What is granular activated carbon?

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dingxinda9

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Made from a variety of carbon based materials such as coal, petroleum, nut shells and fruit pits.
Activated carbon has been found extremely effective in and is the industry standard for reducing/removing organic chemicals, including chlorine, pesticides, industrial chemicals, THM's, PCB's and other similar halogenated organic compounds, as well as bad taste & odor.
 
Can be POE or POU; When used as POE it is effective at removing chlorine and many tastes and odors from household water. coconut shell based activated carbon pellet  Recently, because of concern over health effects from inhaling toxic organic chemicals found in shower water etc. there is interest in more effective POE carbon treatment systems.  When used as POU there is a vast range of types of systems and degrees of effectiveness.
 
Lower quality ones remove only chlorine, tastes and odors for a short time.  High quality ones remove this plus a wide range of toxic organic chemicals (VOCs).  Chlorine is easier to "hold on to" than VOCs, so if the manufacturer takes shortcuts on the processing or amount of carbon in the filter, the filter will not grab the VOCs, or will grab them initially, then let them go in favor of incoming chlorine.
 
Granular Activated Carbon (GAC)
Granular activated carbon is a form of charcoal that has been treated by high temperatures and steam in the absence of oxygen. This process produces small granules that are extremely porous with a high surface area. GAC filters remove organics from the water by holding them to its surface, a process known as adsorption. As water passes around each little particle of carbon, the organics adhere to the particles.
 
One pound of granular activated carbon has a total surface area of about 125 acres, giving each filter the ability to handle large amounts of water before becoming "used up". When GAC is used in a tall column, most of the unwanted organic pollutants are adsorbed in the top layers, and as the water passes downward it progressively contacts cleaner and cleaner carbon. This in depth filtering "polishes" the water as it passes out of the column and provides a wide margin of organic removal.
 
While a wide variety of filters are made of GAC, not all will perform equally. activated carbon for air purification  Effectiveness varies with the kind of carbon used in the filter, the filter design, the way it is used and maintained, its age, and the condition of the water being treated.

Posted 20 Oct 2020

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