The effect of temperatures and γ-ray irradiation on silica-based calix[4] arene-R14 adsorbent modified with surfactants for the adsorption of cesium from nuclear waste solution

摘要

1,3-[(2,4-Diethylheptylethoxy)oxy]-2,4-crown-6-Calix[4]arene(Calix[4]arene-R14), used as an extractant of Cs(I) from nitric acid, modified by dodecanol and dodecyl benzenesulfonic acid (DBS), was loaded into the pores of macroporous silica-based polymer support (SiO2-P) particles. To evaluate the stability of the adsorbent, the adsorption data at different temperatures (298-323 K) and y-ray absorbed doses (10-200 kGy) were analyzed by the Langmuir isotherm. The minimum adsorbed amount was calculated to be 0.121 mmolg~(-1) at 323 K, approximately 23% reduction compared to 298 K. The maximum adsorbed amount of not-irradiated adsorbent with 0.156mmol g~(-1) decreased by 20% than that irradiated in 0.5 M HNO3. The thermodynamic parameters have revealed that this adsorption reaction is an exothermic and spontaneous process. The reduction in 3 M HNO3 was about 45% by the comparison between the before- and after-irradiation. It was found that both the concentrations of HNO3 and DBS have significant influence on the degradation of the adsorbents.