Influence of different substrates on the formation of biofilms in a biofilm airlift suspension reactor

The effect of different C-1 carbon substrates (formate, formaldehyde, metha nol) on biofilm formation in biofilm airlift suspension reactors was studie d. The biofilm structure depended on the type of substrate. There seems to be a trend that more reduced substrates or substrates allowing a tower biom ass growth rate lead to more dense biofilms. Variations in detachment force s (biomass hold up and carrier concentration) during the experiments affect ed biofilm characteristics and detachment. Detachment of biofilm biomass un der non-growing conditions was studied. The detachment experiments clearly showed that detachment of a growing biofilm is larger than for a non-growin g biofilm subjected to the same detachment forces. It is hypothesized that the growth zone of a biofilm forms a more weakly attached biofilm. A trend between biofilm density and the weakly attached fraction of biomass in the biofilm was found.