Membrane Bioreactor (MBR) Technology – a Promising Approach for Industrial Water Reuse

Abstract

Membrane bioreactor technology (MBR) a combination of the activated sludge process with micro- and ultrafiltration is widely regarded as an effective tool for industrial water treatment and water reuse due to its high product water quality and low footprint. Due to their robustness and flexibility submerged MBR systems are more and more preferred. This paper highlights two case studies for industrial application in a commercial laundry and in a textile factory. A large-scale integrated water reuse process based on MBR+RO technology (capacity 200 m3/d) has been designed and established in a German laundry within an EC funded project eventually resulting in a reuse ratio of around 80% of the total wastewater. The process was in full operation at the beginning of 2007 and has been operated economically since that time without any failure. Within another EC funded project a small-scale MBR (capacity up to 0.4 m3/d) has been successfully tested in a Chinese textile factory. Despite high concentration of low biodegradable chemical in the wastewater, the COD removal rate achieved around 90%. However, the MBR permeate quality was not as high as in the laundry due to remaining colored dyestuff what makes an additional treatment step such as nanofiltration or reverse osmosis necessary in order to increase the proportion of reused water. In order to improve rejection of low molecular weight organics Karlsruhe University of Applied Sciences and the Institute of Membrane Technology have started a new EC funded project within a consortium of 11 partners in total which aims at developing novel membrane materials providing a basis for the development of a NF MBR reactor.