Reducing sulfur and ash from coal using Bacillus subtilis and Paenibacillus polymyxa

The reduction of harmful impurities, i.e., ash and sulphur was investigated using bioflotation. Two types of bacteria were tested, namely, Bacillus subtilis and Paenibacillus Polymyxa. The interaction of bacteria with coal was investigated using adsorption kinetics, adsorption isotherm, FTIR and zeta potential. The bioflotation results indicated that the B. subtilis is better than for reducing both sulfur and ash content. A coal concentrate contains 0.92% total sulfur and 1.95% ash was obtained.