Carbon Filter removes contaminants through adsorption.  Adsorption means that contaminants are attracted to the surface of the activated carbon and held to it, much the same way a magnet attracts and holds iron filings.

Carbon filters also act as a catalyst to change the chemical composition of some contaminants. Activated carbon is ideal for removing chlorine, organic chemicals such as pesticides.THMs like chloroform, and many VOCs that are components of gasoline, solvents and industrial cleaners.