Activated carbon adsorbs. The chemical process of absorption is commonly compared to a sponge soaking up water. The water is fully integrated into the sponge, not being limited to the surface area. Differently, adsorption is a process whereby molecules stick to the surface area only. As mentioned above, activated carbon has a large surface area due to being a porous material. The unwanted substance sticks to the surface area of the carbon particles.
One of the common utilizations of this porous carbon is to filter gas. Not as in fuel, but the gaseous substances that are either naturally produced or expelled from various machinery. Take, for example, air filters. Air is technically a gas, and when the air contains impure elements, a purifier in the form of a filter will help remove these impurities. In a slightly different form, the activated charcoal will perform the same function with water—a use common in fish tanks.
Yet one of the long-standing functions of activated charcoal is oral ingestion. Companies make pills that contain activated charcoal which dissolve in the stomach, allowing the granular carbon to remove toxins. You can find a ton of claims on the Internet about the magic that taking a dose of activated charcoal performs, many of which aren’t medically confirmed, however, it is common for hospitals to use activated charcoal for this use. It is widely known to be safe to ingest and acts as a poultice.
Another use gaining momentum is using activated carbon as a teeth stain removal device. Your teeth’s health is important, and the way activated charcoal works also helps to bind plaque, making it an effective whitening tool. Put some of it on your toothbrush with liquid water. It will be weird to brush with at first—seeing the black get smeared on your teeth will feel counterproductive. However, it will rinse off your teeth easily enough and you’ll love the results. Just be careful to avoid staining your sink—keep soap handy to quickly clean up any messes which ensue. Many people swear by this method to whiten their teeth, and its use on teeth as a cleaner and whitener goes back for centuries.
One of the things that using active charcoal as a filter does is the loss of odors in gasses. Odors, and any other prone elements of the gas, get trapped in the activated charcoal through a process called adsorption. Through adsorption the particles bind to the surface of the activated charcoal—which is why it is imperative that activated charcoal actually be activated; the greater the available surface, the better the grade it gets for trapping.
It is effective enough that there are underpants available for purchase which make use of activated charcoal for moments of flatulence. Let’s face it—suspension of flatulence detection would do everyone a world of good. If only they could make activated underwear for dogs and cats; the media would have a field day!