To be able to use water of the highest quality, which is perfectly suited for its intended use (drinking water, process water, etc.), it is necessary to carry out many treatment processes, including ultrafiltration.
This method is intended to separate suspended solids, bacteria, viruses, colloids or macromolecules. It also retains non-ionic substances and can be therefore used as a pre-treatment, e.g. before the actual reverse osmosis process.
Ultrafiltration is also used to recover water, e.g. water from swimming pool filters or in water treatment plants, where large quantities of highly purified water are used. Obviously, these processes are not cheap, so it is worth investing in ultrafiltration in such facilities to benefit from cheaper water recovery and to reduce your ecological footprint. Using ultrafiltration brings very good results when cleaning wastewater.
Ultrafiltration technology is based on carefully selected screens. Membranes with a pore size in the range of 1-100nm are used in this process. The efficiency of the separation and screening of the above substances depends directly on the size of the particles, the flow conditions and the pore size of the membrane used. For that reason, it is important to match the particular screen configuration to each system in the best possible way.
The membranes used for ultrafiltration are very similar to those used in the reverse osmosis process. They have slightly larger pores (0.001- 0.02 microns). Ultrafilters work on the same principle as microporous membranes so if used in the right way they can achieve excellent results in preventing the growth of bacteria and other contaminants.
Much depends on the matching of the membranes to the technical conditions of the system. If they are correctly and precisely matched, the desired effect is achieved and we can enjoy perfect, clean water.
Ultrafiltration, or as it is also called, molecular filtration can be performed with various types of membranes. Basic types include: ceramic, cylindrical and spiral membranes.
The latter are the cheapest - they are quite efficient, but more susceptible to some contaminants.
Ceramic membranes are more resistant, durable and efficient than other types of membranes, but at the same time they are more expensive.
Cylindrical membranes, on the other hand, have really high resistance, so they are ideal for more difficult and larger contaminants.
Spiral membranes are the most common, but not due to their low price. They simply have the largest surface.
As for the material of membranes for ultrafiltration, acetate cellulose and polysulfone materials are the most popular.
The end result of ultrafiltration depends on the factors above, but sometimes also on the use of other water treatment technologies. If the quality of water is extremely poor, the success of ultrafiltration may depend on other processes, e.g. pre-filtration, which guarantees best water quality after ultrafiltration is performed.
Today, with the technology at our disposal, we can carry out a fully successful ultrafiltration process under diverse conditions. We use both traditional and more innovative solutions. Compact ultrafiltration units, for example, are becoming increasingly popular. To a large extent, ultrafiltration today is a fully automated process.
Ultrafiltration is used both to treat water for domestic and municipal purposes, as well as in various industry sectors. Its quality is particularly important for the food industry, but also for the metal industry.
