The central water supply in the country is a rarity in our country and a real luxury. More often, the owners and land plots have to equip the well on their own. But this is done mainly by those for whom the dacha is a place of frequent stay. Rare visitors to their "estates" prefer trips for water to the column. It's good if the latter is close.

If there is no access to clean water in the country, then it is necessary to have a filter for cleaning it.

Always in the country rests on the shoulders of the summer resident. Each owner of a suburban area is responsible for the quality and purity of the water he receives. Some people think that the water away from the city is essentially drinkable. Allegedly, there are almost no cars, and the factories are far away. But if the water is clear and odorless, this does not mean that it is clean and safe for health. It may contain over ten million unsafe substances! Boiling saves far from everyone. Clean water can be brought from the city, but this option is only suitable for short trips for a day or two at most. Much more often summer residents stay out of town for a week. water in this case is the only way to purify the liquid from numerous harmful impurities and dangers of organic origin.

The well water filtration system is different: today's market offers a rich assortment and an inexperienced buyer can get confused in the choice. But everything is not so complicated: the installation from the well is divided into types according to the filtration method and the impurities removed. According to the first feature, they are divided into 2 groups: those that operate under water pressure (membrane) and those that operate under minimal pressure (jugs).
The following filters are distinguished by the types of impurities removed:

• universal, struggling with all kinds of inclusions;
• removing rust, sand and other solid suspensions;
• softeners, removing lime and salts using an ion exchange reaction (limestone water filter or salt filter for well water);
• absorbent, eliminating the unpleasant taste and smell of water;
• oxidizing (cleaning);
• antibacterial.

If you need soft water that does not harm household appliances (), then use a salt filter to purify the water. In addition, modern wells differ in the place of installation.

But it should be borne in mind that filtering all the water entering the house, even if you live in the country for months, is not a good idea. Drinking water should be clean and that which is used for cooking. Otherwise, you can go broke on consumables.

A few words about electrohydrolysis

Before choosing which well water filtration is right for you and purchasing the appropriate treatment plant, you need to find out the composition of the water in the area. The fact is that impurities are different, including viruses and bacteria, which require special filters to remove.

In addition, by removing these substances from water, it can be made, although clean, but absolutely useless, that is, literally “dead”, by clearing the liquid of useful components. A full-fledged laboratory analysis is needed, which is neglected by the owners of summer cottages.
Filtration equipment vendors are pulling the trick with electrohydrolysis, an action that "visibly" shows water breaks down into H2O and impurities that precipitate out. An interesting sight, but in fact there is no question of a complete purification of water.

Yes, the decomposition of the components occurs, but which of these impurities are harmful and which are necessary for the human body, it is impossible to say. Marketers use this method to show how dirty the water is and that you just need to buy their expensive filter device as soon as possible.

Remember that under no laboratory analysis is water capable of so radically changing color and smell. An electrical impulse passed through water during electrohydrolysis splits the substance into its constituent components. The water is completely purified. A membrane filter for water purification of a reverse osmosis system has a similar efficiency.

The technology is different, but in terms of filtration quality it is similar, since absolutely everything can be excluded from the water - both harmful and necessary for our health. For this and some other reasons, many consider membrane water purification methods not the most successful solution for country use, but it is worth saying a word about such filters separately.

Features of membrane filters

A reverse osmosis system is a solvent purification (in our case, it is water for drinking and cooking), in which the liquid passes through a semi-permeable membrane from a more concentrated solution to a less concentrated one. With this method it is fashionable to desalinate sea water and obtain crystal clear water for medical needs.

The internal structure of the membrane filter for water purification

In country conditions, a membrane filter is good only if there is a water supply system of at least 4 atmospheres. So you need a plumbing osmosis system, that is, to increase pressure. It is not difficult to assemble such a system and make reverse osmosis with the proper amount of money and time. But here's the problem - to get 5 liters of pure drinking water, you will need to process 40 liters of dirty water. Need a drain.

How many summer residents can build something like this? More often in the country every centimeter counts and you don’t have to think about installing complex water treatment plants from a well. And the holes in the membrane are so small that only molecules of hydrogen and oxygen pass through - the purest water, from which the substances necessary for the body on a daily basis have been removed.

Drinking such water for weeks and months is also a kind of harm to the body. Although one can argue with this, because even if there is no calcium in such water, there is as much calcium in 1 glass of milk as in almost 300 glasses of water purified by reverse osmosis! Therefore, it is entirely up to you to install a membrane filter for water in the country or not. Water with such a filter will be clean to the maximum.

But the membrane filter for water purification is not only reverse osmosis. Reverse osmosis membrane - the variant with the smallest pores (from 0.0001 to 0.001 microns). At the choice of the consumer, manufacturers of membrane filters also offer:

• membranes for microfiltration with pores from 0.1 to 1.0 microns;
• ultrafiltration - 0.02 - 0.1 microns
• and nanofiltration - 0.001 - 0.02 microns.

The working water pressure directly depends on the pore diameter of the membrane: the smaller it is, the higher the pressure. Micro-level membrane filtration is only suitable for light filtration with a view to further more thorough cleaning. The ultrafiltration membrane purifies the liquid from most impurities except salts. Nanofiltration is a filter for softening well water. On sale there are the most convenient mobile membrane filters that are suitable for summer cottages. They are specially designed to work in the field. Such a compact filter is placed in a bottle or bucket of untreated water, and the pure liquid is discharged into another container through a tube. Plumbing is not needed, but the volumes of filtered liquid are small.

Flow filtration for country needs

A more convenient and compact solution for water purification in a summer cottage is a flow filter. It happens in, connected to a water tap, or in the form of a full-fledged stationary device, mounted directly into the pipeline under the sink.

As in the case of membrane counterparts, flow-through water filters perform their functions under pressure, therefore, it is necessary to have a pipeline in the country. Depending on the type of filter chosen, you will receive two levels of filtration (faucet attachment) or three (installation). Two-level filtration usually includes mechanical purification and absorption of harmful impurities by activated carbon.

If your well is well maintained and the water in it is clean, but unsuitable for safe fresh drinking, then a two-stage treatment is sufficient. But if the plumbing system is powered by a pump, then the nozzle on the faucet will slow down the movement of water, up to 1 glass per minute. The pump itself will turn on and off too often, experiencing overloads and wear out faster.

Where the best solution is flow filters for giving under the sink. They do not pose a threat to accelerated pump wear, and the filtration process itself is faster. But even here there is a minus for those whose well water includes a variety of suspensions. Activated charcoal clogs quickly and becomes a good breeding ground for bacteria. Therefore, replaceable cartridges need to be changed more often, and it is more difficult to disassemble a stationary system than a faucet nozzle. Here is such a dilemma, which, nevertheless, equalizes the two types of flow filters in pros and cons.

Filter jugs

Pitcher filters are a simple and cheap way to purify water. The benefits are visible to the naked eye even for those who are poorly versed in water filtration. Filter jugs:

1. They are compact and independent (membrane water purification loses to them especially strongly in this).
2. Easy to operate even for small children.
3. Convenient to use in the country and do not take up much space.
4. They have a large selection of filter components that solve various problems.

The last point deserves a special mention. The fact is that most of the well-known manufacturers of pitcher filters offer consumers replaceable cartridges that can simply purify water from impurities harmful to health or those that, in addition to filtering, also saturate the water with useful microelements (fluorinate). Some companies claim that their cartridges not only reduce the amount of hardness salts in the water, but also fight the presence of E. coli.

Cons of pitcher filters? Only two. Such a water purification device is suitable for filtering a small volume of liquid - only for drinking: one jug is enough for one family to use. At the same time, replaceable cartridges have their resource. And it fluctuates on average from 150 to 500 liters. Thus, the filter jug ​​is suitable for home use or for occasional trips to the country. In this area, he performs the functions assigned to him with a bang.

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Conclusion

Thus, it is not difficult to guess that the best solution is a filter jug: a simple and effective tool for water purification in country conditions. A cheap, compact and mobile filter for summer cottages, but not at all suitable for permanent residence. It is better if the water in the well meets sanitary standards. In this case, a pre-filter embedded in the pipe will suffice. It will not affect the operation of the pump and will protect the water from sand during rains and floods.

Incoming in Houses And apartments drinking water contains many impurities, dissolved chemicals and bacteria. Most elements have a negative impact on human health, especially young children. The constant use of water of inadequate quality leads to the development of dangerous chronic diseases. The optimal solution to the problem is to install a membrane filter that can purify water as much as possible and increase its drinking quality.

What is a membrane and how does it work

The main element of membrane filters for an apartment, country at home or industrial the enterprise is a membrane - an ultra-porous thin film that allows oxygen and water to pass through. All organic and inorganic substances whose particle size is larger than the pore diameter remain on the surface of this element. The movement of the liquid is implemented according to the tangential scheme - water is collected from both sides of the membrane. A larger volume is supplied for cleaning through the filter and enters the storage tank, and the rest of the liquid is used for cleansing films from the accumulated dirt with a directed flow and diverting it into the sewer system.

Membrane filtration systems are designed not only for household needs, but also for obtaining ultrapure water for technical and medical purposes, desalination of sea water, and neutralization of wastewater. Track the membrane in a special configuration is also used for water purification in emergency situations, the service life allows its reusable use.

The water purification membrane is made mainly from lavsan, polysulfone, polypropylene, acetate, ceramics, but other materials with similar properties are also used.

Filtration system installed under the sink

Membrane device for water treatment household destination is mounted under the sink and connected to a pipe that supplies cold water to an apartment or house. The cleaning process includes several steps:

1. Coarse cleaning - retention of solids, partial removal of chlorine used to disinfect tap water;
2. Filtration through the membrane - cleaning from most microbiological and chemical contaminants;
3. Accumulation of purified water in the tank;
4. Additional mineralization of the liquid (when installing a special cartridge);
5. Improving the organoleptic qualities of water - filtering through the so-called post-filter of pressed activated carbon;
6. Purified water supply through a separate tap, additionally installed next to the sink.

Membrane filtration devices are also produced, the operation of which is based on a completely different principle. A working element is placed in a container with water, into which the water to be cleaned enters, while pollutants remain in the device case. The filtered liquid is discharged through a special hose into another container. Such membrane filters are indispensable in the country or on a hike, when there is no way to connect to a centralized water supply.

Nerox filter for outdoor use

The disadvantages of this type of water treatment devices are the need for regular cleaning of the membranes with the help of special tools, as well as a short service life.

The performance of membrane filters depends on several factors:

• source water quality;
• type of cleaning membrane film;
• the level of pressure under which water enters;
• thickness and area of ​​the membrane;
• water temperature.

Most of the water treatment plants, for example, the brand " Geyser”, are supplied with all the parts necessary for connection - hoses, fittings, a tap. In Tyumen, you can purchase any filters that implement membrane water purification technology at the KVANTA + company at the best prices in the city.

Geyser Nanotek filter with a storage tank and a faucet for purified water

Types of membrane filters

By membrane type

• "micro"

Pore ​​sizes in membranes of this type vary from 0.1 to 1.0 micron. The film is capable of retaining fine impurities and colloidal particles that impair water transparency.

Microfiltration membranes are used for coarse cleaning: preparation for the next stage of filtration or for wastewater treatment.

• "ultra"

Ultrafiltration membranes with pores with a diameter of 0.02-0.1 microns retain macromolecular compounds and colloidal impurities, algae, bacteria, macromolecules, but are powerless against dissolved salts.

Such membranes are installed in household and industrial filters designed to purify water from mechanical impurities while maintaining the salt composition.

• "nano"

In nanofiltration membranes, the pore size is 0.001-0.02 µm. They are used to purify hard water and soften it, remove about 90% of organochlorine substances and heavy metal ions.
When using flow filters with a nanomembrane, the salt composition of water changes slightly less than when using reverse osmosis membranes.

Water purification using membrane technology

• reverse osmosis membrane filters

Reverse osmosis membranes, characterized by the smallest pores (0.0001-0.001 microns), are able to filter:

• all viruses and bacteria;
• organic impurities that affect the color of water;
• a significant part of the dissolved salts;
• heavy metals and iron;
• pesticides, herbicides, insecticides.

Membrane elements of this type trap almost all impurities present in the liquid, passing only pure water molecules, gases dissolved in it and a small percentage of mineral salts.

Filters with a reverse osmosis membrane are designed to produce high-quality water not only for domestic purposes, but also for production beverages, in the pharmaceutical industry, in the food, medical and electronic industry.

Due to their extremely small size, the pores of the reverse osmosis membrane are subject to periodic clogging by large particles. For efficient and long-term operation of the filter, preliminary preparation of treated tap water is required, namely:

• coarse filtration;
• fine cleaning;
• softening of hard water.

In this case, the pre-treated liquid must be supplied to the membrane at a pressure of at least 3 bar, otherwise the filtration will be too slow. If the pressure in the system is too low, special pumps are used to increase it to the required level.

By design type

Filters are equipped with membrane elements of various shapes:

• flat (disk);
• tubular;
• rolled;
• hollow fiber.

Membrane filters of different types have different working surface area.

flat

Flat membrane elements are made in the form of films of the following types:

• membranes with a substrate, consisting of a working layer and a substrate of large-pore material;
• membranes without a substrate, made of a homogeneous substance;
• reinforced, in which the porous material is applied to the fabric base.

Flat reverse osmosis membranes are most often thin-film composite and consist of three layers

Sectional flat membrane

As a base (1st layer), a polymeric material (polystyrene) is used, on which polysulfone with micropores (2) is applied. The second layer passes water well, but does not shrink or deform under pressure. The third layer, which acts as a barrier, is made of aromatic polyamide.

Disc membranes are used for the production of filter press machines.

filter press

The filter consists of membrane elements (1), porous plates (2), two covers (4, 5), pins (6), collector (7).

Tubular

This type of membrane is a tube made of a porous material (metal fabric, cermet, ceramic, plastic).

Membrane tubular filters can be symmetrical, in which the porosity is the same throughout the volume, and asymmetric - one of the surfaces is covered with a layer of a denser material. It is the dense layer that is working and traps pollutants, the material with larger pores is the substrate and performs the functions of drainage.

Membrane tube filter

Liquid purification is performed as follows. Water, passing through a tube (1) with a semi-permeable membrane element, is filtered and collected in a container (2), while the concentrated pollutant leaves a separate tube. The pump (3) increases the pressure on the incoming solution, after which the throttle (4) dumps the pollutant at the outlet.

Rolled

The membrane filtering device consists of a drainage tube with three layers of material wound around it: the main membrane, and drainage gaskets, in which the membrane material is wrapped on both sides.

Water is supplied from the end of the filter, passes in a spiral through the membrane and gaskets, and then enters the drain pipe. The pollutants dissolved in water are discharged from the roll filter from the other end.

Membrane roll filters differ in a convenient design. Thin the working layer allows us to classify this type of filter as one of the most productive, besides, its pores are rarely clogged.

Membrane roll filter

hollow fiber

Hollow fiber membranes are tubes with a diameter of about 1 mm with porous walls. The size of the micro-holes through which water is filtered does not allow even the smallest contaminants to penetrate through them.

Hollow fiber membrane filters are capable of:

The only brand of water filters in Russia using membranes of this type is Aquaphor. The technology is used for final water treatment in filters of the Kristall series, in which a hollow fiber membrane element is combined with a carbon block in one module. You can buy Aquaphor membrane filters and systems of other popular brands at the best prices in Tyumen at Kvanta+.

Household or ceramic

Ceramic filters are designed for post-treatment of water supplied from a centralized water supply system.

The popularity of membrane water treatment devices of this type is due to several reasons:

• performing water purification using ceramic membrane elements without the use of reagents;
• high-quality neutralization of extraneous tastes and odors, impurities, bacterial microflora;
• the presence of protection against drying out;
• resistance of the outer surface to the effects of abrasive cleaners;
• no need to replace membrane elements.

Membrane ceramic filter

The membrane block is placed in a housing with a diameter of up to 10 cm and a length of up to 35 cm, made of stainless food steel. The membrane is a bundle of finely porous ceramic tubes through which liquid is supplied under pressure.

The advantages of cleaning in ceramic membrane filters are considered to be the production of high-quality drinking water without iron impurities and hardness salts. The systems are not demanding on the quality of the incoming wells or main water pipes, have a long service life.

Ceramic membranes are made of a durable but brittle material, therefore the main conditions for durability and reliability of cleaning are the correct transportation of filters and installation and cleaning. To clean the instrument, rinse it with a clean flowing water using a soft sponge or brush. Cleaning agents should not be used to prevent them from entering the drinking water. High-capacity membrane water treatment plants are cleaned by backwashing with demineralized water.

Advantages and disadvantages

Membrane filters differ from other types of water treatment systems in their high efficiency - due to the small pore size, the installation water becomes absolutely pure and suitable for any needs.

A significant disadvantage of membrane devices can be called a relatively high cost, which is offset by a lot of pluses:

• high quality of water purified using membrane technology;
• ease of use and maintenance;
• partial preservation after cleaning of the salt composition of the liquid;
• removal of the smallest particles suspended in water;
• compact size;

The disadvantages include:

• relatively low water filtration rate, its adjustment requires the installation of storage tanks;
• the need for regular replacement or cleaning of membrane blocks.

Operating conditions of the membrane filter

The service life of any membrane filter, the frequency of cleaning and replacement of working elements are determined by the conditions of its operation:

• the quality of the water to be treated;
• volume of the passed liquid;
• pressure in the plumbing system.

The exact time for cleaning or replacing the membrane element cannot be determined in advance.

If the owner has the financial ability, then it is recommended to change the membrane unit in filtration devices every year or when the taste of water deteriorates, its pressure decreases. If yearly replacement is burdensome, the membrane should at least be flushed. The design of some models provides for the possibility of backwashing (turning on the reverse water supply mode) or cleaning by changing the pressure of the supply stream.

It is almost impossible to wash the membrane elements at home, but in the event of a temporary lack of funds, you can try to at least slightly improve the quality of filtered water.

The filter film is thoroughly rinsed under the pressure of warm running water or in a soapy solution and put back. In case of severe contamination, the membrane unit is immersed in warm water with the addition of citric acid, and after being installed back into the filter, it is washed for half an hour to completely remove the "lemon".

Industrial membranes installed on production lines are washed with a special solution of acid and alkali.

Flushing the membrane filter

How to choose a membrane filter

In addition to membrane filters, there are many other filters that work on a different principle. The main factor for the selection of a membrane filter is what kind of impurities it is necessary to rid the water of, as well as the required filter performance. Before choosing a treatment system, it is necessary to determine which substances are present in the water in the largest amount and compare the indicator with the maximum allowable value according to SanPin 2.1.4.1074-01. It is also desirable to perform a bacteriological analysis of water.

For example, if the content of heavy metal salts in water is within the limits established by SanPin, there is no need to install a filtering membrane device. In this case, you can get by with a conventional carbon sorption filter.

When buying a reverse osmosis membrane filter, it should be noted that its operation requires preliminary purification of incoming water, which leads to the cost of purchasing and installing additional filters. The operation of reverse osmosis technology is impossible at a pressure in the system below 3 bar, since water will not be able to pass through the pores of the membrane material at the required speed. Low pressure will either stop the water supply completely or slow down the cleaning process.

Reverse osmosis membrane filters are sold as a single system consisting of several treatment units. Each node is located in a separate case, which has its own marking. The more complex or technologically implied water purification, the higher the cost of the device, the more difficult the installation.

When selecting a filtration device with a membrane, it is necessary:

• determine its purpose - for wastewater treatment, obtaining water for household needs, drinking and cooking, using it in a laboratory, etc .;
• take into account that the price of the filter is directly proportional to its capabilities;
• to reduce the hardness of water in the filter, a nano-membrane is sufficient;
• for a filtering device operating on the principle of reverse osmosis, it is desirable to retrofit with a mineralizer;
• when treating heavily polluted water, its additional passage through microfiltration membranes is required.

Myths about the membrane filter

Membrane filters make water "dead"

A well-performing filtration system allows you to get water that can be used for both drinking and technical purposes. To improve the quality of already purified water, systems operating on the principle of reverse osmosis are used. Together with the purification from all harmful impurities, there is a complete or partial desalination of water, the removal of useful substances. Such water is considered "dead", but not dangerous.

In fact, the water after purification is not “dead” at all, but demineralized and still contains a certain amount of dissolved substances. Such water retains all the taste qualities of products and is perfect for gourmets - for making the best varieties of tea or coffee, other drinks, cooking. Since a person receives the main amount of microelements and minerals from food, food and drinks can be prepared on “dead” water, and for drinking it is desirable to pass it through a mineralizer that adds useful substances.

Filtered water somehow affects food

During the filtration process, substances are removed from the water that do not have the best effect on the taste of cooked dishes. The full taste change is felt in the prepared drink, such as coffee. Water passed through a membrane filter is considered the optimal basis for making juices and cocktails.

Water purified using reverse osmosis technology does not leave lime deposits inside kettles and other utensils, unlike ordinary tap water.

Everyone wants to drink clean water. For example, you probably want to forget about the smell of chlorine, a brownish tint, rust ... Our rating includes the best (according to customer and expert reviews) popular water filters. You can choose exactly the product that you need, whether you live in a densely populated metropolis or in a country house. We read and become owners of truly pure water!

Types of household water filters

Cumulative

• Filter jugs. One of the most popular varieties due to its mobility, accessibility and ease of maintenance. The design consists, in fact, of a jug and an upper funnel with a lid and a cleaning cartridge installed inside. Water flows through several filter layers, is purified and ends up in the storage tank. Cartridges can be of several types - universal or with certain properties (for example, reducing water hardness, removing iron, etc.);
• Dispensers-cleaners. The principle of operation is also simple and unpretentious - water is poured from above and passes under its own weight through the filter system into the lower tank. The main difference from jugs is a noticeably larger volume and the presence of a drain tap.

Flowing

• Faucet nozzles. Inexpensive and easy-to-install filters with a one- or two-stage cleaning system, usually reduced to the neutralization of chlorine and rust. Cassettes do not last long, but they are available and inexpensive;
• Desktop systems "next to the sink". Representatives of this category have an average performance, differ in the method and degree of water filtration, and, accordingly, in price. The disadvantage is that they take up a lot of space in the kitchen;
• Under sink systems. The most efficient devices with multi-stage filtration, including disinfection and water softening. The most advanced varieties are reverse osmosis models, the key component of which is a semi-permeable membrane that only allows water molecules to pass through. But bacteria, viruses, heavy metals and other harmful impurities are not given a chance to “leak out”. The degree of purification is so great that additional mineralization is used to make the water drinkable.
• Main or pre-filters. They are installed directly into the water supply system and can be used both for individual taps and for the entire apartment or house. A special cartridge acts as a filter element, and in the simplest instances, an ordinary metal mesh.

Tap water contains many harmful impurities and microorganisms. According to experts, ordinary boiling is not able to completely rid the water of harmful impurities. And the asking price is quite high. The ingress of these substances and bacteria into the body can cause irreparable harm to health.

To solve the problem, many resort to installing high-purity filters with membranes. The practice of buying bottled water is also widespread. However, in the latter case, there are questions about the quality of water treatment. In addition, it is difficult to satisfy all needs with a few bottles, and the price of such water is not small. As for membrane filters, they purify water from suspended particles, impurities, bacterial cells and viral particles and preserve the structure and properties of water.

Types of membrane filters

The history of the appearance of membranes dates back to the 19th century. Then they were made from fiber, but were not widely used. Only in the 60s was the membrane, the prototype of modern devices, made.

The membrane is an ultra-thin synthetic film with pores that is able to pass water and oxygen while retaining impurities. The membrane is produced from polypropylene, lavsan, cellulose acetate, etc.

The main property of water purification filters is the retention of small colloidal particles and compounds.

Membrane filters for water purification differ in pore size and membrane design. Reducing the size of micro-holes in the membrane leads to an increase in water pressure in the filter. The number of filter cleaning steps increases the quality of water and the price of equipment.

Membranes are distinguished by pore size:

1. Membranes for microfiltration. Membrane microperforations are 0.1 – 1.0 µm. Membranes are designed for primary purification of water from particles and impurities that cause turbidity. In fact, this type of membrane is a preparatory step before the subsequent water filtration. The membrane is often used for wastewater treatment.
2. Ultrafiltration membrane filters - 0.02 - 0.1 microns. These membranes allow filtering out colloidal particles and macromolecular compounds, bacterial cells. Membranes are not able to stop salts dissolved in water. Basically, ultrafiltration membranes are used in industrial and domestic filters to purify water from insoluble impurities while maintaining the salt composition.
3. Nanofiltration membrane filters - 0.001 - 0.02 microns. Membranes with such a pore size are designed to soften water with high hardness. The membranes retain organochlorine substances and heavy metal ions. The degree of water purification from the latter reaches 30%. At the same time, the membrane passes 90% of salts dissolved in water.
4. Reverse osmosis membrane filters. These membranes have the smallest holes - 0.0001 - 0.001 microns, therefore they are characterized by selective properties of water purification. The membranes are designed to remove most of the impurities and solutes. The membranes in the filter allow water, gases and some salts to pass through. When sea water is filtered in this way, it is desalinated by 97%. Purification on such membranes leads to deep desalination, removal of viral particles, bacterial cells, oil products, etc. The filter produces high quality water, which is used for bottling, beverage production, in the pharmaceutical, food and electronic industries, for microbiological purposes. The price of such filters with a reverse osmosis membrane is quite high. It is recommended to carry out mineralization after the filter.

The price of any type of filter can be specified on the manufacturer's website and read the detailed description.

Principle of operation

The membrane filter is an ultra-thin membrane with a large number of pores. The membrane in the filter provides the highest degree of water purification. Also, after the filter with a membrane, the composition of salts and microelements is almost completely preserved.

As a result of water filtration through the membrane, it is characterized by a high level of purification, biological value and saturation with minerals.

Membrane filters have a "tangential" system of water movement near the membrane and there is one inlet and two outlets. This means that water is collected from both sides of the membrane. One part of the water passes through the membrane and is discharged into the tank. The other one is designed to wash the sediment from the membrane surface and bring it to the drainage zone of the filter.

The performance of a membrane filter depends on:

1. Membrane areas.
2. The pressure level in the filter.
3. membrane thickness.
4. Water temperatures.
5. The amount of impurities.

Also in field conditions, membranes for water purification are common, for example, Nerox, which work on a completely different principle. A membrane filter is placed in a vessel with dirty water. At the same time, clean water is discharged through a special hose into another vessel. The disadvantage of this method is the need for periodic cleaning of the membrane from contamination. This is done manually using special tools. Nerox filter membranes can be washed with plain water.

Inorganic sediment from the membrane in the filter is removed by acid means. Organic compounds and biomass from the membrane in the filter are washed out with alkaline compounds.

Advantages and disadvantages

Advantages of membrane filters for water purification:

1. Ease of use and maintenance of membranes.
2. High level of water purification in membrane filters.
3. Preservation of the salt composition of water after the filter.
4. The membranes remove the smallest impurities.
5. Many membrane filters are compact (Nerox).
6. Some membrane filters can be used in the field and for wastewater treatment.
7. Some filters, such as Nerox, do not require replacement membranes.

The disadvantages of membrane filters include high cost. Also, some filters have a low water filtration rate, which requires the installation of storage tanks.

Ultrafiltration membrane filter: video

In the video presented on the site, you can clearly see and study the reviews of how the ultrafiltration membrane filter works for water purification. It also talks about benefits.

Separation by design type

According to the design of the membrane filter, there are:

1. Flat disc membranes are available:

• from one substance (supportless membranes),
• on a fabric basis and porous raw materials (reinforced membranes),
• from large-porous raw materials and the working layer (substrate membranes).

Disc reverse osmosis membrane filters are most often composite thin membranes, each layer of which is made of different compounds.

1. Tubular membranes are tubes made of porous raw materials (plastic, ceramic, metal, metal-ceramic, etc.). The membrane diameter reaches several centimeters.

There are symmetrical and asymmetric tubular membranes. In the first case, the pore density of the membrane is the same throughout the entire volume. In asymmetric membranes, a denser material is provided on one surface. It is a worker and shows the degree of water purification. The role of the large-pore membrane in the filter is reduced to the passage of filtered water.

1. Roll membrane filters for water purification are a system in which a membrane is wound onto a drainage hose. When water is supplied, it passes in a spiral. It then collects in a drain hose and exits the other end as a concentrate.

The convenient shape and ultra-thin working layer guarantee the membrane filter high performance and low clogging susceptibility. The membrane can be used for waste water treatment.

Among the advantages of the membrane filter are an increased packing frequency and a small degree of metal consumption of the membrane.

1. Hollow fiber membranes, which are made in the form of tubes. A number of membranes are placed in a water filtration device. The result is a filter with an increased working surface and performance.

The disadvantage of membranes is the difficulty in controlling the flow of water along the fibers. Therefore, such membrane filters are prone to clogging. Membranes are not recommended for use in wastewater treatment. Also, judging by the reviews, the membranes are difficult to clean. And the price of filters is high.

In this regard, before supplying water to hollow fiber membrane filters, it must first be processed.

Prices

The cost of a membrane filter depends on the performance of the filter and the degree of water contamination. The table below shows indicative prices for the most popular filters.

Filter name	Main characteristics	price, rub.
Nerox-03	Membrane filters are designed for water purification. Salt composition is preserved. The filter is compact and lightweight. The filter can be used to purify water at home and in nature. The filter requires periodic cleaning of the membrane under running water.	1350
Aqua expert	The membrane filter is designed to purify water of any quality, wastewater. Water after the membrane has a restored structure. The filter is easy to use and clean.	1450
Honeywell FF 06 - 3/4″ AAM	The filter is intended for purification of hot water of flow type.	5110
Atoll A-460E	The filter has 4 stages of water purification. Reverse osmosis membrane	10000
Atoll A-575 E	5 degrees of water purification. reverse osmosis membrane. Purifies water, softens it. The filter is suitable for waste water.	12280
GE Merlin reverse osmosis	The membrane filter is designed to purify running water.	44450
AquaPro ARO-3000GPD	Filter with reverse osmosis membrane. It is applied to purification of large volumes of water for commerce and microbiological purposes.	470300

More detailed information about each type of filters, membranes and price can be found on the manufacturer's website.

The current water supply system has significantly progressed and improved, a person has the opportunity to create a completely automated complex without spending a huge amount on it. The quality of water, unfortunately, has not improved, and even worse. This necessitates the use of special filters that should be present in every home. The most popular are membrane filters, which are highly efficient, they allow you to purify water at the molecular level. To better understand the advantages of this mechanism, you need to get to know it better.

Distinctive features

It is believed that these filters carry out a rough method of water purification. They are used to purify the liquid, mainly water, from various harmful substances.

The main element responsible for filtration is the membrane. The size of its pores can be varied, which directly affects the quality of the cleaning. All contaminants leave the filtered water because they cannot pass through the membrane and are retained. As a result, a person receives purified water.

Purification systems made using membrane filters are very often used in domestic conditions, as well as in order to obtain the purest water used in industry or medicine. Such systems are often used to perform seawater desalination or wastewater treatment. The presented system can also be used in emergency situations, while its service life allows using track membranes multiple times.

The purification system is connected to the pipeline through which water enters the house or apartment.

Such a system consists of several elements:

• Primary filter.
• Two elements with special cleaning cartridges. The first contains granular coal, and the second contains block coal.
• Membrane, the pore cross section of which can be different, as will be discussed in more detail below.
• Tanks for collecting purified water.
• An automatic valve that is required to shut off the water supply when the storage tank is filled with purified liquid.
• A cartridge that provides additional mineralization of water.

Filtration takes place according to a certain technology. It is important to note that the design and content may differ for each manufacturer and depending on the need for purchase, which directly affects its cost.

What causes high demand?

The systems under consideration are characterized by high efficiency. Due to the small cross section of the pores, the water that has passed through the cartridge becomes completely clean. Membrane filters used for water purification are characterized by high cost, which is their main disadvantage, however, they have many advantages, including:

• use and maintenance are characterized by ease and does not require much effort;
• purified water is of excellent quality. It can be drunk directly after filtration without boiling;
• allows you to achieve the required mineralization and retains the salts necessary for a person;
• there are certain models of the filters in question that can be used when it is not possible to connect the device to the pipeline.

Systems that are installed to treat wastewater make contaminated liquid safe for humans. It can easily be then poured onto the ground. A certain disadvantage of this device is the need for a fairly frequent change of the membrane and some filter elements, which usually do not last more than 3 months. This is not such a significant minus, since almost all types of filters that exist today need such frequent replacement.

Varieties

All existing types of membranes should be considered according to various criteria.

By level of cleaning

Water or gas can easily pass through the membrane, however, other particles will be retained. Large inclusions are removed from the water by means of mechanical and other types of filters. Membrane filtration is used to remove small particles.

The following types can be distinguished by pore size (pore sizes are presented in microns):

• micro- (0.1-1), ultra- (0.02-0.1), nanofiltration (0.001-0.02);
• with reverse osmosis (0.0001-0.001).

Microfiltration membranes are able to remove significant pollution from water. This category includes those particles that cause the water to become cloudy. Substances that have been dissolved in water cannot be eliminated by this filter. The second option (ultrafiltration system) is capable of retaining colloids, various microorganisms and macromolecular inclusions. Such purification allows you to remove various impurities from the water, however, the salt composition necessary for a person is preserved in it.

Therefore, to soften hard water, such a system is not suitable. To make water softer and eliminate hardness, nanofiltration is required. The latter type of membrane is capable of retaining all kinds of contaminants of various sizes.

By design

In this case, the membranes differ in their shape:

• Disc-shaped. It is characterized by low sensitivity to pressure. Can be applied up to a pressure of 1000 mm of water column. It can be made in three different versions. A disk-shaped membrane can be made of one component, be a porous tissue, or have 2 layers (porous and working).
• with tubular elements. Such membranes mean a tube made of a porous material. It can be made from a variety of materials, but the most common are plastic and ceramic. The diameter of this tube can be several millimeters or up to 2 cm. The walls of the tube can be symmetrical or not. The first method provides for the same thickness and porosity along the entire length, and the second implies that a certain part of the walls is denser and has fewer pairs than the other. Water enters this porous tube with the help of a pump. It passes through the pores and, accordingly, is cleansed. The filtered liquid accumulates in the tank, and the dirty liquid is sent to the sewer.

• Roll. This filtration system includes drainage tubes that are wrapped in a filter layer. Drainage pads in this situation cover the membrane on both sides, which results in a layer with three layers that wraps around the tube. This mechanism implies that contaminated water is supplied to the system from one side. Then it goes through the purification process and goes to the tank. The fluid flow is divided into 2 parts. One goes through the purification stage, and the second washes away the contaminants that are sent through the end part to the sewer. This design is characterized by convenience, there is a thin working layer, which increases the performance of this filter. Clogging is extremely rare.
• Hollow fiber, consisting of many tubes with a small diameter. Since they have a compact size, it is possible to increase the number of these tubes in the device, which allows you to increase the amount of filtered water. As disadvantages of such a system, it is worth highlighting frequent clogging and relatively difficult cleaning. To avoid such situations, it is necessary to first carry out a high-quality cleaning, which can remove large contaminants.

Functioning

The membrane cleaning system is one of the best, as the filtration quality is at a high level. It is able to remove various contaminants and viruses from the liquid, but at the same time retain useful properties and essential trace elements.

At the output, a person receives natural and completely purified water, which is biologically complete. It is rich in minerals that are required for the human body. The system has one inlet through which water enters the filter for purification, and 2 outlets, due to the fact that one outlet is designed for clean and purified water, which is sent to the storage tank, and the second outlet is required to remove contaminants to the sewer.

The device in question is the best and affordable tool for home use, however, the presented systems are also used in the industrial sector. Such water does not need additional treatment, it can be drunk immediately after filtration, since the membrane removed all viruses, microorganisms and bacteria from it, and the salts required for humans are preserved.

The cleaning process is carried out in 5 stages:

1. There is a preliminary purification, in which the mechanical purification of water takes place. This step eliminates most of the chlorine used for disinfection.
2. Water is filtered through reverse osmosis membranes, thanks to which it can be purified from various contaminants.
3. Filtered water accumulates in a special tank.
4. Further, the liquid is supplied through a special tap connected to the storage tank.
5. In the process of distributing water, additional mineralization can be performed. To do this, you need to install a special mineralization cartridge through which water will pass immediately before supply.

Membrane performance can be improved if:

• increase the area of ​​the processed surface;
• increase pressure;
• reduce its thickness;
• raise the temperature of the water that is being filtered. One degree Celsius can increase flow by up to 3%.

Today, manufacturers offer membrane filters that operate according to a different scheme. They are installed in a container with contaminated water and clean water enters another container through a tube. This option is great for hiking and when there is no possibility of connecting the system to the water supply.

It is possible to remove an inorganic type precipitate from the membrane using acidic agents. Biomass and organic sediments are washed out through the use of alkaline compounds. Do not use sulfuric or nitric acid, as they can harm the filter of the type in question.