Reverse Osmosis - What can it do for you?

Reverse osmosis is an increasingly older technology that was developed in the 1950s. The purpose of the technology is, unlike a carbon filter, to more or less eradicate all components in the water. That is, when the water "comes out on the other side", the water is so pure that it does not actually contain anything other than its own molecules. The idea was originally to extract drinking water from seawater, which to this day is still relevant. At Ultrafilter, we sell Reverse Osmosis systems both for the private household and for industry.

Diffusion and osmotic pressure

A reverse osmosis plant consists of a semipermeable membrane. This means that it is permeable to certain types of substances. It is the same membrane found in plants. This makes it usable for reverse osmosis, where the desired result is to leave contaminants behind and let the clean water seep through. Membranes used for reverse osmosis are often made of polyamide, as this material has a high permeability to water and on the other hand is impermeable to other substances, such as salts and minerals, hence the name "semipermeable".

To understand reverse osmosis, we must first talk diffusion. Diffusion is about a sum of particles or ions going from a high concentration to a low concentration; or in other words: they go from being assembled to being scattered so that the concentration is evenly distributed. A good example of this is having a jug of water in it, to which you add a quantity of red juice. After some time, one will see that the juice water has distributed in water, so that the particles of the juice are evenly represented in the amount of water.

In osmosis, as previously mentioned, we add a semipermeable membrane. Let us again imagine a jug of water in which we have added our membrane. In both sides of the jug we have a concentration of 10 water molecules in both sides of the jug. In this case, no water will flow through the membrane, as the concentration of water is the same on both sides.

Let us then assume that we have the same jug of water, where this time we have added 10 salt molecules in one side of the jug, so we have 10 water molecules in page 1 and 10 water and salt molecules, ie 20 molecules in total, in page 2. With our rule from diffusion, where we saw that the concentration goes from high to low, the water will thus increase in page 2, so page 1 and page 2 will contain an equal distribution of water molecules.

We have now explained osmotic pressure. When the water level rises in page 2 from the aforementioned example, the pressure also rises, which is what causes the water to rise, and thus we see that an osmotic pressure goes from high to low concentration of water; or that water will always seek to equalize its concentration using osmotic pressure, so that there are equal numbers of water molecules present on both sides.

Reverse Osmosis - How the system works

In reverse osmosis, we want the water we get through the membrane to be 100% purified of various constituents. This is done by turning the rule of concentration upside down so that the water will go from high concentration to low concentration. Or to put it another way: we leave one side of the jug empty and fill it with water from the other side. In order for this to be possible, we must add a pressure that is higher than the osmotic pressure, because otherwise the water we purify and which must end up on side 2 of the jug, will run back through the membrane to equalize the number of water molecules. It is very common to use reverse osmosis for desalination of water, where a pressure higher than the osmotic pressure causes the water to seep through the membrane so that on the one hand there is pure drinking water and on the other hand there are various minerals, saltions, etc.

What can the system be used for?

A reverse osmosis system can be used both in private homes, but is also widespread in industry, where clean water is a necessity. In industrial contexts, you will often need these systems in laboratories, nurseries, car washes, refrigeration systems, etc., where after using the water there must be no residue on the surfaces, which over time reduces div. device life.

In the private home, the plant, as previously mentioned in the article, can be used to purify water, which can then be used as drinking water. If you are in doubt whether you will benefit from an osmosis system in the home, please give us a call on 82 30 30 20 and we will talk about your needs.