DEGRADATION OF TETRAETHYLLEAD DURING THE DEGRADATION OF LEADED GASOLINE HYDROCARBONS IN SOIL

For over 50 years, leaded gasoline was the only fuel for automobiles, and tetraethyllead (TEL) was the major octane number enhancer used in leaded gasoline. Ample information is available on the fate and remedi ation of gasoline hydrocarbons in contaminated subsoils and groundwate r. However, little is known regarding the fate of TEL in leaded gasoli ne-contaminated subsoils and groundwater. In soil not contaminated wit h gasoline, TEL was rapidly degraded and completely disappeared in 14 d. In gasoline-contaminated soil. TEL degradation was slower: after 77 d, 4 to 17% of the applied TEL still remained in the contaminated soi l. Disappearance of total petroleum hydrocarbons (TPH) was initially r apid but slowed appreciably after 7 to 14 d. As a result, after 77 d. 33 to 51% of the applied gasoline still remained in soil. The retardat ion of TEL degradation in leaded gasoline-contaminated soil is due to the presence of gasoline hydrocarbons. As long as gasoline hydrocarbon s remain in soil, TEL may also remain in soil, most likely in the gaso line hydrocarbon phase.