Concerned about the presence of sediments or metal shavings in the domestic water supply? Or is the supply system prone to chemical contamination?
Water filters improve drinking water quality by removing all the contaminants (including magnesium and calcium compounds that cause limescale and build-up), and the water also tastes better!
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.
To explain the process in the simplest way possible, we’ve curated this short guide about water filtration systems.
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
Most 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 because chemicals like chlorine are used to remove infection-causing bacteria and germs.
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. And this is the tap water you drink.
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:
1. Absorption
The absorption process in a water filtering system is mostly carried out using carbon, which effectively captures water-borne contaminants. Carbon’s superior absorption power stems from its large internal structure, full of nooks and crannies that can successfully trap chemical impurities like chlorine.
Most domestic filters come with a granular activated carbon filter 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 noteworthy point is that carbon filters can be made using various materials, including coconut shells and wood. And though the former is more effective, it comes at a higher price.
2. Mechanical Filtration
A filtration system removes dirt, sediment, and other particles from water by using a barrier. 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 generally 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 Unit
Popularly referred to as RO systems, these filters are designed to remove inorganic solids and volatile organic compounds dissolved in water, such as magnesium and calcium ions. They do this by passing water under pressure through a semipermeable membrane so that most contaminants are trapped. Also, reverse osmosis systems filters solely utilise water pressure for their filtration mechanism and don’t require electricity.
This method is highly effective in removing impurities in water and is generally used with several other filters, such as mechanical and absorption filters. Such a filtration system removes maximum contaminants, providing almost 100% pure and safe filtered water.
Adding extra filters to establish a multi-stage filtration system makes an RO unit costlier than other water filters. However, an RO unit is the most suitable choice for specialised production procedures requiring 99.9% pure water.
4. Ion Exchange
This term refers to softening hard water by exchanging calcium and magnesium ions with hydrogen, sodium, or similar ions. The exchange of ions physically removes hard minerals, making water ideal for keeping at high temperatures, such as in large-scale coffee machines.
These filtration systems use a resin for ion exchange available in tiny beads. But, the water filters come as sealed units enclosing the resin, so you’ll need to replace them with new ones when the ion exchange mechanism ceases to work.
5. Sequestration
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. 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 filter systems help provide fresh-tasting, clean water for various applications.
You might have understood that every filter has limitations, so they’re better off when combined differently. 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 drinking water.
If you need assistance installing or maintaining your water filter system, please speak to our Perth Plumbers. Our team is highly skilled and experienced with all types of water filters.
Take care!
Water Filter FAQs
What is the difference between chemical and water filtration processes used in activated carbon filters?
Chemical filtration removes contaminants through ion exchange, where filter media chemically interacts with contaminants to trap them. Activated carbon filters use physical absorption, where contaminants are trapped in the porous physical structure of the carbon material.
Is bottled water or unfiltered tap water better?
Bottled water undergoes purification processes like reverse osmosis to remove contaminants and disinfect them. However, unfiltered tap water can contain heavy metals, chemicals, and other contaminants depending on the water source. For purified drinking water, filtered tap water is generally better than unfiltered options.
How do activated carbon filters purify water?
Activated carbon filters use highly porous carbon material to physically trap contaminants through absorption, adsorbing chemicals, heavy metals, and impurities. This allows them to effectively remove chemicals and purify water without harsh chemical treatments.
What contaminants can water filtration remove?
Water filters remove many contaminants, including heavy metals like lead and mercury, organic chemicals like pesticides and VOCs, chlorine, microorganisms like bacteria and protozoa, and turbidity. The specific contaminants removed depend on the filtration method.
Why is water filtration necessary?
Water filtration is essential to remove dangerous contaminants and purify water for safe drinking. It improves taste and odour by removing chlorine used to disinfect tap water. Filtration also removes minerals that cause scale build-up in pipes and appliances.
