Pilot-plant treatment of a high-strength brewery wastewater using a membrane-aeration bioreactor

The membrane-aeration bioreactor is a small footprint modular process, suited to on-site treatment of high-organic-strength industrial wastewater. A pilot-plant membrane-aeration bioreactor was operated under completely mixed, low-flow, and plug-flow conditions during treatment of a high-strength brewery wastewater. Hydrophobic dead-end hollow fibers supplied pure oxygen in a bubbleless form to a biofilm attached to the shell side of the fibers. Biofilm development was rapid and fibers were cleaned regularly to control excessive growth and sloughing. Organic removal rates of 27 kg total chemical oxygen${\rm demand}/{\rm m}^{3}\cdot {\rm d}$and removal efficiencies of 81% were achieved during plug-flow operation. Biodegradation of organic matter within the wastewater was almost exclusively (99.8%) carried out within the biofilm.