Moving Bed Bio Reactor Plants (MMBR)
The Moving Bed Bio Reactor technology is a variation of the standard activated sludge process, but has specific properties which give advantages in both design of new and upgrading of old plants. By introducing a plastic biomass carrier into the biological process section of the sewage plant, efficiencies of transfer are improved.
This improvement can be easily understood by the following factors:
- Contact between the bacteria growing on the biocarrier, the air supplying the oxygen and the sewage liquor itself is vastly improved so that the treatment process will be enhanced.
- The quantity of bacteria that can be held within a reactor is increased so that additional transfer will occur.
Some plants have used the idea of a submerged biocarrier but using it as a static system. It is found however that this often leads to clogging within the plant after some operation, at which time efficiency drops creating efficiency problems. In a moving bed reactor the biocarriers are moved constantly using a specially designed aeration system or by a specially designed mixer. By moving the biocarriers in such a manner, excessive bacteria growth is not possible and this is removed constantly. This ensures that the plants retain their original design efficiency advantage and plants operate with constant long term high quality effluent values. This fact however does mean that excessive bacteria are removed continuously and a clarifier is required to ensure this excessive sludge is removed from the effluent. The new technology also presents an opportunity for special nutrient removal designs using special recycles and additional stages.
By introducing Moving Bed Reactor technology, it is thus possible to increase both the design flow and operational efficiency of any sewage plant, resulting in higher throughput in existing plants or smaller footprint in new plants.
As the cost is slightly higher than the standard fibreglass alternative, this technology becomes applicable where space is limited or very costly.