Occurrence and behavior of arsenic in groundwater-aquifer system of irrigated areas
Article
Article Title | Occurrence and behavior of arsenic in groundwater-aquifer system of irrigated areas |
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ERA Journal ID | 3551 |
Article Category | Article |
Authors | Li, Chengcheng, Bundschuh, Jochen, Gao, Xubo, Li, Yong, Zhang, Xin, Luo, Wenting and Pan, Zhendong |
Journal Title | Science of the Total Environment |
Journal Citation | 838, pp. 1-12 |
Article Number | 155991 |
Number of Pages | 12 |
Year | 2022 |
Publisher | Elsevier |
Place of Publication | Netherlands |
ISSN | 0048-9697 |
1879-1026 | |
Digital Object Identifier (DOI) | https://doi.org/10.1016/j.scitotenv.2022.155991 |
Web Address (URL) | https://www.sciencedirect.com/science/article/abs/pii/S0048969722030881 |
Abstract | Groundwater arsenic pollution has received much attention worldwide for decades as a serious threat to public health, but the mechanisms responsible for arsenic mobilization are not fully understood. Groundwater and bore drilling sediment samples from Qiji county, a small geographical agricultural area with endemic arsenicosis, are collected for demonstrating the occurrence and speciation of arsenic in groundwater and sediments, and arsenic release between solid-liquid phase influenced by human activities. Results show that arsenic concentrations in groundwater vary from 5 μg/L to 19.6 μg/L, with 80% exceeding the maximum permissible limits required by WHO (10 μg/L) for drinking water and therefore constituting a health risk for humans. In a weak oxidizing environment (oxidation-reduction potential (ORP): 12.9 mV–151 mV), inorganic As(V) accounts for 85% of total dissolved As, which to some extent alleviates the harm of As pollution on humans. Total As content in the sediments is in the range of 6.98 mg/kg and 14.34 mg/kg (median of 10.71 mg/kg), three times higher than the average value of many countries. Sequential chemical leaching indicates that 11% of arsenic in sediments is labile bound and may be closely related to the arsenic in groundwater. Additionally, irrigation intensity contributes to arsenic release with diverse As3+/As5+ by dissolving weakly bound arsenic rapidly. Subsequently part of As(III) is oxidized to As(V). Competitive and/or alkaline desorption of As(V), which had been adsorbed by Fe–Mn (hydrous)-oxides and carbonates in the unsaturated zone and the aquifer, exerts a significant role in releasing arsenic into the groundwater. Our study indicates that systematic management and regulation of irrigation intensity are required to prevent further deterioration of groundwater resources. |
Keywords | Adsorption-desorption; Arsenic release; Irrigated areas; Oxidation; Sequential extraction; Species of arsenic |
ANZSRC Field of Research 2020 | 3707. Hydrology |
Public Notes | Files associated with this item cannot be displayed due to copyright restrictions. |
PubMed ID | 35588806 |
Funder | University of Southern Queensland |
Byline Affiliations | China University of Geosciences, China |
University of Southern Queensland | |
School of Engineering |
https://research.usq.edu.au/item/yy785/occurrence-and-behavior-of-arsenic-in-groundwater-aquifer-system-of-irrigated-areas
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