Influence of Different Conditions for Biofilm Formation on the Oxidation Activity of Acidithiobacillus Ferrooxidans

摘要

The dynamics of formation and functioning of biofilm of Acidithiobacillus ferrooxidans JCM 3863 have been investigated in batch in two quite different types of biofilm reactors design?￠????shake flasks (SFBFR) and bubble columns (BCBFR). However the packed bed has been consisted of the same elements?￠????long thin expended polystyrene parallelepipeds. The bioreactors have been very different by the hydrodynamic conditions ensured and their mode of aeration. It has been observed that the biofilms formed in SFBFR and BCBFR under the same conditions (temperature, pH, ferrous and ferric ions concentrations) had different surface structure and thickness. The influence of the bioreactor design and their capacity to ensure conditions for ferrous ion oxidation has been investigated by moving the biofilms, formed and functioning in one type of biofilm reactor to the another type of bioreactor design. Under such conditions, the average specific surface oxidation rates of ferrous to ferric ions have been about five times higher in SFBFR that those in BCBFR. The comparison of the experimental results obtained in the two types of biofilm reactors also showed that these rates obtained with biofilm formed in SFBFR have not been influenced significantly by the change of the type of bioreactor in which the biofilm functions, then it has been of crucial importance for the biofilm of BCBFR.