Osmosis is ... What is reverse osmosis?

Osmotic processes are built on the natural ability of the solvent to pass from the concentrated medium, leaving foreign mineral particles. The delay of the latter is promoted by semipermeable membranes and pressure, under the strength of which diffusion takes place (overflow). In the ordinary sense, osmosis is a filtration that provides water purification. For a visual representation of this process, one can turn to technologies of desalination and sterilization of water.

The production of pure liquid occurs as a result of its natural passage through special barriers, behind which undesirable microelements remain. On sea vessels, the installation of reverse osmosis allows you to save water from salt. In industry and medicine, as a rule, careful treatment of aqueous media is required to produce certain formulations.

Reverse osmosis

From the point of view of the purifying function, it is expedient to use reverse osmosis. Scientists have long discovered the ability of multicellular organisms to pass or to retain water. Each cell has membranes protruding by filters that provide water passage, but leave solid and semi-solubilized elements. In the course of these processes, the metabolism is carried out - useful remain in the body, and toxins with waste products - on the contrary, are output. It should be noted that osmosis is a natural procedure, but to achieve higher purification results, pressure is often applied.

So, in the case of water, the semipermeable membrane will ensure the passage of H2O and the delay of the elements dissolved in it only until the moment of equilibrium with the concentrated medium. It is important to note here that osmosis is direct diffusion, which can be talked about when the force of natural pressure begins to exceed the hydraulic one.

Reverse osmosis membranes

In the manufacture of membranes for osmosis, synthetic polymers are used . The main task of such elements is to create a barrier for high-molecular pollutants, while allowing passage of low-molecular substances, including oxygen, carbon dioxide and chlorine.

The reverse osmosis water systems built on polymer membranes facilitate the separation of pure liquid from impurities. Unlike other methods of modern filtration, osmosis involves the presence of water on both sides of the filtration component. However, on the one hand there is a permeate (pure water), and on the other - a liquid with impurities, among which there may be salts, colloids, microorganisms and various organic substances.

Productivity of membranes for osmosis

The artificial reverse osmosis process is capable of processing an average of 20% of the total water volume. However, some high-tech installations bring this figure to 80%. Another thing is that it is mostly narrowly specialized osmotic filters that are inaccessible to the mass consumer. Nevertheless, the reverse osmosis system is currently considered to be one of the most high-quality and promising technologies allowing to purify water of any quality.

Prefilters

As a rule, reverse osmosis systems provide for several stages of filtration. The initial barrier for impurities and impurities in the water is the prefilter. Its task is not so much the preparation of water for domestic needs as its primary purification from the elements capable of damaging the membranes of the main filter. In particular, at this stage, the reverse osmosis system delays the chlorine and other impurities that are undesirable for contact with the post-filter.

As a rule, for initial cleaning, carbon filters are used - they are usually used in cartridge models. Coal "drainage" removes liquid from chlorine, which is harmful to the polymer membrane. That is, it is important to understand the importance of preparing the liquid, which will later be treated with osmosis. Purification of water - what is this in terms of safety of filtration equipment? First of all, protection from chemical processes that destroy the structure of cleaning elements. Elimination of the same chlorine in the preliminary stage will significantly improve the longevity of the system.

Post-filtration membranes

There are two types of membranes for basic filtration - flat and tubular. Flat models are film products that have reinforcement or a substrate in the form of a substrate. For reverse osmosis osmosis, multilayer versions are usually used, where each film is designed for specific loads. The base layer of the membrane usually performs a strengthening or carrying task, the second - directly participates in the filtration, and the final one - provides external protection.

Tubular models - water filters, the osmosis of which is provided by special fibers, have a diameter of up to 0.5 mm. The hollow structure of the fibers is considered to be the most effective in cleaning. Due to the small size of the membrane fibers, a significant working surface is provided. But the principle of careful filtration naturally leads to a significant disadvantage - the tubular membranes quickly become contaminated, requiring high-quality water treatment.

Installation and operation of filters

To ensure a durable and efficient cleaning, an appropriate installation of the equipment is required, which involves the design of a filter and pump connection. Typically, the installation of reverse osmosis involves the introduction of boost pumps, which create artificial pressure. There are high and low pressure sensors.

Water comes to the reverse osmosis plant directly from the water pipe, after which it passes processing in prefilters with coal. The pump is installed immediately after the pre-water filter, but before the membrane. Passing the initial cleaning, water enters the inlet of the pumping unit. The output of this device is connected to a shut-off valve. On the other side of the valve, it is necessary to connect a tube passing to the tap with clean water and a membrane.

Manufacturers and prices

Implement osmosis at home, having the opportunity to use high-quality and clean water, offer both Russian filter manufacturers and foreign firms. In particular, the company "AquaFor" and "Geyser" will allow the installation of reverse osmosis, the price of which varies from 8 to 14 thousand rubles. The difference of several thousand is due to the performance and functionality of the filters. For example, the Prestige MP model is the top model in the Geiser line and allows the mineralization of water. Atoll relies on improving the basic parameters of its models, offering a modification of "Patriot" with a 5-step cleaning and a 12-liter tank for 8,5 thousand.

Decent options in the domestic market of membrane filters are offered by Japanese developers. For example, the company Expert Osmos in the budget line provides a functional reverse osmosis, the price of which is 9 thousand. After paying another 6 thousand, it is possible to provide the house with a filtration system Praktic Osmos, which is also equipped with a pump, electronic control and automatic membrane flushing.

Pros and cons of reverse-osmosis treatment

The quality of execution of the main task of reverse osmosis filters is not equal. For example, alternative installations-jugs, even in the best modifications are incomparable in the depth of cleaning. But it is this factor that raises doubts about the usefulness of membrane devices, since osmosis is a process in which water becomes completely distilled. True, many modern models allow you to control the purification, while retaining the mineralization of the liquid.

Among the drawbacks of reverse osmosis and the need for using compound equipment. Several filters, the presence of a tank and a branching system exclude the possibility of compact installation of such systems. Anyway, reverse osmosis filtration, provided it develops in the direction of increasing ergonomics, may well become an absolute leader in the category of means of providing clean and healthy water.