Study of the adsorption capacity to Co2+, Ni2+ and Cu2+ ions of an active carbon/functionalized polyamine hybrid material

The retention of Co2+, Ni2+ and Cu2+ metal ions from aqueous solution, on a functionalized hybrid material obtained by the anchorage of N-(4-amino-1,6-dihydro-1-methyl-5-nitroso-6-oxopyrimidin-2-yl)-N'-[bis(2-aminoethyl)] ethylenediamine ligand on a low-functionalized activated carbon, at pH 4.5 has been studied. The adsorption isotherms fit the Langmuir equation and the calculated maximum adsorption capacities were compared to those obtained by using the un-functionalized activated carbon as well as to other analogous hybrid materials as adsorbent of the same metal ions. These studies were carried out by rationalizing the resulting adsorption data regarding the stability constant values of the complexes formed by the three metal ions with the free tri-amine function of the ligand. The results demonstrate that the adsorption capacities of the activated carbon-ligand hybrid material towards the three metal-ions studied correlated with the stabilities of the tri-amine-metal-ion bonds formed during the adsorption processes. (C) 2009 Elsevier Ltd. All rights reserved.