PHOSPHORUS REMOVAL IN FLUIDIZED-BED BIOLOGICAL REACTOR (FBBR)

The biological phosphorus removal in fluidized bed biological reactor (FBBR) has been investigated. The feasibility of excess phosphorus upt ake, assured by exposition of biomass to anaerobic-aerobic conditions, has been demonstrated on a bench-scale biofilm reactor working as seq uencing batch reactor (SBR) and the limiting parameters have been esta blished. Although the reactor worked effectively, it took several week s for both acclimatization of biomass and selection of a biofilm rich in poly-P-bacteria. The highest phosphate uptake rates have been obser ved when strict anaerobic conditions were reached during the anaerobic phase. Using a fluidized bed, a thin biofilm, characterized by high s urface/volume ratio and hence highly disposed towards substrate uptake , has been obtained and the overall phosphorus abatement, referred to the biomass present in the reactor, proved particularly effective.