Our fields of activity
Our activities can be roughly divided into four areas:
- Circulation treatment with ultrafiltration for pools
- Water recycling in swimming pools and water works
- Centralized and decentralized drinking water treatment
- Process water treatment in industry
Advantages of UF preparation plants:
The biggest advantage of ultrafiltration is the sterility.
The water leaves the membrane absolutely virus- and bacteria-free. The membrane cleans and disinfects itself several times a day automatically. With this technology filter contamination is impossible.
An ultrafiltration unit is flushed automatically at regular intervals for a period of less than a minute. This eliminates labor costs.
- Compact design
Common ceiling heights of 2.2 m (7.3 ft.) are completely sufficient for the installation of a UF system. Ceiling heights of 4.5 m (15 ft.) and more are a thing of the past.
- Space saving
By eliminating the conventional steel filters, the space required for the treatment plant halved. The previous stocking of backwash water reserves is not necessary any longer.
How it works:
How ultrafiltration works:
Ultrafiltration (UF) is comparable to filtering coffee, only much better, just ultra.
During ultrafiltration, the water to be filtered is forced under pressure through small plastic tubes which have an inner diameter of about 0.5 - 2 mm. The actual filters are the walls of these tubes, the pores of which are 0.01 microns small (for comparison, a human hair has a diameter of about 50 microns - this is the 5000-fold value). These walls (membranes) can retain dirt up to a certain size. Particles or contaminants, which are too large for the ultrafiltration membranes are rinsed out again at the end of the tube, while solutes (salts and organic solutes) can pass through the membranes of the filter tube.
However, the great advantage of ultrafiltration over conventional filtering methods is the absolute sterility of the filtered water. The pores of UF membranes are so small that bacteria and even viruses are held back by the UF membrane.
By combining many of these filter tubes in so-called “filter modules” the filter area becomes big enough to allow a flow of water in bigger dimensions. Depending on the application, these modules are of different sizes, thus allowing different filter performance. The use of multiple modules leads to performances in water treatment that virtually leaves nothing to be desired.
Ultrafiltration (UF) pore size in comparison with known water germs
- bacteria- and viral free filtrate
- Pore size from 0,02 to 0,05 µm
Principal of RO:
The reverse osmosis can only be broadly referred to as a filtration method, because the membrane is not porous, but semipermeable. This means that the membrane is not permeable to water as such, but can absorb water in its molecular structure. This in turn means that the resultant concentrate contains all the contaminants that are supplied through the raw water, while the permeate contains mainly water molecules.
Originally, the reverse osmosis is used for seawater and brackish water desalination, but it is also increasingly being used in the separation of purely organic mixtures.
The principle of reverse osmosis is shown in the figure below:
How it works:
If, for example, you separate a salt solution from pure water using a semi-permeable membrane, the system will naturally try to balance out the concentrations. This can only be achieved by pure water getting through the membrane into the salt solution. This process is known as osmotic flow. It results in the originally equal volume ratio of the two liquids changing in favour of the salt solution. The level of the liquid on the salt solution side rises as the level on the water side drops. Osmotic equilibrium is achieved when there is no osmotic flow. The difference in the levels of the two liquids corresponds to the osmotic pressure and is proportional to the initial salt content of the solution.
If pressure that exceeds the osmotic pressure is exerted on the side with the salt solution, the process is reversed, so pure water flows from the side with the salt solution through the membrane into the water side. This process is called reverse osmosis. The process delivers a constant flow of pure water with low salt content, that is virtually free from colloids, solids and bacteria. The gases dissolved in the water, such as oxygen or carbon dioxide, are not separated off.
Principal of Reserve Osmosis
Integrity test – increased safety
by leak testing of the membranes
The wet membranes are exposed to air pressure by the filtrate side. Due to the surface tension of the water the air cannot pass through the membranes. Damaged fibers can be detected by the drop in pressure. Each filtration street can be tested separately.
If the pressure values drop below the specified pressure values determined for new modules, this points towards a likely membrane defect.
By means of the transparent pipe section on the module it can be determined which module is affected.
After removing the module and detaching the end caps a visual control shows bubbles appearing at the leaking capillaries.
After mechanical sealing of both sides of the leaky capillaries, the module is leak-proof and again ready for operation without restrictions.