MBR processes can produce effluent of high enough quality to be discharged to waterways or to be reused for wash water or irrigation. Other advantages of MBRs over conventional processes include:
- Their smaller footprint. It is possible to operate MBR processes at higher mixed liquor suspended solids (MLSS) concentrations compared to conventional settlement separation systems, thus reducing the reactor volume to achieve the same loading rate.
- Due to the higher biomass concentrations (MLSS) and sludge ages, MBR’s are typically more stable than other activated sludge plants and are better suited to treating highly variable loads.
- It is relatively easy to retrofit and upgrade old wastewater treatment plants into MBR’s to achieve higher capacity and better quality effluent.
Membrane fouling is the most serious problem affecting system performance and leads to a decrease in the filtration rate. The MBR filtration performance inevitably decreases with filtration time. This is due to the deposition of soluble and particulate materials onto and into the membrane, attributed to the interactions between activated sludge components and the membrane. Frequent membrane cleaning with chemicals is therefore required, increasing the operating costs of the plant.