This also means that there will be places of relatively stagnant water within the filter, which can become a breeding ground for bacteria.

These channels mean that the water overall is coming in contact with less of the GAC surface area than it would otherwise, and GAC already has the smallest surface area of the activated carbon filter types. Water naturally wants to travel down the path of least resistance, and this means that it will often form and follow channels as it flows through the GAC media.

While GAC filters are great in theory, there are two main downsides to this carbon filter type: they’re inefficient, and they can harbor bacteria. While it has relatively little capacity to form chemical bonds, this property is especially pronounced if the GAC granules have been impregnated with other substances during their formation and activation. They can also be electrostatically trapped by being more attracted to the surface of the granules than the surrounding water, or contaminants can even form chemical bonds with the activated carbon. The contaminants in the water can then be physically trapped by the small pore sizes of the granules. Water then flows through these containers and comes into contact with porous surfaces of the GAC granules. GAC filters work by taking chunks or granules of activated carbon and packing them in a canister or other container. They can be found as stand-alone water filters or as add-ons to more comprehensive filtration systems, and they’re usually not very expensive. Granular activated carbon (GAC) filters, also called fixed-bed carbon filters, are a common form of carbon filtration. These are the different types of carbon filters, how they work, and what contaminants they’re best at removing. While the process of making activated carbon remains the same, not all carbon filters are created equal. It’s also used to recover gold and other precious metals from ore, and by far the most widespread application residentially is in water filtration. Applications of Activated CarbonĪctivated carbon isn’t just used to purify water – it has widespread industrial applications for reducing gas emissions as well. The activated carbon surface is now able to interact with and adsorb (trap) contaminants in the water that passes over it.

Some of these pores are only microns wide or less, and that gives it an extremely large surface area. You can read more on the process of carbon activation and impregnation here.Īctivated carbon as a finished product is different from regular carbon because its surface now has millions of tiny pores. This char is then treated chemically, usually with argon and nitrogen, before once again being heated – this time to 1,100-2,200 degrees.įrom there the now-activated carbon can be impregnated with different materials that will boost its filtration properties. To “activate” these carbon sources, first, the coconut shells or coal chunks are heated without oxygen to 1,100-1,650 degrees Fahrenheit until they burn down into a carbon char. The most common sources of activated carbon for water filtration are coconut shells or coal. It’s essential for life itself, hence the moniker carbon-based life forms, and it also makes up many other things including diamonds and fossil fuels.Īctivated carbon is produced by taking something that contains carbon and putting it through thermochemical processing.

4 How Often Do You Need to Replace Carbon Filters?Ĭarbon is the element that is found in every organic compound.

3 Is the Carbon in Water Filters Dangerous?.

Activated carbon