 223:628-635. [PMID: 30798058 DOI: 10.1016/j.chemosphere.2019.02.080] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/01/2018] [Revised: 01/08/2019] [Accepted: 02/13/2019] [Indexed: 06/09/2023]
Abstract
Quinones are components of electron transport chains in photosynthesis and respiration. Acetylacetone (AA), structurally similar to benzoquinone (BQ) for the presence of two identical carbonyl groups, has been reported as a quinone-like electron shuttle. Both BQ and AA are important chemicals in the aquatic environment. However, little information is known about their interactions if co-existed. We found here that AA significantly enhanced the conversion of BQ. By analyzing the evolution of chemical concentration, solution pH, dissolved oxygen, and the final products, the interactions between AA and BQ were elucidated. The reactions between BQ and AA generated oxygen but ultimately led to the reduction of solution pH and dissolved oxygen. The reactions proceeded faster under indoor lighting condition than in the dark. The formation of semiquinone radicals is believed as the primary step. The secondary AA-derived radicals might be strongly oxidative or reductive, depending on the concentration of dissolved oxygen. Insoluble humus was generated in the mixture of BQ and AA. These results suggest that the presence of AA might interfere with photosynthesis and respiration through the interactions with quinones.
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Affiliation(s)
- Jiyuan Jin
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, 210023, China
| | - Zhihao Chen
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, 210023, China
| | - Xiaojie Song
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, 210023, China
| | - Bingdang Wu
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, 210023, China
| | - Guoyang Zhang
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, 210023, China
| | - Shujuan Zhang
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, 210023, China.
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Zhang Y, Liu W, Hu X, Zhang A, Ma L, Shi Y, Gong G. Extraction and Functional Group Characterization of Fulvic Acid from Hami Lignite. ChemistrySelect 2019. [DOI: 10.1002/slct.201803291] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Yingjie Zhang
- Key Laboratory of Coal Processing and; Efficient Utilization of Ministry of Education; Xuzhou 221116 China
- College of Chemical Engineering & Technology; China University of Mining and Technology; Xuzhou 221116 China
| | - Wenjing Liu
- College of Chemical Engineering & Technology; China University of Mining and Technology; Xuzhou 221116 China
| | - Xiaofeng Hu
- College of Chemical Engineering & Technology; China University of Mining and Technology; Xuzhou 221116 China
| | - Ao Zhang
- College of Chemical Engineering & Technology; China University of Mining and Technology; Xuzhou 221116 China
| | - Lulin Ma
- College of Chemical Engineering & Technology; China University of Mining and Technology; Xuzhou 221116 China
| | - Yongming Shi
- College of Chemical Engineering & Technology; China University of Mining and Technology; Xuzhou 221116 China
| | - Guanqun Gong
- Key Laboratory of Coal Processing and; Efficient Utilization of Ministry of Education; Xuzhou 221116 China
- College of Chemical Engineering & Technology; China University of Mining and Technology; Xuzhou 221116 China
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Chen Z, Jin J, Song X, Zhang G, Zhang S. Redox Conversion of Arsenite and Nitrate in the UV/Quinone Systems. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2018; 52:10011-10018. [PMID: 30063337 DOI: 10.1021/acs.est.8b03538] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Whether superoxide radical anion (O2•-) was a key reactive species in the oxidation of arsenite (As(III)) in photochemical processes has long been a controversial issue. With hydroquinone (BQH2) and 1,4-benzoquinone (BQ) as redox mediators, the photochemical oxidation of As(III) and reduction of nitrate (NO3-) was carefully investigated. O2•-, singlet oxygen (1O2), H2O2, and semiquinone radical (BQH•) were all possible reactive species in the irradiated system. However, since the formation of As(IV) is a necessary step in the oxidation of As(III), taking the standard reduction potentials into account, the reactions between the above species and As(III) were thermodynamically unfavorable. On the basis of radical scavenging experiments, hydroxyl radical (•OH) was proved as the key species that led to the oxidation of As(III) in the UV/BQH2 system. It should be noted that the •OH radicals were generated from the photolysis of H2O2, which came from the disproportionation of O2•- and the reaction of O2•- with BQH2. Both the photoejected eaq- from 1(BQH2)* and the direct electron transfer with 3(BQH2)* contributed to the reduction of NO3- in the UV/BQH2 process. No synergistic effect was observed in the redox conversion of As(III) and NO3-, further demonstrating that the role of BQH• was negligible in the studied systems. The results here are helpful for a better understanding of the photochemical behaviors of quinones in the aquatic environment.
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Affiliation(s)
- Zhihao Chen
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment , Nanjing University , 163 Xianlin Avenue , Nanjing , 210023 , China
| | - Jiyuan Jin
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment , Nanjing University , 163 Xianlin Avenue , Nanjing , 210023 , China
| | - Xiaojie Song
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment , Nanjing University , 163 Xianlin Avenue , Nanjing , 210023 , China
| | - Guoyang Zhang
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment , Nanjing University , 163 Xianlin Avenue , Nanjing , 210023 , China
| | - Shujuan Zhang
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment , Nanjing University , 163 Xianlin Avenue , Nanjing , 210023 , China
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Golubenko DV, Yaroslavtsev AB. New approach to the preparation of grafted ion exchange membranes based on UV-oxidized polymer films and sulfonated polystyrene. MENDELEEV COMMUNICATIONS 2017. [DOI: 10.1016/j.mencom.2017.11.011] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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12
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Pozdnyakov IP, Romanova TE, Cai X, Salomatova VA, Plyusnin VF, Na P, Shuvaeva OV. Near-UV photooxidation of As(III) by iron species in the presence of fulvic acid. CHEMOSPHERE 2017; 181:337-342. [PMID: 28456035 DOI: 10.1016/j.chemosphere.2017.04.103] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/17/2017] [Revised: 04/05/2017] [Accepted: 04/23/2017] [Indexed: 06/07/2023]
Abstract
Photooxidation of As(III) in ternary As(III) - Fe(III) - Fulvic acid system at pH 4 was investigated by optical spectroscopy, steady-state photolysis (365 nm) and atomic-emission spectrometry with inductively coupled plasma techniques. It was found that at all values of [FA]/[Fe] ratio the main photoactive species is OH radical formed by photolysis of Fe(III) hydroxocomplexes. Addition of fulvic acid leads to mainly negative effect on As(III) photooxidation due to the following reasons: (i) slow dark reduction of photoactive Fe(III) species with formation of scattering particles and photoinert Fe(II) species; (ii) formation of photoreductive Fe(III)-FA complexes incapable to oxidize As(III), (iii) competition of both FA and Fe(III)-FA complexes for UVA quanta with FeOH2+ complex and for OH radicals with As(III). Aging of ternary system is also very important parameter leading to one order decrease of quantum yields of both Fe(II) formation and As(III) photooxidation.
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Affiliation(s)
- Ivan P Pozdnyakov
- V.V. Voevodsky Institute of Chemical Kinetics and Combustion, 3 Institutskaya St., 630090 Novosibirsk, Russian Federation; Novosibirsk State University, 2 Pirogova St., 630090 Novosibirsk, Russian Federation.
| | - Tamara E Romanova
- Novosibirsk State University, 2 Pirogova St., 630090 Novosibirsk, Russian Federation; Nikolaev Institute of Inorganic Chemistry, 3 Acad. Lavrentiev Ave., 630090 Novosibirsk, Russian Federation
| | - Xiaojiao Cai
- Institute of Chemical Technology, Tianjin University, 92 Weijin Rd, 300072 Nankai, Tianjin, China
| | - Victoria A Salomatova
- V.V. Voevodsky Institute of Chemical Kinetics and Combustion, 3 Institutskaya St., 630090 Novosibirsk, Russian Federation
| | - Victor F Plyusnin
- V.V. Voevodsky Institute of Chemical Kinetics and Combustion, 3 Institutskaya St., 630090 Novosibirsk, Russian Federation; Novosibirsk State University, 2 Pirogova St., 630090 Novosibirsk, Russian Federation
| | - Ping Na
- Institute of Chemical Technology, Tianjin University, 92 Weijin Rd, 300072 Nankai, Tianjin, China
| | - Olga V Shuvaeva
- Novosibirsk State University, 2 Pirogova St., 630090 Novosibirsk, Russian Federation; Nikolaev Institute of Inorganic Chemistry, 3 Acad. Lavrentiev Ave., 630090 Novosibirsk, Russian Federation
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Efficiency of singlet oxygen generation by fulvic acids and its influence on UV photodegradation of herbicide Amitrole in aqueous solutions. MENDELEEV COMMUNICATIONS 2017. [DOI: 10.1016/j.mencom.2017.07.028] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Qiu H, Geng J, Ren H, Ding L, Xu K, Zhang Y. Aquatic transformation of phosphite under natural sunlight and simulated irradiation. WATER RESEARCH 2017; 109:69-76. [PMID: 27866104 DOI: 10.1016/j.watres.2016.11.023] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/17/2016] [Revised: 10/24/2016] [Accepted: 11/05/2016] [Indexed: 06/06/2023]
Abstract
The phototransformation of phosphite (HPO32-, H2PO3-, +3) from Lake Taihu water (THW) under natural sunlight was evaluated. No direct phosphite photoreaction was observed under sunlight. Suspended solids were shown to play important roles in the indirect photoreaction of phosphite in lake water. The phototransformation of phosphite followed pseudo-first-order reaction kinetics and the kinetics constants (k, d-1) decreased as: 0.0324 (original THW), 0.0236 (sterilized THW), 0.0109 (filtered THW) and 0.0102 (sterilized filtered THW). Original THW with 1 mmol L-1 NO3- added was used to simulate the phosphite removal in lakes with serious N pollution. The results showed that the phototransformation was accelerated (with k increased to 0.0386-0.0463 d-1), and sterilization or filtration shown little effect to the transformation, as the half-lives of phosphite drew closer. Under simulated irradiation in NO3- system, increasing NO3- concentration or decreasing pH value promoted phototransformation. The addition of Fe3+ or Fe2+ accelerated photooxidation, while the addition of Mn2+ or Cd2+ inhibited phototransformation. Br-, NO2- and HCO3- in environmental concentrations decreased phototransformation, and HCO3- showed the strongest inhibition. Suwannee River humic acid or Suwannee River fulvic acid strongly inhibited the photooxidation process, and the inhibiting effects varied with their structure. Phosphite photooxidation was strongly inhibited by adding isopropanol or sodium azide as reactive oxygen species (ROS) quenchers. Electron spin resonance analysis indicated that OH was a main oxidant produced in this system. The increased amount of phosphate coincided with the decreased amount of phosphite, which indicated that the transformation product of phosphite was phosphate. Phosphite is a considerable component of the P redox cycle in Lake Taihu.
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Affiliation(s)
- Huimin Qiu
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, China
| | - Jinju Geng
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, China.
| | - Hongqiang Ren
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, China
| | - Lili Ding
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, China
| | - Ke Xu
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, China
| | - Yan Zhang
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, China
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