Properties of the biofilm of Thiobacillus ferrooxidans formed in rotating biological contactor

The physico-chemical properties of the Thiobacillus ferrooxidans biofilm formed on the surface of rotating disks in a rotating biological contactor (RBC) were studied under steady-state conditions. The main independent variable was the input substrate (ferrous iron) concentration in the bioreactor. It has been shown that the biofilm thickness was maximal, the biofilm density was minimal and the specific surface area of pores in the biofilm was maximal when the input ferrous iron concentration was between 1 and 2.1 g/l. The biofilm volume remained nearly the same when input substrate concentrations were between 0.49 and 14.21 g/l, corresponding to oxidation rates between 0.35 and 8.6 g/m(2) h. (C) 2002 Elsevier Science B.V. All rights reserved.