How Activated Carbon Treatment Works
These devices are commonly known as carbon filters. They actually absorb contaminants to an activated carbon medium. Activated carbon filters are used to remove unwanted tastes, odors, radon, some man-made volatile organic contaminants and are primarily used to remove chlorine and chloramines from drinking water. The efficiency of the unit depends on the type of activated carbon installed, the filter bed depth, the type and concentration of contaminants in the water, and the contact time between the water and the carbon filter. Activated carbon filters are recommended for water without bacteria present.
Carbon filters are easy to install and maintain, and operating costs are usually limited to filter replacement. Depending on the type and concentration of the contaminant being removed, some carbon filters may require special hazardous waste handling and disposal, which can be costly. Other filter types are also available including charcoal and ceramic materials.
Granular activated carbon treatment is most common for private water systems. Granular activated carbon is an effective filter for removing organic chemicals that may be in drinking water. Many other small devices use carbon that has been pressed into a solid block. Use of block carbon may result in a significant drop in home water pressure. These devices also clog easily if the water is cloudy or contains particles. A synthetic resin may be a substitute for carbon. Although activated carbon is efficient in removing a variety of organic chemicals, a specially formulated synthetic resin may be a better absorber for a specific contaminant.
Activated carbon filters do not adsorb every type of contaminant equally. The solid material used in an activated carbon filter is a specialized carbon manufactured for these purposes. Contaminants adhere to the surface of these carbon granules or become trapped in the small pores of the filter. Generally, an activated carbon filter is used with a pre-treatment filter to remove sediment or iron particles that may be present and can clog the carbon filter.