Preparation and metal-adsorption properties of the polyacrylamide-grafted. sawdust having carboxylate functional group

Abstract

<span style="font-size:11.0pt;line-height: 115%;font-family:Calibri;mso-fareast-font-family:" dejavu="" sans";mso-bidi-font-family:="" mangal;color:#00000a;mso-ansi-language:en-us;mso-fareast-language:en-us;="" mso-bidi-language:ar-sa"="" lang="EN-US">A new adsorbent media containing carboxylate group has been synthesised by the surface modification of a polyacrylamide grafted sawdust. The product exhibits a very high adsorption potential for Pb(II), Hg(II) and Cd(II). The adsorption of metal ions on sorbent have been found to be dependent on initial concentration, <i>p</i>H, temperature and shaking speed. The optimum <i>p</i>H range for the removal of Pb(ll) is 5-9 whereas the maximum uptake for Hg(ll) and Cd(ll) is in the <i>p</i>H range 5-10. Kinetics of adsorption indicates the process to be diffusion controlled. The diffusion coefficients, energies of activation and entropies of activation were calculated and were used to determine the theoretical behaviour of sorption process. Acid regeneration has been tried for several cycles with a view to recover the adsorbed metal ions and also to restore the sorbent to its original state.</span>