Nature Environment and Pollution Technology

Man-Li Lin ¹, He-Rong Gui ¹, Wei-Hua Peng ²

Affiliations
1 School of Resources and Civil Engineering, Suzhou University, Suzhou 234000, Anhui, CN
2 School of Chemistry and Environment, Beihang University, No. 37 Xueyuan Road, Haidian District, Beijing 100191, CN

Abstract

To investigate the health risk posed by heavy metals in the groundwater of a coal mining area in northern Anhui Province, China, six types of heavy metals (Cr, Cd, Cu, Pb, Zn, Ni) were identified and analysed by obtaining 59 water samples from four aquifers (UF, CA, TA, OA) through the use of an atomic absorption spectrophotometer. The values of these heavy metals were then compared with the permissible limits set by the Chinese Environmental Protection Agency (EPA) and World Health Organization (WHO) (2008). The health risk posed to adults and children was assessed based on the American Environmental Protection Agency's health risk assessment model. The concentrations of Cd, Cr, Cu, Zn, and Pb are within the permissible limits set by the Chinese EPA, but the concentration of Ni is higher than the permissible limits. The concentrations of Cr, Cu, Zn, and Ni are within the permissible limits set by the WHO (2008), whereas Cd and Pb concentrations are higher than the permissible limits. The health risk assessment performed shows that the HRI values of the selected heavy metals are in the order of Cd>Ni>Pb>Cu>Zn>Cr. Although most of the heavy metals pose no health risk (HRI<1), several HRI values of Cd in the selected water samples exceed 1, indicating a small health risk imposed on local people. This health risk assessment of heavy metals in a deep groundwater mining area can serve as a reference for groundwater resource exploitation and protection.

Keywords

Heavy Metals, Health Risk Assessment, Chronic Daily Intake, Groundwater, Wanbei Coal Mining Area.

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Jie Ma ¹, Lin-Hua Sun ¹, Song Chen ¹, He-Rong Gui ¹, Hai-Tao-Zhang ¹

Affiliations
1 School of Resources and Civil Engineering, Suzhou University, Suzhou, Anhui 234000, CN

Abstract

Major ion concentrations were measured in 22 groundwater samples collected from a coal bearing aquifer in Zhuxianzhuang coal mine, northern Anhui Province, and the ion source and geochemical characteristics were discussed by the methods such as traditional graphic and multivariate statistic analysis. The results showed the presence of three water types, i.e., HCO₃-Na, Cl-Na and SO₄-Na. The surrounding rock weathering and evaporation, both controlled the chemical characteristics of groundwater, evidenced by the Gibb’s diagrams. In detail, the features of ion ratios such as Ca/Na, HCO₃/Na and Mg/Na show that the evaporate dissolution and silicate weathering were the dominant water-rock interactions. Multivariate analysis, such as correlation analysis, cluster analysis and FA analysis were also conducted to reveal the ion source in groundwater, and the Ca²⁺ and Mg²⁺ were mainly released from the dissolution of gypsum and/or magnesium and/or anorthite; while the Na⁺ is influenced by the weathering of feldspar and halite, with the cation exchange in a certain extent. In contrast, the Cl^-, HCO₃^- and SO₄^2- are also controlled by the halite dissolution, silicate mineral weathering and sulphate mineral dissolution, respectively. In addition, the SO₄^2- in groundwater could be influenced by the oxidation of pyrite, which is abundant in the coal bearing aquifers.

Keywords

Coal Bearing Aquifer, Groundwater, Cation Exchange, Hydrochemistry.

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