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 uptake, assured by exposition of biomass to anaerobic-aerobic conditions, has been demonstrated on a bench-scale biofilm reactor working as sequencing batch reactor (SBR) and the limiting parameters have been established. Although the reactor worked effectively, it took several weeks for both acclimatization of biomass and selection of a biofilm rich in poly-P-bacteria. The highest phosphate uptake rates have been observed when strict anaerobic conditions were reached during the anaerobic phase. Using a fluidized bed, a thin biofilm, characterized by high surface/volume ratio and hence highly disposed toward substrate uptake, has been obtained and the overall phosphorus abatement, referred to the biomass present in the reactor, proved particularly effective.