Membrane filters: advantages and disadvantages. Water filtration system

In the water, which every day millions of people drink, contains a huge number of very different harmful impurities, substances and bacteria. Many people are sure that all these substances can be neutralized by boiling. This opinion is erroneous. Experts reasonably argue that with the help of boiling from all the water can not be cleaned. The stakes are high - everything that is in the water can provoke serious diseases and cause irreparable damage to health.

In order to save your body, many people install membrane filters for water, which, according to the manufacturers, are able to maximize the purification of water of any quality. So, these systems can remove from it the most diverse bacteria, harmful suspensions, impurities and even heavy metals, while maintaining the structure and its salt balance unchanged.

What is a membrane?

One of the main properties of almost all water treatment systems is the retention of various harmful substances, impurities and their compounds.

Membrane filters perform these tasks using a thin film of synthetic materials. It has special pores through which only oxygen and water pass. All the rest, and this is the mass of the most diverse organic and inorganic substances, remains on the surface. Polyurethane, cellulose, acetate and lavsan are used for the production of such membranes, but there are other materials that have similar properties.

Types of cleaning systems

Membrane type filters are not a new technology. Their history begins back in the 19th century. Then the first filters were made on the basis of fiber, however, for some reason this system was not able to get proper distribution. And only in the 60s of the last century engineers have developed a new membrane. This is the prototype of what is used today.

Differences between such membranes are in the size of the pores, as well as in the structure. For example, with small hole sizes inside the filter, there will be a higher pressure. Several steps, each of which will purify water from various pollutants, will significantly improve the quality of drinking water. However, the price grows.

Membrane for microfiltration

In systems of this type, the size of microscopic holes can vary from 0.1 to 1.0 μm. These products are used in first level cleaning devices. They purify the water of those compounds that make the water cloudy. This type of filter membranes is nothing more than a preparatory level. Only after this you can proceed to a more refined cleaning. Often this solution is used when it is necessary to treat wastewater.

Ultrafiltration

The ultrafiltration membrane can have pores, the size of which varies from 0.02 to 0.1 μm. At this stage, all colloidal particles and various high molecular substances are removed from the water. In addition, this filter perfectly copes with bacterial contamination. The only nuance - this product is not able to remove salt. Often these solutions are used in industrial wastewater treatment plants. They can also be found in household filters, where the content of salts in the water is allowed.

Nanofiltration

Nanofiltration membranes have pores from 0.001 to 0.02 microns. These elements are responsible for softening very hard water. This membrane can retain in its pores chlorine and heavy metal particles. If we talk about the level of purification from heavy metals in percentage terms, then the system is able to keep them only 30%. However, this nanofiltraznaya part almost completely passes dissolved salts.

Reverse osmosis membrane

In it, the pores have the smallest dimensions - they can range from 0.0001 to 0.001 μm. The product has high selective properties and is designed in such a way as to remove virtually all impurities, impurities, harmful substances that people consume with water.

This membrane is able to pass gases and a small amount of salts. If it is necessary to filter the sea, the water filtration system with these elements allows to desalinate it by 97%. The purification process with the help of these membranes leads to the fact that salts, viruses, various bacteria, oil products and much more are neutralized almost completely.

Filters make real quality and harmless water from running water, which is then bottled, used for making a wide variety of drinks, used in the pharmaceutical and other industries. It is also widely used in electronics, microbiology. This technology of water treatment is very effective. However, the prices for such items are very high.

Operating principle

So, these filters are a very thin membrane with a huge number of pores of various sizes. These elements are capable of providing the maximum level of purification. In addition, after the water has passed through the membrane filters, it does not change its composition. In it there are salts and important for human microelements.

During filtration with membranes, water has a high level of purification, and is also full, saturated with all the necessary minerals.

In these and similar systems with the use of membranes, the tangential principle of fluid motion near the membrane works. Water enters the filter through one channel, and leaves after two. It follows that water accumulates on the two sides of the membrane.

The efficiency of these filters generally depends on the area and thickness of a membrane. The water pressure and its temperature also significantly affect the productivity.

HAND FILTERS: THE OPERATION

For hikers there are popular elements of Nerox, the principle of operation of which differs significantly from stationary installations. Thus, membrane filters are placed in a container containing dirty water. Clean water will be discharged to another container by means of a special channel.

These filters are quite effective and allow maximum purification of the liquid. But they have one serious flaw. It is necessary to periodically clean the membrane of the sediment. Manufacturers argue that the system must be cleaned manually.

How and what to process the membrane

If the sediment is inorganic, then it is easier to remove with agents that contain acid. Organic substances, their compounds, biomass are easily washed out by solutions based on alkalis. Do not use nitric and sulfuric acid for cleaning. With their help, it is easy to disable an expensive membrane element.

Advantages and disadvantages

Among the advantages of this water filtration system are the simplicity, ease of operation and maintenance of the membrane. In addition, the liquid after all the purification steps is very clean, but at the same time the salt composition remains in it. The membrane can remove even the smallest impurities. Most systems have fairly compact dimensions. Some models can be successfully used in the field, as well as as wastewater treatment systems. Disadvantages - a high price. In addition, note that, with all the efficiency of the work, the speed of this process is incredibly low. It will be necessary to install the storage tanks.

Types of systems by design

So, in terms of design, several types of membrane filters are distinguished. These are models based on a single substance, without substrates. Also there are membranes on a fabric basis or from various porous materials. These are elements of a reinforced type. Still produce products from raw materials with large pores.

Reverse Osmosis Filters

The osmotic membrane of the disk type in most cases is a thin element based on composite materials. Each layer of such a filter is made of a variety of connections.

Tubular

Systems of this type are made of porous materials. It can be plastic, ceramics, metal or cermets. As for the dimensions, the diameter of such a membrane in different models can be up to several centimeters.

In addition, an asymmetric and symmetrical tubular membrane can be distinguished. The first density of pores on the entire volume is the same. In the second case, one of the surfaces can be made of a denser material. This is the working layer that reports the degree of purification. Large porous membranes only pass purified water.

Rolling filters

This is a system where the membrane is installed on the drain hose. When the water supply starts, the liquid moves spirally. After that, the entire volume of it accumulates in a special hose and is removed from the second end.

The design is characterized by a convenient shape, and the working part is ultra-thin. This is a guarantee of high performance. Also in this case, the risk of contamination is significantly reduced. These solutions can be used for a variety of purposes, including for wastewater filtration.

Hollow fiber

Also, hollow fiber membrane filters can be distinguished. They have the shape of tubules. A certain amount fits in the filter device. As a result - the solution, where the working surface is significantly increased, which best affects the performance.

The disadvantage is the practically absent control of the flows along the filter fibers. These models are often clogged. Because of this feature, they should not be used for wastewater treatment.

Price list

Manufacturers set different prices for equipment. In most cases, the cost depends on the productivity and the degree of purification. Consider the most popular models from different manufacturers and their price.

Nerox - 1350 rubles

These products are suitable for waste water filtration. The osmosis filter allows you to maintain the salt balance. The product is light and compact. This model can be used both permanently and in nature. In order for the system to work properly, it is necessary to periodically clean the membrane.

"Aqua Expert" - 1450 rubles

This model is designed to work with water of any quality. It is also possible to apply a filter to sewage. As stated by the manufacturer, the membrane allows you to restore the structure of the liquid. The system is very simple to use and clean if necessary.

Solutions from the company "Aquaphor"

Reverse osmosis "Aquaphor" is a productive, compact home system for purification of drinking water. A series of these filters differed from the familiar reverse osmosis systems in that it has a nice design.

The system has a special design. So, the model consists of a collector and a replaceable cartridge. Unlike traditional reverse osmosis purification systems, this filter is much easier to maintain and operate.

The manufacturer claims a high resource of replaceable cartridges. Also, these models are easy to change filters. To do this, just press the button, remove the cartridge and insert a new one. Reverse osmosis "Aquafor" does not require permanent disinfection: when replacing a cartridge, virtually all surfaces on which bacteria could settle would be perfectly clean. Purified water after these filters will contain only oxygen. All other impurities will be eliminated. The filtration quality is very high.

Filters from the company "Ecosoft"

Ukrainian producer "Ecosoft" produces household systems under the brand "Our Water". Among the product lines are pitchers, flowing, reverse osmosis systems. Today this company is quite successful, and the products are in demand and receive positive feedback.

The unique technologies developed by scientists from Ukraine make it possible to effectively purify water from virtually all impurities known to date. The osmosis filter is able to cope with iron, manganese, organic compounds, heavy metals. Ready-made solutions of the company are in great demand. These systems really make the water quality and clean.

The cost of making "Our Water" is quite high. However, this is not just a filter. This is a whole complex of equipment that is designed to make the lives of most people better. In the complete set all necessary equipment. Also the company produces replacement filters for the entire product line. All those who care about health, it is worth to buy such a system. Water is life, and pure water is a healthy and happy life.