Abstract
This work concerned with the evaluation of different heavy metals concentrations in used lubricant oils for different type of gasoline vehicles. Used oil considered a significant environmental pollutant. Metals studied are Fe, Cu, Al, Cr, Pb, Zn, Ni and Cd. Most of these metals are carcinogenic or toxic to humans and environment, also increasing their concentration in lubricant oils leads to engine vehicle problems. ICP-MS was used here because of its fast multi-element analysis abilities with highly sensitivity. Saudi Arabia was selected because it has the highest number of gasoline cars in Middle East, hard weather and rich earth with minerals and petroleum. Trusted oil samples were collected with knowing oil type, car type, model, engine capacity, car mileage, and oil mileage. Metals concentrations versus car model, engine capacity, oil mileage changes and vehicle mileage spend were studied. It's found that virgin oils are not clear from harmful metals for examples the concentration of Pb and Ni reached around 2600 and 850 mu g/L, respectively. General descending order of the concentration of these metals in used oil were as following: Zn > Fe > Cu > Pb > Al > Cr, Ni, Cd. Aluminum showed higher concentration levels (reached around 4000 mu g/L) in new cars in comparison with around 1000 mu g/L in old one. Zinc concentration increased in new cars than in old cars, but it is decreased as oil mileage or car mileage increased. The engines capacity studied do not show a strong impact in metals concentrations; however, the big engine capacity generating approximately double volumes of used oil contaminations in every changing time than small engines. In general, old cars in addition for increasing of oil mileage changed, car mileage and engine capacity lead to increase of harmful metals in used oil which increases the environment problems.