Increased concentrations of dissolved iron (Fe 2+) affect not only the domestic sphere of our lives, but also our health. To get rid of it, various filters and iron removal stations are used.

Not long ago we wrote about how to purify water from heavy metals. Today we will look at ways to purify water from the iron present in it. Sometimes the answer to this question lies on the surface, sometimes it is very difficult to find a solution.

If we are talking only about improving the taste of a small volume drinking water, then a simple, convenient Brita filter jug ​​will do. It will not solve serious problems, but it will have a positive effect on the taste, color and smell. Just like faucet attachments, tabletop filters, dispenser filters, etc. If you need more high quality cleaning, you need to pay attention to reverse osmosis. But what if the problem is even larger?

Ferrous water

Of course, iron is not present in water in the form of pieces or fragments: it is dissolved, however, with the naked eye you can sometimes see that the water is cloudy. What types of iron can we find when we turn on our water tap?

• iron divalent or Fe 2+ ions dissolved in water are present mainly in groundwater;
• iron trivalent: Fe 3+ sulfates and chlorides are perfectly soluble in water, Fe 3+ ions are converted into insoluble hydroxide Fe(OH) 3, which is contained in water in the form of sediment or suspension. Ferric iron appears in water upon contact with an oxidizing agent, such as air;
• iron organic– these are all kinds of soluble complexes containing organic acids and often having a colloidal structure;
• iron bacterial– this is iron, which is contained in the shell of iron bacteria and is a product of their vital activity.

Organic and bacterial iron is found in large quantities in surface waters. But water extracted from underground sources, in addition to ferric iron, quite often contains manganese. Therefore, along with iron removal from water, manganese is often removed. This process is called demanganization.

How to determine the amount of dissolved iron in water?

Method number 1. Observation

Clear signs of ferruginous water are:

• its subtle reddish tint,
• red-brown stains on the bathtub, sink, toilet,
• rusty deposits in pipes.

Method number 2. Analysis

With the help of water analysis, you will find out what impurities and in what quantities are contained in the liquid. To do this, you need to collect water samples according to certain rules, take it to one of the public or private organizations, and wait a few days. Analysis, of course, costs money. But the information you gain from it is priceless. She will help you organize in your apartment or private house effective system water purification from the most various contaminants, including from dissolved iron.

What is the danger of exceeding the maximum permissible concentration?

Fe 2+ enters the water due to the geological features of the area. Can cause harm to a person and his life. If we talk about people, they need iron in a certain form and in a certain quantity. Its deficiency can lead to anemia and other ailments. But there is too much of it in liquid. It is not able to be absorbed and bring benefit to the human body. It accumulates in it and after some time becomes the cause of cancer.

Now about what concerns everyday life. Modern man uses to organize his life activities a large number of liquids. In some cases (watering plants, lawns, vegetable gardens), the concentration of dissolved iron is not very important. In others (heating system, plumbing, household appliances, etc.) it plays an important role. Why? The fact is that Fe 2+ is oxidized by air and turns into an insoluble form, into what we call rust. It settles wherever possible - in pipes, in household appliances, in boilers and heating systems. It clogs them and gradually destroys them.

That's not all. Do not forget about aesthetic damage, about rusty stains on your favorite plumbing fixtures - near the bathroom drain, on the walls of the toilet, on the walls, at the joints of tiles, etc. Agree, it is unpleasant to make repairs, and then watch how the result of the efforts spent deteriorates day by day.

In short, iron is not an impurity that you can ignore. Over time, it accumulates in the body and can cause unpleasant diseases. The economy suffers from it, which leads to more and more expenses. It is not clear what to do other than look for some options for deferrizing water.

How to remove iron from water?

One of the most difficult tasks in water treatment is removing iron impurities from water - this process is called deferrization. There are many ways to deferrize water, but a universal method that is economically justified and applicable in any case has not yet been invented. This or that method, which we will discuss later, is used only in specific cases, since each has its own advantages and disadvantages. The optimal one can be chosen only after determining the quantity and quality of iron in the water.

We list the main options for purifying water from iron and give a brief description of them.

Using household drinking filters

1. Reverse osmosis . A membrane with tiny pores traps all impurities larger than H2O molecules, including divalent iron.
2. Ultrafiltration. The use of a membrane with larger pores than in the case of reverse osmosis. Effectively reduces the concentration of dissolved iron.
3. Zeolite. Some manufacturers make cartridges for flow filters from this material. The material oxidizes Fe 2+, converts it into an insoluble form, and retains the resulting precipitate.
4. Aragon. This material is used Russian manufacturer"Geyser". Designed to purify moisture from many impurities, including reducing the concentration of iron.

Note that flow filters and reverse osmosis are best used to purify water that has already been either treated at a municipal water treatment station or has been treated at a semi-industrial station for cottages.

Not all flow filters are ready to remove iron from water. There are, for example, options for softening water, improving its taste and eliminating odors, and neutralizing bacteria and viruses. Among the variety of devices, you need to find those that have special iron removal cartridges.

Manufacturers offer different variants deferrization cartridges. Some make filter elements based on synthetic zeolite. It acts as a catalyst for iron oxidation. It becomes insoluble in water and is retained by other components of the cartridge. Other manufacturers offer calcite-based cleaning elements. In this case, purification of water from iron is carried out using the alkaline precipitation method.

Note that you can buy a cartridge for water deferrization for your filter, even if it is not initially provided. The main thing is to consult with specialists first.

Using water treatment plants

The first thing we offer you is a cabinet-type filter from the Geyser company. Small, attractive, it is ready to work tirelessly for your benefit, purifying up to 0.3 cubic meters of water per hour. What you need for small house. Purifies water with special iron-removing agents.

If you have enough big house and the amount of dissolved iron is large - more than 15 mg per 1 liter, then it is better to pay attention to a more solid option for deferrization of liquids - semi-industrial water treatment stations. These are fiberglass cylinders, which, again, contain a special backfill. This installation can handle any amount of dissolved iron. Your house with its heating boiler, household appliances, your plumbing will be completely safe.

We have already said that there are many ways to purify water from different types gland. For this purpose, modern filters and water purification systems use special fillers: anthracite, sand, pyrolusite, sulfonated carbon and other filter materials. IN Lately Fillers with catalytic properties are becoming increasingly popular. But let's take a closer look at the deferrization methods:

1. Aeration is the process of saturating water with air. In contact with oxygen, dissolved divalent iron takes the form of insoluble ferric iron;
2. “Dry” filtration: to retain ferric iron, granular media with a role are used, which fine quartz sand, filter Ag, expanded clay, and vinyl plastic work well in water purification filters.
3. Clarification: coagulation, flocculation. These methods allow you to remove colloidal dispersed substances and suspended matter from water. Thus, coagulant reagents promote the formation of flakes in water, which adsorb contaminant particles on their surface and precipitate. Flocculants contribute to a significant enlargement of this sediment and acceleration of the process as a whole.
4. Introduction of oxidizing reagents: chlorination, treatment with potassium permanganate. Under the influence of chlorine, humates and other organic iron compounds transform into the form of inorganic salts of ferric iron, and these, in turn, are easily hydrolyzed. Despite its high cost, water chlorination allows for only a slight improvement in water quality and contributes to the appearance of toxic substances in it. Treatment with potassium permanganate is much cheaper and is used, as a rule, to treat complex waters in order to oxidize divalent iron.
5. Ozonation. This process is considered the safest and quite effective. Ozone is one of the most powerful oxidizing agents: it disinfects water, oxidizes divalent iron and manganese, decolorizes water, and improves its organoleptic properties. However, the quality of such processing must be confirmed experimentally in each specific case.
6. The use of catalytic charges is the most common method for removing various types of iron and manganese in flow-through water treatment systems. All filter materials of this class differ not only physical properties, but also the level of manganese dioxide content. This allows them to work in different ranges of values ​​inherent in water parameters. But the principle of operation of all loads is the same: it is based on the ability of manganese compounds to change valence, oxidizing divalent iron.

All of the above methods are good and effective only if they are applied to water, with suitable chemical composition. Therefore, in order to select the most economical and effective filter for water deferrization and the optimal filter material, it is best to first do a chemical analysis of your tap water.

Our health directly depends on the quality of drinking water. Water, as a good solvent, contains many chemical compounds. Iron is one of the contaminants most commonly found in drinking water. It is not difficult to detect its excess in water. Such water looks cloudy, acquires a specific odor and a metallic taste. It leaves rusty stains on laundry, clogs pipes and damages electrical appliances. How to remove iron from water? Is it necessary to get rid of iron at all and how to do it?

In moderate doses, iron is even necessary for normal functioning human body. As part of hemoglobin, this element is involved in the transfer and delivery of oxygen to all vital organs and systems, and promotes the removal of carbon dioxide. It is part of respiratory enzymes and some types of cells.

It should be noted that the absorption of iron from water is quite difficult. Nothing bad will happen after a single dose of water with excess iron levels. Therefore, there is an opinion that the harmful effects of increased iron concentrations on health are greatly exaggerated. However, most experts are convinced that exceeding permissible levels in drinking water is a serious problem for the body.

Safe iron content is set at 0.1 to 0.3 mg per liter of water. Systematic consumption of water exceeding these indicators leads to the accumulation of iron in internal organs human and various disorders:

• blood composition changes;
• dermatitis and dryness appear skin, allergic reactions;
• the functioning of the gastrointestinal tract is disrupted;
• food poisoning occurs;
• the functioning of the liver, kidneys, and pancreas is disrupted;
• metabolic processes become difficult;
• Nervous disorders are noted.

In addition, an unpleasant aftertaste degrades the quality of cooked food.

Iron concentration in water

The standards set the maximum permissible amount of iron in water to 0.3 mg per 1 liter. Often this norm is exceeded tens of times. Sometimes these indicators are tap water are 5 mg per liter, and in some disadvantaged areas reach 10 mg/l. How to determine the concentration of iron in water?

Excess permissible norm up to 1 mg/l remains visually invisible. Water by appearance Remains transparent, no foreign odor is noticeable. However, characteristic rust stains begin to appear on washed laundry, plumbing fixtures, and the walls of electric kettles.

If the iron content exceeds 1 mg/l, the water looks cloudy, acquires a dirty yellow tint, and a metallic taste is felt.

First of all, household appliances suffer. Solid iron particles act on sealing gaskets as an abrasive, damaging washing machines and dishwashers. Rust settles on the enamel of plumbing fixtures and quickly clogs the pipes.

Forms of iron in water

In order to correctly select a purification system, it is necessary to find out not only the level of iron in the water, but also in what form this element is present. Iron in water is found in several main forms:

1. Ferrous iron– dissolves in water and is not noticeable at first glance. When interacting with oxygen, it oxidizes and becomes trivalent with a characteristic brown color and “rusty” taste.
2. Ferric iron– present in water in the form of a coarse insoluble suspension. Enters the water from rusty pipes or municipal wastewater treatment plants. It has a characteristic color and smell.
3. Colloidal iron– is present in water in the form of a suspension, which does not settle even during long-term storage, leaving the water cloudy.
4. Bacterial iron– consists of iron bacteria, which are present in water in the form of viscous, soft mucous formations. Most often it enters water from various wastes. industrial enterprises. Usually these bacteria are harmless, but if they grow, they lead to rapid corrosion and wear of water pipes.

You can determine the presence of iron in water yourself. If clear water after settling, it acquires a brown precipitate, this indicates the presence of divalent iron. If the water is already yellowish-brown in color, then it contains ferric iron. An iridescent oily film on the surface indicates the presence of bacterial iron in the water. A mucous coating inside the pipes also indicates the presence of bacteria.

However, determining the shape of iron on your own is not so easy. Water can contain several forms of iron at the same time. Undoubtedly, the most accurate method will be chemical analysis of water in the laboratory. Based on the results of the study, it is possible to select the most correct and effective system for purifying water from iron.

Homemade methods for removing iron from water

To purify water from iron, theoretically it is enough to transfer it from a dissolved form to a trivalent one and filter it. For small volumes of water, home methods are also suitable. There are several simple ways self-cleaning water:

1. The most affordable and simplest option is to settle the water. To do this, choose a container relatively large sizes, pour water and leave it for a while, preferably overnight. Then pour two-thirds of the settled water into another container.
2. Boil longer. Under influence high temperatures for at least 10 minutes, suspended iron particles precipitate.
3. To freeze. If there is not much water, you can freeze it halfway. All impurities will remain in the liquid; it must be drained. Thaw the ice part again and use it.
4. The water can be mineralized. For this you will need silicon and shungite. The stones must be placed at the bottom of the container, pour in water, then pour two-thirds of the volume into another container. The sediment will remain on the stones.

The above methods for purifying drinking water from iron are effective only when the standards are slightly exceeded, up to approximately 1 mg/l, and only as temporary measures. Constant purification and removal of large concentrations of microelements from water is a rather complex process that requires a serious professional approach.

Modern systems for removing iron from water

Clean thoroughly rusty water only possible with the help of modern filters. Systemic removal of iron from drinking water must be established in houses with old water pipes, as well as in users of personal wells.

Different forms and concentrations of iron respectively require and various technologies cleaning it. Iron impurities in most cases are contained in divalent and trivalent states, each of which is purified in its own way.

Methods for purifying water from iron

There are two main methods for removing iron - using reagents and without reagents.

Reagent-free water purification from iron- the most common method among modern technologies. Effective at iron concentrations up to 10 mg/l. The method is based on the property of divalent iron to oxidize under the influence of oxygen. The water is saturated with oxygen by force using a compressor.

The positive point is the absence of chemical reagents. Purification systems are relatively cheap but cumbersome. Usually is initial stage in a multi-stage system. Requires subsequent settling and filtration.

Reagent water purification from iron– used at iron concentrations above 10 mg/l. Strong chemical oxidizing agents are used to purify water. Most often it is sodium hypochloride or potassium permanganate (potassium permanganate). Reagent filters are easy to use. However chemical substances are hazardous to health and require careful dosing, and the concentration of iron in natural water may vary. In addition, reagents require constant updating and are quite expensive. The method is more suitable for technological rather than household needs.

Methods for purifying water from iron and types of filters

Currently, the most popular methods of removing iron are filtration and aeration - oxidation of water with oxygen.

Ion exchange filters– used when iron concentration is not higher than 5 mg/l. Granulated ion exchange resins are used for cleaning. The mass of the ion exchanger retains iron ions, which are replaced by sodium ions. In addition to iron, impurities of other metals and hardness salts are removed.

With this cleaning method, it is impossible to exclude the process of iron oxidation with oxygen. As a result, the coarse particles of the resulting ferric iron quickly clog the resin granules. A film forms on their surface, which serves as a breeding ground for bacteria. For efficient work preliminary water preparation and regular restoration of resins are required. Resins can only be partially restored, and their full use life is no more than 2-3 years. Therefore, this method is practically not used in domestic conditions. It is often used for water purification for technological purposes - in the operation of thermal power plants, boiler houses, etc.

Reverse osmosis filters– used to purify water containing ferrous impurities up to 20 mg/l. A reagent-free method in which water passes through a special membrane under pressure. Membrane pores effectively retain up to 99% various substances, including ferrous iron. Using filter technology, impurities are drained into the sewer system without being retained in the membranes.

The water is then well purified, but almost completely loses its mineral composition. Therefore, drinking water requires additional installation mineralizer. This cleaning method is often used in small-capacity household filters, but is not practical for large volumes. Ideal for apartments and small cottages. To use this method, it is necessary to maintain good water pressure, otherwise the filters will not be able to work. Maintenance is relatively economical, but requires systematic replacement of the membrane or flushing with chemicals.

Electromagnetic filters- comparatively new way, in which water is exposed to ultrasound, then passed through a special electromagnetic apparatus and the purification of water from iron is completed using quartz sand. The electromagnetic field separates iron particles, which are subsequently retained by a mechanical filter.

Mechanical cartridge filters– used for purifying water from insoluble large fractions of ferric iron. Cartridges retain particles larger than 15 microns in water pretreatment systems and up to 5 microns in fine filtration systems.

Most often, this method of purifying water from iron is used in apartments and houses with centralized water supply. Well water cannot be purified this way. Mechanical filters in cottages can only be used after preliminary aeration.

Catalytic oxidation- a fairly common method of cleaning iron from private homes, cottages and small industrial production. With the help of special granules with catalytic properties, the oxidation reaction of iron occurs. The insoluble sediment settles on the filter and is washed off during the next flush into the sewer. Currently, there are many backfills made from both synthetic and natural materials.

Catalytic oxidation systems are efficient and compact. The disadvantage of wash filters is their sensitivity to low temperatures. If the temperature drops below 0°C, the filters may fail. Suitable for use only in heated rooms and require frequent cleaning and rinsing.

Electrochemical aeration- the most modern and advanced method of purifying water from iron, used with high iron content - up to 30 mg/l. Aeration involves treating water with a flow of air, as a result of which soluble iron from an artesian well is oxidized and deposited in the form of flakes on the filter. In this method, oxygen is formed directly from water molecules during electrolysis. chemical reaction and does not require the use of additional chemical reagents.

This method is energy-efficient and cost-effective, since aeration units are compact, operate autonomously and do not require constant maintenance.

Ozonation of water– involves the oxidation of ferrous iron in wells and boreholes using an ozone-generating installation. Ozone is the most effective oxidizer of metals, purifies water from inorganic impurities and pathogenic bacteria.

Ozonation is the most expensive method. Due to the toxicity of ozone, strict adherence to safety measures during operation of the installation is required. As a result of purification, water acquires a strong oxidizing ability, therefore water pipes and water storage containers must be made of highly resistant materials - stainless steel or PVC.

Biological filters– this method uses the ability to purify water with the help of certain microorganisms. Sometimes a biofilter is the only way to purify water from high iron content - more than 40 mg/l, as well as high content of carbon dioxide and hydrogen sulfide

First, you need to determine the degree of water contamination and in what form iron is in the water.

The following types are distinguished:

• elemental, in undissolved form;
• 2-valent, in dissolved form;
• 3-valent, undissolved;
• organic, which is divided into: colloidal, in the form of insoluble very small particles contained in water in a suspended state, do not settle and give it turbidity; bacterial; soluble organic

For a basic test, just pour water into a glass and let it sit for several hours.

• Ferric iron will appear as a rusty residue.
• Bivalent will give the water a cloudy red color.
• The bacteria forms an iris on the surface.

Reagent-free filtration

Does not involve the use of chemical reagents. Water purification from excess iron, manganese and hydrogen sulfide occurs using natural sorbents, which provide an oxidation reaction of dissolved iron.

Such filters eliminate:

1. turbidity,
2. chromaticity,
3. removes suspended particles,
4. sand,

Reagent-free filters have an automatic self-cleaning function by backwashing the filter sorbent.

Reagent cleaners

Their work is based on the use of chemical reagents, which significantly accelerate the oxidation process and the formation of ferric iron.

Such filters are equipped with a special tank for preparing a regeneration solution.

Actively The following types of reagents are used:

• sodium hydrochloride;
• potassium permanganate or potassium permanganate.

The deposited sediment is removed using mechanical filtration. Based on the cleaning method, the following types of filters can also be distinguished.

Load type

Load-type filters operating on the basis of catalytic media, where the cleaning process occurs thanks to various fillers and sorbents.

These treatment systems can use one type or several fillers of different compositions, which are laid in layers and provide comprehensive cleaning water not only from iron, but also from other impurities.

Reverse Osmosis

, the basis of which is the passage of liquid under pressure through a membrane that has minimal gaps that can only pass water molecules.

Almost all other elements are successfully filtered. That's why water approaches distilled water in its properties and in case household use requires additional mineralization.

Using electromagnets

Filters using electromagnets, which are based on ultrasonic water treatment, which leads to coagulation of iron and greatly facilitates its removal using various sorbents.

Depending on the model, such devices may contain:

• solenoidal electromagnet,
• permanent magnet.

Aeration

Aeration deferrization devices , work on the principle of oxidation of ferrous iron with the help of air.

In these filters There are two ways to saturate water with oxygen:

• non-pressure aeration, when water receives oxygen during the spraying process;
• pressure, when oxygen is supplied to water under pressure.

Ion exchange filters

Systems operating on the basis of ion exchange resins: anion exchanger or cation exchanger. Such systems can be classified as multifunctional because they are used:

• to remove salts and soften liquids;
• to reduce the content of iron, manganese and other metals in an undissolved state.

Adsorption systems

They work on the basis of adsorbents, which can be:

• ash,
• clay,
• coconut shell,
• shungite,
• other artificial or natural materials.

The most popular filler is activated carbon, an environmentally friendly adsorbent with excellent filtering qualities.

Which one should I use for iron removal?

To make the choice easier, cleaning systems can be divided into 3 groups:

• single-stage filters for removing 2- and 3-ferrous iron;
• multifunctional systems that not only deferrize water, but also soften it by removing salts;
• complex purification systems designed to remove not only all types of iron, but also other elements, including manganese, hydrogen sulfide, salts, pesticides and various organics.

Main selection criteria:

1. The degree of contamination and the list of elements and impurities for which the standard content in water is exceeded. This information should be contained in the water composition analysis.
2. For what purposes will the water be used?

If contamination is severe, it is better to use reagent systems, in which chemical components are used to purify water. Such treatment systems are less environmentally friendly, but they are more efficient and can quickly purify large volumes of water.

For apartment

Water supplied to city apartments undergoes pre-filtration at wastewater treatment plants, But its characteristics do not always meet drinking liquid standards.

This fact is facilitated by the initial severe pollution of natural sources, as well as old rusty water supply systems. Therefore, purification of tap water from iron and other impurities is necessary.

Filters for purifying water from iron in this case can be:

1. cartridge with additional mineralization and water softening,
2. reverse osmosis filters,
3. special and anti-scale protection.

To purify water in an apartment For household needs, main filters are installed. They cleanse tap water mechanically.

They are also popular with replaceable filters, due to their compactness, low price, ease of maintenance and sufficient efficiency. This option will do for a small family. But such a filter will not protect household appliances and plumbing fixtures from rust.

Cottage and private country house

When choosing a filter for a summer house or cottage, you must take into account the fact that water from a well or well does not undergo pre-treatment, unlike city water supply systems. There is an opinion that water from a well is 100% pure, but in practice this is far from the case.

The composition of such water depends on:

• type of soil;
• height of the site;
• well depth.

On summer cottage a lot of water is spent on irrigation and economic needs. To clean it, a single-stage cast iron filter is sufficient.

Water filtration for domestic needs will require more complex cleaning, which will not only remove all types of iron, but also eliminate:

1. excess manganese,
2. hydrogen sulfide,
3. softens the water.

Therefore, in cottages and in the country, it makes sense to install two treatment systems: for economic and domestic purposes. Complex systems are designed for better purification of water used for cooking, washing dishes, laundry and cleaning.

The following are well suited for such purposes:

• ion filters;
• reverse osmosis systems;
• purification systems, including not only deferrization, but also the removal of other impurities, as well as water softening.

How to make a filtration system with your own hands?

If there are no opportunities to buy iron removal systems yet, but there is a need for them, you can make an iron filter with my own hands. One option is an aeration filter.

Aeration

To make it you will need a large container of food grade plastic barrel-shaped.

The liquid will flow into the container through a pipe with a sprayer at the end.

During the spraying process, water will come into contact with oxygen, which will lead to an oxidation reaction of dissolved iron and the precipitation of a rusty sediment to the bottom of the container.

To remove sediment to the bottom of the container at a height of 10-20 cm, another pipe is installed, which will remove settled rust from the container.

Adsorption

Another variant homemade filter– adsorption.

Manufacturing stages:

• We take a 3-5 liter container, make a hole in the bottom, and drill holes in the lid.
• We take cotton wool, foam rubber and gauze, put them in layers on the lid of the container.
• We pour fine river sand and crushed sand through the hole in the bottom. charcoal layers.
• We pour water from the source into a container and collect purified water, which undergoes mechanical purification.

We invite you to watch a visual video guide on how to make your own cleaner:

Selection criteria when purchasing a removal system

The choice of filter depends on the degree of water contamination, volumes and purposes of consumption. Multifunctional filters belong to a higher price category. When purchasing, it is also worth considering future costs associated with replacing removable cartridges and maintenance treatment system.

Domestic manufacturers offer a wide selection of filters for removing iron from the following brands:

• Geyser;
• Equolos;
• Barrier;
• Brita.

Inexpensive models are presented by Chinese manufacturers Runxin and Canature.

The price of the filter depends on the manufacturer, the complexity of the system, and the components used. The cost of sorption purification filters varies from 4,200 to 10,000 rubles. Reverse osmosis filters will cost between 6,000 and 12,000 rubles. depending on the manufacturer.

Conclusion

A high-quality water purification system is the key to the health of your family and a guarantee of long-term operation household appliances and plumbers.

The main point in the matter of choice is preliminary chemical analysis water, which will help make right choice and don't overpay for additional functions cleaning systems you don't need.

It happens that in order to obtain a liquid suitable for use, it is necessary to deferrize water from the well.

1. Weathering, destruction and dissolution of rocks with subsequent release into underground sources.
2. Wastewater from industrial enterprises entering surface water bodies.
3. Washing away from agricultural lands the remains of mineral and organic fertilizers not absorbed by plants.
4. Effluent from livestock farms.
5. Corrosion of water supply parts.

In water extracted from underground sources, the metal is contained in the form of chemical compounds:

• Divalent, which, when oxidized, is converted into metal hydroxide, giving the liquid a brownish tint.
• Trivalent, found in insoluble form.
• Colloidal, which is difficult to remove due to its small size. Such a solution cannot be purified by settling.
• Bacterial, formed during the life of bacteria.

What to do in cases where it is not possible to quickly conduct laboratory analysis? You can determine that there is a lot of iron in water from a well by organoleptic signs:

• Metallic taste.
• The appearance of red stains on plumbing fixtures that are difficult to get rid of.
• The red, gelatinous sediment begins to smell unpleasant when it comes into contact with air.
• A rust-colored sediment when heated.
• Changing the shade of laundry after washing.

Samples

The research is carried out by mobile laboratories that go to the collection site under concluded contracts, and by the SES.

Important! Only accredited laboratories that have received documented permission can carry out analyzes.

It is important for the consumer to know how to correctly collect samples for analysis of iron in well water:

Norm

After the analysis, a test report is issued.

The permissible norm for Russia is 0.3 mg/l.

Consequences of underperformance or overperformance.

Excess as well as deficiency chemical element in the body, negatively affects the health and well-being of a person.

Elevated metal levels cause:

• Deposits of the element in tissues and internal organs.
• Headache, fatigue, dizziness.
• Change in skin color.
• Problems with the gastrointestinal tract - nausea, vomiting, intestinal ulcers.
• Liver and kidney failure.
• Diseases of the heart and blood vessels.
• Risk of malignant tumors.
• Anemia.

A reduced content of a chemical element provokes:

• A decrease in the concentration of hemoglobin, which is involved in the transport of oxygen to organs, tissues, and the brain.
• Decreased muscle tone.
• Mental disorder.
• Decreased immunity.
• Increase in body weight.

Important! main reason increasing the concentration of iron in the human body - its excess intake from drinking water.

How to clean it yourself

Purification methods come down to the procedure of converting the divalent form of a metal, which cannot be filtered due to its small size, into a trivalent one. The metal concentration can then be reduced by mechanical filtration.

You can deferrize water using reagent-free and reagent methods of carrying out a chemical reaction.

The simplest and most cost-effective method of water purification is to collect water from a well into a settling tank. Interaction with oxygen leads to the conversion of iron into a trivalent form, which precipitates. Water is drained from the layer above the sediment. In the absence of oxygen, it settles completely within 24 hours in an open system with additional aeration for 4-6 hours.

Iron removal plants for cottages and homes

To accelerate the chemical oxidation reaction, use:

1. Aeration.
2. Ozonation.
3. Ion exchange.
4. Chlorination.
5. Reverse osmosis.
6. Use of hypochlorite.
7. Introduction of reagents and catalysts.

Aeration

Injected oxygen oxidizes divalent iron, removing carbon dioxide, which also accelerates the oxidation process.

The following methods are used for this:

• Flowing with spray installations;
• Spraying – smothering;
• Air injection by compressors.

The above methods are effectively used in the presence of iron up to 10 mg/dm3. In cases where the concentration is exceeded, to maintain the intensity of the process, preliminary water treatment is carried out using the aeration method with the introduction of reagents (chlorine, sodium hypochlorite, potassium permanganate).

Ozonation

The method is based on the structure of the ozone molecule. The element is unstable and easily gives up an extra oxygen atom, which is an active oxidizing agent. By combining with molecules of other substances, it actively oxidizes and destroys them.

In addition to iron, ozonation helps purify liquids from insoluble magnesium and calcium compounds that can be removed by mechanical filtration.

It also disinfects, discolors, and removes foreign odors and tastes. During ozonation, many bacteria die and toxic impurities are removed.

Ion exchange

You can remove iron from water using an ion exchange resin. IN last years natural components are replaced with synthetic resins that have high efficiency.

The main task of filtration using the ion exchange method is to get rid of other divalent metals: calcium and magnesium.

In laboratory conditions, this method will remove high concentrations of metal, but on an industrial scale it is difficult to use the method. The presence of oxygen in the liquid passing through the ion exchanger causes precipitation and rapid clogging of the sorbent. The process has to be stopped to wash the resin.

Ferric iron reduces effective removal calcium and manganese. The resin quickly becomes overgrown with an organic film.

The ion exchange method is used when additional water purification is necessary.

Chlorination

Chlorine is an oxidizing agent that accelerates the process of converting an element from a divalent to a trivalent form. Chlorination solves the problem of disinfection, removal of hydrogen sulfide and manganese, and organic substances.

Liquid chlorine is highly toxic; delivery and handling of it requires compliance with strict safety measures.

Hypochlorite

It is served by dosing pumps. At the same time, the necessary proportions for different degrees of contamination are observed.

Benefits of sodium hypochlorite:

• The solution of the substance does not form suspensions and does not require settling.
• The use of hypochlorite does not increase water hardness compared to bleach solutions.
• The chemical is obtained at the filtration site by electrolysis of table salt - a substance that is safe for transportation.
• The drug has bactericidal properties - the process of cleaning from metal is combined with disinfection.

The calculation of the dosing installation is made on the basis of data obtained from a chemical laboratory analysis of the composition of the liquid. In addition to the iron content, the presence of heavy metals and hydrogen sulfide is taken into account.

Catalytic oxidation

The method has become widespread for water supply to small enterprises, cottages and private homes. Catalytic filtration units with compact sizes are capable of purifying from 0.5 to 20 m 3 /hour of liquid.

Oxidation occurs in a special tank made of of stainless steel or fiberglass.

Used for backfilling synthetic materials with high efficiency and low cost.

Before being supplied to the catalyst, the water is intensively aerated, which accelerates oxidation.

The deposited sediment is removed by backwashing.

The disadvantage of synthetic backfill is the consumption resulting from mechanical destruction.

The backfill made of dolomite, zeolite and glauconite is free from disadvantages. The materials are porous and resistant to high temperatures.

Reverse osmosis

The systems use membranes whose openings allow only H20 molecules to pass through. Impurities of salts, heavy metals, microbes and bacteria are retained by 80-95%.

But osmosis is not just a filter, where the entire volume of water passes through the filter element. In reverse osmosis, such a process is impossible - the membranes very quickly become clogged with impurities.

Construction of household appliances reverse osmosis provides for the supply of liquid under pressure. The device filter divides the flow into 2 parts. A third of the liquid manages to leak out and ends up in a clean outlet, and about two-thirds of the water goes into the sewer.

Thus, the membrane (that’s what the filter is called in devices) becomes less dirty and lasts from 2 to 4 years.

Before being supplied to the diffuser, the water is purified by coarse and fine filters. Preliminary preparation allows you to extend the service life of the membrane to two to four years.

The advantage of the system is the clean release of water from impurities. The disadvantages of reverse osmosis are the high costs of purchasing equipment and periodic costs of replacing the membrane. It is worth taking into account that most of the liquid goes to waste. This increases the cost of electricity to operate the pump to supply it from a well or borehole.

Advice! It is not economically feasible to use osmosis to purify bath water. The purpose of the device is purification for drinking.

Coagulation and clarification

Bivalent iron in the form of suspensions and colloidal dispersed substances is a liquid that acquires a whitish tint that does not disappear after settling. They are freed from suspensions by introducing coagulant reagents. They adsorb metal on their surface and precipitate, which is removed by filtration.

Sulfates and chlorides are used as coagulants. Their choice depends on the acidity of the source liquid.

Electrochemical purification method

Electrochemical cleaning methods are technologically simple and do not require the use of reagents. The disadvantage that reduces the prevalence of the method is energy costs.

The essence of the method is the passage of liquid through the interelectrode space, where electrolysis, electrophoresis and removal of dissolved substances occur.

There are varieties of the electrochemical method:

1. Electrolysis.
2. Electroflotation.
3. Electrodialysis.
4. Electrocoagulation.

Filtration system

The described methods are technologically difficult to implement with your own hands without the use of industrially manufactured equipment.

An effective and technologically advanced method for a private home is the catalytic method of iron oxidation. These iron removal plants are distinguished by their productivity and compactness. Price Supplies relatively small. The choice of oxidizing agent and its dosage is based on the results. This allows you to reduce reagent consumption when obtaining quality water at the output of the device.

Filter media is produced under the following brands: MZhF, BIRM, GREEN SAND, MFO, MTM, AMDX. The choice of a specific sample is based on the composition of the original liquid.

The filter units are equipped with automatic regeneration units, allowing the reagent to be replaced once every 5-7 years.

What is a reagent-free method

Traditional methods of deferrization

Folk, or old-fashioned, cleaning methods are used when obtaining clean water is required from time to time and purchasing expensive equipment is impractical.

Advocacy

This is a simple, least expensive method of deferrization.

For implementation home method you will need a reservoir equal to the daily fluid consumption. Use a container made of neutral materials - food-grade plastic, stainless metal.

The manufacturing process is simple; cheap components are used in the design.

To prevent freezing in winter, the container is placed in a room with a positive temperature.

Install at the entrance stop valve to prevent overflow. The oxidation process is accelerated by a compressor. Water is supplied to the container through a food hose with a spray nozzle at the end of the tube.

There are two holes at the bottom of the tank:

• The first one, at the bottom level, will be used for draining dirty water with cereal.
• The second hole is made at a level of 20-30 cm above the bottom, through which the clarified liquid is taken.

Important! Clean water is taken no earlier than 10-15 minutes after the last air supply. Otherwise, mixed dregs will enter the house. To improve cleaning, magnets are installed that attract iron residues.

Advantages of the method:

• Simplicity and possibility self-made sump.
• A water reserve is created in case of a power outage.
• Hydrogen sulfide present in artesian wells is removed from it.

Flaws:

• Incomplete removal of iron.
• Labor-intensive maintenance. It is necessary to regularly drain the sediment and periodically wash the walls of the container from sediment. Frequency depends on degree.
• It is necessary to monitor the liquid level in the reservoir.

Aeration

This method and the principle of its effect on water were described above. The method can be used at home. For this purpose, a special installation is made. The operating principle can be understood from the figure.

Boiling, freezing

The methods are used to obtain a small amount of clean water.

Iron precipitates after 10 minutes of boiling.

Freezing allows you to combat salt impurities. The water is placed in the freezer. Pure water molecules freeze first; salts turn into ice at higher temperatures. low temperatures. After freezing half the volume of liquid, the remainder is drained. Thawed ice – without impurities.

Purifying water from iron requires a careful and responsible approach. Self-purification is a method applicable to obtaining small volumes of liquid for one-time use. The best option will be contacting specialized organizations for the purpose of purchasing and correctly placing a filter system. This will allow you to avoid mistakes when choosing equipment, installing it, and will allow you to obtain a guarantee.

Iron removal and demanganization of water. How to remove iron from water?

Deferrization- removing iron and manganese from water is difficult task for everyday life and production. There is no universal method for all cases that would be economically justified at all sites. If he existed, we would know everything about him. However, there are many methods and each of them is applicable within certain limits and, of course, has its drawbacks. Most people write to me: “Paul, there is iron in the water. Firms offer different methods from 30 to 150 thousand rubles. Who to believe? What to do?"

Iron remover control valve

Install on top of the filter

The control valve is a system of channels through which water moves, a locking mechanism that directs water along the channel required at this stage of the cycle, and an electric control unit for an automatic valve, or a handle for manually switching modes for manual valve management.

Filters are three-cycle for reagent-free deferrizers, or five-cycle for reagent washing. Reagent washing is not just loosening the charge, but passing a reagent (for example, a solution of potassium permanganate) through the charge to deeply clean the charge and restore its catalytic properties.

By switching modes using a knob, or automatically using an electronic control unit, we organize filter washing.

When washing the filter, water does not flow to the consumer, but is thrown into the drainage system.

Washing takes place in several stages, each with its own important nuances. I recommend studying

After completing the next flush, the filter is ready for use again. Loading the filter at correct operation usually “lives” (works) from 3-5 years.

Oxidation and filtration with pyrolusite (MnO2).

This method is excellent for removing small amounts of ferrous iron Fe(OH)3 in simple conditions and for low water consumption. High pH, ​​lack of organics and hydrogen sulfide in water - prerequisites. The essence of the method is that we oxidize iron using a magical filter loading component without aeration, without dosing, without ozone, without reagents - only an iron remover with loading: sorbent + pyrolusite.

Pyrolusite is a natural mineral. Manganese dioxide. It is used for production batteries. Potassium permanganate (KMnO 4) is made from it and in general it is quite widely used in the chemical industry. In water treatment, pyrolusite MnO2 is used as a catalytic material for the removal of iron, manganese, organic compounds, and hydrogen sulfide, because pyrolusite is a good oxidizing agent.

Pyrolusite in water treatment- the material is unique. Almost all catalytic materials are made using pyrolusite:

BIRM is a lightweight, complex-porous aluminosilicate with pyrolusite applied as the outer catalytic layer. The idea is great, but it doesn’t last long and is afraid of organic matter.

Greensand Plus is quartz sand with pyrolusite applied to the surface of the grains. It only works with constant dosing of hypochlorite or flushing with potassium permanganate.

MZhF, MSK, Pyrolox, Sorbent MS and many other materials - all made using pyrolusite.

Iron remover based on pyrolusite. Softener is an option. It may not exist.

Wherein pyrolusite is a mineral containing 75-95% MnO2, it is supplied granulated, of a suitable fraction. Cheap, but very heavy. A fast flow of water is required to flush it. The larger the column diameter, the greater the pressure required in the system to create a flow of the required speed to liquefy the charge.

However, pyrolusite can be used as a reagent additive to the MS sorbent to remove small amounts of iron and manganese without oxidation. You have one column - a deferrizer with loading - sorbent + pyrolusite. No reagents. No aeration or other type of oxidizing agent. This system is somewhat unique. No other material except pyrolusite is capable of oxidizing metals dissolved in water for years without active oxidation or reagent regeneration. Because we do not use products containing pyrolusite (BIRM, Greensand, MZhF, etc.), but actually pyrolusite itself. During operation, it is practically not consumed, it can “dust” a little - produce gray water - when worn out, it is washed into the water supply in the filtration mode, but this applies not only to pyrolusite, but to all loads in general. You can install a carbon filter with a cartridge at the outlet to avoid pyrolusite particles getting into the water supply and I recommend installing a reverse osmosis system to obtain drinking water in the kitchen, because... under some additional conditions, pyrolusite can release manganese to the consumer, possibly slightly exceeding the MPC.

Conditions for using PYROLUSITE as an iron oxidizer:

• Iron Fe(OH)2<3мг/л
• Manganese Mn2+<0,2мг/л
• pH >6.8
• Permanganate oxidability<2
• Hydrogen sulfide< 0,005

If these conditions are met, I recommend using column 1354 to obtain up to 1.5 cubic meters of clean water per hour. The filter should be washed every few days. In the case of a manual valve, it is acceptable to extend the flushing cycle once a week.

Cost of iron remover based on pyrolusite

Ion exchange (Softening)

To remove various impurities from water, including dissolved metals and organic compounds, ion exchange resins have been used for more than 50 years - cation exchangers and anion exchangers in various combinations, requiring regeneration with NaCl table salt in tablets.

The process of removing salts and metals using ion exchange resins is called softening. Initially, this method was used and is now used mainly to remove hardness salts (calcium and magnesium salts). However, now there is a large selection of ion exchange resins for removing iron and organic matter.

Ion exchange resins are a very broad topic. We are talking here exclusively about household water treatment and I will only tell you what you need to know about resins in the context of our task - to purify water in a private home or in a small industry from dissolved metals.

What is Resin? These are synthetic balls made from polymer materials. They are very small, there are many of them, they look like small pollock, pike caviar or “tobiko” - flying fish caviar. We water treatment installers, even for fun, call resin “caviar” in professional slang.

The essence of the process softening fundamentally different from deferrization. Resins do not oxidize or convert dissolved substances into solid form for subsequent filtration, but replace (“absorb”) dissolved substances in water with sodium cations, which does not give water such a property as hardness. The total salt saturation of the water remains unchanged or even increases. This depends on the type of solutes the resin picks up.

Based on the above, an important parameter of ion exchange resins arises - ion exchange resin container. The resin capacity is similar to the capacity of an electric battery. There is a supply of sodium, which is gradually consumed during ion exchange, thereby reducing the ability of the resin to take dissolved substances from the water. When the sodium runs out, the cleaning ends too - water passes through the thickness of the resin without changing its properties.

We calculate the operation of the softener in advance in such a way as to regenerate (rinse) the resin with a solution of table salt before a noticeable decrease in capacity occurs. This period is called in water treatment filter cycle. For information on calculating the amount of resin, salt for regeneration, and filter cycle, read the article on softening.

Multi-component downloads such as Ecotar, Ecomix, FeroSoft, APT-2, Ionofer with different indices A, B, C etc. are designed for ionic removal of dissolved salts, metals, organic compounds, as well as a wide range of other substances: heavy metals, ammonium ions, organoferron compounds, phosphorus, calcium, silicon and many others.

As I already said, the resin is regenerated using tableted table salt NaCl, salt is sold at all construction markets, in plumbing stores, it costs about $7 for a 30 kg bag. Salt consumption is determined mainly by the amount of substances removed.

On average, about 1 bag of salt per month is spent on water softening.

Reverse osmosis.

Reverse osmosis systems are a fundamentally different method of water purification. Here we are dealing with filtering water through a membrane. Roughly speaking, this is a network through which water molecules pass, but molecules of hardness salts and dissolved metals do not pass through. In this case, the retained molecules do not form a sediment on the surface of the membrane, but are immediately drained into the drainage system. During the reverse osmosis filtration process, water is divided into two streams - permeate(purified) and concentrate(dirty water) .

On average per 1 cubic meter. With purified water, we get one and a half cubic meters of concentrate, which needs to be drained somewhere.

Reverse osmosis systems are effective in removing dissolved metals and hardness salts. They do not replace some substances with others, like ion-exchange resins, but actually purify water from impurities, this is a huge advantage of reverse osmosis. But this is perhaps the most expensive water treatment process and, for reasons of expediency, it is the least used for removing dissolved iron and manganese.

However, at high contents of dissolved ferrous Fe2+ iron and low pH<7 осмос может быть весьма эффективен для удаления 20 и выше мг, потому что молекулы железа гораздо крупнее пор мембраны — их легко фильтровать.

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