Title: Contamination of soil around an abandoned gold mine tailings dam with trace elements in a small town, northeastern Zimbabwe

Authors: Artwell Kanda; France Ncube; Tinashe Gadaga; Violet P. Dudu; Peter Makumbe; George Nyamadzawo

Addresses: Department of Environmental Science, Bindura University of Science Education, P. Bag. 1020, Bindura, Zimbabwe ' Department of Crop Sciences, Lupane State University, P.O. Box 170, Lupane, Zimbabwe ' Department of Environmental Science, Bindura University of Science Education, P. Bag. 1020, Bindura, Zimbabwe ' Department of Environmental Science, Bindura University of Science Education, P. Bag. 1020, Bindura, Zimbabwe ' Sustainability Research Unit, Nelson Mandela University, George Campus, Madiba Dr, 6531, George, South Africa ' Department of Environmental Science, Bindura University of Science Education, P. Bag. 1020, Bindura, Zimbabwe

Abstract: Abandoned mine sites are a threat to the quality of the ambient environment. Tailings from an abandoned gold mine were characterised for physicochemical properties. The contamination of soil around a tailings dam with trace elements was assessed using geochemical indices. Tailings had low pH (5.67 ± 0.67), high SO₄²⁻ content (116.00 ± 23.88 g/kg) and electrical conductivity (3,918.40 ± 673.17 μS/cm). Surrounding soil had elevated concentrations of trace elements which decreased with increasing distance away from the tailings dam, and with increasing depth. The geoaccumulation and degree of contamination indices showed strong to extreme contamination of soil with Cd, Cr and Cu within 10 m from the tailings dam. Soil contamination was high in the downslope and downwind (S, W and SW) directions. Multivariate statistics suggested a common source of Cd, Cu and Pb, the tailings dam. Rehabilitation of the tailings dam may reduce tailings erosion and soil contamination.

Keywords: abandoned mine; acid drainage; geoaccumulation index; mine tailings; soil contamination; trace element; northern Zimbabwe.

DOI: 10.1504/IJGENVI.2019.110429

International Journal of Global Environmental Issues, 2019 Vol.18 No.4, pp.283 - 302

Accepted: 07 Jul 2020
Published online: 19 Oct 2020 *

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