Multilevel factorial design for removing lead from used lubricating oil by zeolite Na-A

The urgent requirements for saving the environment and the reusing of lubricating oil low cost have contributed to the need for green and a unique method for carrying out the optimization of chemical processes. In this study, a unique statistical technique called Multilevel Factorial Design and aluminosilicate material, zeolite Na-A, to optimize the removal process of lead from used lubricating oil has been applied and studied. Two variables with three levels have been used in the factorial design to obtain the experimental data. The two factors were the quantity of zeolite Na-A as adsorbent and the time of stirring. It turns out that the zeolite Na-A has the potential in removing lead ions from used lubricating oil. Lead ions concentration based on the results of Inductive Coupled PlasmaOptical Emission Spectroscopy (ICP-OES) was lowered from 2.4 ppm in the untreated used oil to 1.3 ppm in the zeolite treated oil. The results showed the same main effect of the two factors on the removal of lead from used oil, as the concentration of the removed lead was directly proportional to the high level of both factors.