POTENTIAL OF THIOBACILLUS-FERROOXIDANS FOR WASTE-GAS PURIFICATION .2.INCREASE IN CONTINUOUS FERROUS IRON OXIDATION-KINETICS USING IMMOBILIZED CELLS

Thiobacillus ferrooxidans could be used to regenerate ferrous sulphate solution produced in a process to remove H2S from waste gas if the re action rate could be increased. The aim of the present study was to in crease the volumetric productivity by using immobilized cells. Kinetic data of ferrous iron oxidation were determined in fixed-bed and fluid ized-bed reactor configurations with different support materials in or der to find the most practical system for scale-up. By using a fixed-b ed reactor the iron oxidation rate can be increased to 3.6 g l(-1) h(- 1), fivefold higher than suspended cells, and results in a bioreactor of reasonable size. With the kinetic data obtained, the biological rea ction is no longer a limiting factor for industrial-scale application.