Determination of Heavy Metal Contents in Refined Petroleum Products

Abstract

Heavy metals were determined in petroleum products sold in Agbor, Delta State. Metals analysed for include Cd, Cr, Cu, Pb and Zn. Petroleum products sampled were kerosene, diesel and gasoline respectively. Samples were digested with a mixture of nitric, sulphuric and hydrochloric acid to make the metals available for determination and the concentration levels of the metals analysed using Atomic Absorption spectrophotometer(A.A.S, Buck Scientific Model VGP-210). Anomalous values were found for Cu and Pb except for Cd, Cr and Zn which fell within permissible levels. Petroleum products analysed were perceived to be highly polluted in Cu and Pb from the results obtained. Kerosene showed a higher degree of pollution in Pb than the others. High levels of Pb and Cu could be attributed to anthropogenic sources such as additives applied during refining process, absorption of the metals from storage tanks and supply vessels as well as natural presence of the metals in the source rock from which the crude was obtained. This high level could pose serious ecological and environmental threat within the vicinities where these products are utilized.