WASTEWATER TREATMENT WITH SUSPENDED GROWTH AND MEMBRANE AERATED BIOFILM

摘要

A hybrid membrane aerated biofilm reactor (MABR) and activated sludge (AS) system and process are described herein. At least a portion of the AS system includes aerobic mixed liquor, for example in an aerobic tank or zone downstream of a tank or zone containing membrane aerated biofilm modules. The flow of air to the membrane aerated biofilm is modulated considering the ammonia loading rate to the system or to the aerobic mixed liquor, for example according to a diurnal cycle. For example, air flow to the membrane supported biofilm can be below an average or initial air flow rate during a period of low ammonia loading. Air flow to the aerobic mixed liquor may remain essentially constants during the same period. Optionally, mixed liquor around the membrane aerated biofilm modules may be aerated during a period of high ammonia loading.