氨基膦酸树脂吸附镉的性能及机理

Adsorption Mechanism of Cd on Amino Methylene Phosphonic Acid Resin

研究氨基膦酸树脂对Cd(Ⅱ)的吸附行为。结果表明,pH=5.6时,静态饱和吸附容量为294.5mg/g·树脂,用2.0mol·L^(-1)HCl解吸,一次解吸率为95.2％。等温吸附服从Freundlich经验式,表观吸附速率常数k_(298)=1.35×10^(-5)s^(-1),表观吸附活化能E_a=15.7kJ·mol^(-1),吸附反应的ΔH=19.9kJ·mol^(-1),吸附物中树脂功能基与Cd(Ⅱ)的配位比约为1:1。

The adsorption behavior of Amino Methylene Phosphonic Acid Resin (APAR) for Cd(Ⅱ) is investigated. The results show that the statically saturated adsorption capacity is 294.5mg/g·resin at pH=5.6 in the HAc-NaAc medium. Cd(Ⅱ) absorbed on APAR can be eluted with 2.0mol·L-1HCl and elution percentage is as high as 95.2% . The adsorption behavior of APAR for Cd(Ⅱ) is consonant with the Freundlich isotherm. The apparent adsorption rate constant and activation energy are k298 = 1.35×10-5s-1 and Ea = 15.7kJ·mol-1, respectively. The enthalpy change AH of adsorption is 19.9kJ·mol-1. The molar ratio of functional group to Cd (Ⅱ) is about 1:1.