Wastewater Treatment Using the IFAS Method

The IFAS (Integrated Fixed-Film Activated Sludge) method is a subset of activated sludge treatment that combines attached growth technology, significantly reducing BOD in both sanitary and industrial wastewater. In this system, fixed media are used to promote microorganism growth within treatment tanks, enhancing the digestion of organic matter by aerobic bacteria.

 

Wastewater Treatment Using the IFAS Method

One of the most common methods for removing organic matter from industrial and sanitary wastewater is biological treatment, which operates based on the digestion of pollutants by aerobic and anaerobic bacteria. To enhance the digestion of organic matter in biological treatment methods, it is essential to optimize conditions for microorganism growth. In other words, the greater number of microorganisms in the wastewater, the more organic matter they will decompose and consume, ultimately reducing BOD. Wastewater treatment using the IFAS (Integrated Fixed-Film Activated Sludge) method is a biological approach based on activated sludge that also incorporates attached growth technology.

Tanks and treatment plants that implement IFAS (Integrated Fixed-Film Activated Sludge) treatment are equipped with deep aeration systems and fixed packing media plates, which are installed vertically. Microorganisms in the wastewater passing these plates, rapidly growing by breaking down organic matter and utilizing oxygen in the water, thereby accelerating the removal of pollutants. The packing media used in IFAS wastewater treatment are made of polyethylene, PP, or PVC, are lightweight, and provide an optimal environment for biomass growth.

Picture3

Stages of Wastewater Treatment Using the IFAS Method

In general, IFAS shares many similarities with the MBBR wastewater treatment method, with the only difference being the type of packing media used. In MBBR, medias carriers are dispersed throughout the tank, while in IFAS, fixed or suspended vertical plates are used for this purpose. The IFAS treatment process generally consists of the following three main steps:

  • Physical Wastewater Treatment: Removal of solids and trashes from effluent using manual or mechanical screens.
  • Wastewater is directed to specialized equalization tanks where pumps and other equipment ensure consistent quality throughout all sections. (If gravity transfer is not possible (
  • Packing media plates are placed in the aeration tank, and deep aeration is performed using diffusers. At this stage, oxygen required for microorganism growth and reproduction is supplied, and biomass gradually accumulates on the packing media. The placement of these plates in different parts of the tank or their suspended state allows organic matter to be largely digested by biomass, significantly improving wastewater quality through the IFAS method.
  • After extensive microorganism growth, portions of the biomass detach from the packing media and, due to their weight, settle at the bottom of sedimentation tanks.
  • The final step involves disinfection and reduction of chemicals and toxins in the wastewater using disinfection techniques.

 

Features of Wastewater Treatment by IFAS Method

  • By providing ideal conditions for microorganism growth, this method reduces up to 95% of COD and up to 95% of BOD.
  • The use of packing media plates reduces the internal volume of aeration tanks, thereby lowering the plant setup costs.
  • Given that the required hydraulic retention time (HRT) for this treatment method is only 4 to 6 hours, it significantly accelerates the treatment process.
  • Due to the lack of need for advanced equipment, this treatment method is cost-effective.
  • IFAS treatment is highly stable and exhibits strong shock resistance against influent with varying qualities.
  • The amount of sludge produced by this method is lower compared to other activated sludge wastewater treatment processes.

Applications of IFAS Wastewater Treatment

Among the most important applications of the IFAS (Integrated Fixed-Film Activated Sludge) method are the following:

  • Treatment of residential complex wastewater
  • Industrial wastewater treatment
  • Effluent treatment for refineries and power plants
  • Suitable for hospital wastewater treatment packages
  • Reduction of organic matter in industrial wastewater
  • Slaughterhouse wastewater treatment
  • Textile and dyeing industry wastewater treatment
  • Paper manufacturing plant wastewater treatment