COMPARISON OF THE KINETICS OF FERROUS IRON OXIDATION BY 3 DIFFERENT STRAINS OF THIOBACILLUS-FERROOXIDANS

Three different strains of Thiobacillus ferooxidans were grown in aqueous ferrous sulfate solutions at 30.5-degrees-C and at pH 2.0 in a bioreactor. Their specific growth rate followed Monod kinetics. Their maximum specific growth rate (mu(m)) was between 0. 138 and 0.148 h-1 and their saturation constant (K(s)) was in the range from 0.338 to 0.479 g Fe2+/L. Comparing our data with other data from the literature, we concluded that the kinetics of ferrous iron oxidation is independent of the strain used A good approximation of the growth kinetics on ferrous iron of Thiobacillus ferrooxidans between 20 and 32-degrees-C and pH 2.0-2.5 is obtained by using mu(m) = 0.14 h-1 K(s) = 0.4 g Fe2+/L.