Heavy metals in the water and sediments of Oued Es-Souk, Algeria, a river receiving acid effluents from an abandoned mine

Abstract

The Sidi Kamber Mine, abandoned since 1976, is still a source of acidic drainage entering the Oued Es-Souk River. An investigation of the rate of pollution of the Oued Es-Souk and the variation of its water quality showed that the mining waters are very acidic, with high concentrations of sulphate ions and dissolved heavy metals. Only lead reaches a significant level in the suspended matter. During mixing of the acid stream waters with uncontaminated river water, an amorphous orange precipitate forms and contributes to the removal of sulphate and certain heavy metals by adsorption and co-precipitation. Downstream, zinc and lead are concentrated in the sediments, while cadmium is mainly transported in the dissolved phase.