Diffuser
An air diffuser or membrane diffuser is an aeration device typically in the shape of a disc, tube or plate, which is used to transfer air and with that oxygen into sewage or industrial wastewater. Oxygen is required by microorganisms/bacteria residents in the water to break down the pollutants. Diffusers use either rubber membranes or ceramic elements typically and produce either fine or coarse bubbles. Diffusers are typically connected to a piping system which is supplied with pressurized air by a blower. This system is commonly referred to as a diffused aeration system or aeration grid.
There are two main types of diffused aeration systems, retrievable and fixed grid, that are designed to serve different purposes. In the case of a plant with a single tank, a retrievable system is desirable, in order to avoid stopping operation of the plant when maintenance is required on the aeration system. Fixed systems are typically less costly, and often more efficient because it is easier to make full use of the floor. Fixed systems can be used in multiple tanks.
The two main types of diffusers are porous & non-porous fixed orifice diffusers. The porous diffusers have types like Disc, plate or membrane (Fine Bubble). The non-porous diffusers are perforated piping, spargers & slotted tube (Course Bubble).
- Large bubble diffuser
The Course Bubble Diffuser, as its name implies, is capable of producing bubbles as large as 3 mm. This group of deep aeration systems is mostly used for treatment plants that need to create turbulence in the fluid. This system can also be used to prevent the deposition of various materials on the floor of the treatment plant. The amount of energy required for large bubbles is more than for small ones.
- Fine bubble diffuser
Fine Bubble diffuser is one of the most common types of deep aeration systems for sewage, which produces a good amount of aeration in sewage due to the production of bubbles with a size of one to 3 mm. Due to the fact that the number of bubbles produced by this type of diffuser is high, as a result, the contact surface of the wastewater with it is higher and the aeration and mixing of materials is better. Among the positive features of the fine bubble diffuser compared to the large bubble type, we can mention less energy consumption and better aeration.
- Deep aerator Tube Diffuser
Tubular diffusers consist of plastic tubes and cylinders lined with EPDM membranes. The air in the plastic cylinder creates bubbles to pass through the EPDM membrane, causing bubbling and oxygenation to occur at the desired surface. The material of this type of pipe is often PVC and they are completely resistant to corrosion.
Application :
- Aeration of wastewater treatment by activated sludge method
- Industrial wastewater treatment such as textiles and drug factories
- Treatment and aeration of fish ponds and other aquatic animals
- Lagoon and successive SBR canals and reactors
- Ozonization of wastewater treatment plants and swimming pools
- Domestic, industrial and municipal wastewater treatment