DETERMINATION OF OPTIMAL BIOFILM ACTIVITY IN A BIOLOGICAL FLUIDIZED-BED (BFB) REACTOR

Experimental tests were carried out in order to ascertain the biomass activity in a biological fluidized bed reactor. A semi-pilot fluidized bed reactor was used with two different supports (sand and glass part icles). The specific biomass activity was followed during the tests. I t reached a maximum and after declined vs. biomass hold up and bed exp ansion. The results clearly put in evidence as the activity is strongl y effected by liquid-solid mass transfer and support roughness which i n turn determines the compactness of biofilm and its diffusive propert ies. By controlling the bed expansion it is possible to decide the mac ro reaction regime of work: external mass transfer, biokinetics or dif fusive control according to incoming substrate concentration, in order to maximize the bioreactor performance.