Kinetics of the liquid‐phase oxidation of acid ferrous sulfate by the bacterium <i>Thiobacillus ferrooxidens</i>

Abstract

Abstract The kinetics of the batch‐wise liquid‐phase oxidation of ferrous sulfate by the organism Thiobacillus ferrooxidans has been studied over a range of temperatures from 20°C to 31°C and in the presence of an abundant supply of oxygen, carbon dioxide, and other nutrients. The rate of oxidation was found to be accurately described by the equation where t = time hr, S = concentration of ferrous ions g Fe ++ /1., μ m = maximum specific growth rate of bacteria, hr −1 . Y = mass of bacteria produced per gram of iron oxidized g/g, K = saturation constant, g Fe ++ /l., and X = concentration of bacteria g/1. The value for the maximum specific growth rate, μ m , was found to vary from 0.12 hr −1 at 20°C to 0.20 hr −1 at 31°C, while the value for the saturation constant K varied randomly between 1 and 2 g/1. A method has also been described which permitted evaluation of the relevant rate constants μ m and K without direct knowledge of the bacterial population. This method was found to yield values of μ m and K which agreed with values determined accurately by a statistical regression analysis of the experimental data.