Operational Retrofits of AB Process for Biological Removal of Nitrogen and Phosphorus

The operational retrofits to improve nitrogen and phosphorus removal of AB process treating low concentration municipal wastewater in Luofang WWTP, in Shenzhen China, are described in this paper. The problems occurred during the 5-year operation since its start-up and the specific efforts devoted to the troubleshooting are presented roundly as well. As a result, a steady and efficient performance of AB process can be assured and a novel method of operation to improve phosphorus and nitrogen removal is developed. With the effluent quality of TN <14mg/L, NH₃-N<2.5mg/L and TP<1.0mg/L, the operational retrofits are surely of practical value to those facilities that apply AB process and are poorly operated.