Sorption Of U(Ⅵ)、Th(Ⅳ) And Eu(Ⅲ) On P(DEA-co-AA) Microgels

A series of N, N’-diethylacrylamide-co-acrylic acid microgels which carry chelatable functional groups were synthesized by modified surfactant-free emulsion polymerization method. The surface and structure properties were characterized by elemental analysis, fourier transform infrared spectroscopy(FTIR) and transmission electron microscopy(TEM). The effects on the sorption(such as contact time, solid-to-liquid ratio, ionic strength, initial adsorbate concentration and temperature) of U(Ⅵ), Th(Ⅳ) and Eu(Ⅲ) on P(DEA-co-AA) microgels, and the recyclability of the adsorbent was investigated by desorption and regeneration experiments.The experiment results indicated that the sorption of U(Ⅵ), Th(Ⅳ) and Eu(Ⅲ) onto P(DEA-co-AA) microgels increased with increasing m/Ⅴ. The sorption of U(Ⅵ), Th(Ⅳ) and Eu(Ⅲ) was dependent on aqueous pH. With the increase of ionic strength, U(Ⅵ) and Th(Ⅳ) sorption decreased significantly, while the effect of ionic strength on the sorption of Eu(Ⅲ) was not obvious. There are very good correltion coefficients of linearized equations for Langmuir isotherm model, and the sorption of U(Ⅵ) and Th(Ⅳ) process was spontaneous(△G0<0). The effects of temperature on the sorption of U(Ⅵ), Th(Ⅳ) and Eu(Ⅲ) were different. Temperature is advantageous to the adsorption of U(Ⅵ) on the microgels and disadvantageous to the sorption of Th(Ⅳ). After five times’consecutive sorption-desorption processes, microgels still remained excellent adsorption capacity for U(Ⅵ) and Th(Ⅳ).