Surface and ground water quality affected by coal mine tailings as road construction material

Abstract

Coal mine tailings occupy approximately 20% and 70% of the area suitable for urban development in Bechar and Kenadsa, respectively (southwestern Algeria). These tailings pose environmental risks, as toxic contaminants can leach into groundwater and surface water if improperly managed. This study investigated the potential use of coal mine tailings as embankment or road pavement material and its environmental impact, particularly on water resources. Cement and lime were independently used to treat an optimal mixture of coal mine tailings and tuff to enhance contaminant retention and maintain water quality. Leaching tests were conducted on four soil samples, and the leachate was analyzed for heavy metals (Cd, Pb, and Zn) using atomic absorption spectroscopy (AAS). Results suggest that utilizing treated coal mine tailings as a pavement base layer or embankment material may mitigate associated pollution. Leaching tests demonstrated that cement treatment effectively retained heavy metals and other toxic elements, potentially protecting surface and groundwater from contamination.