All IFAS systems, whether based on dispersed or fixed media, require adequate preliminary treatment design and operation. Primary clarification or fine screening will prevent ragging and material build-up on the media in the aeration basin and clogging of the dispersed media and retaining screens. All operational activities must be carried out by skilled laborers.

IFAS technology has been incorporated into municipal/industrial wastewater facilities for both new construction and upgraded plants in many variations of suspended growth systems. When included in new plant design, reduced tank volumes result. New tanks must be designed to incorporate fixed or dispersed media and additional auxiliary screens should be added if a dispersed IFAS media reactor is chosen.

Similarly, in retrofit applications, increased treatment capacity may be realized, along with the other benefits of fixed film type processes. The existing aeration capacity needs to be evaluated to determine whether it is adequate for the increased BOD removal and biomass respiration expected with the higher level of treatment performance associated with IFAS. Media installation needs to be planned carefully to ensure that the existing basins can accommodate the fixed media modules or dispersed media systems.

:Advantages

• The fixed biomass combines aerobic, anaerobic and anoxic zones and increases the Sludge Retention Time, promoting better nitrification compared to simple suspended growth systems
• System nitrification is also restored faster since a large mass of nitrifiers is retained on the fixed-film
• Improved process stability
• In various studies and discussions with practitioners, it has been noted that the Sludge Volume Index (SVI) improves and has less variation when IFAS upgrades are implemented

Reduced Sludge Production