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.