Tap water filter - The most common water filtration methods: advantages and disadvantages
Table of contents
Drinking water is essential to our health and well-being, and having a clean and safe source of water is paramount. Whether you're looking for general water filtration or a specific tap water filter, methods vary in terms of technology, efficiency and cost. In this article, we'll look at the most common methods of water filtration, along with their advantages and disadvantages.
Mechanical filtration
Mechanical filtration, often used in tap water filters, involves passing water through a porous material (such as sand, activated carbon or a ceramic membrane) to remove suspended solid particles.
Benefits
- Effectively removes solid particles such as mud and sand.
- Relatively inexpensive.
Disadvantages
- Does not remove bacteria, viruses or dissolved chemicals.
- Filters can become clogged and require regular maintenance.
UV (ultraviolet) filtration
UV-C filtration
UV filtration uses ultraviolet rays to mutate the DNA of pathogenic micro-organisms present in the water, such as bacteria, viruses and protozoa, thus preventing them from proliferating.
Benefits
-
- Effective against micro-organisms, reducing the risk of water-borne diseases.
- Does not generate harmful chemical by-products.
Disadvantages
-
- Does not remove solid particles or dissolved chemicals.
- Requires an electrical power source to operate.
UV-A tap water filter
LaVie water purifiers use innovative UV-A technology. LaVie's solution with UV-A radiation causes chlorine photolysis.
Through this reaction, chlorine is eliminated, generating free radicals with strong oxidising power that attack contaminants in the water (traces of medication, bacteria, traces of pesticides, etc.).
This eliminates tastes and odours as well as harmful substances, while preserving trace elements such as calcium, which are essential for well-being!
As far as the PH of the water is concerned, nothing changes. Then, as for the energy required, you should know that it costs around €1.5 for 1000 litres of water, a straw... 🙂
Benefits
- Removes contaminants from water (traces of medication, bacteria, traces of pesticides, etc.)
- Eliminates tastes and odours
- Preserves trace elements
- PH unchanged
- Low energy consumption
Disadvantages
- Limited to between 0.5 and 5 litres of water purification per session
Infographic summarising LaVie's UV-A technology:
Reverse osmosis
Reverse osmosis uses a semi-permeable membrane to remove unwanted particles from the water, as well as bacteria, viruses and dissolved chemicals.
Benefits
- Removes a wide range of contaminants, including heavy metals and nitrates.
Disadvantages
- Produces water of mediocre quality because it removes all minerals indiscriminately
- Expensive and requires sufficient water pressure to operate.
- Generates a certain amount of wasted water (reject water) during the filtration process (3 litres of reject water for 1 litre consumed!).
Activated carbon filtration
Activated carbon filtration, a common technique in tap water filters, is based on the adsorption of contaminants by activated carbon, which is a highly porous material.
Benefits
- Effectively eliminates chlorine, pesticides and organic compounds responsible for bad tastes and odours.
- Inexpensive and easy to install.
Disadvantages
- Does not eliminate bacteria, viruses or heavy metals.
- Filters must be replaced regularly to maintain their efficiency.
See our article:Â Â Binchotan carbon to filter tap water, from dream to reality to find out more
Distillation
Distillation involves heating water until it turns to vapour, then cooling it to turn it back into a liquid, capturing any impurities left behind.
Benefits
- Effectively eliminates dissolved salts, heavy metals and certain chemicals.
- Can destroy micro-organisms if water is heated to a sufficiently high temperature.
Disadvantages
- Consumes a lot of energy to heat water.
- Does not remove volatile organic compounds (VOCs), which can evaporate with water.
Ion exchange
This is the principle used by water softeners. These machines generate an exchange of ions in the water that consists of eliminating undesirable ions from the water by replacing them with other ions. It is often used to soften water by eliminating the calcium and magnesium ions responsible for water hardness.
Benefits
- Effective for softening water and removing certain heavy metals.
- Improves the taste of water and prevents scaling of household appliances.
Disadvantages
- Does not eliminate bacteria, viruses or organic chemicals.
- Ion exchange resins have to be regenerated with saline solutions, which increases the sodium content of the water and pollutes the environment during regeneration cycles.
Read also: Glass, plastic, aluminium or stainless steel water bottles: which to choose?
Gravity filters
Gravity water filters, although not directly connected to the tap, can be an alternative or a complement to tap water filters. They are simple, portable devices that use the force of gravity to pass water through a filtering material, usually activated carbon or a ceramic membrane.
Benefits
- Portable and do not require electricity to operate.
- Inexpensive and easy to use.
Disadvantages
- Filtration speed can be slow, depending on the type of filter used.
- Does not remove all types of contaminants, particularly viruses and certain chemicals.
As you can see, each water filtration method has its advantages and disadvantages. However, if your main objective is to filter tap water, certain systems like LaVie's UV-A purification system or activated carbon filters could be particularly well suited to your needs.Â
See our article:Â Tap water filter: What to choose to find out more
Summary table of filtration methods
This table summarises the main features of the different water filtration methods, along with their advantages and disadvantages. It can help you compare and choose the filtration method best suited to your needs.
| Filtration method | Benefits | Disadvantages |
|---|---|---|
| Mechanical filtration | - Effectively removes solid particles such as mud and sand. - Relatively inexpensive. |
- Does not remove bacteria, viruses or dissolved chemicals. - Filters can become clogged and require regular maintenance. |
| UV (ultraviolet) filtration - UV-C | - Effective against micro-organisms, reducing the risk of water-borne diseases. - Does not generate harmful chemical by-products. |
- Does not remove solid particles or dissolved chemicals. - Requires an electrical power source to operate. |
| UV (ultraviolet) filtration - UV-A | - Removes contaminants from the water (traces of medication, bacteria, traces of pesticides, etc.) - Eliminates tastes and odours - Preserves trace elements - PH unchanged - Low energy consumption |
- Limited to between 0.5 and 5 litres of water purification per session |
| Reverse osmosis | - Removes a wide range of contaminants, including heavy metals and nitrates. | - Produces water of mediocre quality because it removes all minerals indiscriminately - Expensive and requires sufficient water pressure to operate. - Generates a certain amount of wasted water (reject water) during the filtration process (3 litres of reject water for 1 litre consumed!). |
| Activated carbon filtration | - Effectively eliminates chlorine, pesticides and organic compounds responsible for bad tastes and odours. - Inexpensive and easy to install. |
- Does not eliminate bacteria, viruses or heavy metals. - Filters must be replaced regularly to maintain their efficiency. |
| Distillation | - Effectively removes dissolved salts, heavy metals and certain chemicals. - Can destroy micro-organisms if water is heated to a sufficiently high temperature. |
- Consumes a lot of energy to heat water. - Does not remove volatile organic compounds (VOCs), which can evaporate with water. |
| Ion exchange | - Effective for softening water and removing certain heavy metals. - Improves the taste of water and prevents scaling of household appliances. |
- Does not eliminate bacteria, viruses or organic chemicals. - Ion exchange resins have to be regenerated with saline solutions, which increases the sodium content of the water and pollutes the environment during regeneration cycles. |
| Gravity filters | - Portable and do not require electricity to operate. - Inexpensive and easy to use. |
- Filtration speed can be slow, depending on the type of filter used. - Does not remove all types of contaminants, particularly viruses and certain chemicals. |
Article written on 19/06/2023 by Pascal Nuti - CIO Solable - Passionate about energy, I'm constantly on the lookout for new targets for improvement, exploring cross-disciplinary paths using novel methods.
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