Studies on adsorption behavior and mechanism of copper(II) onto amino methylene phosphonic acid resin

The adsorption behavior and the mechanism of a novel chelate resin, amino methylene phosphonic acid resin (APAR) for Cu(II) were investigated. Cu(II) was quantitatively adsorbed by APAR in the medium of pH=4.09. The statically saturated adsorption capacity is 181 mg/(g resin). Cu(II) adsorbed on APAR can be eluted by 1.0-3.0 mol/L HCl. The rate constant is k(298) = 5.58 X 10(-5) s(-1). The adsorption of Cu(II) on APAR follows the Freundlich isotherm. The DeltaH of the adsorption is 3.91 kJ/mol. The apparent activation, energy is E-a = 21.4 kJ/mol. The coordination molar ratio of APAR to Cu(II) is 1/1. It is shown that the nitrogen and the oxygen atoms in the functional group of APAR coordinate to Cu(II).