Long-Term Remediation of Acid Mine Drainage from Abandoned Coal Mine Using Integrated (Anaerobic and Aerobic) Passive Treatment System, in South Africa: A Pilot Study

摘要

Acid mine drainage from abandoned mines is primarily responsible for degradation of scarce water resources in South Africa. Owing to the nature of previous legislations, the South African government has inherited environmental liabilities of most of the abandoned mine sites, and hence there is a need to develop long-term sustainable remediation solutions. To contribute towards development of sustainable mine water management solutions in South Africa, a pilot passive treatment plant consisting of integrated anaerobic and aerobic units has been constructed to treat 1440 liters of acid mine drainage per day from an abandoned underground coal mine. During the first six months of operation, the pilot plant has successfully neutralized the water and substantially removed contaminants, such as Fe, Al, Co, Zn, Ni, As, Pb, V, but with limited SO_4 reduction (only 30% removal rate was achieved). Thereafter, there has been a decrease in treated water quality with time, and this was largely due to clogging and/or depletion in the treatment materials. The study demonstrated that passive treatment can be used as a long-term remediation of polluted mine water from abandoned mine sites in South Africa. The results of this pilot-scale test will be used to design an optimised full-scale plant, and also assist in an optimized design of additional pilot plants in other abandoned mining areas.