13 - Advanced membrane bioreactors and hybrid membrane bioreactors configurations

Abstract

Membrane bioreactors (MBR) have become a well-established technology for advanced wastewater treatment, and is predicted to represent a USD 8.27 billion market by 2025. Commercial MBR technology is synonymous with the activated sludge (AS) and MF/UF filtration where a submerged membrane filtration unit replaces the conventional sedimentation tank. MBR technology had seen a substantial growth in the last 2–3 decades and is considered state-of-the-art for advanced wastewater treatment. Drivers for the development have the ability of MBRs to produce a high-quality treated water at a lower carbon foot print than conventional systems, making it the preferred technology for wastewater reclamation and reuse. This is particularly important in water-scarce regions where growing populations and increasing water demand make it necessary to find nonconventional water sources. Although MBRs are an established industry, alternative MBR processes and configurations have gained a lot of interest in the last 15–20years. These solutions have to date not had the commercial growth or industry acceptance as the AS-MBR. Some highlights of the ongoing research and development for alternative MBR concepts using other membrane filtration processes such as nanofiltration (NF), membrane distillation (MD), and forward osmosis (FO) are presented in this chapter. The need to increase wastewater reclamation and reuse for both potable and nonpotable use is the main driver of the work being undertaken.