Effect of operation conditions on biological Fe oxidation with rotating biological contactors

Oxidation of ferrous iron (Fe²⁺) by acidophilic iron-oxidizing bacteria was conducted with a laboratory-scale rotating biological contactor (RBC) in order to investigate the effects of Fe²⁺ concentration, pH, temperature and rotation rate. Fe²⁺ oxidation rate on RBC was expressed as a first-order reaction with respect to Fe²⁺ concentration when it was below 150 mg 1⁻¹. Fe²⁺ oxidation rate was not affected by pH from 1.0 to 2.6 nor by temperatures from 10 to 40°C but was accelerated by increasing peripheral disk velocity from 4.7 to 28.2 m min⁻¹.