Biological nitrogen and phosphorus removal in UCT-type MBR process

摘要

A lab-scale UCT-type membrane bio-reactor (MBR) was operated for biological nitrogen (N) andnphosphorus (P) removal simultaneously. In order to examine biological nutrient removal (BNR)ncharacteristics of MBR, the lab unit was fed with a synthetic strong and weak wastewater. Withnstrong wastewater, a simultaneous removal of N and P was achieved while application of weaknwastewater resulted in a decrease of both N and P removal. Recycled nitrate due to the limitednorganic in weak wastewater operation probably caused a nitrate inhibition in anaerobic zone.nIn step feed modification with weak wastewater, both N and P removal capability recovered innthe system, indicating that the allocation of COD for denitrification at anoxic zone was a key tonincrease the biological P removal. In addition, the analysis on the specific P uptake rate in anoxicnzone demonstrated that denitrifying phosphorus accumulating organism (dPAO) played annimportant role to remove up to 40% of P along with N. The sludge production characteristics ofnUCT-type MBR were similar to ordinary activated sludge with BNR capability.