Water treatment and water purification for a cottage and a country house

Water purification for cottages is a very common, but often a special case of water treatment for domestic and semi-industrial needs, and has its own characteristics, which this section is devoted to. These features will be considered at the regional installations of the city of Dnipro.

 

First of all, it is necessary to decide why water treatment and water purification are so important for a cottage and a private house in Ukraine. In most cases, cottage water treatment or water treatment plants are designed for autonomous water supply at home, as well as the surrounding area, and are used in cases where centralized water supply is not available or its implementation is extremely costly. In this case, the source of water supply is artesian wells, which have two fundamental designs: with a surface pump and with a submersible (borehole) pump. Often, it is the depth of the aquifer that leaves its mark on excess, water-polluting components and, consequently, on the entire subsequent water purification system for a cottage and a country house.

1. Water purification for a cottage and a country house of not deep horizons

Surface pumps of almost all manufacturers have a self-priming function, which allows you to raise water from a depth of up to 12 m in relation to the pump installation site. Thus, the water intake horizon will be close enough to the surface – up to 12 meters. These water horizons in the Dnieper Delta are characterized by excessive amounts of suspended solids, organic impurities, iron and, sometimes, hardness salts, with a fairly moderate content of other water-soluble salts. In other words, in the process of water passing from the surface to aquiferous underground arteries, natural filtration with natural materials (soil, clay, sand), with a layer depth of up to 12 meters, often does not ensure the removal of organic components acquired in the upper (soil) layer.

The owners of such wells are recommended to organize their own water treatment and water purification system for a cottage and a private house from the following equipment:

Mechanical filtration on granular loading.

Appointment. Thanks to such a water treatment system for a cottage and a private house, it is possible to separate insoluble substances of organic and mineral origin from the water, visible to the human eye.

Principle. Water under pressure passes through a layer of granular material, in the thickness of which mechanical impurities are retained. After passing the calculated amount of water, determined by the conditional dirt capacity of the filter bed layer, the material is washed with a reverse flow of water, in which the accumulated impurities are discharged into the sewer, and the granular bed is loosened for the next filtration cycle. Grain load filtration rating is 35 – 70 microns depending on the type of material.

Execution. The filter housing (cylinder) is made of polyethylene, reinforced with fiberglass, into which filtering granular material of various grain size (quartz sand, anthracite chips, porous materials) is loaded. The filter housing is equipped with an automatic control valve that provides filtration and backwashing modes.

Водоподготовка и водоочистка для коттеджа и загородного дома Украина, Киев, Днепр, Одесса, Запорожье, Харьков, цена
Водоподготовка и водоочистка для коттеджа и загородного дома Украина, Киев, Днепр

Peculiarities. To remove this filtration equipment, including iron dissolved in water, which leaves a brown color on plumbing equipment, pre-treatment of the water flow with an oxidizer (air oxygen, sodium hypochlorite, additives in the filter load) is required. Such water purification for a cottage and a private house will allow iron to be transferred from a soluble form to an insoluble one (the familiar coloring of water in a yellow-brown hue over time), which is delayed by the filtering granular loading of a mechanical filter.

Common mistakes. Incorrect selection of the proportions of the filter housing (diameter and height of the filter layer) and / or type of automatic control valve (with reference to the required performance of the equipment) may not provide high-quality cleaning from deposits accumulated in the thickness of the filter layer. As a result – slippage of suspensions, iron and / or loss of pressure in the water consumption system.

Softening using ion exchange resins.

Appointment. This water treatment for a cottage and a private house in Ukraine allows you to soften the water – to separate calcium and magnesium salts from the water (hardness salts that form scale when heated). When using combined ion-exchange materials, it allows additional separation of organic impurities (color) from water.

Principle. Water under pressure passes through a layer of granular material – an ion-exchange resin, in the thickness of which calcium and magnesium ions are replaced by ions of another metal – sodium, the compounds of which do not form insoluble precipitates when heated. At the same time, hardness ions pass into the matrix of the ion-exchange resin. After passing the calculated amount of water, determined by the amount of sodium ions in the ion-exchange resin (ion-exchange capacity), backwashing of water and regeneration of the ion-exchange material takes place. Regeneration is understood as pumping a solution of table salt (sodium chloride) into the softener, in which, due to a large excess of sodium in the regeneration solution, the reverse process occurs – “sodium squeezes out” calcium and magnesium from the resin matrix into the regeneration solution, which is then discharged into the sewer. The filtration cycle is then repeated.

Execution. The filter housing (cylinder) made of polyethylene, reinforced with glass fiber, into which the ion-exchange resin is loaded. The filter housing is equipped with an automatic control valve that provides filtration, flushing and regeneration modes. Also, the package necessarily includes a tank for saline solution with hydraulic systems for leveling in the tank itself and supplying the solution to the control valve.

Peculiarities. To remove these filtration equipment and organics dissolved in water, the use of additional ion-exchange materials (organ absorbers) is required, similar in principle of operation, but differing in the replaced ion.

Common mistakes. Incorrect selection of the proportions of the filter housing filter (diameter and height of the filter layer) and / or type of automatic control valve (with reference to the required performance of the equipment) may not ensure high-quality removal of hardness salts, or vice versa – make the water too soft for domestic use (large excessive water consumption due to poor laundering of soapy surfaces). With the additional use of organ absorbers and the absence of an appropriate adjustment of the regeneration solution, it is possible to plaster the filter material with an irreversible loss of ion-exchange functions.

Degassing (if necessary).

Appointment. Allows you to exclude extraneous odors from the water (hydrogen sulfide, mercaptans – the so-called “rottenness” or “charm”), which water can acquire when passing through the upper layers of the soil (especially if they are characterized by waterlogged soils, peat bogs, etc.).

Principle.The first one is air blowing with oxygen while providing the maximum area of contact with the downward flow of water. The second is the use of special bulk materials that act as an oxidizing agent (or, more precisely, a catalyst for the oxidation process with oxygen in water).

Execution. Such a water purification system for a cottage and a country house involves several principles. According to the first principle, the simplest thing is to perform in the volume of piping the equipment: air is introduced into the water stream using an ejector, followed by spraying the water stream in the tank (showering). A more technological version is the manufacture of a small degasser from polypropylene (for the required capacity): a special container with a high neck into which the estimated amount of inert material with a large surface area is loaded; water is supplied to the upper part of the neck, and air is blown into the lower part by a fan, followed by removal from the upper part (above the water supply and immediately outside the premises). According to the second principle, the filter housing and automatic control valves are used (as in the case of softening – point 2 of this section). But such installations are rare, because require the use of strong oxidizing agents for regeneration of the filtering load – potassium permanganate (potassium permanganate) and / or sodium hypochlorite (whiteness), which is very inconvenient and dangerous at home.

Features. Despite the simplicity of the process, the result is quite difficult and painful to achieve, because. in addition to the calculated parameters, experience in selecting the ratio of water and air is required. Air preparation must also be taken into account.

Common mistakes.Quite diverse and do not have a pronounced systematics, with the exception of air preparation, the absence of which can lead to secondary water pollution, including microbiological.

Disinfection (if necessary, obtaining drinking water)

Appointment. This water treatment and water purification for a cottage and a country house is to ensure microbiological purity.

Principle. The first is ultraviolet radiation with a certain wavelength and intensity. The second is the use of special-purpose chemicals (oxidizing agents with a permanent or temporary disinfecting effect).

Execution. According to the first principle, this is a pressure vessel (reactor) in which a lamp with ultraviolet radiation is installed. The safety of contact between the lamp and the water flow is ensured by a separating quartz cover. According to the second principle, dosing pumps are used, which, proportionally to the water flow, introduce into it the calculated amounts of the reagent used from the consumption (dosing) tank, equipped with visual and electric level control, or directly from the commodity tank.

Features. Ultraviolet disinfection has no residual effect, i.e. microbiological purity is ensured exclusively in the reactor itself at the time of exposure to radiation on water. Disinfection with oxidizing agents (sodium hypochlorite, dioxide, ozone) forms oxidation by-products, which, like the oxidizing residues themselves, adversely affect the human body.

Распространенные ошибки.Неэффективность ультрафиолетового излучения в питьевых точках зачастую обусловлена неправильным подбором оборудования (интенсивности излучения в единицах мДж/см2) или отсутствием периодической санации трубопроводных сетей (делается один раз в 6 – 12 месяцев в объеме сервисного обслуживания). An excess amount of oxidizing agents, which is possible with simplified dosing logic or lack of service, can lead to very sad consequences – up to chemical burns.

Ultrafiltration (modern alternative to technologies 1.1. и 1.4. simultaneously!)

Appointment. Removal of all mechanical impurities and ensuring microbiological purity.

Principle. Pressure dead-end filtration through a set of polymeric (polysulfonamide or polyvinylidene fluoride) capillaries with a filtration rating of 0.1 – 0.01 microns, which are combined into a product – an ultrafiltration membrane. In the filtration mode, the membrane retains on its surface all mechanical impurities, insoluble iron, large-molecular organics, as well as all known microorganisms and viruses. In the flushing mode (carried out with clean water by reverse current), the accumulated impurities are washed out and discharged into the sewer. Such installations for cottages (low capacity) are becoming more affordable due to the well-deserved popularization of this technology in the industrial segment and the adaptation of membranes to the needs of cottage water treatment systems.

Execution. Such a water purification system for a cottage and a private house in Ukraine involves one or more membrane elements, united by a common system of supply and discharge pipelines for source, purified and flushing water with appropriate shutoff valves. The logical controller, a set of sensors and electric actuators on the valves are responsible for compliance with the calculated indicators of operating modes (filter cycle, pressure drop across the membrane, productivity, levels, emergency and warning alarms, etc.).

Peculiarities.One of the most effective and developing methods of water treatment. To reduce the cost of this technology in the segment of cottage water purifiers, manufacturers are moving away from individual design developments in favor of standard (template) designs. Therefore, for effective and long-term operation of the membrane element (up to 8 years), high qualification of personnel is required. It consists in the correct adaptation of a typical installation for a specific chemical analysis of the potential Customer’s source water (sometimes, even at the cost of equipment performance).

Common mistakes.Exceeding the maximum allowable operating pressure (due to an incorrect operation algorithm, water hammer, failures in the logic controller, uncontrolled clogging of the membrane, etc.) leads to rupture of the capillaries inside the membrane and a sharp deterioration in the quality of purified water.

Nanofiltration (modern alternative to technologies1.2. и 1.4.!)

Appointment.Allows you to soften water – isolate calcium and magnesium salts from water (hardness salts that form scale when heated), remove organic impurities (color), and ensure microbiological purity.

Принцип. Напорная фильтрация на рулонном полимерном (полисульфонамидном) мембранном элементе с номиналом фильтрации 10-9 м. In filtration mode, the membrane divides the source water flow into two. The first flow – purified water (permeate) is sent with a residual low pressure to the reservoir in the amount of 70 – 80% of the volume of the original flow. Together with water, a part of mineral elements gets into it – commensurate with the pore size of the membrane (mostly these are monovalent elements: sodium, potassium, chlorides, etc.). The second stream – saline water (concentrate) is sent to the sewer in the amount of the remaining 30 – 20% of the volume of the original stream. In the concentrate, along with water, there remains that part of the mineral elements that have not passed the pore of the membrane (mainly these are divalent elements: calcium, magnesium, sulfates, bicarbonates, etc.).

Execution. With this method of water treatment and water treatment for a cottage and a private house, one or more membrane elements are united by a common system of supply and discharge pipelines for source, purified (permeate) and saline (concentrate) water with appropriate shutoff valves. The logical controller, a set of sensors and electric actuators on the valves are responsible for compliance with the calculated indicators of operating modes (capacity, pressure drop across the membrane, quality, levels, emergency and warning alarms, etc.).

Peculiarities.Similar ultrafiltration technologies (clause 1.5.). Additionally, this technology does not allow the ingress of impurities larger than 5 microns, which in shallow wells requires the use of mechanical filtration technology (paragraph 1.1.) or ultrafiltration (paragraph 1.5.) as a preliminary treatment. Another additional feature is the constant presence of a stream discharged into the sewer. Those. for every 700 – 800 liters of purified water, 300 – 200, respectively, will be discharged into the sewer.

Common mistakes.Incorrect adaptation of the installation to a specific chemical composition of water, as well as neglect of the pre-treatment system from mechanical impurities, leads to premature loss of productivity and quality of treated water, followed by replacement of an expensive membrane element, the estimated operating time of which is 3-5 years.

2. Water purification of deep horizons.

Downhole pumps are installed directly into the well casing to a depth corresponding to the aquifer – from 13 meters and further (the depth of the aquifer can be measured in hundreds of meters). Thus, the water intake horizon will already be sufficiently removed from the surface – as a rule, it is 30 meters or more. These water horizons are characterized by excessive amounts of mineral salts, while suspended matter, organic impurities, iron (all that was present in shallow horizons) are absent. In other words, in the process of water passing from the surface to aquiferous underground arteries, natural filtration by natural soils, with a layer depth of more than 30 meters, often ensures the removal of organic components acquired in the upper (soil) layer, but, at the same time, saturates the water with natural mineral salts ( which is a consequence of the passage of water layers of sand, granite, calcite, chalk, gypsum, etc.).

The owners of such wells will have to organize their own system, in which water treatment and water purification for a cottage and a country house will consist of the following equipment:

Mechanical filtration using cartridges

Appointment. Allows you to separate from water insoluble substances of mineral and organic origin, visible to the human eye, in a relatively small content as impurities.

Principle. Pressurized water passes through the filter element (cartridge or filter bag made of polymer material or cellulose). After passing the calculated amount of water, determined by the conventional dirt capacity of the cartridge, it is replaced. The filtration rating of the cartridges ranges from 5 – 100 microns depending on the type of material and manufacture.

Execution.The most common water purification system for a cottage and a private house is cylindrical-type filter elements, which have several sizes: in diameter (2½ “and 4″) and height (10″, 20”, as well as in diameter 2½ “there are 30” and 40 “). Execution material – polypropylene and polyethylene in various forms (foam, thread, etc.). Cellulose cartridges are also found, but are not common in cottage installations due to the high cost (as a rule, such cartridges have a more exclusive use in filtration Each standard size of cartridges has its own filter holders (with a diameter of 2½” there are filter holders for several cartridges at the same time) in plastic and stainless versions of the material of manufacture with various threaded connections.

Peculiarities.The dirt holding capacity of filter cartridges is relatively small compared to mechanical filtration on a granular feed (paragraph 1.1.). For this reason, this version of mechanical filtration is recommended for use on water with a low content of impurities of mineral origin (sand, rust, etc.). The key criterion for the normal operation of the cartridge is the loss of pressure on it at the time of water draw. So, a pressure drop during drawdown of 0.5 – 0.6 bar is normal, a drop of 0.7 – 1.0 bar is a criterion for clogging the cartridge (replacement is required), a drop of more than 1.0 bar is critical and, as a rule, leads to to damage the integrity of the cartridge and, as a result, the lack of filtering function.

Common mistakes.The absence of pressure gauges for incoming and purified water does not allow an objective assessment of the condition of the cartridge. The absence of a bypass (bypass) pipeline with appropriate shut-off valves does not allow replacing the cartridge without turning off the water supply at home.

Softening using ion exchange resins (similar to paragraph 1.2.)

Особенности. Дополнительной характерной особенностью на глубоких скважинах является особенно высокое содержание жесткости (более 20 мг*экв/дм3). With such contents of calcium and magnesium ions, the ion exchange technology (water softening) becomes ineffective, since most of the resource of the filter material (ion exchange resin) is already lost during the regeneration process. As a result, this leads either to a poor quality softening process, or to a high consumption of common salt. More efficient methods may be nanofiltration (section 1.6.) or reverse osmosis (described below).

  • Nanofiltration (similar to paragraph 1.2.)

Peculiarities. On artesian water sources with a high content of chloride ions, corrosion of all metal parts of the equipment occurs. For chloride content over 500 mg/dmThe service life of equipment (pumps, valves, flanges, supporting frames, etc.) made of carbon steel and brass is from one to two years, after which corrosion appears, which is accompanied by leakage, excessive consumption of water and / or electricity, failures in work, etc. For chloride content over 1000 mg/dm3 – то же самое произойдет с оборудованием из нержавеющей стали, стандарта AISI304 (и аналогам, например – непищевая нержавейка), а более 1500 мг/дм3 – the same fate awaits equipment made of stainless steel, AISI316 standard (and analogues, for example, food grade stainless steel). For the end customer, it is better to take this into account in the form of the duration of the warranty period for the equipment.

  • Reverse osmosis.

Appointment. Allows you to desalinate water (in whole or in part – depends on the task and / or qualification of the equipment executor), which is often expressed as a percentage of salts in relation to the original highly mineralized water.

Принцип.Напорная фильтрация на рулонном полимерном (полисульфонамидном) мембранном элементе с номиналом фильтрации 10-10м, аналогично нанофильтрации (пункт 1.6.), но на более высоких давлениях ввиду уменьшения поры мембраны. In filtration mode, the membrane divides the source water flow into two. The first flow – purified water (permeate) is sent with a residual low pressure to the reservoir in the amount of 65 – 75% of the volume of the original flow. Together with water, a part of mineral elements gets into it – commensurate with the size of the pores of the membrane (as a rule, 5 – 10% of the salt content in the source water). The second stream – saline water (concentrate) is sent to the sewer in the amount of the remaining 35 – 25% of the volume of the original stream. In the concentrate, along with water, there remains that part of the mineral elements that have not passed through the pore of the membrane.

Execution.Similar to nanofiltration technology with one exception: the operating pressure for the reverse osmosis membrane separation process is much higher. This leaves its mark not only on the energy intensity of the filtration process, but also on the requirements for equipment manufacturing materials. For example, water desalination from wells in coastal regions (mineralization 4,000 – 7,000 mg/dm3, resort Odessa or the coast of the Sea of Azov) will take place at pressures of 15 – 25 bar, desalination of the Black Sea (mineralization 15,000 – 20,000 mg / dm3) – from 30 to 40 bar, and for the desalination of the Mediterranean Sea (mineralization 28,000 – 33,000 mg / dm3) it is necessary to apply technologies with a pressure of more than 60 bar.

Peculiarities.As in nanofiltration (clause 1.6.), there are quite a lot of them, which is associated with the adaptation of specific equipment to the needs of a particular customer. This is a consequence of the fact that manufacturers of reverse osmosis membrane elements have their own gradient (step) in terms of size, filtration area, selectivity, etc., which, when modeling (calculating) the membrane technology for the specific water of the Customer, determines the individual features of the equipment settings – reverse osmosis installations.

Common mistakes.As a rule, this water purification for a cottage and a country house in Ukraine comes down either to an incorrect calculation of the operating modes of the reverse osmosis unit, or to poor-quality (inferior) pretreatment of the source water (all manufacturers of reverse osmosis membrane elements have strict requirements for water supplied to the membrane; in Otherwise, the failure of the membrane is not a warranty case). For the end customer, all these reasons come down to one thing – a sharp decrease in the expected life of the membrane element: instead of the minimum 3 years or the optimal 5 years, the membrane has to be changed every year – one and a half.

  • Disinfection (if it is necessary to obtain drinking water; similar to paragraph 1.4.).

Peculiarities. If the source is saline water, to which reverse osmosis technology has been applied (point 2.4.), then, as a rule, drinking water has already been obtained at the outlet, including with microbiological purity. The task of disinfection technology is only to maintain microbiological purity in the tank.


3. Organization of water supply of the cottage.

This issue deserves special attention, because. also represents a resource to a potential customer in terms of the distribution of capital and operating costs. It is based on the performance of the water purification system for a cottage and a country house in terms of equipment performance, which is directly affected by the presence or absence of a purified (and source) water storage tank.

Purification of water without storage.

Appointment. It allows minimizing the dimensions of equipment placement and saving on energy consumption (since there is no need to use an additional pump after the storage tank).

Principle. The pressure pipeline from the borehole pumping station supplies the source water to the filtration equipment. The filtrate is immediately discharged into the pressure networks of the house to all points of water intake.

Execution.The engineering calculation should take into account not only the consumption and hydraulic losses of the house networks (its height, the remoteness of each water intake point, etc.), but also the technological pressure losses on the filtration equipment, as well as the needs of the filtration equipment itself in water for their own needs.

Особенности.И скважинный насос, и фильтрационное оборудование должно подбираться исходя из максимального возможного потребления дома, учитывая пики в режимах водоснабжения – вечернее и утреннее время, когда задействуются большая часть точек водоразбора одновременно! This fact requires large capital investments in equipment (because it will be more productive – see paragraph 3.2.), but gives savings in its energy consumption and space. Also, the lack of purified water supply may be an inconvenience for some Customers.

Common mistakes. As a rule, they come down to the fact that engineering calculations did not take into account either the additional pressure loss on the cleaning equipment (for example, the mechanical filter just started to clog, and on the second floor the pressure became noticeably lower), or the additional water intake for the own needs of the cleaning equipment (for example , the mechanical filter came out for washing at night and the automatic irrigation system did not have enough water). Well, if the issue is solved by a simple replacement of pumping equipment. Worse, when the pumping unit is not the only one in this chain, an additional increase in the diameters of pipelines and / or power supply is required. And in some cases, this may be additionally accompanied by the instability of the operation of the pumping unit in one of the modes (with a large or small water intake, when fluctuations in the water pressure at the water intake point become noticeable and annoying) – also replacing the automation system of pumping equipment.

  • Water purification for a cottage and a country house with the use of a drive.

Appointment. It allows minimizing the performance of water treatment equipment and organizing the supply of purified water while increasing the size of the placement and energy consumption.

Principle. This water purification for a cottage and a country house assumes the following principle of operation: a pressure pipeline from a borehole pumping station supplies source water to filtration equipment. The filtrate is immediately discharged into the storage tank, where the jet breaks – the loss of pressure energy of the borehole pump. The pumping unit from the storage tank supplies purified water to the pressure networks of the house to all points of water intake.

Особенности.И скважинный насос, и фильтрационное оборудование должно подбираться исходя из среднесуточного потребления дома, все пики в режимах водоснабжения при этом будут компенсироваться запасом в накопительном резервуаре! This fact allows you to save capital investments on equipment (because its task will be to gain the required daily volume in 18-20 hours, and not to provide the necessary performance here and now in the flow). Satisfaction of the needs of the house will fall on the second pump – at the outlet of the storage tank (the cost of its energy supply and the additional dimension of the tank are partial increases in operating costs when water supply is provided at home according to this principle). This principle is the only applicable when using nanofiltration technologies (paragraph 1.6.) And / or reverse osmosis (paragraph 2.4.), Since purified water (permeate) loses pressure energy after passing through the membrane and cannot be directed to the points of water intake by a pressure pipeline (or rather, it can , but this is a completely different performance of the equipment, which will greatly affect the capital costs).

Common mistakes. They are not frequent and mainly come down to high-quality disinfection of water in the storage tank (contact of water with air can cause secondary mechanical and / or microbiological contamination). Also, when using low-quality plastic tanks as storage and subsequent supply of purified water for drinking, water can acquire an extraneous taste from plastic – the issue is also solved, but with the use of additional sorption materials.

Conclusion.

Our company is ready to offer services for the manufacture, installation and maintenance of water treatment equipment for cottages, taking into account many features of high-quality performance, based on two statements:

  • we value our free time very much; therefore, we do not allow ourselves the execution of low-quality engineering solutions, which would take away the free time of our Customers and, as a result, ours;
  • we are not exclusive exporters or dealers of certain manufacturers; therefore, in the choice of engineering solutions and their implementation, we are free to fully use our own: intellectual potential, experience in industrial installations and knowledge of offers on the component market.

We will perform water treatment and water purification for a cottage and a country house in Kyiv and Kyiv region, Dnipro, Zaporozhye, Kharkov, Odessa, Lvov and other cities of Ukraine.

We will be glad to cooperate and remain at your disposal …