Activated carbon filters can be found in your refrigerator water filters, Brita pitcher filters, faucet mounted filters, and most portable water filters that comprise of 1 to 3 stages.
Activated carbon filters have several uses: taste and odor control, chlorine reduction, organic reduction, and reduction of hazardous organic chemicals. Activated carbon filters use a mechanism called adsorption in which matter adheres to the surfaces of an adsorbent (activated carbon). It is referred to as organic adsorbing media because organic molecules, such as herbicides, pesticides, and industrial solvents, tend to adhere to the surface of activated carbon. All activated carbons have a surface whose texture is much like a sponge, and as a result of its porous characteristic, a teaspoon of activated carbon will have a total surface area equal to a football field.
Though activated carbon has the ability to reduce certain types of impurities, there are many types of contaminants which will not be removed by a simple activated carbon filter.
Bacteria, viruses, Arsenic, Cyanide, Lead, Flouride are some examples of impurities which are not removed by activated carbon.