Today, the most advanced water purification system is reverse osmosis. Like all similar systems, it has some weaknesses. How is fluid filtered in such a system? What is reverse osmosis?
Water treatment system
Osmosis is a property of the flow of water from a weak saline solution to concentrated. And reverse osmosis is a progressive system that works the other way around; with it, the salt concentration in the liquid decreases.
Therefore, at first, this type of filtration was used to create fresh salt water.
How does reverse osmosis water treatment system work?
The liquid passes through a special membrane, which is called semipermeable. Only water, oxygen, or smaller molecules can pass through its structure. The membrane does not remove organic chlorine compounds and herbicides from the liquid, because their molecule is smaller than the osmotic membrane. In the osmosis system, water treatment is carried out in several stages, let's consider them in more detail.
The first step is pre-cleaning.
This step is very important. Its most expensive replaceable element is a reverse osmosis membrane. The duration of its service is affected by the quality of the fluid supplied. At this stage, 3 elements are used having replaceable reverse osmosis water purification filters, which prepare the water even before it is fed to the membrane.
The first element has a five-micron polypropylene mechanical cleaning cartridge, which performs an important function, it filters water from undissolved particles larger than 5 microns (helps to get rid of rust, sand and other impurities).
In the second filter element is a cartridge containing granular activated carbon, it allows you to clean the water from chlorine, organochlorine compounds, pesticides and herbicides, unpleasant aftertaste and smell.
In the third filter element there is a cartridge which contains pressed briquetted coal. It must remove organic compounds, volatile organic substances (tetrachloride, benzene, carbon) and small particles of coal dust from the water, which have a detrimental effect on the membrane, they are washed out at the 2nd stage of filtration.
Second phase
At this stage, the water, after preliminary treatment, is sent to the membrane, which is the main filtering element of the osmosis system, while the liquid is cleaned at a deep level, allowing you to get drinking water of the highest quality. In other words, it is a kind of grid, and the size of its cells can be compared with the size of water molecules.
Of course, either liquid particles or substances having a smaller molecule size — hydrogen, oxygen, dissolved in water, can pass through this “grid”.
Disadvantages of a cleaning system
Since for proper functioning (osmosis system) water purification must be carried out under some pressure, and it can not always be provided by our water supply, it may be necessary to use a special pump (pump) that will increase the pressure. In addition to the pump, you will also need to connect the system to electricity - this is also its drawback.
Water purification reverse osmosis has advantages over other filtering systems, which consists in the possibility of removing 99% of contaminants. But this does not mean the ability of the membrane system to retain all the minerals and salts that are contained in the water. This means that the water obtained after such treatment will be demineralized and therefore cannot be considered beneficial to human health. Rather, on the contrary, water, in which salts and minerals are completely absent, leaches useful elements necessary for it from the human body, which can provoke serious diseases. Therefore, the best option is osmosis - water treatment. Customer reviews also speak in favor of this purification system, but there are those who prefer to buy bottled water.
Filtered or bottled?
When choosing between bottled water and a reverse osmosis system, the second option is better. Bottled water, as a rule, is filtered just by the osmotic method, but the source or method of purification is not always mentioned on the bottles. Even when conducting detailed tests, it happens that the manufacturer does not give any reasonable explanation about the quality of the liquid contained in the bottle.
In addition, there are often recommendations to pass water through osmosis, water is purified according to the system above, this allows to improve the taste and improve the beneficial properties of the liquid. The result is a large mineralization, and hence the best regulation of the nutrient diet, which enables minerals and useful substances in the body to be fully replenished.
It is believed that the human body alone cannot regulate the level of salt and water; purification using the reverse osmosis method does not have a particular effect on this process.
Next, we will talk about user reviews about the negative aspects of this system and make an analysis that will help us see if the filters for water purification osmosis really have these shortcomings, or whether they arise in the process of their incorrect use.
Stagnant water
Some people talked about the poor taste of water that appeared after the extra top cartridges of a bioceramic base or mineralizer were replaced. But this is not due to the filters themselves and their ability to spoil the water, but to the fact that the person used the filter incorrectly. Water treatment cartridges contain up to 3 glasses of liquid. This water, like the one in the tank, cannot stagnate. To get rid of extraneous smell and taste you need to either use a mineralizer (bioceramic cartridge) daily, or drain a few glasses of liquid.
If all the water after filtration has a strange smell or taste, the liquid does not stagnate in the cartridges, but in the water storage tank. Here, as a rule, the cause of the problem is that the post-angular cartridge was not replaced on time (and you need to do this once a year), or this is due to incomplete use of the tank's resource (hydraulic accumulator). If you are unable to use the entire filter volume (the tanks have a capacity of 15-12l., 11-8l., 8-6l.), You need to artificially renew the water in the tank once a month.
You can turn off the tap in front of the filter and gradually spend the excess purified water, or you can draw it into a large container or drain it from the tank into the sewer. If the filter is used by 3-4 people, it is better to choose the smallest tank (8 liters).
Purified water tends to stagnate, since when using the osmosis system, water is cleaned to distilled quality. Bacteria can multiply in it, and in the absence of a duct, an aftertaste or an odor can appear. You can store the liquid for a long time only if antibiotics are added to it, such as those added to the pools. They are harmful, and this is the main disadvantage of bottled water, which is also purified by reverse osmosis, but it can be stored longer.
Lack of minerals
We are often told that the liquid that has been purified by the reverse osmosis filtration system is weakly mineralized. And this is so, coming out of reverse osmosis, water has 1/3 of minerals in comparison with the inlet, water, but this does not mean that it can harm human health.
If you want to saturate the purified water with minerals, it is recommended to use a mineralizer.
Low speed clear water
The reverse osmosis water treatment system has a low speed, it accumulates already purified water - this is minus the reverse osmosis filters. Silver will not help here either, since the disinfecting effect that the ions of this metal have is not effective enough and there is a danger of silver entering the purified water. In general, its particles are very harmful to humans. For example, in the United States it is forbidden to mention disinfecting properties in the advertising of children's food products, in our country there are no such prohibitions.
After weighing all the pros and cons, you just need to make a choice, perhaps it will be a balance between different filtering methods. One thing is certain - water treatment is necessary and vital in modern conditions.