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Yan X, Zhu B, Huang H, Chen W, Li H, Chen Y, Liang Y, Zeng H. Analysing N-nitrosamine occurrence and sources in karst reservoirs, Southwest China. ENVIRONMENTAL GEOCHEMISTRY AND HEALTH 2024; 46:112. [PMID: 38472659 DOI: 10.1007/s10653-024-01890-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/05/2023] [Accepted: 01/26/2024] [Indexed: 03/14/2024]
Abstract
N-nitrosamines in reservoir water have drawn significant attention because of their carcinogenic properties. Karst reservoirs containing dissolved organic matter (DOM) are important drinking water sources and are susceptible to contamination because of the fast flow of various contaminants. However, it remains unclear whether N-nitrosamines and their precursor, DOM, spread in karst reservoirs. Therefore, this study quantitatively investigated the occurrence and sources of N-nitrosamines based on DOM properties in three typical karst reservoirs and their corresponding tap water. The results showed that N-nitrosamines were widely spread, with detection frequencies > 85%. Similar dominant compounds, including N-nitrosodimethylamine, N-nitrosomethylethylamine, N-nitrosopyrrolidine, and N-nitrosodibutylamine, were observed in reservoirs and tap water, with average concentrations of 4.7-8.9 and 2.8-6.7 ng/L, respectively. The average carcinogenic risks caused by these N-nitrosamines were higher than the risk level of 10-6. Three-dimensional fluorescence excitation-emission matrix modeling revealed that DOM was composed of humus-like component 1 (C1) and protein-like component 2 (C2). Fluorescence indicators showed that DOM in reservoir water was mainly affected by exogenous pollution and algal growth, whereas in tap water, DOM was mainly affected by microbial growth with strong autopoietic properties. In the reservoir water, N-nitrosodiethylamine and N-nitrosopiperidine were significantly correlated with C2 and biological indicators, indicating their endogenously generated sources. Based on the principal component analysis and multiple linear regression methods, five sources of N-nitrosamines were identified: agricultural pollution, microbial sources, humus sources, degradation processes, and other factors, accounting for 46.8%, 36.1%, 7.82%, 8.26%, and 0.96%, respectively. For tap water, two sources, biological reaction processes, and water distribution systems, were identified, accounting for 75.7% and 24.3%, respectively. Overall, this study presents quantitative information on N-nitrosamines' sources based on DOM properties in typical karst reservoirs and tap water, providing a basis for the safety of drinking water for consumers.
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Affiliation(s)
- Xiaoyu Yan
- Guangxi Key Laboratory of Environmental Pollution Control Theory and Technology, Guilin University of Technology, Guilin, 541004, China
| | - Bingquan Zhu
- Guangxi Key Laboratory of Environmental Pollution Control Theory and Technology, Guilin University of Technology, Guilin, 541004, China
| | - Huanfang Huang
- State Environmental Protection Key Laboratory of Water Environmental Simulation and Pollution Control, South China Institute of Environmental Sciences, Ministry of Ecology and Environment, Guangzhou, 510535, China
| | - Wenwen Chen
- Guangxi Key Laboratory of Environmental Pollution Control Theory and Technology, Guilin University of Technology, Guilin, 541004, China
| | - Haixiang Li
- Guangxi Key Laboratory of Environmental Pollution Control Theory and Technology, Guilin University of Technology, Guilin, 541004, China
- Collaborative Innovation Center for Water Pollution Control and Water Safety in Karst Area, Guilin University of Technology, Guilin, 541004, China
| | - Yingjie Chen
- State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan, 430074, China
| | - Yanpeng Liang
- Guangxi Key Laboratory of Environmental Pollution Control Theory and Technology, Guilin University of Technology, Guilin, 541004, China
- Collaborative Innovation Center for Water Pollution Control and Water Safety in Karst Area, Guilin University of Technology, Guilin, 541004, China
| | - Honghu Zeng
- Guangxi Key Laboratory of Environmental Pollution Control Theory and Technology, Guilin University of Technology, Guilin, 541004, China.
- Collaborative Innovation Center for Water Pollution Control and Water Safety in Karst Area, Guilin University of Technology, Guilin, 541004, China.
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Yu W, Cao Y, Yan S, Guo H. New insights into arsenate removal during siderite oxidation by dissolved oxygen. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 882:163556. [PMID: 37080317 DOI: 10.1016/j.scitotenv.2023.163556] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/20/2022] [Revised: 03/20/2023] [Accepted: 04/13/2023] [Indexed: 05/03/2023]
Abstract
Nowadays, arsenic (As) pollution in aquatic environments severely threatens the health of human beings. Although it has been known that siderite is capable of As adsorption and dissolved oxygen (DO) enhances the adsorption, effects of DO concentrations on As(V) adsorption onto siderite remain elusive. In this study, As(V) removal was investigated by synthesized siderite from aqueous solutions with different DO concentrations. Arsenic(V) adsorption kinetics were conformed to the pseudo-second-order model. As(V) adsorption onto siderite was enhanced in the presence of dissolved oxygen, but the excess DO concentration did not increase As(V) adsorption since Fe(III) oxides were coated onto the pristine siderite surface, preventing the mineral from further oxidation. With the increase in DO concentration, the rate of Fe(II) oxidation decreased, which was the kinetic-limited step during As(V) removal by siderite with the presence of DO. The theoretically generated Fe(III) was stoichiometrically proportional to the consumed oxygen. Microscopic characteristics by means of XRD, SEM, TEM, FTIR and XPS indicated that the adsorption was dominated by the chemical process via the As(V) complexation with siderite and co-precipitation with produced Fe(III) oxides. This study reveals the mechanisms of As(V) adsorption during siderite oxidation under different DO concentrations and emphasizes the importance of siderite oxidation in As(V) fate in aqueous systems.
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Affiliation(s)
- Wenting Yu
- State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences (Beijing), Beijing 100083, PR China; Key Laboratory of Groundwater Conservation of MWR & School of Water Resources and Environment, China University of Geosciences (Beijing), Beijing 100083, PR China
| | - Yuanyuan Cao
- State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences (Beijing), Beijing 100083, PR China; Key Laboratory of Groundwater Conservation of MWR & School of Water Resources and Environment, China University of Geosciences (Beijing), Beijing 100083, PR China
| | - Song Yan
- Beijing Water Business Doctor Co., LTD., Beijing 100083, PR China
| | - Huaming Guo
- State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences (Beijing), Beijing 100083, PR China; Key Laboratory of Groundwater Conservation of MWR & School of Water Resources and Environment, China University of Geosciences (Beijing), Beijing 100083, PR China.
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Ren Y, Cao W, Li Z, Pan D, Wang S. Identification of arsenic spatial distribution by hydrogeochemical processes represented by different ion ratios in the Hohhot Basin, China. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2023; 30:2607-2621. [PMID: 35932348 DOI: 10.1007/s11356-022-22311-6] [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: 04/08/2022] [Accepted: 07/26/2022] [Indexed: 06/15/2023]
Abstract
The Hohhot Basin, a typical inland basin of the Yellow River Basin in China, has high concentrations of arsenic (As) in its shallow groundwater, while the factors dominating the distribution of high arsenic levels remain to be further identified. An analysis of the ratio of hydrogeochemical compositions can help to reveal the spatial characteristics of the shallow groundwater environmental conditions and the distribution of high-arsenic water (As >10 μg/L). In this study, a total of 170 samples of shallow groundwater in the Hohhot Basin were collected and water samples with As >10 μg/L accounted for 29.4% of the total. Based on the slope changes of the cumulative frequency curves of (HCO3- + CO32-)/SO42-, Ca2+/(HCO3- + CO32-), Ca2+/Mg2+, and Na+/Ca2+, the groundwater in the study area can be categorized into six different zones according to the environmental characteristics including redox condition, water recharge intensity, and cation exchange level. The result shows that the groundwater in the front of the piedmont alluvial plain and platform is in a weak reducing condition with high lateral recharge intensity, fast runoff, and weak cation exchange. In the Dahei River alluvial plain, which serves as the groundwater discharge zone, the groundwater runoff is sluggish with poor lateral recharge, sufficient exchange between cations in the groundwater and the aquifer matrix, and enhanced reducibility. The degree of oxidation increased in the groundwater near the Hasuhai Lake and the drainage canal, which adverse to the arsenic enrichment. High-arsenic groundwater is mainly distributed in aquifers of (HCO3- + CO32-)/SO42 > 10, Na+/Ca2+ > 13, and Ca2+/(HCO3- + CO32-) < 0.1, which represent the strong reducing condition, low surface water recharge intensity, and strong cation exchange condition. Reductive dissolution of iron oxide, strong evaporation and concentration process, and competition from phosphate in aquifers jointly lead to the release of arsenic into groundwater.
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Affiliation(s)
- Yu Ren
- Institute of Hydrogeology and Environmental Geology IHEG, Chinese Academy of Geological Sciences (CAGS), Shijiazhuang, 050061, Hebei, China
- Key Laboratory of Groundwater Science and Engineering, Ministry of Natural Resources, Shijiazhuang, 050061, China
- National Observation and Research Station on Groundwater and Land Subsidence of Cangzhou, Shijiazhuang, 050061, Hebei, China
| | - Wengeng Cao
- Institute of Hydrogeology and Environmental Geology IHEG, Chinese Academy of Geological Sciences (CAGS), Shijiazhuang, 050061, Hebei, China.
- Key Laboratory of Groundwater Science and Engineering, Ministry of Natural Resources, Shijiazhuang, 050061, China.
- National Observation and Research Station on Groundwater and Land Subsidence of Cangzhou, Shijiazhuang, 050061, Hebei, China.
| | - Zeyan Li
- Institute of Hydrogeology and Environmental Geology IHEG, Chinese Academy of Geological Sciences (CAGS), Shijiazhuang, 050061, Hebei, China
- Key Laboratory of Groundwater Science and Engineering, Ministry of Natural Resources, Shijiazhuang, 050061, China
- National Observation and Research Station on Groundwater and Land Subsidence of Cangzhou, Shijiazhuang, 050061, Hebei, China
| | - Deng Pan
- Henan Institute of Geological Environmental Monitoring, Zhengzhou, 450016, China
| | - Shuai Wang
- Henan Institute of Geological Environmental Monitoring, Zhengzhou, 450016, China
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