Laboratory Assessment of Ebullition-Facilitated Migration of Coal Tar through an Amended Sand Cap

摘要

Coal tar migration from sediment to surface water is often facilitated by ebullition in areas were where coal tar product was co-deposited with other organic matter. Ebullition can drag coal tar from sediment upward through the water column to surface water at these sites. When coal tar migrates from sediment it vastly increases the potential for human exposure to high concentrations of PAHs and other constituents. Sediment capping has been used at several sites at pilot scale and field scale to control migration of tar from sediment. Organoclay has been used in a number of configurations (as an amendment to sand, or as a component of a reactive core mat) to adsorb coal tar or other nonaqueous phase liquids (NAPLs) to slow migration from sediment. We performed a laboratory experiment to assess whether organoclay-amended sand was effective for controlling ebullition-facilitated NAPL migration from sediment.