Which type of filter is utilized in Membrane Bioreactors?

Membrane Bioreactors (MBRs) typically employ ultrafiltration as the filtration process. Ultrafiltration membranes have pore sizes ranging from 0.01 to 0.1 micrometers, which allows them to effectively separate bacteria and suspended solids from the liquid phase while still permitting the passage of water and solutes. This capability is crucial in MBRs, where biological treatment and membrane filtration operate simultaneously, enhancing the treatment efficiency of wastewater.

Using ultrafiltration in MBRs also offers a significant advantage in terms of operational flexibility and effluent quality. The small pore size provides excellent pathogen removal and retains larger particles and colloids, leading to higher quality effluent that can be suitable for various reuse applications. Additionally, the combination of biological activity and membrane separation helps in minimizing the footprint of the treatment system.

While microfiltration is used in some applications, it may not provide the same level of separation from smaller pathogens and colloids, and reverse osmosis, although highly effective for removing dissolved solids, is typically not used in conjunction with biological treatment due to fouling potential and the requirement for more sophisticated pre-treatment processes. Activated carbon is more suited for adsorbing organic compounds but does not function as a barrier for microorganisms or suspended