Study of formation of jarosite mediated by thiobacillus ferrooxidans in 9K medium

Thiobacillus ferrooxidans, occurring extensively in mine districts, have important effects on the oxidation of metal sulphide and the formation of jarosite. In the coal bio-desulphurization, jarosite mediated by microorganisms decreases the bacterial absorbability of nutrients, occupies the available sites of coal surfaces, ultimately results in residual sulfur, which cannot be removed from coal. The thiobacillus ferrooxidans cultivation conditions with minimal jarosite in 9K medium by varying the initial pH, the initial Fe2+ concentration and the applied potential were studied and determined. Experimental results show that the optimal combination giving the minimal jarosite precipitates (3.73 g/L) and the good growing activity of bacteria is the initial pH of 1.6–1.7 with the Fe2+ concentration of 9–10 g/L and the applied potential of −0.5 V for 7 hours. The results will be of significant importance for the further research on the bacterial cultivation and coal desulphurization.