Comparison of Extractants for Removal of Lead, Zinc, and Phenanthrene from Manufactured Gas Plant Field Soil

Abstract

Polycyclic aromatic hydrocarbons (PAHs) and heavy metals found at former manufactured gas plant (MGP) sites are of major environmental concern. An investigation is made into evaluating the capability of various extractants including surfactants, cosolvents, chelating agents, acids, and cyclodextrins for removing phenanthrene, lead, and zinc from a contaminated MGP soil. The determination of the most promising extracting solutions is critical for the development of effective treatment technologies such as soil washing/flushing and electrokinetic remediation. MGP contaminated soil was silty sand with 11% organic matter containing higher levels of phenanthrene and two heavy metals (lead and zinc). Several batch tests were conducted using the soil with different extracting solutions at various concentrations to enhance the removal efficiency and to optimize the concentration of each extractant. The test results showed that both surfactants (Igepal CA-720 and Tween 80) at a wide range of concentrations were effective for the removal of phenantherene from the soil. Only selective cosolvents and cyclodextrins (