NUTRIENT REMOVAL USING A COMBINED PROCESS WITH ACTIVATED-SLUDGE AND FIXED BIOFILM

A new nutrient removal system combining activated sludge with fixed bi ofilm was developed in this work. Fully and partially submerged rotati ng biological contactors (RBC) were added in the anaerobic, anoxic and aerobic reactors, respectively. The pilot-scale plant was fed synthet ic municipal wastewater with the different operating parameters (i.e., hydraulic retention time, return sludge ratio and mixed liquid recycl e ratio) to evaluate its performance. High degree performances of nutr ient removal were obtained in the experiments. The specific substrate utilization rates in each reactor were also conducted in this work. Th e kinetic behaviours presented in the combined process were similar to the performance in a single sludge system. The biokinetics of a singl e sludge system can also be applied to the system that combines biofil m and activated sludge. Copyright (C) 1996 IAWQ.