How BioFOR Works
The effluent to be treated enters continuously from the bottom of the reactor and is distributed over the entire filter surface area by the nozzle underdrain. The water then passes through the Biolite™ filter media which retain the suspended solids. Carbonaceous and nitrogenous pollution is eliminated through the high concentration of fixed-film biomass which is retained on the filter media during the filtration cycle.
In the aerated versions (for BOD removal and nitrification) process air is introduced continuously into the lower part of the reactor by air diffusers.
The use of a co-current upflow design helps to limit odor generation since the treated water is situated at the surface of the filter (in contact with the atmosphere), and the untreated water enters at the bottom of the filter. The number of filters in filtration service is according to the flow entering the plant. During low flow periods, off-duty filters are aerated periodically to maintain the biomass in optimum condition. Since filters can be taken out of service when not required, operating costs (due to process air production) can be reduced.