摘要
The adsorption behavior of241Am(Ⅲ) and Eu(Ⅲ) by silica/polymer-based iso Hex-BTP adsorbent(iso HexBTP/Si O2-P) was investigated by a batch experiment method. iso Hex-BTP/Si O2-P exhibited high affinity and selectivity for241Am(Ⅲ) over152Eu(Ⅲ) in 2–4 mol/dm3 nitric acid solutions. Within the experimental contact time range of 0.5–24 h, iso Hex-BTP/Si O2-P showed high selectivity for241Am(Ⅲ) compared to152Eu(Ⅲ) in3 mol/dm3 nitric acid solution. However, the adsorption kinetics of241Am(Ⅲ) and152Eu(Ⅲ) was slow. Eu(Ⅲ)adsorption followed the pseudo-second-order kinetic model, indicating chemical adsorption as the rate-limiting step of the adsorption process. And the adsorption agreed well with the Langmuir adsorption model at various temperatures. The adsorption kinetics and isotherm data indicated that the equilibrium adsorption capacity, the adsorption rate, the maximum adsorption capacity and the adsorption affinity, increased with temperature. The thermodynamic parameters, negative change in Gibbs free energy, and positive change in enthalpy and entropy,suggested that the adsorption of Eu(Ⅲ) was spontaneous and endothermic process with an increase of entropy.
The adsorption behavior of 241Am（III） and Eu（III） by silica/polymer-based isoHex-BTP adsorbent （isoHex- BTP/SiOz-P） was investigated by a batch experiment method, isoHex-BTP/SiOz-P exhibited high affinity and selectivity for 241Am（III） over 152Eu（III） in 2-4 mol/dm3 nitric acid solutions. Within the experimental contact time range of 0.5-24 h, isoHex-BTP/SiO2 -P showed high selectivity for 241Am（III） compared to 152Eu（III） in 3 mol/dm3 nitric acid solution. However, the adsorption kinetics of 241Am（III） and 152Eu（III） was slow. Eu（III） adsorption followed the pseudo-second-order kinetic model, indicating chemical adsorption as the rate-limiting step of the adsorption process. And the adsorption agreed well with the Langmuir adsorption model at various temperatures. The adsorption kinetics and isotherm data indicated that the equilibrium adsorption capacity, the adsorption rate, the maximum adsorption capacity and the adsorption affinity, increased with temperature. The thermodynamic parameters, negative change in Gibbs free energy, and positive change in enthalpy and entropy, suggested that the adsorption of Eu（III） was spontaneous and endothermic process with an increase of entropy.
基金
Supported by National Natural Science Foundation of China(Nos.11305102,91126006,21261140335 and 91226111)
Doctoral Fund of Ministry of Education of China(No.20130073110046)
