IFAS Wastewater Treatment Systems

Design

At a glance, IFAS systems can seem somewhat similar to moving bed biofilm reactor (or MBBR) processes — both processes use biofilm growth to help remove organic materials from waste streams, but there are a few key differences between the two.

In an MBBR system, a biofilm carrier, typically made of plastic or fabric, gets mixed in an aeration tank with water. The bacteria that accumulate on the biofilm will then break down the organics in the waste stream and convert them to biomass, which can be extracted from the waste stream later in the treatment process. This treatment method provides a few different advantages for wastewater treatment plants — primarily increased treatment capacity at an economical price without much of a footprint.

IFAS systems do things a bit differently. With IFAS, the biofilm carriers are instead mixed in an activated sludge basin or combination of activated sludge and water, rather than water alone. Activated sludge that has already passed through the reaction tank is also recirculated in IFAS systems. These IFAS systems are often retrofitted onto existing activated sludge systems to take advantage of existing treatment infrastructure and upgrade conventional activated sludge systems with tech similar to what’s used in MBBR systems.

Like MBBR systems, these IFAS upgrades can significantly improve treatment capacity without requiring much extra space — part of why they’re so effective at upgrading existing wastewater treatment systems. Also like MBBR systems, IFAS systems are commonly used for BOD removal, nitrification, denitrification and full Biological Nutrient Removal.

IFAS systems often have very high BOD and TSS removal rates — as high as 98.2% and 97.1%, respectively — making these systems a highly effective means of wastewater treatment.