OUR range of carbon filter cartridges are manufactured using the full spectrum of carbon technology available today, resulting in the continued improvements in performance across the range of three distinct carbon filter categories. To understand how activated carbon functions is not necessary although "How activated carbon works" is offered, it is the performance that is of paramount importance and hence correct specification for the application.
The primary functions of activated carbon are the the removal of chlorine, volatile organic compounds (VOC), chlorinated hydrocarbons and organic impurities whilst acting as a mechanical filter for particulate reduction due to the cartridge construction. The latest technology has led to the carbon block cartridges using natural coconut shell being considered the best all-round performing filter.
HOW ACTIVATED CARBON WORKS:
Activated carbon is produced under carefully controlled conditions by grinding bituminous coal, peat or coconut shells and heating them in the absence of oxygen. Heated to 540oC to bake off the impurities then treated with superheated steam to 870oC to activate it, this creates a network of cracks and pores that greatly increases the surface area of the carbon. The large surface area is the reason that carbon can adsorb large quantities of various organic molecules.
 Activated carbon filters work in two ways. The first is adsorption. Activated carbon removes dissolved organic contaminants from water by adsorbing them onto the surface of the activated carbon. Adsorption occurs in the pores of the activated carbon where forces attract and hold organic contaminants like a magnet. Hydrophilic (water loving) molecules such as aqueous salts, hardness and other water soluble molecules are not adsorbed onto activated carbon. Hydrophobic (water fearing) molecules are organic solvents and various organic contaminants. When hydrophobic organic molecules are given the choice between activated carbon and water they will adsorb onto the carbon. Hydrophobic molecules are typically hundreds and thousands of times more attracted to carbon than water. This would be equivalent to removal rates of equal to, or better than, 99%.
The second way that activated carbon works is as a catalyst. This is one of the largest applications of carbon for point-of-use. Activated carbon does not remove chlorine but changes it from molecular chlorine CL2 to chloride Cl- . Activated carbon also oxidises hydrogen sulphide to sulphates that do not cause taste and odour problems. The longer the water is in contact with the carbon the more adsorption or catalytic reactions that will take place.
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