THE CALCULATION OF SIMULTANEOUS EFFECTIVE DIFFUSION-COEFFICIENTS OF THE SUBSTRATES IN A FLUIDIZED-BED BIOFILM REACTOR

In this study, a pure culture of Zoogloea ramigera was film-wise grown on activated carbon particles in a differential fluidized bed biofilm reactor (DFBBR). In biofilm, effective diffusion coefficients of the essential substrates; glucose, ammonium chloride and dissolved oxygen were simultaneously calculated. The multisubstrate biokinetic expressi on used to calculate effective diffusion coefficients was derived by n onlinear regression analysis of the data of continuous fermenter exper iments. This equation was utilized to solve diffusion and reaction mod el for effective diffusion coefficients in active biofilm. The results of the model solution revealed that the effective diffusion coefficie nt for all three substrates through the biofilm decreased with increas ing biofilm density.