?What is IFAS wastewater treatment
Wastewater treatment by IFAS method is one of the types of activated sludge processes in the form of attached growth. In this method, fixed or moving media pages are used under the title of media packing. As the wastewater flows over the packing media, microorganisms stick to their surface as a biofilm, and thus, by increasing the contact surface, the ground is provided for the complete decomposition of organic materials with the help of aerobic bacteria
One of the effective methods in wastewater treatment is the use of biological methods. The purpose of these methods is the biological purification of wastewater by aerobic and anaerobic microorganisms. In a way, in the biological treatment of wastewater, organic pollutants are converted by microorganisms from being soluble in wastewater to suspended solids or sludge (Bio Mass). This is improved by controlling the population of microorganisms. In wastewater treatment by IFAS method, by installing packing media in the ponds, the ground is provided for the increase of the population of microorganisms, followed by the decomposition and consumption of organic pollutants and the reduction of BOD
As mentioned, IFAS wastewater treatment is a combination of activated sludge and fixed bed methods, which increases the efficiency of treatment and removes wastewater pollutants. The activated sludge process has high purification efficiency and high flexibility, and the fixed bed process has high stability and resistance against organic and hydraulic shocks of wastewater
substrate or media in the IFAS wastewater treatment process
:The heart of an IFAS system is the attached substrate or media to complete the growth process. There are two types of substrate or media in wastewater treatment using the IFAS method
- Fixed media packing
- Floating media packing
The media are made of polypropylene (PP) or PVC and are light in weight. The dimensions of floating media packing are between 5 and 50 mm and they are designed in different geometric shapes. Fixed media packing is also installed in aeration ponds with larger dimensions. The geometric shape and dimensions of the bed directly affect the specific surface area and cost of bed production.
:The important points in choosing a substrate or media in wastewater treatment using the IFAS method are
- Type of substrate
- Geometric shape, dimensions and density of the substrate
- Special surface area
- Cost of production
Types of IFAS systems
:Based on the media used in the IFAS process, IFAS systems are divided into the following two general categories
- With fixed media (Fixed Media IFAS System)
- With dispersed media (Dispersed Media IFAS System)
Advantages of IFAS wastewater treatment system
:The proper use of this method in small wastewater treatment plants has advantages that include the following
- Low cost in construction and design
- Increased BOD removal efficiency
- Reducing the time of the wastewater treatment process
- Reducing the production of sludge and not requiring extensive sludge return compared to other methods
- Nitrification and denitrification and to some extent phosphorus removal
IFAS wastewater treatment system design considerations
Effective level of biological mass
The effective purification performed in the IFAS system depends on the following two factors:
- Amount of biological mass
- Activity of the biological mass
The amount of biological mass in the reactor is dependent and proportional to the specific surface of the media. Therefore, the special level of media packing is important.
The location and location of the media in the reactor has very little effect on the amount of biological mass formation on the media
Features of the IFAS system in wastewater treatment
- The average reduction of BOD5 and COD is 95%.
- It is designed in such a way that for each cubic meter of wastewater volume, it creates more than 150 cubic meters of biological area for the contact of bacteria with the wastewater and thus more cleaning power.
- The IFAS system requires less space than the old and conventional systems. For example, the space required to install a reactor that can clean 100 cubic meters of sewage per day is less than 10 square meters, while it is about 35 square meters in the conventional system.
- The aeration of the IFAS system is done in a deep way and through the aeration diffusers on the bottom of the reactor, and therefore, compared to the surface aeration systems, it faces fewer management and maintenance problems.
Usages of wastewater treatment by IFAS method
:The application of the purification system using the IFAS method (aerobic biological reactor with fixed attached growth) includes the following
- Can be used in making sewage treatment package
- Removal of BOD from industrial wastewater
- Can be used in the wastewater treatment system of sugar and sugar industries
- Slaughterhouse wastewater treatment
- Wastewater treatment of paper and cardboard making
- Wastewater treatment of textile and dyeing industries