Phosphorus and nitrogen removal in moving-bed sequencing batch biofilm reactors

A pilot moving-bed sequencing batch biofilm reactor (MBSBBR) fed with primary settled wastewater, was used in order to study organic carbon, phosphorus and nitrogen removal with and without external carbon sources. Patented KMT(R) polyethylene biofilm carriers were used. Organic carbon uptake and phosphorus release has been achieved in the anaerobic phase of the cycle, while nitrification, simultaneous denitrification (i.e., anoxic respiration of sequestered COD in the inner layer of the biofilm) and phosphorus uptake was observed in the aerobic phase. A stable biological phosphorus removal could be achieved only with an external carbon source. Since the process proved flexible and reliable, it is suitable for full scale application to municipal wastewater treatment plants (WWTPs), in order to meet EU total nitrogen and phosphorus limit values for discharge into sensitive receiving waters. (C) 1999 Published by Elsevier Science Ltd on behalf of the IAWQ. All rights reserved.