A comparative study on thermophilic and mesophilic biooxidation of ferrousiron

High temperature biooxidation of ferrous iron was studied in a batch system , using the acidophilic thermophile Acidianus brierleyi. The effect of ferr ous iron initial concentration on the growth and activity of the cells was investigated A. brierleyi was able to grow on ferrous iron at concentration s below 7.5 kg m(-3). The values of specific growth rare and yield were 0.0 43 h(-1) and 2.2x10(14) cells/kg iron respectively. At ferrous iron concent rations of 7.5 kg m(-3) and higher the growth of the cells was prohibited, however the non-growing cells were able to oxidise iron. The maximum biooxi dation rate of ferrous iron, 0.105 kg m(-3) h(-1), was achieved in a cultur e initially containing 7.5 kg m(-3) of Fe2+. The mesophilic iron oxidiser T hiobacillus ferrooxidans was capable of growing on ferrous iron at concentr ations as high as 30 kg m(-3). Moreover the rate of mesophilic biooxidation of ferrous iron was significantly higher than that observed in the presenc e of A. brierleyi. (C) 1999 Published by Elsevier Science Ltd. All rights r eserved.