Kinetic model of CuS oxidation by Thiobacillus ferrooxidans and Thiobacillus thiooxidans bacteria

Kinetics of the process of microbiological oxidation of synthetic CuS perfo rmed with the involvement of pure and mixed cultures of T. ferrooxidans and T. thiooxidans bacteria were studied. The CuS oxidation with T. ferrooxida ns bacteria was found to be best described by the model of inhibition of th e first order with respect to the substrate and the product-inhibitor, whil e the process with T. thiooxidans and mixed cultures of these bacteria is b est described by the first order reaction with respect to the substrate. It was also shown that the adaptation of the bacteria to the CuS rested signi ficantly shortens the induction period and increases reaction rates. The op timum conditions of CuS oxidation were established. The yield of the reacti on was established as ca. 30% and an increase in the reaction rate was obse rved when using mixed cultures of T. ferrooxidans i T. thiooxidans bacteria adapted to CuS at 35 degrees C, in the medium containing 1 % (wt./vol.) Cu S at the initial pH of the medium of 1.82.