Concerned about the presence of sediments in the domestic water supply? Or is the supply system prone to chemical contamination?
Then, you might’ve already considered installing a water filtration system at home. But, to ensure that the chosen option delivers the desired performance, you’ll need to develop a clear idea about how water filters work.
And to explain the process in the simplest way possible, we’ve curated this short guide for you.
The Types Of Water Filters Used And How They Work
Based on the impurities you’re trying to eliminate, you’ll come across the following types of filters:
- Absorption filters
- Mechanical filters
- Reverse Osmosis Filters
- Ion Exchange Filters
- Sequestration Filters
Note that each type of filter is designed to address a separate issue in the water supply. Several filtration systems utilise a combination of methods to filter the water at multiple levels. Thus, to clearly understand such a multifaceted system, you’ll need to know how each type of filter plays its part in the filtration process.
Their Working Mechanism
The majority of Australian homes get their drinking water supply from a treated municipal source that’s safe but might often feature unpleasant odour and taste. This happens due to chemicals like chlorine used to remove infection-causing bacteria and germs.
And depending on your location, you might also find the main water supply line, causing the formation of limescale deposits that can damage appliances and block pipes. So, how do filtration systems work to remove the hose of impurities? Let’s have a quick look at each of the types of filtration:
The absorption process in water filters is mostly carried out using carbon that effectively captures water-borne contaminants. Notably, the superior absorption power of carbon stems from its large internal structure full of nooks and crannies that can successfully trap impurities like chlorine.
Most domestic filters come with granular activated carbon or GAC to reduce undesirable odour and taste by absorption. On the other hand, the more costly filtration systems apply carbon block elements that are usually more efficient and have a micron rating for the removal of particles.
Another point worth noting is that carbon filters can be made using a variety of materials, including coconut shells and wood. And though the former is more effective, it comes at a higher price.
2. Mechanical Filtration
Such a filtration system basically works to remove dirt, sediment, and other particles in water by the use of a barrier. As such, mechanical filters range from basic meshes that can filter the larger debris to ceramic filters with a complex pore structure to enable ultra-fine filtration. This makes the latter more efficient in filtering out pathogenic organisms.
Also, mechanical filters are usually given micron ratings to indicate their effectiveness through the size of particles they can remove. The ratings that you would normally come across in such filters include:
- 0.5 micron: Can remove cysts such as cryptosporidium and giardia
- 1 micron: Can remove minute particles that can only be seen with a microscope
- 5 micron: Can remove the majority of visible particles
3. Reverse Osmosis
Popularly referred to as RO systems, these filters are designed to remove inorganic solids dissolved in water, such as calcium and magnesium ions. And they do this by passing water under pressure through a semipermeable membrane so that the majority of contaminants are trapped. Also, RO filters solely utilise water pressure for their filtration mechanism and don’t require electricity to operate.
This method is highly effective in removing impurities in water and is generally used in combination with several other filters like mechanical and absorption filters. Such a filtration system ensures the removal of maximum contaminants, providing almost 100% pure and safe water.
That said, adding extra filters to establish a multi-stage filtration system makes an RO unit costlier than other water filters. But, for specialised production procedures requiring 99.9% pure water, an RO unit is the most suitable choice.
4. Ion Exchange
This term refers to softening hard water by exchanging calcium and magnesium ions with hydrogen, sodium or other similar ions. Note that the exchange of ions physically removes hard minerals, thereby making water ideal for being kept at high temperatures, such as in large-scale coffee machines.
These filtration systems use a resin for ion exchange that’s available in the form of small beads. But, the water filters come as sealed units enclosing the resin, so you’ll simply need to replace them with new ones when the ion exchange mechanism ceases to work.
Sequestration, which refers to the chemical isolation of a substance, is applied in many water purification systems to segregate the contaminants. Food-grade polyphosphate is used in such systems to sequester traces of magnesium and calcium in the water that cause corrosion and limescale.
But, as this substance is introduced in small amounts, it inhibits scale formation but doesn’t eradicate this impurity completely. The water isn’t softened, but the minerals are confined within the solution to prevent them from depositing as scales on the surfaces they come in contact with.
Understanding Your New Water Filtration System
So, that was all about how water filters help provide fresh-tasting, clean water for various applications.
You might have understood by now that every filter has its limitations, which is why they’re better off when combined in different ways. So, it’s time for you to select a suitable filtration system for your needs based on the types of filters used in them. You must maintain your water filter so that it continues to provide fresh water.
If you need assistance installing or maintaining your water filter, please speak to our Perth Plumbers. Our team are highly-skilled and experienced with all types of water filters.