Biofilm carrier processes

Moving bed biofilm reactor (MBBR) and Integrated fixed film activated sludge (IFAS) processes are innovative wastewater treatment technologies. They are based on plastic carriers, which moves freely in aeration tank. The bacteria grow as biofilm on the surface of the carriers, and do not exit with the treated water. This ensures that slowly growing ammonia oxiders (nitrifying bacteria) have optimal growth conditions. The MBBR is a pure biofilm process, and do not require recycling of sludge. IFAS is in principle the same as conventional activated sludge process, but it is boosted with biofilm carriers. These processes are still not common in Finland, but, for example in Norway, the MBBR has been successfully used for treatment of cold wastewaters.