Wastewater Reuse Via MBR and Tertiary Membrane Filtration–Case Studies

Rapid population growth and scarce fresh water sources have resulted in the exploitation of more abundant but lower-quality water sources including brackish water and wastewater effluent. With the reducing cost of membranes, reverse osmosis (RO) coupled with low pressure (LP) membranes (microfiltration/ultrafiltration, MF/UF) for desalination and wastewater reuse becomes a primary strategy to exploit water of lower quality. Compared to desalination, effluent wastewater reuse (for both non-potable and potable purposes) has major advantages regarding cost and sustainable environmental benefits which have facilitated its adoption. The two main membrane-based wastewater reclamation and reuse treatment methods for non-potable water usage are the use of low pressure membrane as a tertiary treatment process after conventional biological wastewater treatment (CAS-MF), and membrane biological reactor (MBR). For advanced reuse applications, the level of treatment can be complemented by RO.This paper reviews and compares the two wastewater treatment processes, CAS-MF and MBR, with regard to effluent water quality, cost analyses, and their impacts of effluent natural organic matter characteristics. Performance results and cost analysis of two sewage treatment plants, CAS-MF and MBR, in Australia are compared. Wastewater effluent characterization was conducted at plants and pilot sites in Asia, Australia and North America.