Activated Carbon and Its Uses
The most commonly known use of activated carbon is for the purification of water sources. Activated carbon filters are one of several systems used to purify water drawn from wells and springs for home use. It is most effective in the removal of organic substances from water.
Activated carbon is carbon that has been processed to make it extremely porous. This porosity multiplies the surfaces available to absorb toxins or react with chemicals. It is most often made from charcoal. Because it is a highly absorbent material, carbon removes a wide variety of contaminants and impurities from both air and water. When chlorine and other disinfectants are used in water, certain by-products, which are known to be carcinogenic, are produced. Activated carbon removes these substances—DBPs—from treated water without adding any undesirable substance of its own.
It is not useful for removing mineral substances such as iron. If well water has a high concentration of iron or other mineral, it is wise to combine filters: activated carbon for organic materials and special iron filters for the mineral. Filters may use one of two different forms of activated carbon: solid blocks or granulated carbon. The block form is usually more effective due to having more absorbent surfaces.
Carbon filters are known to be among the oldest of filters used to purify water, perhaps as far back in history as early Egyptian. In the 1970’s it was first manufactured into activated block form and made porous to create more absorbent surfaces.
Activated carbon has other applications as well as air and water purification. It is used in precious metal recovery, in medicine to treat poisonings, in gas purification, and to distill alcoholic beverages. It is used in space suits for air cleaning. Activated carbon is the substance that filters water in fish aquariums.
Substances filtered by activated carbon are purified because the materials being removed are bonded to the carbon surfaces and held there, which is why a greater amount of surface is more effective in the removal.
Derived from organic substances such as nutshells and wood, activated carbon is also used in various environmental applications, such as spill cleanup and capturing volatile compounds from painting, dry cleaning and other processes.
Activated carbon is among the most valuable substances available for the purification of air and water, treating poisoning victims, purifying gas and alcoholic beverages, and much more.