Activated carbon is a crude form of graphite, the substance used for pencil leads. It differs from graphite by having a random imperfect structure which is highly porous over a broad range of pore sizes from visible cracks and crevices to molecular dimensions. The graphite structure gives the carbon it's very large surface area which allows the carbon to adsorb a wide range of compounds.

What is adsorption?

Adsorption is the process by which liquid or gaseous molecules are concentrated on a solid surface, in this case activated carbon. This is different from absorption, where molecules are taken up by a liquid or gas

Activated carbon is used for the removal of dissolved components from, freshwater waste water and marine systems. Activated carbon is effective against the following;

organics

colour

chlorine & bromine

malachite green & many dyes

ozone