Enhancing lead adsorption in waste lubricant oil with activated clay as bleaching earth

Waste lubricant oil is categorized as hazardous waste that contains several contaminants such as polycyclic aromatic hydrocarbon, chlorinated hydrocarbon, and heavy metals. Among these contaminants, lead has been known as one of the contributive contaminants in used lubricant oil in varied concentrations. To remove this contaminant, adsorption process was carried out by using clay as natural adsorbent (bleaching earth). In order to enhance the adsorption efficiency, the clay was activated by acidification with 1 M, 1.5M, 2 M H2SO4 or calcination in the temperature 300°C, 450°C, 600°C. The activated clay indicated the increase of montmorillonite percentage in clay up to 68% and clay’s surface area up to 67 m2/g from its origin characteristics. The adsorption process showed notable improvement of clay adsorption capacity in removing lead in shorter contact time. The lead removal curve showed that the optimum adsorption condition can be obtained by the use of activated clay with 1.5 M H2SO4 and calcined in temperature 450°C. The optimum adsorption contact time with acid and calcination activated clay was 30 minutes and 180 minutes respectively