Water is the basis of all life. Of course, if it's pure water. But, unfortunately, in nature it is very rare, and in most cases, water needs additional cleaning. Untreated water contains minerals, hardness salts, which leave their mark on any surface in the form of scale, deposits, calcareous deposits. Our health also suffers from hard water. Remember the feeling of parched skin after taking a shower, split hair, layered nails ...
These problems are often not related to the quality of domestic water. According to statistics from 100 liters of water used by man, 99% is spent on domestic needs: washing, cleaning, showering, etc. And this is a weighty argument to think about the quality of this water, because the water must be prepared for the further safe use of it! And all of these problems are solved by the use of soft water.
Water treatment consists in coordinating the physico-chemical properties of water with the requirements arising from its designation. The main factor determining the way of water purification is its composition. Therefore, before the choice of water treatment technology, it is necessary to perform physico-chemical analyzes in the laboratory. From the correct assessment of water depends on the choice of the appropriate filters, as well as the completeness of the removal of various types of pollution.
The main stages of water treatment look like this:
Water treatment with mechanical filters is used to remove water, suspended particles, mechanical impurities, sand, scale from water supply pipes, especially in the city water supply system, where all pipes have practically exhausted their life. There are filters for mechanical water treatment:
As a rule, first a coarse filter is used to remove suspended particles, and after the water treatment system a fine water filter. This is done in order to further purify the water of small mechanical impurities that managed to pass the previous stages of purification.
The need to remove excess iron from the water is particularly acute when using artesian wells as a source of water. In groundwater, iron is usually in the form of divalent ions. Upon contact of such water with air, oxidation of iron occurs, which results in the appearance of an orange color in the sediment.
The principle of the action of water deironing filters is based on the oxidation of dissolved ferrous iron to trivalent iron. As a result of the oxidation process, the dissolved iron and manganese pass into un-dissolved hydroxides, which are easily retained by mechanical filtration. In addition, the oxidation of organic substances and hydrogen sulphide in the water occurs, resulting in a decrease in the color of the water, and also eliminates the undesirable taste and odor.
Softening implies the removal of calcium and magnesium salts (so-called hardness salts) from the processed water, based on the principle of ion exchange. During processing, water is filtered through a layer of ion-exchange resin located in the filter housing. As the resin is saturated, it is regenerated with a solution of common salt.
In the process of water treatment using reverse osmosis technology, the dissolved salts are removed by forcing water under pressure through a semipermeable membrane. As a result, they removed 99% of salts and other dissolved in water chemical compounds.
The main element of the reverse osmosis installation is a semipermeable reverse osmosis membrane placed in the body. Primary water comes into it, but two streams are removed: purified and desalted, called permeate, and water with concentrated impurities, called concentrate, which merges. Pressurization of water through the membrane is carried out at high pressure, which is maintained in the water pipe (apartment buildings) or creates a pump (if the pressure is insufficient), usually centrifugal multi-stage or rotary.
To slow the formation of undesirable deposits on the membranes used dosing sedimentation inhibitor. To remove deposits from the surface of membranes, a chemical washing system is used. For quality control of cleaning and pH - flow meters salinity and pH meters. To control the flow of permeate and concentrate - flow meters. reverse osmosis system can be controlled in a semi-automatic or automatic mode. Check the quality of the reverse osmosis membrane can be TDS meter.
An example of domestic water purification reverse osmosis membrane can serve as a filter cartridge having at least 3:
Or a variant with 5 stages of cleaning:
Such filters are widely used in America, Europe and Asia. Interesting are also the latest models of compact reverse osmosis filters with a number of innovations, namely: an automatic water shutoff valve when detecting leaks, a pressure boosting pump, replaceable filters with quick-release fittings.
On the average, the reverse osmosis membrane purifies water at a molecular level of 10-9 m (1 nm).