Water softening methods. Types of stiffness

Water hardness is determined by the presence in its composition of a certain amount of admixture of soluble magnesium and calcium salts.

Water hardness is determined by the amount of calcium and magnesium salts impurity.

One of the main criteria by which the quality of water is determined is the level of its hardness. Stiffness can be adjusted using different methods softening water.

Types of water hardness

There are several main types of stiffness:

1. Overall hardness. The total hardness can be determined by summing the amount of calcium and magnesium ions present in the water. This amount includes general and permanent hardness.
2. Carbonate hardness. Determined by the amount of calcium and magnesium carbonates and bicarbonates. This type of hardness is called temporary for the reason that you can neutralize this effect by simply boiling the water.
3. Non-carbonate hardness. It is considered constant hardness and boiling water does not affect it in any way. It occurs due to the presence of salts of strong acids of calcium and magnesium in the water.

Water softening

Naturally, almost everyone thinks about such a question as the quality of the water he drinks.

The water that is supplied to residential buildings through piped water goes through certain levels of filtration, but often they are not enough to provide the drinking water with the necessary level of softness.

A piece of silicon can be used to soften the water.

Therefore, most people prefer to use additional filters, of which there are a very large number today, using other methods of water softening.

The first signal that the water you drink and from which you prepare meals for the family is tough is the presence of scale in the kettle and pots where the water is boiling.

Signs of excessive water hardness can be not only scale. When boiled in such water, vegetables fall apart, and the meat becomes more rigid. White stains remain on plates and glasses after washing.

Drinking too hard water can cause health problems.

On this moment there are a wide variety of water softening methods.

Water softening is carried out using certain devices, the task of which is to purify water from two types of heavy carbonate salts.

The simplest and oldest known method of water softening is placing a small piece of silicon in a container with a liquid that will be used for food and drink. The size of such a piece should be approximately 5 by 5 cm. It should be enough to clean a three-liter can of water at a time. It takes about a week to settle water with silicon.

This is how long it takes this mineral to charge and soften the water, neutralizing magnesium and potassium salts.

This method is suitable only for domestic use.

Basic methods of water softening

There are many ways to soften water. At the moment, there are such main methods of water softening:

The physical way. When using this method of softening hardness, the use of chemicals of any kind is excluded. This cleaning method is ideal for softening water that is used in the home - for cooking and drinking.

Membrane method. There are several basic methods of membrane methods.

One of the most popular types of membrane purification is reverse osmosis or electrodialysis. The essence of this method is that with the help of pressure, water is desalinated. This water becomes drinkable.

In the device for such cleaning, there is a membrane, which is a perforated layer made of expensive materials in the filter. Perforation, i.e. application through holes, is made taking into account the size of the water molecule. This makes it possible to retain on the membrane surface any impurities that exceed the size of a water molecule.

Filtration by means of reverse osmosis is of such high quality that such water can be used not only for drinking, but also in various fields of production, for example, in pharmacology.

The second method of membrane purification is nanofiltration.

Nanofiltration is carried out under low pressure. The main advantage of this method is that water can be obtained with exactly the same degree of purification and softness that is necessary for certain purposes. And you can get different cleaning results by replacing the membrane in the filter device.

The main disadvantages of this method include the fact that most of the water being treated is in the device for a long time.

This situation occurs due to the fact that water seeps through the membrane at a low speed. In addition, there are more than one filters in such a device, respectively, and a certain amount of time will be spent on passing each of them.

In one device, reverse osmosis, a mechanical filter, and an air conditioner can be combined and installed.

This method is ideal for water purification not only from all types of impurities, but also from various kinds of bacteria. Drinking water must be free of bacteria.

That is why the air conditioner is usually installed on those appliances whose task is to produce drinking water.

However, the use of such an installation at home is currently a difficult cleaning method.

Chemical method. For the chemical cleaning method, chemicals are used accordingly. These include both sodium chlorine and phosphates.

With this method of cleaning in water pipe special dispensers are mounted.

But chemical method may be hazardous in that the cleaning agents may contribute to the formation of additional impurities, which will result in new sludge.

Ion exchange method. Ion exchange is one of the most technologically simple ways purification and softening of water.

Its simplicity lies in the fact that no complex structures need to be erected to carry out this process.

This method works on the basis of ion exchange.

The main element of such cleaning devices is a gel-like resin. The resin contains a huge amount of sodium. Sodium, in contact with hard water, is exchanged into calcium and magnesium crystals.

Thus, it is incredibly simple and quick cleaning water and its softening.

But the household resin cartridge needs to be replaced from time to time, as sodium tends to wash out of it.

And cartridges used in industry can be restored using a special solution. The cartridge is rinsed with this solution, and the chemical reagents restore the sodium level.

With this method, the water is purified very quickly and efficiently. But you can't call it inexpensive or even affordable. After all, cartridges require considerable expenses, as well as their restoration.

Household jugs - filters based on this method have a low performance: only a few liters.

To provide drinking water with a sufficient level of purification and softening, it is necessary to additionally use one or more filters based on other methods.

Reagent-free method. In order to understand what a reagentless method of water softening is, it is worth considering one of the most common methods - magnetic force.

The instruments of this cleaning method are based on the use of permanent magnets reinforced power.

This installation does not require special efforts when assembling, as well as subsequent dismantling.

It is also incredibly easy to maintain and does not require any special replacement accessories in the form of cartridges or any additional cleaning.

The cleaning process takes place due to the fact that the magnetic force field passes through the water in a special way. At the same time, heavy salts, which make water hard, change their formula, acquiring the shape of needles. This shape makes it possible to rub the surfaces affected by old scale, as a result, completely eliminating it.

The water to be purified in this way must be room temperature, its flow should not be variable, but constant, like the speed of its movement.

To neutralize the disadvantages of this method, a electricity... As a result, an installation was invented that combines both types of exposure - electromagnetic.

The difference between domestic and industrial softeners

The most common method is ion-exchange softening.

The main difference between industrial devices for cleaning and softening water from household ones is that they have different tank capacities, and additionally use different classes of ion-exchange resin.

Since all devices need a recovery period, the volume of water that can pass through them will be strictly defined.

In the case when the volume of water is small, then household appliances can be used.

When it comes about large volumes of water, then it makes sense to install duplex softeners.

Two cylinders are such a device, which are controlled by one adjacent valve.

Such a device is called a continuous-action device for the reason that when water softens in one cylinder, the resin of the other cylinder has time to recover.

The ion exchange resin class also plays a huge role. Household softeners only use food grade resin, and industry can use different resin grades.

A high level of hardness provokes the formation of limescale, impairs efficiency detergents... Such unfavorable conditions the risk of damage to the functional components of heating equipment and other equipment increases. The operating costs and the costs of complying with sanitary and hygienic rules are increasing.

Modern manufacturers offer different water softening methods and related kits. It will not be difficult to choose the best option after reading this publication. There is useful data here that will help you to implement a project inexpensively and quickly.

Basic definitions

The general level of hardness is defined as the sum of the permanent and temporary components. As a rule, the first part is of little practical importance, so it can be excluded from the review. The second is determined by the concentration of magnesium and calcium cations. These chemicals, when heated, are converted into an insoluble residue - scale.

It is they who clog the technical ducts, which is accompanied by a deterioration in the performance of the boilers. Such formations are characterized by porosity and low thermal conductivity. When the heating element accumulates on the surface, this layer blocks the normal heat removal. If you do not use an effective method for softening hard water, Washer or other equipment with a heating element will be disabled due to limescale.

In practice, they solve the issues of reducing the level of rigidity, or the complete elimination of harmful phenomena. The second option is better! He assumes reliable protection expensive products, effective prophylaxis with the prevention of emergencies.

Method 1: Heating

The principle of operation of these methods of water softening is clear from general definition... Every person knows that when boiling (heating), a layer of scale is actively formed on the walls of the kettle. After completing the procedure, the hardness will be reduced.

The theoretical simplicity of the method is the only advantage. A detailed study of the issue reveals the following shortcomings:

• duration of the process;
• a small amount of liquid that can be processed into living conditions;
• significant costs for electricity, gas, other types of fuel.

It should not be forgotten that on finishing stage you have to remove stubborn limescale. These are time-consuming work steps that can ruin the working capacity.

Method 2: Treatment with an electromagnetic field

An intermediate conclusion can be drawn from the descriptions given. To remove harmful compounds using chemicals, ion exchange, boiling and membrane filtration have to solve complex engineering problems. This will be discussed below. Costs increase accordingly. Polyphosphate compounds are more effective. They are inexpensive, but reliably block the negative process. The method can be considered ideal if it were not for the contamination of the liquid.

There are no listed disadvantages in the technology of electromagnetic processing. Exposure to a strong field changes the shape of the scale particles. The created needle-like protrusions do not allow them to combine into large fractions. This blocks the scale formation process.

To get the field optimal power and configurations employ a high frequency electromagnetic oscillator. It works according to a special algorithm that does not cause the "addictive" effect. A decrease in positive impact is observed when working with permanent magnets.

In the course of studying the current market offers, attention should be paid to modern high-quality models of electromagnetic water treatment devices:

• perform their functions with minimal power consumption (5-20 W / h).
• A coil is created from several turns of wire. The device is connected to the network. Additional customization need not.
• The operating range reaches 2 km, which is enough to protect the object as a whole.
• The durability of the devices is over 20 years.

In any case, you need to choose a manufacturer who has solid experience in the specialized field of activity!

Chemical methods of water softening

A well-known technique for specialists in the field is the addition of slaked lime to the solution. Chemical reactions bind calcium and magnesium molecules with the subsequent formation of an insoluble precipitate. As it accumulates at the bottom of the working tank, it is removed. Fine suspended particles are captured through the phosphate method. A similar technology is used to reduce the non-carbonate content using soda.

The main disadvantage of this and other methods in this category is the contamination of the liquid with chemicals. In order for such processing to be safe, it is necessary to precisely observe the optimal dosages, carefully monitor all important stages. High-quality reproduction of the technology at home is not possible without excessive difficulties and costs. It is used at municipal and collective water treatment plants of the professional category.

However, one "chemical" technique has become popular in everyday life. The researchers found that polyphosphate compounds form shells around the smallest insoluble fractions. They prevent coarse particles, adhesion to pipe walls and external surfaces heating devices.

This useful property is used by manufacturers of phosphate detergents. Also, specialized flow tanks are used, in which polyphosphate salts are placed. The devices are mounted on the inlet in front of boilers and washing machines. The method is not suitable for cooking drinking water.

Filtration

The desired effect can be obtained by reducing the size of the cells to the size of molecules. These microscopic ducts are created in reverse osmosis membranes. They are only able to skip clean water... The contaminated liquid accumulates in front of the obstacle and is removed to the drain.

Is the problem solved? Don't jump to conclusions. The filtration technique is really good, but only for processing 180-220 liters / day. Such is the performance of serial products with a reasonable cost. This amount is not enough for a single shower or other household needs.

To increase productivity, several membranes are installed in parallel. For the kit to function, it is necessary to raise the pressure of a special pumping station... Such equipment for water filtration is expensive and takes up a lot of space.

Ion exchange water softening

Reduce start-up and operating costs with this category of equipment. A special filling is used, which retains calcium and magnesium ions. At the same time, the liquid is filled with harmless sodium compounds.

The benefits are summarized in the following list:

• In addition to the salty taste, the initial characteristics of the water do not change for the worse.
• After processing a certain amount of liquid, the useful functions of the backfill are restored by flushing and regeneration.
• These procedures are performed repeatedly in automatic mode, without careful control and intervention by the user.
• Subject to the rules of operation, the resin backfill remains operational for more than six years.

The availability of the regeneration mixture must be emphasized. This is an inexpensive solution of common table salt (good cleaning).

As before, here are the nuances that deserve mention for a complete analysis of water softening by the ion-exchange method:

• The ion-exchange method of water softening interrupts the supply of the object during regeneration (lasting more than an hour). To eliminate this disadvantage, two functional capacities are installed in parallel.
• A high performance set for a family of 2-3 occupies several square meters. meters of area.
• The work makes a lot of noise during the flushing process, therefore effective sound insulation of the room is needed.
• Any significant change in hardness level must be corrected by manual adjustment.
• A well-equipped set with an automation unit and several working tanks is expensive.

Ultrasonic exposure

Treatment with vibrations of the corresponding frequency range is used to reduce the level of rigidity. At the same time, a layer of old scale is destroyed, which is useful for cleaning pipes without aggressive chemical compounds.

Ultrasound is used with professional precautions to clean and protect industrial equipment. Large elements of these structures and threaded connections have better resistance to strong vibrations.

What water softening methods are suitable for different properties?

The optimal technique is selected taking into account the actual conditions of future operation. Experienced experts advise to create a common design with mechanical and other filters to accurately match all functional components.

In a city apartment, you can count on maintaining an acceptable quality of hard water. The corresponding obligations are specified in the contract with the supplying organization. However, at home, accidents on highways, pressure surges are not excluded. To protect against these negative influences, a phosphate or mechanical filter with a pressure regulator and control pressure gauges is installed at the inlet. It is necessary to emphasize the advantages of an electromagnetic converter, taking into account the characteristics of objects of this category:

• compactness;
• light weight;
• lack of noise;
• cute appearance.

For autonomous suburban water supply prudent owners prefer to use an artesian well. Such a source provides high degree purification by natural filtration. But at great depths, the concentration of impurities washed out from rocks increases. Among them are salt compounds in a sufficiently high concentration.

In a private house, it is easier to find a free space for technological equipment... Here you can install ion-exchange water softening kits. The necessary network engineering... We must not forget about good insulation. It is necessary to maintain the temperature set by the manufacturer. Chlorine and other chemical compounds that can damage the existing backfill should be removed.

It is imperative to know the hardness of the water used. Many aspects of our life depend on the hardness index of drinking water: how much washing powder to use, whether measures are needed to soften hard water, how long will aquarium fish live in water, whether it is necessary to introduce polyphosphates into reverse osmosis etc.

There are many ways to determine stiffness:

• by the amount of detergent foam formed;
• by district;
• by the amount of scale on the heating elements;
• by the taste of water;
• using reagents and special devices

What is stiffness?

The main cations are present in water: calcium, magnesium, manganese, iron, strontium. The last three cations have little effect on water hardness. There is also a trivalent cation of aluminum and iron, which form a limestone deposit at a certain pH.

Rigidity can be of different types:

• overall hardness- the total content of magnesium and calcium ions;
• carbonate hardness- the content of hydrocarbonates and carbonates at a pH greater than 8.3. They are easy to remove through boiling: during heating they decompose into carbonic acid and sediment;
• non-carbonate hardness- calcium and magnesium salts of strong acids; cannot be removed by boiling.

There are several units of water hardness: mol / m 3, meq / l, dH, d⁰, f⁰, ppm CaCO 3.

Why is water hard? Alkaline earth metal ions are found in all mineralized waters. They come from dolomite, gypsum and limestone deposits. Water sources can have different hardness ranges. There are several stiffness systems. Abroad, they approach her more "harshly". For example, our water is considered soft at a hardness of 0-4 meq / l, and in the USA - 0-1.5 meq / l; very hard water in Russia - over 12 mg-eq / l, and in the USA - over 6 meq / l.

The hardness of low-mineralized waters is 80% due to calcium ions. With an increase in mineralization, the proportion of calcium ions decreases sharply, and that of magnesium ions increases.

Often surface waters have less rigidity than underground. The hardness also depends on the season: during the melting of the snow, it decreases.

The hardness of drinking water changes its taste. The threshold of sensitivity for the calcium ion is from 2 to 6 mg-eq / l, depending on the anions. The water becomes bitter and has a negative effect on the digestion process. WHO does not give any recommendations on water hardness, as there is no clear evidence of its effect on the human body.

Hardness limitation is necessary for heating devices. For example, in boilers - up to 0.1 mg-eq / l. Soft water has a low alkalinity and is corrosive to plumbing. Utilities use special treatment to find a compromise between plaque and corrosion.

There are three groups of water softening methods:

• physical;
• chemical;
• psychic.

Reagent water softening methods

Ion exchange

Chemical methods based on ion exchange. The filtering mass is an ion exchange resin. It represents long molecules that are collected in balls yellow color... Small processes with sodium ions protrude from the balls.

During filtration, the water soaks all the resin, and its salts replace sodium. The sodium itself is carried away by the water. Due to the difference in ion charges, 2 times more salts are washed out than deposited. Over time, the salts are all replaced and the resin stops working. Each resin has its own period of work.

Ion exchange resin can be in cartridges or poured into a long bolon - a column. Cartridges have small size and are used only to reduce the hardness of drinking water. Ideal for water softening at home. An ion exchange column is used to soften water in an apartment or small production. In addition to the high cost, the column must be periodically loaded with the restored filtering mass.

If there are no sodium ions left in the resin of the cartridge, then it is simply replaced with a new one, and the old one is thrown away. When using an ion exchange column, the resin is recovered in a special brine tank. To do this, dissolve the tableting salt. The saline solution regenerates the resin's ion exchange capacity.

The downside is the added ability of water to remove iron. It clogs the resin and makes it completely unusable. Water analysis should be done on time!

Use of other chemicals

There are a number of less popular ones, but effective ways water softening:

• soda ash or lime;
• polyphosphates;
• antiscalants - compounds against scale formation.

Softening with lime and soda

Water softening with soda

The method of water softening using lime is called liming. Slaked lime is used. The carbonate content decreases.

A mixture of baking soda and lime is most effective. For clarity, softening water at home, you can add soda ash to the water for washing. Take 1-2 teaspoons per bucket. Stir well and wait for the precipitate to settle. A similar method was used by women in Ancient Greece using oven ash.

The water after lime and soda is not suitable for food purposes!

Softening with polyphosphates

Polyphosphates are able to bind hardness salts. They are large white crystals. The water passes through the filter and dissolves the polyphosphates, binding the salts.

The disadvantage is the danger of polyphosphates for living organisms, including humans. They are a fertilizer: after entering the reservoir, an active growth of algae is observed.

Polyphosphates are also not suitable for softening drinking water!

Physical method of water softening

Physical methods combat the consequences of high hardness - scale. It is reagent-free water purification. When using it, the salt concentration does not decrease, but it simply prevents harm to pipes and heating elements. The water becomes soft or, for better understanding, softened.

The following physical methods are distinguished:

• usage magnetic field;
• using an electric field;
• ultrasonic treatment;
• thermal method;
• the use of low-point current pulses.

A magnetic field

Reagentless water softening using a magnetic field has many nuances. Efficiency is achieved only if certain rules are followed:

• a certain water flow rate;
• matched field strength;
• certain ionic and molecular composition of water;
• entering and leaving water temperature;
• time of processing;
• Atmosphere pressure;
• water pressure, etc.

Changing a parameter requires a complete reconfiguration of the entire system. The reaction must be immediate. Despite the complexity of parameter control, magnetic water softening is used in boiler rooms.

But to soften water at home using a magnetic field is almost impossible. If you want to purchase a magnet for the pipeline, think about how you will select and provide the necessary parameters.

The use of ultrasound

Ultrasound leads to cavitation - the formation of gas bubbles. The likelihood of the meeting of magnesium and calcium ions increases. Crystallization centers appear not on the surface of the pipes, but in the water column.

When softening hot water ultrasound crystals do not reach the size required for deposition - scale does not form on heat exchange surfaces.

In addition, high-frequency vibrations occur, which prevent the formation of plaque: they push the crystals away from the surface.

Flexural vibrations are detrimental to the formed scale layer. It begins to break off in pieces that can clog the canals. Before using ultrasound, it is necessary to descale the surfaces.

Electromagnetic impulses

Reagent-free water softeners based on electromagnetic pulses change the way salts crystallize. Dynamic electrical impulses are generated with different characteristics... They go along the winding wire on the pipe. Crystals take the form of long shelves, which are difficult to fix on the heat exchange surface.

In the process of processing, carbon dioxide is released, which fights with the already existing limescale and forms protective film on metal surfaces.

Thermal softening

Someone hears about this method for the first time. But in fact, everyone has been using it since childhood. This is the usual boiling water for us.

Everyone noticed that after boiling water, a precipitate of hardness salts forms. Coffee or tea is made with softer water than tap water.

How much should you boil? It's simple: with an increase in temperature and its effect, hardness salts are less soluble and more precipitate. In the process of heating, it is released carbon dioxide... The faster it evaporates, the more limestone deposits are formed. The tightly closed lid prevents the release of carbon dioxide, and liquid quickly evaporates in an open container.

When using a heat softener, leave the lid slightly open in the container. It should also be ensured maximum area precipitation of salts to accelerate the softening of drinking water.

At hardness up to 4 mg-eq / l, thermal softening is not necessary: ​​salts will settle more slowly than water evaporates. The remaining water will have an increased concentration of many impurities.

One filter simultaneously removes from water: mechanical impurities, dissolved, colloidal and organic iron, manganese, natural organic compounds(humic and fulvic acids and their salts), hardness and heavy metal salts.

Price: from 32 900 rubles.

We will find a solution for you!

According to statistics, 90% of water heating and plumbing equipment breaks down due to hard water. Scale forms, pipelines become clogged, water heaters lose power, Appliances fails. High rigidity is also dangerous for people. Sand and stones form in the organs, blood vessels and the heart suffer, the skin becomes dry, dermatitis occurs. So that there are no accidents at home and health does not deteriorate, they produce water softening using filters.

Hardness is a property of water, depending on the content in the dissolved form of calcium salts (Ca) and in a lower concentration of silicon (Si lat. Silicium), magnesium (Mg).

• Carbonate
• Non-carbonate
• General

Carbonate is temporary. Easily removed by boiling. It is determined by the presence of calcium bicarbonates (Calcium), magnesium in the liquid. Chemical formula- Ca (HCO3) 2; Mg (HCO3) 2. Forms scale in hot water pipelines, in a kettle, on water heating elements of boilers, boilers.

Non-carbonate constant. It is not removed by boiling. It is due to the presence of salts that differ in properties from carbonate ones. Basically, these are chlorides (CaCl2, MgCl2), sulfates (CaSO4, MgSO4).

The total hardness is the sum of the 1st and 2nd hardness. The final indicator of the content in the liquid of all the ions and compounds of magnesium and calcium present. Since 2014, updated standards have appeared, according to which this parameter is measured in degrees of hardness - ° W = 1 mg-eq per liter. According to the total hardness of water:

• Hard - more than 10 ° W
• Medium hardness - 2-10
• Soft - up to 2

In Europe, the concentration rate is 2.5; in the Russian Federation - 7.

V well water"Hard" chemical compounds come from soluble rocks, which consist of dolomite, lime, gypsum. If the region is rich in these minerals, they will definitely be in the water. Needed water softener filter.

"Hard" salts gradually accumulate in the body. Vessels are clogged. The heart suffers. Stones appear in the kidneys and other organs and body cavities. Urolithiasis occurs. Drinking water with increased hardness causes serious harm to health. Besides:

• Scale formed on heaters and inside heating radiators reduces heat transfer
• Detergents produce little foam. Household chemicals consumption increases by 60%
• Dishes take longer to cook. Meat remains tough after cooking
• 1 millimeter of limescale increases energy consumption by 10%
• Leads to overheating of heating elements. Causes 90% of water heater breakdowns

Hard water degrades the appearance. The skin dries up, flakes. Dermatitis, acne, redness appear. Hair is not washed, looks unkempt, becomes unruly. Plaque builds up on the teeth.

Hard water is dangerous for newborns. Increases the likelihood of eczema and atopic dermatitis with constant use, bathing. Symptoms appear as early as 3 months. Eczema causes the appearance of autoimmune allergies and further to food allergies, asthma.

The best protection is to buy and install water softener filter... Water treatment and purification devices soften well, make household water suitable for drinking, household use.

Strong magnets are also used in water treatment. The liquid is passed through a powerful magnetic field. As a result, the water changes physical characteristics, dissolved impurities lose their ability to form salts, and, consequently, scale. In addition, the magnetized water destroys and removes scale layers that have already been deposited. The technology is effective with a low content of calcium, silicon and magnesium ions.

The liquid is affected electric field high charge using special membranes... Ions of hardness and some other substances are removed. The technology is used for desalination of sea water in industrial volumes, in the production of table salt and for the preparation of water in heat and power plants.

Do with reagents. Slaked lime Ca (OH) 2, sodium orthophosphate Na3PO4 or soda ash Na2CO3 are used. When interacting with the reagent, the hardness salts take on an insoluble form, settle to the bottom and are easily filtered out. This technology is justified when cleaning large volumes of liquid. When applied, a number of specific technological problems arise. The exact dosage of the chemical reagent is needed.

The technology belongs to the reagent softening methods. For water purification, granular filter media are used, mainly ion exchange resins, which are loaded into water softening filters... When interacting with resin granules, ions of "hard" compounds, as well as iron and manganese, are captured from the liquid. Depending on the type of filter material, ions of sodium, potassium or hydrogen are formed during ion exchange. With a well-chosen loading, it is possible to reduce the hardness to 0.1-0.01 ° F even with ultra-high mineralization.

Advantages of ion exchange filters:

• The price is 20-50% lower
• Universal. Suitable for cottages, country houses, city apartments. Placed on wells, wells, cut into pipelines of city water supply
• Productive. Remove hardness, iron, excess minerals, manganese, organic compounds and other contaminants in one cylinder
• Eliminate ultra-high iron concentrations - up to 30 mg

Over time, the resins become clogged with chemical trapped pollutants and cease to soften the water. However, the ion exchange reaction is reversible. If a solution of sodium chloride is passed through the resin, the impurities will separate, and the sodium contained in the salt will fill the voids formed. The separated contaminants are flushed into the drain. The renewed resin cleans and softens the water again.

There is a widespread belief that water from deep aquifers can be eaten without preliminary preparation... Indeed, the water from them is much cleaner than from the top water, however, and there are impurities in it, the presence of which can negatively affect human health and the operation of equipment. To understand the issue in detail, we will turn to the specialists of the water treatment systems department of the BIIX company.

Water is an excellent solvent. Being in constant contact with rocks, it is saturated with the substances of which these rocks are composed. Over time, a huge number of compounds accumulate. The composition of the water depends on the type of rock in which the aquifer passes. Moscow and the Moscow region are characterized by a high content of carbonate hardness salts and iron compounds.

Prolonged consumption of water of increased hardness leads to deposits of calculi in the kidneys (stones), upon contact, the skin and hair become dry. During heating, the compounds precipitate, forming a hard, poorly removable plaque. Heating elements become unusable, pipes and hoses become clogged, the rate of wear of moving parts of equipment increases.

Exceeding the stiffness can be determined:

• visually: plaque formation on plumbing fixtures and heating elements (in a kettle, on heating elements of washing and dishwashers, boilers);
• to taste: in comparison with bottled water of known hardness;
• foaming: less foam is formed in hard water and the consumption of detergents is higher;
• in the laboratory.

Water softening is a decrease in the concentration of hardness salts and bringing these indicators to the recommended values.

Water hardness standards

Depending on the concentration of hardness salts, water is divided into:

• soft - the salt content is not more than 2 mg-eq / l;
• normal - the salt content is within 2 - 4 mg-eq / l;
• hard - salt content in the range of 4 - 6 mg-eq / l;
• high hardness - the salt content is above 6 mg-eq / l.

The Russian standard regulating the quality of drinking water sets the limit value for the concentration of hardness salts at the level of 7.0 mg-eq / l. While the WHO sets this indicator at 2.5 mg-eq / l, and the EEC has adopted a standard of 2.9 mg-eq / l. Thus, as a drinking tap water in Russia, the supply of very hard water is permissible, with a twofold excess of the WHO recommendations.

Water softening methods

Thermal

In other words, boiling. As the temperature rises, soluble calcium bicarbonate (the most common compound that causes hardness) breaks down into insoluble calcium carbonate and carbon dioxide. The insoluble part precipitates, the gas evaporates. Partially during boiling, the concentration of calcium sulfate also decreases. The thermal method is the most affordable in domestic conditions, but it is not the most convenient and has low productivity. Moreover, it is not suitable for magnesium compounds.

Membrane

To soften water in this way, molecular membranes are used, which allow only water particles to pass through, removing most of the impurities (up to 98%). This is how reverse osmosis filters work.

You don't need to drink contaminated water for some of the supposedly beneficial salts that it also contains. It is much better to feed your body with the same substances, but found in ordinary foods. Actually, humanity all its life and takes them exactly in bread, milk, meat, fish, vegetables and fruits. For example, there is hundreds of times more calcium in a glass of milk than in a glass of tap water. In some cases, a mineralizer is installed to prepare drinking water in this way.

Chemical (reagent)

The essence of the method is to transform soluble compounds into insoluble ones. For this, various reagents are used, depending on the predominance of salts of one type or another in the water. For salts of the carbonate type, lime, sodium compounds, soda and synthetic compounds, for example, trisodium phosphate, are used. As a result, the water softens, but due to the presence of reagents in food, it cannot be consumed.

Magnetic

The water is influenced by the induction of a constant magnetic field. Passing through a magnetic field changes the structure of the hardness salts. The molecules cease to combine when heated and do not form a precipitate, and also loosen the layer of existing scale, which dissolves in water. This method does not reduce the concentration of salts, but prevents them from deposition in the form of a sediment. For domestic purposes, such water is well suited: pipes, pump equipment and heating elements will last longer. It is possible to effectively soften water using magnets only in small volumes and a flow rate of no higher than 0.5 m / s. The iron content is also reduced with a magnetic softener.

Electromagnetic

It is an improved version of the magnetic one with the difference that the excess of salts not only loses the ability to fall out in the form of sediment, but is also removed through the sump into the sewer.

Ion exchange

The essence of the method is to replace calcium and magnesium ions with sodium ions, the compounds of which are soluble and do not adversely affect health and equipment.

Modern drinking water treatment systems often combine several methods that depend on the analysis of water from a well. Water treatment specialists can help you determine which type of softener you need in your situation. For artesian wells in the Moscow region, where carbonates predominate, it is recommended to install ion-exchange-type water softeners.

Structurally, the device is a plastic cylinder, inside of which a polymer ion-exchange resin is poured in the form of granules, capable of releasing sodium ions and absorbing calcium and magnesium ions. The water entering the cylinder slowly passes through the resin on which the displacement reaction takes place. When the concentration of sodium ions in the resin drops, it is necessary to carry out a rinsing and regeneration process. A saline tank is connected to the cylinder for these purposes, from where the sodium chloride solution comes. The process is controlled by an automatic control unit. During flushing, the supply of softened water is interrupted, therefore the regeneration is programmed for night time. If the analysis of water takes place continuously, then it is recommended to install two cylinders and start the regeneration one by one. From time to time, on average after 3-4 years, the resin must be changed, since the number of cycles of its recovery is limited. The performance of the system depends on the volume of loading in the cylinder.

The article was prepared with the participation of specialists from the department of water treatment systems of the site