Sorption behavior of iminodiacetic acid resin for indium

In(III) was quantitatively adsorbed by iminodiacetic acid resin (IDAAR) in the medium of pH = 4.52. The statically saturated sorption capacity of IDAAR is 235.5 mg·g⁻¹. 1.0 mol·L⁻¹ HCl can be used as an eluant. The elution efficiency is 97.9%. The resin can be regenerated and reused without apparent decrease of sorption capacity. The sorption rate constant is k₂₉₈ = 1.94 × 10⁻⁵ s⁻¹. The apparent sorption activation energy of IDAAR for In(III) is 20.1 kJ·mol⁻¹. The sorption behavior of IDAAR for In(III) obeys the Freundlich isotherm. The enthalpy change is ΔH = 17.2 kJ·mol⁻¹.