Studies on the Adsorption of Amino Methylene Phosphonic Acid Resin for Holmium（III）
摘要
The adsorption behavior and mechanism of a novel chelate resin, amino methylene phosphonic acid resin (APAR) for Ho(Ⅲ) were investigated. The statically saturated adsorption capacity is 258 mg·g-1 resin at 298 K in Hac-NaAc medium. The Ho(Ⅲ) adsorbed on APAR can be repeatedly eluted by 3.0 mol·L-1 HCl and the elution percentage is as high as 95.8%. The resin can be regenerated and reused without apparent decrease in adsorption capacity. The apparent adsorption rate constant is k298=1.14×10-5 s-1. The adsorption behavior of APAR for Ho(Ⅲ) obeys the Freundlich isotherm. The ther modynamic adsorption parameter, enthalpy change ΔH of APAR for Ho(Ⅲ) is 11 .4 kJ·mol-1. The apparent activation energy is Ea=15.8 kJ·mol- 1. The molar coordination ratio of the functional group of APAR to Ho(Ⅲ) is a bout 2∶1. The adsorption mechanism of APAR for Ho(Ⅲ) was examined by using chemical method and IR spectrometry.