Sequestering polycyclic aromatic hydrocarbons in asphalt

Abstract

This invention is based upon the discovery that activated carbon can be used to sequester polycyclic aromatic hydrocarbons that may be present in asphalt and creosote compositions. The treatment of asphalt and creosote compositions with activated carbon accordingly reduces the level of free polycyclic aromatic hydrocarbons in such compositions by sequestering them therein or removing them from the composition. After being sequestered the polycyclic aromatic hydrocarbons remain trapped in the asphalt or creosote composition, and are not available to the environment during normal processing into useful industrial products. This sequestration reduces the risk of exposing humans and the environment to the polycyclic aromatic hydrocarbons which would otherwise be free to migrate from the asphalt or creosote product during manufacturing and the service life of the product. In other words, the polycyclic aromatic hydrocarbons are absorbed onto the activated carbon and are not available for bioaccumulation from the environment.

Dependencies are inferred from the claim text.