Mechanical purification cartridges
Able to filter out large insoluble particles with a diameter of 5-50 microns, making the water more transparent. Mechanical cleaning also contributes to some extent to the longer service life of household appliances and water pipes.
Carbon cartridge (filter with granulated coconut charcoal)
Works to improve organoleptics: purifies water, making it clearer and more pleasant to taste. The porous structure of activated carbon absorbs free chlorine and removes, along with other organic compounds, from the water the user eventually receives.
There are two elements at work here. On one side is the polypropylene pre-filter, the outer shell of the unit, and on the other is the inner part, the pressed carbon, which filters chlorine and organics from the water, ultimately making it cleaner and more palatable.
It works optimally in a three-stage filtration system. The first of these is the coarse mechanical purification stage, the second is the ion exchange resin capsule, and the third is the carbon block.
The activity of ion exchange resins is due to their structure. The molecules form a network with active ions (functional groups), creating a special environment capable of exchange reactions.
The synthetic medium is a combination of solid electrolytes resulting from the special treatment of the resins. Polymerization of the substance leads to the formation of functional groups intended for electrolytic dissociation.
To store such resins it is necessary to create certain conditions. Temperature in storage should not be less than 2 ° C. Resin should be stored under warm conditions, but not near heating appliances. The ion-exchange resin has a warranty period, after which its quality indicators should be checked. Its anionites and cationites can lose their properties. The same will happen if stored in unfavorable conditions. When resin loses its properties, it takes longer to filter water, regeneration also becomes longer. Decreased strength properties of the resin contributes to the fact that it begins to crumble. As a result, resin crumbs can be carried from the filter into the water supply, and this is unacceptable.
Granular Activated Carbon Cartridges
Activated carbon is a porous material. Depending on the size of the granules, the properties of the cartridge will vary. Along with the ability to collect all unnecessary substances contained in the water, coconut charcoal emits very little dust. This is its undoubted advantage. But in addition to granular charcoal, the cartridge must contain a mechanical cleaning agent, so that coarse particles of sand and rust do not erode the granules.
Pressed activated carbon cartridges
Carbon can be used not only in granular form, but also pressed. Then the cartridge works as a carbon block. The charcoal can be coconut charcoal, or it can consist of a mixture of different kinds of it. This charcoal is pressed to create a dense and strong mass. In the manufacture, the desired level of porosity is achieved. Due to the dense block structure, the possibility of washout of carbon particles is practically eliminated.
Each manufacturer tries to develop a unique way of filtration. And so the carbon blocks of each brand is different from each other. Some add hydrophilic fiber – aqualen, which helps water penetrate into all parts of the carbon block and increases its absorptive properties. The additives in the blocks allow the strength of the pressed carbon to be increased, virtually eliminating the possibility of flushing.
Powder activated carbon cartridges
It is not uncommon to find filters with powdered charcoal cartridges. In this state, it has an increased ability to adsorb impurities. It has a larger working surface than other types of charcoal devices. The longer the water is in contact with the charcoal as it passes through the filter, the better the cleaning result is. There is a mechanical filter at the outlet, which keeps the powder from coming out of the filter capsule.
Whatever the charcoal cartridges, whatever type of charcoal they use, all cleaning systems based on the properties of activated carbon have the following characteristics:
- Are excellent adsorbents capable of eliminating not only organic compounds, but also heavy metals or oxidizers like chlorine and ozone;
- Are a breeding ground for viruses and microbes. They are not capable of disinfecting water;
- They are not designed to soften water because they are indifferent to the hard calcium and magnesium salts it contains;
- Excellent against impurities with a high molecular weight and poor solubility;
Activated carbon does not absorb water. When water passes through it, it tends to create tubules of itself that allow it to flow more easily through the filter. The pressure of the water forces it to look for every possible way to overcome the retention of the carbon filter. The more tubules form in the charcoal, the less effective the water filtration becomes. After all, not all water will now interact with the charcoal, but only that which has failed to pass through the grooves;
Charcoal dust often gets into the water;
The cartridge works more effectively if the area of contact of the carbon with the water is larger, and therefore its sorption capacity is greater;
For effective water purification it is necessary to prolong the time of contact of water with the working body. So, the cartridge must retain water for the most favorable result. When buying a filter, look at its efficiency index, which reflects the properties of the cartridge that is part of it.
Carbon filters are not bactericidal, they are a bacteriostatic type of filter. While bactericidal filters cause bacteria and pathogens to die, bacteriostatic filters, on the other hand, promote the growth and multiplication of bacteria.
In an effort to improve the performance of filters, manufacturers fill carbon cartridges with a small amount of silver, which has no harmful effects on the human body (no more than 50 micrograms / liter). But this minimum is not enough to kill harmful bacteria. They are killed only when the concentration of silver molecules is 150 µg/L or higher. It is easy to guess that using this element in such minuscule quantities does not eliminate the problem of bacteriostaticity of carbon cartridges. The requirements of sanitary norms and rules set the maximum amount of silver at the outlet of the device at 0.05 mg/liter. In other words, it must not wash out of the filter.
What do you need to pay attention to when choosing the most suitable of the many types of filters? Consider the following information:
- The service life and life span of the water to be filtered;
- The life span of the cartridge (frequency of replacement);
- Type of water suitable for use by the filter (utility water, industrial water, etc.). Each particular type of filter is designed only to operate under the conditions for which it was designed. The manufacturer declares these requirements in the characteristics of the product;
- The possibility of extending service life through the use of bacteriostatic additives.
Some manufacturers set the cartridge life at 1 year, others at 1.5 years. But whatever the case may be, when the cartridge reaches the end of its life, it must be replaced, even if it has not yet exhausted the declared resource. Because at the end of its life in the cartridge accumulates a large number of bacteria and harmful microorganisms. This means that by continuing to use it, you risk harming your body with contaminated water.
If the cartridge has not reached the end of its life, and the limit of filtered water has already been used up, it is also not advisable to use it. The volume of water was stated for a reason. It is when this amount of liquid passes through the filter that it becomes significantly contaminated. So it is not recommended to use it in the future.
At best, the cartridge will become useless. At worst, it will introduce bacteria into the clean water during sudden water hammering of the cartridge (this happens as a result of pressure surges in the water supply system).