Mixed bacterial consortium as an emerging tool to remove hazardous trace metals from coal

This paper presents the results of experimental work on the possibility of removal of environmentally sensitive trace elements from coal through treatment with mixed bacterial consortium. In the coals of Kalimantan area, Indonesia the metals like Cd, Cu, Cr, Ni, Pb and Zn have been found to occur in concentrations of 1.96, 59.34, 26.98, 102.68, 14.4 and 172.54 ppm respectively. The concentrations of these elements are higher when compared with Clarke values in bituminous coals. Mixed bacterial consortium has been used to explore the possibility of removal of these toxic trace elements. The result reveals that the bacterial consortium is efficient to remove more than 80% of metals like Ni, Zn, Cd, Cu and Cr while the removal of Pb is nearly 45%. The removal is seen in the order: Zn > Ni > Cd > Cu > Cr > Pb.