22. Removal of hazardous trace element from coal in biodesulfurisation process

Abstract

Biodesulfurisation (BDS) of coal by use of Thiobacillus ferrooxidans was investigated. The % removal of inorganic S was 37-88% when the BDS was carried out for 30 days. The BDS efficiency was varied with the kind of coals, while the efficiency tended to decrease as the pH in the medium increased. The degree of pH was ruled by the amount of Ca leached from coal. When the pH in the medium was artificially controlled to be below 3.0, the BDS efficiency was greatly improved. The BDS process also resulted in effective removal of hazardous heavy metals, such as As, Hg, and Se.