Remediation of Coal Tar Contaminated Porous Medium Systems

The legacy practice of municipal gas production has led to thousands of tar contaminated subsurface systems, which have resulted from the disposal and handling practices of combustion by-products formed during gas manufacturing. These tar wastes can vary widely in composition, but they are essentially always complex mixtures that contain all of the 16 poly-nuclear aromatic hydrocarbon (PAH) priority pollutants, and lOO's of other compounds as well. Conventional physicochemical remediation methods have not proven effective for remediating such sites. In this work, a novel approach is investigated based upon alkaline flushing to mobilize the residual tar contamination using a one-dimensional column. A follow-up approach is performed with an ethanol flush to further reduce the flux of PAHs from the treated source zone. More than 50% of the tar residual was removed during the alkaline flushing. Mechanistic understanding of the effects of alkaline solution flushing on wettability and tar mobilization deserve further consideration.Master of Science in Environmental Engineerin