In this study we examined the adsorption, kinetics and thermodynamics of heavy metals of used engine oil that come during engine operation and forsaw the possibility of polluting soil and ground water. the effect of temperature on
adsorption was investigated in the range (15 – 45o C) and results showed that maximum removal occurred at 45C. Effect of pH indicated that maximum removal of both Zn and Pb was at pH =13. Increasing adsorbent (soil) dosage from 0.5 to 3g showed that maximum adsorption of both Zn and Pb onto soil occurred with 3 g of soil. Equilibrium concentration happened at 90 minutes. Lanqmuir and Freiundlich models were used to study adsorption process at equilibrium and the
results showed that Frenundlich is better for Zn while Lanqmuir fits better with Pb. In order to investigate adsorption behavior of Zn and Pb on soil, three kinetic models applied; Pseudo-first order, Pseudo-second order and intra- particle diffusion models were applied to fit kinetics data. The rate constants and correlation coefficients were determined for the three models. Thermodynamic parameters such as Gibbs free energy, standard enthalpy and standard entropy change were calculated for both zinc and lead.