Water filters: what, why and how?
Before it is fit for purpose, water filters are used to remove impurities, such as odour, bacteria, sediment and hardness.
By filtering water, its quality is drastically improved and can be used, whether that is drinking water, cooking or manufacturing. At a basic level, contaminants must be removed from water so it is as safe and as clean as possible.
Water filtration techniques
These filtration techniques are used singularly or in combination to improve the water’s quality. Here are the different types of water filters:
- Absorption filter
- Sequestration filter
- Ion exchange filter
- Reverse osmosis filter
- Mechanical filter
Why are water filters important?
Water accounts for a huge 71% of the earth’s surface and is woven into a number of practices across the world, such as agriculture, medicine, heating, science, transport, food manufacturing and drinking.
Drinking water goes through thorough processes to ensure it is safe for humans, however, this means sometimes chemicals and odours linger in drinking water as these important factors keep it free from bacteria.
Depending on where you live in the country, the ‘hardness’ of water can vary. This means that it may taste nicer in some areas than others. Also hard water is responsible for limescale build up in places like kettles and boilers. To manage this it may be worth investing in a water filter.
Let’s discuss each type of water filter in a little more detail
The five types of water filter are listed above.
Absorption filters
These filters often contain carbon and are very effective at removing any contaminants. Since carbon has a textured internal surface, it is a great component to trap chemical impurities such as chlorine. Most domestic water filters use absorption filters to remove unwanted tastes and odours.
Sequestration filters
This filtration method involved chemically isolating a substance. Usually polyphosphate is used to prevent scaling on metals. This is a preventative method as opposed to softening the water itself. This is not suitable for all types of water, where water is very hard other methods such as ion exchange is usually more suitable.
Ion exchange filters
This process softens hard water by replacing magnesium and calcium ions in the water with sodium and hydrogen ions. This in turn removes the harder minerals which reduces limesales. This is typically carried out through small beads which are added to the water. This method is not commonly used on drinking water as it raises the salt levels due to the addition of sodium.
Reverse osmosis filters
RO for short, involves removing inorganic solids (like magnesium) by adding pressure so water passes through a semipermeable membrane in which the contaminants are left behind. This is a highly efficient way to purify water that is usually used in combination with mechanical filters.
Mechanical filters
This process physically removes sediment and dirt from water as it flows through a filter made of mesh. This allows larger debris to be removed. This filter can be compared to water flowing through a sponge. The water on the other side would flow through a lot cleaner as most debris would not be able to pass.
Which water filter system is right for my business?
Typically more than one filtration system is used to purify any sample of water. For example, drinking water will go through at least mechanical and absorption filters. By understanding the five different types of filters it should be easier to identify which are needed for certain types of samples.
Water filters are often categorised by domestic (usually attached to a sink) or commercial (for use in a restaurant kitchen for example). The most popular types of filters include: coffee machine filters; inline water filters; fridge filters; drop in filters and commercial water filters.
We hope this gives you a good overview of how water filters work and what they are used for. This helps build a bigger picture of how they could be used in your business.