Optimized Substrate Removal and Energy Consumption in Membrane Aerated Biofilm Reactor With Intelligent Biofilm Thickness Measurement and Control

摘要

A membrane aerated biofilm reactor (MABR) pilot was operated for more than 240 days to demonstrate the importance of biofilm measurement and control for optimized performance with respect to substrate removal and energy consumption. The pilot consisted of two MABR modules in series which received primary effluent from a municipal water resource recovery facility (WRRF). The MABR modules employed a pressure decay test (PDT) to define a biofilm thickness index and monitor biofilm growth. An air scour decision processor was used to manage biofilm thickness, promoting the growth of nitrifying organisms while minimizing diffusional limitations and optimizing substrate utilization by the biofilm. Nitrification rates of 1.3 g NH_4/m~2-d and oxygen transfer rates greater than 12 g O_2/m~2-d were observed. The piloting showed a strong correlation between the PDT, biofilm weight and nitrification rates.