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.