Spent NiMo/γA₂O₃ hydrodesulfurization catalyst was regevenated using n-hexane to remove the soluble coke and the oxalic acid to remove the foulant elements and insoluble coke by calcinating it at under the temperature of 500οC for 4 hr. It was then structurally charactrized using AFM techniques, and finally, the lead ion was separated from its aquoues solution via the adsorption batch method with varying concentrations of the lead ions, and then, the absorption efficiency was calculated. The results indicated that the removal efficiency of more than 99% was resulted when the rejuvenated NiMo/Al₂O₃ catalysts were used, compared with 51 % removal when a none rejuvenated one was used.
