Optimized Filter Cleaning with Compressed Air in Water Treatment Plants
July 10, 2025
Efficient filter cleaning is the key to sustainable water treatment.
Why is Water Filtered in Water Treatment Plants?
In industrial plants or in drinking water production, groundwater is treated to the desired quality. For example, drinking water is passed through sand filters to remove residual iron and manganese components and to clarify the water.
The Importance of Filter Cleaning in Water Treatment Plants
Since water filters collect the residues of the filtered water, they must be cleaned from time to time. Therefore, cleaning water filters is an essential part of water treatment – in industrial as well as public sewage treatment plants.
By cleaning the filters, sewage treatment plant operators ensure the quality of the water. Without cleaning, deposits and impurities accumulate in the filter and, depending on the degree of contamination, are released into the drinking water.
This protects the plants because a regularly cleaned filter runs more efficiently and has a longer service life.
How Water Filters in Sewage Treatment Plants Are Cleaned with Compressed Air
The best-known method of cleaning a water filter is backwashing.
This involves pumping water backwards throught the filter in order to prevent the filter media from becoming too dirty or even unusable. This removes dirt and particles from the filter sand or filter medium.
The Use of Compressed Air Enables Effective Filter Cleaning
To optimize backwashing, compressed air can be added to the backwash water. This means that the filter is cleaned not only with pure water, but with a mixture of air and water.
The improved cleaning effect is due to the fact that contaminants can often be dissolved more effectively by adding air than by using pure water alone.
The air creates more turbulence within the filter chambers, which helps to remove particles and deposits from the filter surface more effectively. The flushing water can also be used to remove the dissolved particles.
In addition to improved cleaning performance, the use of compressed air has other advantages:
- More efficient cleaning generally leads to a longer filter service life and maintains consistent filtration performance
- The use of air reduces water consumption during the backwashing process
- Energy-efficient compressed air compressors or blowers often operate at lower operating costs than alternative cleaning methods.
Areas Of Application and Uses of Compressed Air for Filter Cleaning
Filter cleaning with compressed air can be used for various types of filters. In water treatment plants, it is used to purify:
- Sand filters
- Activated carbon filters
- Membrane filters
In addition to the treatment of drinking water, process water and wastewater are also optimized through the use of compressed air. Compressed air is also used for filter cleaning in the field of ultrafiltration (UF).
Which Compressor Should be Used for Filter Cleaning?
Blowers or low-pressure compressors are generally used for backwashing. These generate compressed air at pressure below 4 bar. The pressure level of the blower to be selected depends on the specification of the application and can be finely adjusted.
