Waterguide
Ultrafiltration
What is ultrafiltration?
Ultrafiltration is used in drinking water treatment, waste water treatment and in the food, beverage and pharmaceutical industries. It is an effective method of purifying water from harmful impurities without having to rely on chemical additives. In the membrane process, pore filters are used whose separation limits are between 0.1 and 0.01 µm. This means that dirt particles and suspended particles (including germs) are prevented from passing through the membrane by the pores. In this process, the system technology utilises the existing supply pressure. In contrast to nanofiltration and reverse osmosis, ultrafiltration requires low pressure values.
What is the process principle of ultrafiltration?
This technology uses the available supply pressure. All of the water that needs to be cleaned is conveyed through the membranes (dead-end filtration), and the dirt accumulates on the membrane. The transmembrane pressure keeps increasing until the backwashing process with filtrate is triggered and cleans the membranes again.
For a more effective clean, the backwashing process can be assisted by the use of chemicals (CEB = Chemical Enhanced Backwash). This results in a continuously defined water quality with a filtrate yield of 90 – 95 %.
For which application areas can ultrafiltration be used?
- Surface water
- Sterile filtration
- Swimming pool water
- Drinking water
- Decontamination
- Water recycling
Depending on how dirty the raw water is, disc filtration, or flocculation or precipitation may be required before the ultrafiltration stage. That is why Herco recommends running an experimental preliminary investigation with a specially designed pilot unit before planning a large project. Once you have substantiated findings from the pilot project, you can start designing the final unit. Herco also supplies turnkey unit technology as a supplement to an existing water treatment process.
The experts at Herco would be more than happy to advise you and help you in configuring your unit.
The above is an image of a finished ultrafiltration unit.
You can find more information about our ultrafiltration units in the product center:
Advantages of ultrafiltration
- Considerable reduction in operating costs through use of raw water (e.g. surface water or well water) instead of city water
- Ultrafiltrate is ideal as a raw water supply for reverse osmosis
- Fully automatic operation with cyclical backwashing of UF membranes with ultrafiltrate
- Used for raw water that has a large quantity of particles ranging from 20 to 0.2 µm and turbidity values of > 1 NTU
- Fully automatic operation via Siemens S-1200 PLC controller with convenient touchscreen operation
- Already contains a backwashing tank/cleaning tank with a powerful, frequency-controlled backwashing pump
Ultrafiltration enables you to use alternative raw waters instead of city water, which helps to conserve valuable raw water.
In the food industry, it is often used to pre-treat or purify water that is required in various production processes.