Effect of surface materials on initial biofilm development

The effect of the support characteristics on the substrate degradation kinetics and on the adherence and growth of biofilms is a subject of considerable importance in wastewater treatment. Many works deal with the kinetics, but less work has been reported concerning the surface differences. In this paper, the results of an experimental programme studying the biofilm growth in rotating biological reactors (RBC) with different solid material in each biodisk, are presented. Results from two phases have been obtained; the first phase of colonization, of about 1–2 days, was followed by a growth phase with a specific growth rate constant between 1•1–1•3 d−1. The biofilm dry matter (DM) ranged between 7 mg DM/cm2 for the glass particle and diatomite earth support materials, and 9 mg DM/cm2 for the sand disk and 10 mg DM/cm2 for the activated carbon disks. All these results indicated that carbon was the best of the tested support materials for biofilm formation. No dependence was observed between position of the biodisk in the RBC and the organic layer formation or the initial biofilm development.