Effects of aeration intensity on pyrite oxidation by Thiobacillus ferrooxidans

The oxidation of pyrite in suspension by the bacterium Thiobacillus ferroox idans B5 was studied under different aeration conditions in the shake flask s and a bubble column to establish the effects of aeration intensity on the bioprocess. Agitation is of the greatest importance for the bioprocess and has to be adequately intensive to suspend pyrite particle in the medium. S tronger agitation decreases biodissolution efficiency, due to the reduced a ction of the direct mechanism in the first part of the bioprocess. Although biooxidation in the bulk solution depends on ferrous iron realized from py rite by direct bacterial actions, a stronger intensity reduces the contribu tion of the free suspended cells in the biooxidation process.