Comparison of the kinetics of ferrous iron oxidation by three different strains of Thiobacillus ferrooxidans

Abstract

Three different strains of Thiobacillus ferooxidans were grown in aqueous ferrous sulfate solutions at 30.5°C and at pH 2.0 in a bioreactor. Their specific growth rate followed Monod kinetics. Their maximum specific growth rate (μ_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°C and pH 2.0–2.5 is obtained by using μ_m = 0.14 h⁻¹ K _s = 0.4 g Fe²⁺/L

Keywords:

• Biooxidation
• ferrous iron
• Thiobacillus ferrooxidans