Biological phosphorus and nitrogen removal in a sequencing batch moving bed biofilm reactor

Biological phosphorus and nitrogen removal in biofilm processes have a pote ntial advantage compared to activated sludge processes, because of less vul nerability with respect to sludge loss and because biofilm processes, in ge neral, are more compact with a smaller footprint. Experiments have been car ried out in a moving bed biofilm reactor operated as a sequencing batch rea ctor (SBR),with simultaneous nitrification, phosphorus uptake and denitrifi cation in the aerobic phase. In order to achieve good phosphorus and nitrog en removal, the length or the anaerobic period should be tuned to achieve n ear complete removal of easily biodegradable COD in the anaerobic period, a nd the length of the aerobic period should be long enough for complete nitr ification. The total GOD-loading rate must be at the same time be kept high enough to achieve a net growth of biomass in the reactor.