DEVISE - Model MBBR - IFAS - Moving Bed Bioreactor & Integrated Fixed Activated Sludge

The hybrid nature of the MBBR-IFAS process relies upon the simultaneous incorporation of suspended and attached biomass in the same reactor. The former (i.e. MLSS) is usually kept well below 3000 mg/L, whereas the latter (i.e. biofilm) is established by using specially engineered plastic carrier elements for biofilm attachment held in suspension throughout the reactor by turbulent energy incurred by diffused coarse-bubble aeration, liquid recirculation, or mechanical mixing energy. In the majority of applications, the reactor is filled between one-third and two-thirds full with carriers. Perforated plates or sieves installed on the effluent-end of the reactor allow treated water to pass though to the next treatment step, but retain the media inside the reactor.

The MBBR-IFAS process has demonstrated reproducible success with biochemical oxygen demand (BOD) elimination, ammonia oxidation, and nitrogen removal applications, in a variety of different treatment configurations, aimed to meet a wide range of effluent quality standards, including stringent nutrient limits.

Perhaps the most impressive aspect of the MBBR - IFAS process lies in its versatility, allowing creative solutions by design engineers. Specifically, the MBBR-IFAS process offers the following basic advantages in comparison with other more conventional wastewater treatment technologies:

• Ability to increase capacity or improve performance by adding more media (high retrofit and/or upgrade potential)
• Additional biomass for treatment without increasing the solids loading on final clarifiers
• Higher-rate treatment processes possible, thus resulting to greater treatment in a significantly smaller footprint
• Development of specialized biomass for carbon and nitrogen removal in multi-compartment reactor configurations
• Improved settling characteristics (reduced SVI values)
• Reduced sludge production
• Improved recovery from process upsets