Activated carbon filters are pretty miraculous in terms of their abilities to remove contaminants, odor and bad taste from tap water. But how do they work and do you need one?
Here's a simple overview of how active carbon filters work, what they remove and the limitations.
This blog is also summarised in a 2 min video. For details continue reading below.
How do activated carbon filterswork?
Activated carbon filters, also called charcoal filters, have small porous carbon pieces. Just 4 grams of activated carbon cover the area of a football field (6400 sqm). This large surface area makes them very effective at removing.
When the water flows through active carbon filters the chemicals stick to the carbon resulting in purer water output. The effectiveness depends on the flow and temperature of the water. Therefore most smaller active carbon filters should be used with low pressure and cold water.
In addition to the surface area active carbon filters may have different capabilities in terms of the size of contaminants they remove. One factor is the quality of the activated carbon with coconut shells proven to have the best efficiency. Activated carbon can also be made of wood or coal and sold as granular activated carbon or carbon blocks.
One of the top activated carbon manufacturers in the world is Swedish Jacobi used by TAPP Water. Jacobi produces the highest quality activated carbon such as Aquasorb based on sustainable and fair sourcing of coconuts.
What does active carbon filters remove and reduce?
The activated carbon filter for water is able to eliminate pollutants and also remove the bad taste and odor of tap water, so it is advisable to have them in the house to get the advantages and benefits of drinking filtered water.
In activated carbon filters for water, both pollutants and some chemicals that are added to it, are adsorbed by the carbon, leaving a much more purified result. Within this process, there are natural pollutants such as bacteria, mites or viruses and chemicals. Among all the chemical substances that this type of activated carbon water filter can remove, are the following:
Chlorine: Almost all of this substance in the water can be removed, the figure being greater than 90%.
Chlorine by-products: Such as chloride, most pesticides and herbicides, lithium, phosphate, nitrate or micro plastics among many others.
Special Activated Carbon Filters
In addition to normal activated carbon, some filters either uses treated carbon such as catalytic activated carbon or ads other materials to improve the filtration.
In the case of EcoPro this means that the activated carbon block also removes/reduces:
- 95% or more of Chloramine
- 95% Lead and Zinc (NSF-53 compliant)
- 95% of Copper
- 100% of Microplastics (thanks to the 1-2 micron carbon block)
- 70% of heavy metals such as mercury
- 30-70% of Nitrate
- 70-90% of Lithium
- 30-70% Arsenic and Asbestos
- 80% of Limescale - new version of EcoPro cartridges.
- 70% of Fluoride
- Microbial cyst including giardia and cryptosporidium
By adding Ion Exchange and/or ultrafiltration layers it's possible to remove further content including calcium (limescale) and pathogens (bacteria, coliform and viruses). TAPP Water provides an ultrafiltration filter for countries with non-potable water.
What Activated Carbon doesn't filter
Despite the 80+ contaminants Activated Carbon filters there is also some materials it doesn’t remove
- Healthy minerals such magnesium, potassium, sodium and Calcium (this means TDS is generally not reduced with activated carbon)
- Dissolved solids including minerals, salts or metals such as iron that are not considered contaminants
- Some microbiological contaminants incl coliform, viruses and small bacteria
- Inorganic contaminants such as arsenic and asbestos (only partially reduced)
- Radionuclides although these are reduced
Activated carbon water filters generally do not reduce minerals or TDS (Total Dissolved Solids) which is a common measure used by water filter sales people. Read our separate blog about TDS and minerals in tap water. Read more about TDS and minerals in tap water.
Microbiological contaminants
This is one of the most common drinking water issues in countries with poor infrastructure. Especially for waterborne gastrointestinal diseases (e.g. diarrhea that visitors not used to the local water get).
Natural water represents an adequate environment for bacteria and viruses to grow. Viruses are the smallest form of microorganisms capable of causing disease, particularly those of a fecal origin infectious to humans by waterborne transmission; bacteria are typically single-celled microorganisms that can also cause health problems in humans, animals or plants.
Generally the chlorine in tap water will kill all bacteria and viruses which is why filtering of these substances is not necessary for public water in Europe and North America. Activated carbon filters on their own are generally not sufficient to remove such contaminants.
Activated Carbon filters do not filter/remove corona viruses that may cause Covid19. But don't worry, corona viruses have never been found in disinfected tap water. Read more about how to protect yourself from Coronaviruses and Covid19.
Arsenic
Common in some places where the groundwater has been contaminated. Activated Carbon removes 30-70% of arsenic but is not sufficient in places where this is highlighted as a real problem.
If your local water contains one or more of these substances then you should ensure that the filter reduces them to a safe level. Most of the time this means combining activated carbon with other types of filters such as Ion Exchange. Read more about the best filtering technologies.
Conclusion about activated carbon filters
Activated Carbon is an exceptional material and technology for water filtering and solves many issues but not all.
- Make sure you understand the limitations of activated carbon and chose a filter based on your specific needs
- High quality activated carbon filters such as Ecopro by Tappwater use treated materials to enhance the filtering efficiency including lead, other heavy metals, microplastics and some bacteria
- Activated carbon filters retain the healthy minerals and therefore generally do not reduce the TDS in tap water unless combined with other filtration technologies
- Activated carbon or charcoal filters are also used as one of the stages in most Reverse Osmosis (RO), whole house filters, UV filters and other filter technologies
- If you are looking for an affordable high quality water activated carbon water filter then try EcoPro
In case of uncertainty about which contaminants are filtered feel free to contact us on support@tappwater.co
Read about TAPP Water in comparison with other water filters such as Brita, PUR and Culligan.
Sources:
- Complete list of what activated carbon filters and doesn't filter - https://tappwater.co/en/complete-list-activated-carbon-filtration/
- Learn more about activated carbon water filters - Filter guide for drinking water
- How Activated Carbon adsorption works - http://www.lenntech.com/library/adsorption/adsorption.htm
- What does Activated Carbon remove - https://iaspub.epa.gov/tdb/pages/treatment/treatmentOverview.do?treatmentProcessId=2074826383
- How does Granular Activated Carbon Work - http://www.health.state.mn.us/divs/eh/hazardous/topics/gac.html
- What does Activated Carbon remove http://www.purewaterproducts.com/articles/carbon
- Microbiological contaminants - https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4372141/
Originally posted 15 January 2018. Last updated 22 July 2024.
