MBBR and MBR
MBBR (Moving Bed Biofilm Reactor) and activated sludge are both commonly used biological wastewater treatment processes that use microorganisms to remove pollutants from wastewater. However, there are some differences between these two processes:
Reactor Configuration: In an activated sludge process, the microorganisms responsible for treating the wastewater are suspended in the water and form a sludge. This sludge is continuously mixed with air in an aeration tank to provide oxygen for microbial growth and metabolism. In contrast, MBBR uses a biofilm process where the microorganisms grow on a media carrier in a fixed-film reactor.
Biomass Retention: In activated sludge, the biomass (microorganisms) are kept in suspension in the aeration tank and are separated from the treated wastewater in a secondary clarifier. The biomass is then returned to the aeration tank to maintain a steady-state concentration. In MBBR, the media carrier provides a surface for the microorganisms to grow, and the biomass is retained within the carrier instead of being suspended in the wastewater.
Reactor Size: Because of the biomass retention provided by the media carriers in MBBR, it is possible to achieve a higher concentration of microorganisms in the same reactor volume as an activated sludge process. This means that the MBBR can achieve the same level of treatment with a smaller reactor size compared to activated sludge.
Process Control: Activated sludge systems are sensitive to changes in wastewater quality, and the system needs to be carefully controlled to maintain stable operation.
In contrast, MBBR is more tolerant of changes in wastewater quality due to the
biofilm's resilience. The MBBR process can adapt more quickly to changes in organic load or toxic shock loads.
Nutrient Removal: Activated sludge systems can be designed to remove nutrients such as nitrogen and phosphorus, while MBBR can remove only a limited amount of nutrients. However, MBBR can be combined with other processes, such as a separate anoxic reactor, to achieve nutrient removal.
Both processes have their advantages and disadvantages, and the choice between MBBR and activated sludge will depend on site-specific conditions and treatment objectives. MBBR is generally considered to be more suitable for decentralized or containerized wastewater treatment systems, while activated sludge is more commonly used in municipal wastewater treatment plants.
