Equilibrium and Kinetic Studies of Cu(II), Ni(II) and Cd(II) Adsorption from Aqueous Solution by Chemically Modified Corn Cob

Abstract

Adsorption of copper, nickel and cadmium ions from aqueous solution by poly(acrylic acid) and polyacrylamide modified corn cob was investigated. The modified corn cob was characterized by optical microscope, FTIR, CHNO elemental analysis and N₂ adsorption-desorption. The effect of parameters on heavy metal adsorption including contact time and concentration were studied. The results showed the maximum adsorption capacities of chemically modified corn cob were 239.55, 156.46 and 361.89 g kg^-1 for Cu(II), Ni(II) and Cd(II), respectively. Langmuir isotherm was fitted with the adsorption equilibrium and the pseudo-second order was fitted with the adsorption kinetics for all metal ions. The adsorbents were easily regenerated by 0.1 mol dm^-3 HCl solution up to four cycles with the removal performance of 59-100%.