If you are not an owner of water purification system or an aquarium, you might be surprised how come an activated carbon is used as an air purifier filter. The use of carbon filters for water purification is considered as the oldest method of water purification.
It is used by people for centuries to filter impurities from drinking water. In the industry of aquarium, activated carbon is currently one of the most effective adsorbents used and the largest selling maintenance product. It is used to remove dissolved organic molecules, chloramines, chlorine, and some heavy metals. It is also used to remove residual dyes medications like dyes and antibiotics.
What is an Activated Carbon?
Activated carbon, also known as activated coal or activated charcoal is derived usually from charcoal. It is a form of carbon which has a small charge of electro-positive added to it. The added charge makes it more attractive to impurities and chemicals that are negatively charged. Charcoals used in making activated carbon are made by burning coconut husks, nutshells, hardwood, and other materials that are carbon-based.
To make it available for chemical reactions and adsorption, carbon is also processed to have an extremely large surface area and make it very porous. Through the help of nitrogen gas adsorption, it is determined that with only 1 gram of activated carbon usually has a surface area of 500 square meters or 1/10 the area of a football field and 1 pound of activated carbon has 200 miles of fissures and pores with an area of 4 million square feet.
Activated carbon, especially the granulated one combined with packed tower aeration method is recognized by EPA (United States Environmental Protection Agency) to remove carbon tetrachloride from drinking water to below 0.005 milligram per liter or 5 ppb. source
Activated Carbon Filter Used in Air Purifiers
Activated carbon is frequently joined with other minerals like zeolite when used in air purifiers. Zeolite can act as a chemical sieve and a filer for absorbing molecules and ions.
In several units of air purifier, the carbon is impregnated with potassium iodide and mixed with impregnated active alumina in order for the absorbent qualities to increase. People with MCS (Multiple Chemical Sensitivity) will benefit from these air purifiers because they can absorb formaldehyde found in furniture upholstery, wood paneling, and carpet. These air purifiers can also remove perfumes and household cleaning chemicals, making your house more fresher and breathable for elderly, children, babies, asthma sufferers, and people in general.
Type of Air Contaminants Activated Carbon Air Filters Can Remove
Most fumes from household cleaners, cooking, and organic odors can be removed or reduced by activated carbon filters. It can also remove VOC (Volatile Organic Chemicals), solvents, radon, THM (trihalomethane), benzene, chlorine, herbicides, pesticides, and other manmade chemicals.
Below is a chart which rates the activated carbon filter’s performance on its ability to remove the following contaminants:
Choosing the Right Activated Carbon Air Purifier
When buying an activated carbon air purifier, you should choose a filter with a big amount of activated carbon. A lot of low quality air purifiers sold in the market contains only a very tiny amount of activated carbon. These air purifiers will perform poorly compared to those with bigger volumes of activated carbon.
Another point to consider is whether the activated carbon media can be replaced without changing the whole containing cartridge. Complete cartridge unit is much expensive compared to bulk media.