It is known that a person can not do without water for more than a couple of days, because all metabolic processes in the body are accompanied by its participation. Therefore, it is important to think about what kind of water we consume. It may have a high content of chlorine, salts of magnesium and calcium, manganese and iron. Each type of impurity is removed in different ways. Consider how water is purified from iron.
Types of iron
First you need to determine what iron is in the water.
Divalent. Iron of this type dissolves well in water, so it cannot be seen with the naked eye. Water has a deceptive transparency. However, if it is in contact with air for some time, then iron is oxidized and its transition to the trivalent form. Then the water takes on a red tint.
Trivalent. This is oxidized iron, in liquid it is found in colloidal form (small particles of a red color). Often in water containing ferric iron, there is also a divalent type. In addition, the sedimentation of red particles can be accompanied by the formation of iron bacteria, and subsequently their increase.
Bacterial. Represents living and dead bacteria, as well as their waste products and shells. In most cases, it accompanies colloidal gland. Outwardly, these are mucous soft deposits, which can be both harmful and not. The presence of iron bacteria in the pipeline leads to peptic corrosion of iron.
Methods for purifying water from iron
Dissolved divalent iron can be removed by conventional methods designed to eliminate dissolved inorganic ions. This is ion exchange, the essence of which is the replacement of special resins with sodium ion during the reaction, and reverse osmosis, its principle is the use of membranes that trap dissolved iron.
Another method of purifying water from ferrous iron is the chemical method. Its principle is catalytic oxidation, during which a chemical element passes from a dissolved state to an undissolved one. After this, the formed ferric iron settles on the filter. Systems of this kind are called de-ironing filters.
Water with a high content of ginger fine particles is purified by ultrafiltration.
When eliminating the bacterial type of iron, chlorine or chelating agents must be used.
It should be remembered that the methods of water purification from iron have their disadvantages and advantages.
Reverse osmosis
Water purification from iron using reverse osmosis consists in forcing it through a very thin membrane. She does not allow even the smallest impurities to pass. A similar purification result is not able to guarantee any filter of water purification from iron, working by a different method. That is why the reverse osmosis system seems truly unique.
For the filter to work properly, it is necessary to ensure a complete absence of oxygen, otherwise oxidation will occur, and ferrous iron will become dispersed, which will subsequently accumulate on the membrane. This is not a problem, because reverse osmosis systems have good tightness.
Also, ferric iron can be removed by this method, if it is present in water in a small amount. The reverse osmosis technology makes it possible to get rid of manganese - a well-known satellite of iron.
Ionic way
This method has been used for a long time, but earlier zeolites and sulfonated coal were used to purify water. Currently, in order to remove iron, special ion-exchange resins are used. With their help, the effectiveness of this method has become much higher. In addition to ferrous iron, the cation exchangers used eliminate calcium and magnesium ions. Also, the ionic cleaning method is able to remove manganese, which is so often present in water.
However, it is worth knowing that this method will not work if the water hardness is at a normal level. After all, the system of water purification from iron by ion exchange involves a decrease in this indicator. The method is used exclusively in limited pH ranges. In addition, organic substances present in the water adversely affect, they can lead to the emergence of bacteria on the filter.
The most difficult task here is to choose the right combination of resins. Then there will be no trace of iron, because water purification by the ionic method is currently one of the most effective.
Chemical method of water purification
Often, an oxidative method is used to purify dissolved iron. It involves the use of oxidizing agents such as potassium permanganate, chlorine, oxygen, ozone. With their help, the process of converting dissolved iron to trivalent is accelerated, and the addition of coagulants (chemicals) to the water facilitates the deposition of particles. This principle is often applied on large cleaning systems.
In living conditions, the catalytic method is used. Water purification from iron is accompanied by an oxidative reaction that occurs on the surface of the filter, whose properties significantly accelerate the oxidation process. Such systems are made on the basis of manganese dioxide, capable of removing iron. To improve the result, you can add potassium permanganate to the water.
Features of iron removal filters
If the choice fell on a water purification system based on iron oxidation, then a number of parameters should be taken into account, these are:
- water temperature;
- pH
- dissolved oxygen;
- alkalinity.
These factors can affect the quality of work. Before use, you should familiarize yourself with the manufacturer's recommendations and follow them with future use. Especially you need to pay attention to the speed of the direct flow of water and during backwashing, as well as the permissible iron content.
Common causes of the poor efficiency of deferrization filters include incomplete oxidation of iron, the supply of large volumes of water for cleaning, and the low water flow rate during backwashing. The coefficient of iron content should not exceed the mark of 15 mg / L. De-ironing filters have a high specific gravity, which is their significant drawback.
Ferric iron removal
With a high content of colloidal iron, ultrafiltration systems are considered the most effective. The principle of operation of such systems is the passage of particles through a membrane network. As a result of this process, water is purified from iron.
For ultrafiltration, special membranes are used, the pore size of which is 0.05 microns. The effectiveness of this method of water deferrization is due to the fact that the system is able to work in different modes. It is especially necessary to note the backwash of the membranes, which eliminates the occurrence of blockages.
To achieve greater efficiency, iron should be converted to an oxidized state before cleaning.
Biological method of iron removal
The biological method is aimed at transforming dissolved iron into an oxide form using iron bacteria. They do not pose a danger to humans, unlike their metabolic products.
Iron bacteria show activity at an iron level of 10 to 30 mg / l, however, they can also develop when the content of harmful impurities is lower than these indications. In order for microorganisms to exist normally, it is necessary to maintain an acidic environment at a low level, while simultaneously providing oxygen from the air.
At the end of the biological method of iron removal, the iron waste products are removed by adsorption, then the water is treated with bactericidal rays in order to finally clean the liquid.
Of course, this method is environmentally friendly and effective, but it has a big minus: the low speed of the process. In addition, in order for the cleaning performance to be at the proper level, it is necessary to have large treatment tanks.
Drinking water purification
At home, water is purified using the following methods:
- Upholding. This is the most elementary way: water is left for several hours, during which impurities and sediments sink to the bottom. However, the effectiveness of this method is low, after the procedure, the liquid will have to be boiled.
- Freezing Water should be poured into a container and sent to the freezer. After the main part turns into ice, the residue must be drained: it contains impurities. Thawing water, you need to throw out the last ice, they also contain harmful substances.
- Shungite and silicon. Minerals must be put at the bottom of the container, then filled with water and left for at least two days. After the lapse of time, the water that is on top can be drained and consumed, and the "bottom" should be poured, sediment will be present in it. Shungite and silicon are good cleaners of liquids from harmful impurities.
- Coal. This drug will get rid of sediment and mechanical impurities. You need to wrap the coal in cotton and let the water through the resulting homemade filter.
Why purify water from iron
The presence of iron in the water, which did not pass the filtration, spoils its smell and taste. In addition, undissolved impurity particles color the liquid brown. The constant use of water with a large amount of iron can lead to various diseases, especially those related to the kidneys and liver. It will also negatively affect the skin condition, allergic reactions may appear, and sediment will accumulate in the drainage system.
In addition to causing damage to human health, the iron in the water will lead to such consequences as the appearance of yellow smudges on plumbing, overgrown pipelines and their corrosion, a significant decrease in product quality and equipment failure at enterprises.
The optimal value of the iron content in water is 0.3-0.5 mg / l. At higher rates, rust will form, and at lower rates, turbidity will appear.
The cost of iron removal
If you have water running from the tap with an unpleasant odor and bite, then cleaning the water from iron will help to cope with this problem. The price of filters depending on the type and mode of action has a different cost.
The most common filter jug is considered, the principle of which is based on the ingress of water into the container through a layer of sorbent. The cost of such a jug ranges from 200 to 2500 rubles.
Filters that require placement under the sink have a higher cost. Reverse osmosis systems are found on the market at a price of 5,000 rubles, and electrochemical filtration will cost about 25,000 rubles.
The cost of goods is affected by the presence of storage capacity, its volume, as well as the degree of purification.
Do not forget that the installation of a water purification installation for iron is best provided to specialists, whose services will also have to be spent.