The working principle of reverse osmosis. Reverse osmosis water filter

Explaining how reverse osmosis works is quite simple. This is an installation with a membrane of a special structure. It allows water to pass through and retains particles. The process is called reverse because the water flow is under pressure. Thanks to this, productivity increases many times over. How such filters are designed and how to choose them correctly is described in detail below.

Principle of operation

The operating principle of reverse osmosis is based on a well-known physical phenomenon. If you pour a solution into a container and install a semi-permeable membrane through which only water can penetrate, you can quickly filter the liquid from impurities, as shown in the diagram.

This process occurs spontaneously and does not require an additional source of energy. If we take a water filter with reverse osmosis as a basis, for this it is necessary to install a pump that will create external pressure. Under its influence, the solution will pass through a special type of membrane. Moreover, water passes through it freely, while impurities will be retained on the surface.

The osmosis system for water purification is used in various filters - industrial and household. They consist of several elements:

1. Frame.
2. Semi-permeable membrane.
3. Shut-off valve (automatically operated).
4. A filter that performs primary cleaning.
5. Cleaning element (contains granular adsorbent).
6. Charcoal cartridge (block).
7. Storage tank.
8. Post filter (charcoal based).

It is clear what this is reverse osmosis and how it works. The process is based on the fact that water containing impurities is forced and passed through a semi-permeable membrane. Thanks to this, the purified liquid goes further - it can be used, and contaminants are retained on the surface of the filter. In most cases, such devices operate with a capacity of 3-15 l/hour.

Pros and cons of reverse osmosis

Considering how a reverse osmosis water filter works, there are several advantages and disadvantages of this technology. If we talk about the advantages, we can highlight the following points:

• effective removal of salt and heavy metals;
• removal of harmful organic impurities;
• neutralization of bacteria and viruses;
• the water has a pleasant taste, without foreign odors;
• cleaning is carried out without high costs;
• no chemical reagents are used;
• filtration is effective due to a multi-stage process.

Although there are some disadvantages. The reverse osmosis method is characterized by the following disadvantages:

• filters work well only at a minimum pressure of 3 atmospheres - otherwise cleaning will not work;
• a semi-permeable membrane cannot retain gaseous impurities;
• the reverse osmosis principle allows you to effectively filter water, but does it much slower compared to a mechanical or sorption system;
• Such systems are quite expensive; their installation is carried out only by experienced specialists.

It is also worth understanding that such a filter removes both harmful substances and a significant part of useful compounds from water. Therefore, it is optimal to install a system with a mineralizer.Passing through it, the liquid will be enriched with mineral components that are needed for the body.

How to choose a filter

To select the appropriate model, it is not enough to know the operating principle of a reverse osmosis filter. Experienced users recommend focusing on several parameters:

1. Dimensions – the body and tank must be compact enough to easily fit under the sink. Moreover, they should not just fit in there. It is also important to leave free access to all elements, which will be useful in case of repair or dismantling.
2. Performance – for ordinary household models it is 2-4 liters per hour, which is quite enough to obtain drinking water. But if more purified liquid is required, it is better to consider more powerful devices with an indicator of 10-15 l/hour.
3. Water consumption – the smaller the characteristic, the better. It is good if it does not exceed the ratio of 10:1 (this is the ratio of source water to purified water).
4. The service life directly depends on the durability of the parts and the quality of the assembly. As a rule, modern filters are designed to process 5000-10000 liters of water.
5. Ease of maintenance – it is better to consider devices whose cartridges can be replaced without the use of special keys.

Reverse osmosis filters are expensive units with low productivity. They usually purify only a few liters of water in an hour. However, thanks to multi-stage cleaning, the result always remains high quality. This liquid can be used for drinking and cooking.