Purification and filtration
Charcoal may be
activated to increase its effectiveness as a filter.
Activated charcoal readily
adsorbs a wide range of organic compounds dissolved or suspended in gases and liquids. Charcoal is often used to filter water to remove bacteria and undesired tastes. In certain industrial process, such as the purification of sucrose from cane sugar, impurities cause an undesirable color, which can be removed with activated charcoal. It is also used to absorb
odors and toxins in gasses, such as air. One striking example is the use of charcoal to remove the smell of marijuana plants in small-scale residential settings. Charcoal filters are also used in some types of
gas masks. The medical use of activated charcoal is mainly the
adsorption of
poisons, especially in the case of suicide attempts in which the patient has ingested a large amount of a drug. Activated charcoal is available without a prescription, so it is used for a variety of health-related applications. For example, it is often used to reduce discomfort (and embarrassment) due to excessive gas in the digestive tract.