Hydrogeochemical assessment of mine water discharges from mining activity. Case of the Haut Beht mine (central Morocco)

Abstract

The rocks are likely to give a geochemical signature to the groundwater circulating there. Therefore the hydro geochemistry of the mine's water is influenced by the mining method. The continuous pumping of the mine water gives discharges that induce harmful impacts on the environment. The Sebou basin is subjected to strong industrial and urban pollution, but in the literature, the evaluation of the mining impact on this area is neglected. This paper is dedicated to this issue and as part of the evaluation of the mining impact on the Sebou watershed, the haut Beht mine was chosen among the four mines which include the watershed, and then we proceeded, as the purpose of this work, to evaluate the physicochemical quality of this mine's water discharges and their metallic trace elements (MTE) load (As, Pb, Cd, Zn, and Cu) through monitoring of four locations during two analysis campaigns in 2014 and 2015. This monitoring was performed by ICP-MS analysis. The results showed absenteeism of the acidic nature of mine's water, characterizing acid mine drainage (AMD). The majority of the analyzed water presents important concentrations of sulfate. During the 2014 campaign, the examination of trace metal element concentrations showed, at station 2, contamination of Iron, Aluminum, Manganese and, Arsenic. However, the concentrations of Pb, Cd, Zn, and Cu elements remain conform and very low compared to the limit of standards. The monitoring of the overtake elements made it possible to identify the degree of contamination of the mine's water discharges and to note an improvement in time in the mine water discharges quality.

Keywords

• sebou river
• environment
• metallic trace elements
• mine water
• discharges