Interestingly, activated carbon filters (aka activated charcoal filters) aren’t like traditional water filters. Instead, they consist of small, black beads or a solid black porous sponge that has undergone some additional processing to make it better at selectively trapping impurities. First, it is injected with heat, steam, or chemicals, which creates millions of small pores in the carbon, vastly increasing the size of the surface area. This activation process creates more pores for the carbon to trap and absorb a broader range of contaminants, making the carbon far more effective as a filter medium.[u]carbon powder[/u]
Each particle of carbon has a large surface area that gives the contaminants the maximum possible exposure to the active sites within the filter media so that more of the pollutants can be absorbed/removed. One pound (450g) of activated carbon contains a surface area of approximately 100 acres, which is almost three times the size of The Pentagon!
This and other remarkable properties of activated carbon make it a useful medium to eliminate impurities from water through adsorption. It’s also used to make respiratory masks, and used in air conditioning units and exhaust fans to rid the air of unwanted odors like smoke fumes, and animal odor.
Activated carbon filters treat water by using a process called adsorption. As the water passes through the activated carbon, the carbon acts like a sponge with a large surface area and absorbs the contaminants in the water. Simply, the activated carbon exerts a magnetic-like pull on the specific impurities and attracts and traps them in the pores of its surface area.
The dissolved impurities migrate from the liquid to areas in the pore channels with the most potent attractive forces. The contaminants are absorbed because the attraction of the carbon surface is much stronger than the attractive forces that keep them dissolved in the fluid. Following that, the filtered water flows to the next stage of filtration, if any.
As for chlorine and other chemicals that do not adhere to carbon, activated carbon filters use a chemical reaction to eliminate such pollutants. Activated catalytic carbon, which is more reactive than regular carbon, chemically alters the chlorine molecules, converting them into a chloride.[u]coal based activated carbon manufacturers[/u]
