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Activated carbon filter, we feels suddenly surrounded by this word. If you are using cosmetic product then I am sure you might have came across charcoal face wash or Activated charcoal skincare products. That black kind of tube promising you skin free from dust and pollutant.
Ever bothered to know more about Activated carbon or activated charcoal more ! With increasing pollution around in water and air and your search for keeping your family safe from this, I am sure you would be curious to know more on activated carbon filter.
What is Activated charcoal?
I am sure you would be very much familiar with charcoal but what does activated means here?
As you would be knowing common charcoal is made from peat, coal, wood, coconut shell, or petroleum. Activated charcoal is manufactured by heating common charcoal in the presence of a gas at very high temperature. This heating process results in charcoal with lots of internal spaces or “pores.”
This ‘activation’ process works at atomic level and inter molecular forces comes in action. The process strips the common charcoal of previously absorbed molecules and frees up bonding sites again. This process also reduces the size of the pores in the charcoal and makes more holes in each molecule, therefore, increasing its overall surface area. As a result activated charcoal become extremely adsorbent, allowing it to bind to molecules, ions, or atoms.
So the ‘activated’ in charcoal means it is now activated to act against any external molecule, ion or atom and ready to bond when exposed in contact.
How does Activated charcoal works?
Let’s deep dive to inter molecular forces, which binds molecules of same element together. Activated charcoal is having a large surface area and holes at atomic level which is ready to bond. What comes here in picture is a weak inter molecular force called dispersion force between charcoal and pollutant.
Dispersion force often called as The London dispersion force is a temporary attractive force that results when the electrons in two adjacent atoms occupy positions that make the atoms form temporary dipoles. London forces are the attractive forces that cause non-polar substances to condense to liquids and to freeze into solids when the temperature is lowered sufficiently.
Carbon filters remove pollutants with a process known as adsorption. Note that this is different from absorption. In absorption, the substance you want to remove (let’s say water) is absorbed into the structure of the absorbent (like a sponge), but it doesn’t become a part of the absorbent on a molecular level. Therefore, when you absorb water with a sponge, the water does not become chemically bonded to the sponge. It just fills in the spaces inside it.
Carbon filters on the other hand use ad-sorption, not ab-sorption. The key difference here is that during adsorption the pollutants stick to the outside of the carbon. Whereas with absorption, the pollutants are absorbed inside the structure itself–as with the sponge
So by this process, activated charcoal or activated carbon traps any pollutants or any external substance where it is exposed to. Because of this behaviour activated carbon finds its uses in poison treatment, for filtering out undigested toxins and drugs in kidney treatment, water and air filtration, cosmetics, teeth whitening and oral health etc.
What is Activated carbon filter?
Activated carbon air filters are the filters most commonly used to remove gases. They are designed with activated charcoal pellets suspended in a honeycomb mesh structure. These Carbon filters are used for trapping unwanted smells, toxic fumes and other volatile organic compounds (VOCs) which are often released from common household products.
Activated carbon filters can particularly benefit people who suffer allergies or aggravation from impure air, including second hand smoke. If you are or live with a smoker, using an activated carbon filter in your home air purification system can provide unparalleled benefits to your respiratory health.
Does Activated carbon filter require any other filter?
Yes, Activated carbon is not very effective at filtering particulate pollution. Filters like HEPA filters are designed to capture particles like the small PM 2.5 particles.
While activated carbon can adsorb hundreds of different chemicals and odours, it cannot remove everything. Carbon is not especially great at removing some common chemicals such as formaldehyde, or hydrogen sulphide. For this
Activated carbon filter cannot remove fine particles like mold, dust, or pollen from the air. so, in air purification systems, activated carbon filters often used in conjunction with HEPA filters to trap known allergens and impurities like
- Mold spores
- Pet hair
- Common household chemicals
- Benzene and other VOCs