AGAR - FFAST

This combination utilizes the MBBR capability to significantly reduce wastewater BOD in a relatively small reactor volume filled with Aqwise Biomass Carriers, followed by the high-quality effluent achievable in an activated sludge system.

Wastewater is introduced into a single-stage roughing filter, with no sludge circulation. Following this treatment, soluble BOD in the wastewater is reduced by 45%-70% before entering the activated sludge process. The activated sludge system is considerably smaller, as it is required to deal with only a fraction of the organic load of an equivalent conventional plant; in effect, it acts to polish the RF effluent to extremely high qualities.

Return Activated Sludge (RAS) from the secondary clarifiers is recirculated to the beginning of the activated sludge tank; provisions may be made for allowing a part of the RAS to return upstream to the MBBR, thereby creating a selector effect for control of filamentous organisms.

Another advantage of the FFAST configuration is its ability to sustain shock loads as well as a certain amount of toxicity, thereby protecting the downstream activated sludge process from upsets. Due to the thickness of the biofilm on the Biomass Carriers, the bio-film is capable of rebounding more quickly from toxicity upsets than an equivalent suspended biomass.

The FFAST process is optimal for plants with limited area, which require consistently high quality effluents coupled with an ability to withstand shock-loads, as well as for new plants or upgrades of high load wastewater treatment plants.