Sorption of Radionuclide ~(63)Ni(II) on Bentonite

In this work,the bentonite was characterized by Fourier transform infrared(FTIR) spectroscopy,X-ray powder diffraction(XRD),scanning electron microscope(SEM).The sorption of radionuclide 63Ni(Ⅱ) on bentonite was investigated by batch technique under ambient conditions.The effect of contact time,pH and coexistent electrolyte cations on 63Ni(Ⅱ) sorption to bentonite was examined.The results demonstrate that the kinetic adsorption data is well described by the pseudo-second-order model and the sorption of 63Ni(Ⅱ) is strongly dependent on pH and ionic strength at low pH values.The sorption of 63Ni(Ⅱ) is dominated by outer-sphere surface complexation or ion exchange at low pH,whereas inner-sphere surface complexation is the main sorption mechanism at high pH.In addition,the removal of 63Ni(Ⅱ) to bentonite is also strongly affected by FA and cations.