BIOMASS CONCENTRATION IN FLUIDIZED-BED BIOLOGICAL REACTORS

Synthetic wastewater treatment was carried out in a fluidized bed biol ogical reactor with sand as support media. Biomass concentration in th e bed was measured as total attached solid and recorded together with the bed expansion characteristics throughout the period of operations. A new method to estimate the reactor biomass concentration was develo ped and tested on the collected data. The method combines the Richards on and Zaki (1954) law for fluidized bed expansion, the definition of overall bed voidage and available literature data on biofilm dry densi ty and gives an estimate of the biomass concentration by means of a no n-linear minimization routine using experimental data of bed height ve rsus fluid superficial velocity. The comparison between the values der ived from the experimental measures and those calculated by means of t he method has proved reasonably successful. (C) 1997 Published by Else vier Science Ltd.