Study of Leaching and Adsorption of Heavy Metals by the Activated Carbon Derived From Sewage Sludges
Six types of activated carbons were produced from digested sewage sludge by different manufacture routes and characterized by the surface area and porosity analysis. They were then subjected to the leaching tests and adsorption tests for heavy metals by batch technique. The results show that all these activated carbons had a notable surface area and porosity. For most sludge-derived activated carbons, although the heavy metals contents retained in the activated carbons were high, the amounts of leached metals were generally low with the exception of Zn. All the produced activated carbons were adsorptive of Cd, Cr, Pb and Ni at high concentrations. Out of the six metals investigated, Pb was most readily adsorbed followed by Cd, Cu, Cr, Ni and Zn.