New generation of MBBR for biological treatment of carbon, nitrogen and phosphorus

The development of a new biofilm process was investigated for two different objectives of treatment: biological removal of carbon and phosphorus only (CP) and biological removal of carbon, nitrogen and phosphorus (CNP). The process is based on the Moving Bed Biofilm Reactor (MBBR) technology operated in a Sequencing Batch Reactor (SBR) mode and can be referred to as a biofilm SBR. It can be implemented either in a 1-stage or 2-stage configuration. Lab and pilot trials have demonstrated that efficient biological P-removal with a MBBR is feasible. For CP applications, treatment performances of the 1-stage configuration are meeting the set targets in a highly compact process. For CNP applications, both nitrification and denitrification were obtained rapidly in the 1-stage configuration while maintaining targeted C and P performances. In some specific conditions, improvement of denitrification was required and was possible with the addition of a post-anoxic period. The 2-stage configuration is expected to improve both compactness and performances. The 2-stage trials are on-going with promising preliminary results.