GAC filters are usually used as a "polishing filter' in the water filtration process and are highly effective at improving the taste and odor of drinking water. GAC stands for "granular activated carbon" and is made of tiny, loose granules of carbon. What is a Granular Activated Carbon (GAC) Water Filter? 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.
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.Ĭarbon filters also act as a catalyst to change the chemical composition of some contaminants. How do Carbon Filters Work?Ĭarbon filters remove contaminants through adsorption. The material is then subjected to 1600-degree steam to “activate” the carbon. The steam leaves carbon granules filled with cracks and pores, enabling them to store large amounts of chemicals and contaminants. To create the filter, material is heated in the absence of oxygen to 1000 degrees to bake off impurities. Of the above-mentioned carbon sources, coconut shells are the most widely used and are highly renewable. In fact, nearly every type of water filter system-whether it's a backpacking water filter, refrigerator filter, shower filter, pitcher filter, reverse osmosis water filtration system or whole-house filter-utilizes carbon filtration in some way.Ĭarbon filters for water filtration are produced by grinding up a carbon source. Carbon is a commonly-used medium in water filtration processes.