Removal of Sulfate and Iron from Coal Mine Waste by Using SRB Batch Bioreactor

Abstract

Leachate from coal mine waste is a serious environment problem, which has been considered as the major pollution problem associated with coal mining activities owing to high concentrations of sulfate, iron and other heavy metals. Biological treatment by sulfate reducing bacteria (SRB) has been considered as one promising alternative method for the treatment of acid leachate from coal mine waste. The treatment is based on the metabolism of SRB with organic carbon as electron donor and sulfate as electron acceptor, and the process can remove heavy metals as sulfide precipitates. In this study, ethanol was investigated as carbon source required for SRB to treat coal mine waste leachate by batch experiment. Inoculation of coal mine waste in batch reactors with SRB resulted in the efficient neutralization and high removal of sulphate (84.3%) and iron (97.2%). The result showed that the removal of sulfate and iron by inoculating coal mine waste pile with SRB could be a potential alternative to traditional treatment of coal mine waste.