If a person can live for a long time without food, he will not survive long without water. The human body consists of 80% water. What kind of liquid forms the internal environment of our body is of great importance. Hardly anyone would argue that the quality of water directly affects a person’s health and well-being. Many of us are convinced that it is sufficient to boil tap water and safely use it for drinking and cooking. But that’s not the case. The issue of low-quality water, which can have a detrimental effect on our body, is now solved simply: it is enough to use certain types of filters. After reading this article, you will learn about what kinds of water filters there are, and you will be able to choose for yourself the most suitable option.
What groups are all types of water filters divided into
A water filter is needed to clean the water supplied from natural sources from impurities, heavy metals, viruses and chlorine. The purification devices that use in their apartments and houses are called household devices. They can be ranked according to the degree of filtration at the simplest, medium purification and higher. The last type of filter is represented by reverse osmosis systems. And today it is the most effective and modern technology.
Each of the three groups of filter types is designed for its purpose and differs appreciably in price. Users, when choosing a method of water purification, are guided by their place of residence and their financial capabilities.
Where should you start when choosing a water filter? First of all, get your water tested. Knowing the parameters of water, you can choose a suitable replacement unit for its filtration system. After all, in order to effectively purify the liquid, you need to figure out what it should be purified from.
Based on the results of the analysis you will know how much iron your water contains (total and dissolved), what its hardness, turbidity, and color, how much manganese it contains, and what its oxidation and PH level are. If the parameters are skewed and deviations, then you need to pick up just such a replacement unit, which will bring the composition of water to normal.
The filtration system does not start with the filter that you install yourself at home, and with the device pre-filtration, which cleans the water from large impurities such as rust and sand. Usually, the water system is equipped with such a device at the very initial level of its equipment.
There are different types of filters for hot and cold water systems. A prefilter for hot water should be made of heat-resistant material. If an ordinary filter is installed on the hot water system, it will instantly fall into disrepair. Therefore, cold and hot water is usually put different prefilters. Heat-resistant at the same time is more expensive.
But the water purification system does not make water clean and suitable for drinking. It is needed just to facilitate the work of fine filters. You need to additionally install basic filters that will turn the liquid coming into your home into safe drinking water.
To determine which water purification device is most suitable for you, you need to carefully read about the features of different types of filters.
What are the different types of water filters
Water filter in the form of a pitcher
This is the simplest device, which can be purchased at a minimum price, consisting of:
- A pitcher with a lid.
- A funnel for drawing water.
- A cartridge for filtration.
The name “pitcher” draws in the imagination a beautiful clay vessel that is easy to drop and break. But in fact, water filters are made in the form of plastic containers, they only remotely – the shape of the spout – resemble a pitcher. Plastic glass has a printed scale, it can hold from 1.5 to 4 liters of water. The cost of the filter depends on the volume and complexity of the device. For example, the lids of some models are equipped with valves that protect the water in the jug from dust and germs
No matter how much water the jug can hold theoretically, in practice only half of it will fit in, because the other part is occupied by the water tank, also made of plastic, the bottom of which is equipped with a purification cartridge. It has its own lifetime. Different models have individual characteristics in terms of the amount of water they can purify by passing through their filter. This quantity varies from 170 to 450 liters. After that, using a pitcher becomes pointless.
If the cartridge in the filter has a liquid meter, you will not forget to replace it. At the beginning of the device, water passes through the valve quickly enough: up to 35 liters per hour. But over time, the rate of passage of the liquid slows down.
What exactly are the fragments of the cartridge are able to clean the passing water:
- Chlorine is removed thanks to a layer of activated carbon. It also disinfects the liquid from bacteria, improves organoleptic (smell and taste) properties of water.
- An ion-exchange resin layer removes extra minerals from the water, making it soft while maintaining the necessary level of important microelements.
- The polypropylene layer filters the mechanical impurities in the water.
Jugs are a budget-friendly option for no more than three people. They are easy to move, and take with you to the cottage, they are easy to handle and inexpensive. However, the cartridge will have to be replaced often, but otherwise, there will be no point in using this filter.
These filters should be installed in the pipes of the water supply system. Their task is to remove large particles from the water. They are designed to be the first stage of liquid purification on the way from the well to the living space. Thanks to coarse filters in the water coming to us there is no sand, silt, clay, and other impurities. If you install such a filter on the water, which entered the apartment, it will clean the liquid from lime, rust, and scale.
The method of coarse purification is primitive: those particles that are not able to pass through the holes of the mesh, remain on the filter. That is, this device is a metal or polypropylene mesh with a small diameter of cells.
There are the following types of filters for coarse water purification:
- Filter in the form of a mesh or in the form of a cartridge.
- Flanged and socket filters.
- With the possibility of washing and without it.
- Straight or oblique.
Filter mesh with apertures from 50 to 400 microns in diameter is used most often. Made of stainless material, it can serve up to 30 years. We are also very familiar with filters that purify water with the help of a cartridge, namely through a replaceable device made of polypropylene fibers.
Flanged and socket filters are often used to clean water in pipes. The latter is distinguished by the fact that the socket connection leads to minimal bending deformation of the flange relative to the body, respectively, its diameter is no more than 50 mm.
The division of filters into direct and oblique filters depends on the location of the tank and outlets from it nipples in relation to the water flow. In oblique filters, the tank is installed at an angle to the flow, and in direct filters – perpendicularly. Large particles of impurities are deposited in the tank itself, and smaller ones – are on the filter screen.
The oblique filters, some straight filters and all cartridge filters are nonflushable. They only have to replace the filter element as it wears out. If the unit is called a washable unit, however, it can be detached from the overall design, remove the filter screen, wash it, clean, and put back.
Straight filters are often flushable. They are equipped with an additional outlet faucet, which can flush out accumulations with a stream of water. But such coarse cleaning devices are only possible in areas where the pipes are horizontal with the reservoir pointing downward. And oblique filters are installed indifferent to the location of the pipeline. The main thing is that the water moves from top to bottom, not vice versa. In this case, the sump will be located at the bottom. Coarse filters are inserted into the pipeline before the installed meters.
Among the many types, coarse pre-filters are used almost everywhere. They are simply necessary for the normal functioning of washing machines and dishwashers, plumbing, and water heaters because if all these household appliances will use untreated water, they will quickly fail. Such filters are installed after the overlapping faucet but before the meters.
They consist of:
- Metal mesh, filtering particles with a diameter of 30-50 microns;
- Cartridge with an inlay of polypropylene fiber that retains particles of about 5-20 microns.
The metal mesh is easy to remove and wash, removing rust and sand. This flushing is done every 1-2 months. Some filter systems are equipped with a self-flushing mechanism that can be used to clean the screen without dismantling it. A more advanced version – automatic flushing with the conclusion of impurities in the sewer.
The more expensive version of the filter has water pressure measuring devices (manometers) installed before and after the filter. Whenever the fluid pressure drops excessively after the filter, you need to flush the screen. The pressure gauge is placed according to the diameter of the pipe.
The screens last a long time and are subjected to flushing. Cartridge filters cannot be flushed, but they have a higher degree of purification. They not only remove mechanical contaminants, but also disinfect the water and enrich it. Often the replacement elements contain not only charcoal, but also silver and ion exchange resins as filtering layers.
Important points when installing pretreatment filters:
- The capacity must match the water flow;
- Cartridge filters are suitable for pre-treated water, while pre-treated filters are only suitable for the mesh;
- It is important to install the filter correctly, so it is worth inviting a specialist.
Consequently, if already installed or planned to install a filter with fine mesh membranes, it will definitely be necessary to install pre-filters to protect the delicate purifying valve from coarse debris. That way you can achieve optimal results.
What a pre-filter does:
- Frees water from large coarse particles that cannot dissolve;
- Accumulates debris and contaminants on the screen, which can be removed from time to time by rinsing it out;
- Protects household appliances from damage by purifying the water they use.
Almost all types of coarse filter types are small in size and easy to use. But their significant disadvantage is that they can only remove large insoluble debris from the water. But what about all the other impurities?
There are filters that can handle running water perfectly by being installed directly in the water pipe. These are mainline filters that consist of either a plastic or a collapsible steel bulb containing a purification element.
Sufficiently high throughput (20-50 l/min) sifts out all coarse particles, as well as ridding the water of chlorine. Thus, not only the quality of water, but also its taste is improved.
The main-line purifier must be suitable for the type of main, the degree of purification to be achieved. Different types of water filters of this property differ from each other by type of housing and cartridge, capacity and level of hydraulic loss. Main-line filters are equally suitable for cold and hot water pipes. Hot water devices are made from heat-resistant materials, they will serve properly and the pipes with cold water. But to put a filter for cold water on a hot pipe will not work. Among the main purifiers there are three types:
Single-stage ones clean the water from sand, fine debris of the sedimentary type and rust;
Two-stage in addition to the properties of single-stage filters also remove chlorine, odor, and organic impurities;
Three-stage models are also capable of softening water by removing excess iron from it.
According to the way main types of water filters function, they can be strainer (the strainer cartridge cleans water from coarse mixtures), corrugated, propylene and coil filters.
Experts know that on higher floors it is important to choose a filter with a lower index of hydraulic losses (no more than 0.1-0.6 bar). Also depending on the water flow rate filters are selected with a body diameter of 114-130 mm (at the most modest flow rate) to 184 mm (with active water use)
An excellent filtration option is the main device with a granular load, which eliminates and large debris, and chemical and biological contaminants softens the water. The filter has a layer filled with rocks, grains of quartz sand, expanded clay, anthracite, and even marble chips – all these natural elements gently clean the water and fill it with natural components. Such filters differ significantly in price.
Filters for iron removal
It only makes sense to put a filter to specifically purify water from iron in areas where it is found to be elevated. It is extremely harmful to human health and to the condition of household appliances. Science knows four states of iron on Earth:
When we analyze the water supplied by the central pipelines, we can only see iron in the divalent and trivalent states. A coarse filter is able to cope with trivalent iron. An ultrafilter with a waste dump and membrane backwash is also suitable for this task.
Bivalent iron can be filtered by more complex plants, such as bulk plants with multi-component mixes (Ferosoft B/L/A/Ecomix) These multi-component mixes are not only ion-ombaid resins but also due to the increased sorption capacity are actively capable of filtering iron and other compounds. Accordingly, such a mix will effectively cope with such water problems as hardness, iron, manganese, etc.
Reverse osmosis system
Why is a reverse osmosis system filter considered the most effective at the present stage? Yes, because it cleans 99% of the water. A high figure, do you agree? The system performs several stages of water purification, as a result, you get a liquid similar to drinking water of the best manufacturers, sold in stores.
Let’s understand what a multi-stage purification system consists of.
Pre-treatment (chlorine is removed from the water, rough impurities that can further damage the membrane for more fine purification, pre-treatment is performed in three flasks).
Membrane filtration (represents purification through synthetic fiber material twisted into a roll, it passes water through its pores with a diameter of 0.0001 micron).
Automatic accumulation of water in the tank as it is consumed (capacity 4-12 liters, made of steel and covered with enamel).
Purified water flowing into the faucet. A special faucet, provided by the system, is cut into the sink, along with the normal water supply faucet (before starting to pour from the faucet, the water passes through a filter of activated carbon).
Now let’s look at what the pre-treatment in three flasks is for. The first is needed for mechanical purification of the liquid from coarse grains of rust, sand over five microns in size. The second contains granular activated carbon, which cleans the water from chlorine and organics. The third bulb also removes mechanical particles, but no more than one micron in size.
Why does the membrane have such small pores? The reason is that only molecules of water and gases enriching it (oxygen and hydrogen) have a size of 0.0001 microns, everything else is larger. These are unfiltered impurities by the flasks, which will now be taken by drainage into the sewer.
The reverse osmosis system is equipped with a mineralizer to fill the water with normal amounts of magnesium, sodium, and calcium. A tourmaline cartridge is provided in the system to structure the water to its natural state. It is made of plastic on the outside, but inside it is a glass container with natural mineral ceramic balls.
The reverse osmosis filter is a set of elements:
- Cleaning flasks (4-6 pieces);
- Replaceable cartridges and membrane;
- Accumulative reservoir;
- Drinking tap;
- Set of mounting tools.
This type of water filter is a fairly bulky system, which is often installed under the sink, hiding the cabinet. A more complex version of the installation involves the connection of additional hoses that will bring clean and dirty water. The osmosis system operates at 2-6 bar. If the pressure is lower or higher than the manufacturer’s stated, a special pump specialists will adjust the pressure to the norm.
As with any other option, in addition to the advantages, this filtration system has disadvantages: the water is purified slowly and most of it goes into the sewer with impurities (2/3 of the volume).
Filters under the sink
The reverse osmosis filter is not the only option for purification systems that are commonly installed under the sink. All those devices that purify water in multiple sections require space for their operation. Sink filters are flasks that can be made of steel, plastic, or glass. Each bulb has its own purification cartridge and is responsible for one of the stages of water filtration. This entire structure is connected to the cold water supply pipe, takes the purified water through a special faucet, and the dirty – in the sewer.
Among the filters under the sink are installed:
- Reverse osmosis.
About the device of the reverse osmosis filter, you already have an idea. The flow filter works as follows:
- The water is first mechanically cleaned in flasks of sand and other water-polluting particles;
- Cleared of insoluble impurities rust, silt, sand, and other debris, the carbon sorbent frees water from chlorine and organic compounds, also filtering out heavy metals and salts;
- A layer of ion-exchange resins makes water softer by removing iron as well as excess magnesium and potassium from it.
To disinfect the water, an ultraviolet lamp is installed in the flow filter. Such devices are more economical to use water than reverse osmosis filters, and purify water faster.
It is not recommended to install the filter blindly. You need to know the characteristics of the composition of the water in the house to choose a particular one. In fact, you can choose the filter that you prefer, but the cartridges for it should be selected taking into account the properties and quality of the water to be filtered.
All water filters under the sink have a lot of advantages:
- They do not cause difficulties in operation;
- All elements of the system can replace each other;
- They save space due to ergonomic installation;
- Long resource elements (in flow-through filters – six months, in the system of reverse osmosis – year);
- Savings in the cost of clean water.
Disadvantages: inability to move the system to another place and high price.
Water passed through filters that can soften it passes through ion-exchange resins that replace heavy calcium and magnesium ions with sodium or potassium ions.
The following types of filters have softening capabilities:
- Mainline ion-exchange filters;
- Reverse osmosis systems;
- Electromagnetic filters;
- Ultrasonic filters.
The ion exchange resin does not last forever. It needs to be regenerated from time to time. This is done through a chemical reaction. The resin is “revived” with a regeneration solution of tableted table salt. Thus, hard ions accumulated in the resin are replaced with sodium ions.
The filter elements can be flushed both manually and automatically. Regeneration takes place as follows: the device stops working for 0.5-2 hours at a regular interval of two times a week. If there is only one ion-exchange filter in the system, the suspension of its work is unavoidable. Among the many types of water purification devices, this one is considered a filter of variable action. But if there are several filter sections, they replace each other.
Water softening filters come in different designs:
- Balloon type;
- Compact, where the filter and tank are connected in a single body;
- Automatic systems.
All types of filters, which are aimed at softening water, remove heavy salts and excessive trace elements, making it healthy and healthy. They last long enough.
The most compact type of softening filter is magnetic. They consist of a device with magnets built into the body, which is installed in the water supply pipe. Because of the magnetic field through which the water passes, hardness salts do not settle on heating devices and pipe surfaces and therefore can not combine into crystals that can destroy the elements of the water system and household appliances. To protect radiators, boilers, washing machines, and other devices that use tap water, softening flasks filled with polyphosphate crystals or ecozone – a special material that lasts about six months – are installed before the water comes in.
But don’t forget that softening water alone is not enough to make it suitable for regular use. There are many other compounds besides heavy salts that need to be removed as well.
Types of water filter cartridges