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The History of Activated Charcoal for Hazardous Waste Uses

A growing society exudes many hazardous waste products, such as wastewater and industrial gasses. The emitted hazardous wastes cannot be disposed of in a manner like trash, but requires treatment for waste removal. Activated charcoal provides a medium for removing harmful wastes from both gaseous and liquid substrates.

  1. Activated Charcoal Type

    • Activated charcoal is not the typical charcoal found at a neighbor's backyard barbecue. Instead of burning wood for barbecue charcoal production, activated charcoal wood oxidizes through hot air or steam processes. The resulting activated charcoal has many small openings, or pores, across its surface area. The pores allow adsorption to occur, pulling hazardous waste products from gasses and liquids.

    Gaseous Hazardous Waste Treatment

    • Activated charcoal has been used as a physical medicine since ancient times. However, use of activated charcoal for gaseous hazardous waste removal did not begin until the 1900s. Medical and municipal wastes were typically incinerated, or burned. The resulting fumes contained harmful heavy metals, such as mercury. Activated charcoal was placed in a fabric filter within the incinerator's flue. The fumes would be forced through the filter. As a result, the activated charcoal adsorbed the harmful heavy metals from the moving gas, leaving cleaner fumes to escape out into the atmosphere. With the enactment of the 2005 Clean Air Mercury Rule, mercury emission control became more stringent, requiring more activated charcoal adsorption for less wastes exuding into the air .

    Liquid Hazardous Waste Treatment

    • Many liquid types are treatable with activated charcoal. Groundwater and wastewater treatments are two of the most common uses for activated charcoal. The 1986 Amendments to the Safe Drinking Water Act, backed by the EPA (Environmental Protection Agency), required limits on drinking water contaminants. Activated charcoal became the treatment of choice. Water is forced through an activated charcoal filter. Contaminants adhere to the activated charcoal's pores, removing harmful contaminant molecules.

    Activated Charcoal Properties

    • Charcoal's adsorption ability declines as more contaminants adhere to it. Instead of disposal, activated charcoal can be reactivated. The adsorbed contaminants are removed from the activated charcoal's surface, freeing surface area for reuse. The length of time between each charcoal reactivation depends on the contaminant volume that passes across the charcoal's surface.

    Charcoal Demand

    • As populations and technology advance, more hazardous wastes are produced from industrial processes. Activated charcoal is created domestically, as well as imported. Demand has increased each year by 1.3 percent between 2000 and 2005. In 2005, 363 million pounds of activated charcoal were needed in the United States for both gaseous and liquid treatment processes.

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