Biosorption of Pb(II), Cu(II) and Cd(II) from Aqueous Solution Using Cassava Peel Waste Biomass

The research of biomass modification from cassava peel waste (Manihot esculenta crans) with nitric acid and mercaptoacetic acid has been carried out. The result of biomass modification was used as adsorbent of single and multiple metal ions Pb(II), Cu(II) and Cd(II). Adsorption capacities of metal ions adsorbed (mg g(-1) adsorbent) were optimum at pH around 4 and 5. From thermodynamic data the adsorption capacities for metal ions Pb(II), Cu(II) and Cd(II) on biomass modified by 1.0 M mercaptoacetic acid are higher than on biomass modified by 0.5 M mercaptoacetic acid and on biomass activated by HNO3, with the order of the adsorption capacities for each metal ion as follow; Pb(II) > Cu(II) > Cd(II). Adsorption energies of the metal ions Pb(II), Cu(II) and Cd(II) on cassava peel biomass modified by mercaptoacetic acid and activated by HNO3 are at a range of 13.239-22.972 kJ mol(-1), forming physical adsorption. On the multiple metal adsorption, Pb(II) ion competitions toward adsorbent are higher than Cu(II) and Cd(II) ions on biomass modified by mercaptoacetic acid and activated by HNO3.