A Review on Membrane Bioreactor (MBR) Technology: It’s Commercial Applications And Possibilities of Hybridization with other Membrane Techniques to Recover Valuable Industrial By-Products for Sustainable Development and Environmental Protection by and Large

Membrane bioreactor (MBR) technology is advancing rapidly around the world both in research and commercial applications. Despite the increasing number of studies and full-scale applications of MBR systems, directions and trends in academic research as well as commercial developments require further analysis. This paper aims to critically characterize and review worldwide academic research efforts in the area of MBRs as well as focus attention to commercial MBR applications. Various research papers published in peer-reviewed international journals were used as the database for the analysis provided in this paper. After a surge of MBR publications, research appears to have reached a plateau in the last 7 years using both submerged and external MBR units. Although much of the pioneering research occurred in Japan, France and the UK, countries such as South Korea, China and Germany have significantly contributed to the research pool in the last 5 years. The primary research focus has been on water filtration MBRs with limited growth in extractive and gas diffusion MBRs which still hold un-tapped potential. Fundamental aspects studied in academic research predominantly involve issues related to fouling, microbial characterization and optimizing operational performance. Zenon occupies the majority of the MBR market in America, whereas Kubota and Mitsubishi-Rayon has a larger number of installations in other parts of the world. Due to more stringent regulations and water reuse strategies, it is expected that a significant increase in MBR plant capacity and widening of application areas will occur in the future. Potential application areas include nitrate removal in drinking water treatment, removal of endocrine disrupting compounds from water and wastewater streams; enhancing bio-fuels production via membrane assisted fermentation and gas extraction and purification MBRs. Treatment technology for water recycling encompasses a vast number of options. Membrane processes are regarded as key elements of advanced wastewater reclamation and reuse schemes and are included in a number of prominent schemes world-wide, e.g. for artificial groundwater recharge, indirect potable reuse as well as for industrial process water production. Membrane bioreactors (MBRs) are a promising process combination of activated sludge treatment and membrane filtration for biomass retention. Many researchers have concluded that wastewater reclamation in intended MBR technology is the method of choice when it is combined with other advanced treatment technologies. As water shortages are increasing, the need for sustainable water treatment and the reuse of water is essential. Water reuse from wastewater can be accomplished in a membrane bioreactor (MBR) in the secondary activated sludge stage of a wastewater treatment plant. To remove viruses, dissolved organics and in organics still present in the MBR permeate, nanofiltration (NF) can be applied. Nevertheless, the major drawback of nanofiltration membranes is the production of a concentrate stream that cannot be discharged to the environment. The research show that the continuous production of reusable water from wastewater in a combined MBR and NF process with NF concentrates recirculation can be successful.