Oxidation of H2S in acid solution by Thiobacillus ferrooxidans and Thiobacillus thiooxidans

Qualitative and quantitative oxidation tests of H2S in acid solution were c arried out using Thiobacillus ferrooxidans and Thiobacillus thiooxidans spe cies, Experiments were performed using solutions of H2SO4 (pH 2.0) containi ng H2S in initial concentrations ranging from 5 to 100 ppm. in shake flasks at 150 rpm and 30(circle)C. In these solution, this gas was not very stabl e and was quickly liberated. However, at low concentration (less than 5 ppm ) it becomes stable and could only be removed from solution by oxidation. T he results obtained indicated that the presence of either T. ferrooxidans o r T. thiooxidans causes a significant reduction in H,S concentration (more than 99%) in relation to the sterile control, No differences in oxidation e fficiency between these two species were detected. (C) 2001 Elsevier Scienc e Ltd. All rights reserved.