Exposure to heavy metals have potential risk for humans being, and due to the proximity of the landfill leachate to underground water resources and ecosystems, treating leachate is essential. The most commonly used method for removing heavy metals is using porous adsorbent especially activated carbon, silicon dioxideand aluminum zeolite. The problems of porous adsorbent are long time to reach equilibrium (due to resistance versus penetration to the pores) and difficulty of adsorbent reactivation. In addition, according to reversible nature of the adsorption, adsorbent can be reused; therefore, the adsorption process is often the first choice for metal removal. Among the available adsorbents, nanosized metal oxides (NMOs), including nanosized ferric oxides, manganese oxides, aluminum oxides, titanium oxides, magnesium oxides and cerium oxides, are justify; LINE-HEIGHT: 80%; TEXT-INDENT: 27pt; MARGIN: 0in 0in 10pt; unicode-bidi: embed; DIRECTION: ltr" There are lots of parameters in the removal of heavy metals from aqueous solutions such as pH, reaction time, amount of adsorbent dose and the amount of metal contaminants in solution. The results showed that with in creasing pH, heavy metals removal efficiency increases. Also Heavy metal removal amount reach edits maximum at 30 min However, increasing the reaction time more than 30 min and the removal efficiency does not affect significantly. Optimizing the parameters for heavy metal removal was at tempted in aqueous solution by using surface response method. Then we discuss removal of heavy metal in leachate. The results showed that in the optimal condition nanosized iron oxides were able to remove more than92% lead, 99% Manganese and 100 % heavy Zinc in aqueous solution. Also the adsorption capacities of 97.8mg/g for the removal of zinc from aqueous solutions were achieved by magnetite nanoparticles. Also, we achieved the percentage removal of 2/41% Lead, 3/46% Manganese and 5/39% Zinc by using 5g/L of nanosized ironoxide adsorbent in leachate, retention time of 30mi and pH=11. Keywords : leachate, adsorption, nanosized iron oxide, lead, zinc, manganese, response surface
