Sorption Behavior and Mechanism of Indium（ Ⅲ ） onto Amino Methylene Phosphonic Acid Resin

Sorption behavior and mechanism of indium(III) onto amino methylene phosphonic acid resin

The sorption behavior of amino methylene phosphonic acid resin (APAR) for In(III) was investigated. Experimental results show that In(III) adsorbed on APAR can be eluted with 2mol·L⁻¹ HCl. The apparent rate constant is k₂₉₈=1.50×10⁻⁵s⁻¹. The sorption behavior of APAR for In(III) obeys the Freundlich isotherm. The thermodynamic parameters of sorption, enthalpy change ΔH, free energy change ΔG and entropy change ΔS of sorption (APAR) for In(III) are 24.1kJ·mol⁻¹, −35.1kJ·mol⁻¹ and 200J·mol⁻¹·K⁻¹, respectively. The coordination molar ratio of the functional group of APAR to In(III) is 2∶1. The sorption mechanism of APAR for In(III) was examined by IR spectrometry. XIONG Chun-hua: Born in 1959 0 This project was supported by Foundation of Zhejiang Provincial Education Bureau(No.20010677) and Lishui Science and Technology Bureau(No.2001012).