Fabrication of cobalt iron oxide alginate nanocomposite as an eco-friendly sorbent for Y(III) and Sr(II) removal from aqueous solution

Abstract

Alginate cobalt iron oxide, Alg-CoFe2O4 nanocomposite was synthesized by ionic polymerization method and employed as a magnetically separable low-cost sorbent for yttrium and strontium removal from an aqueous phase. The produced nanocomposite was characterized using x-ray diffraction, transmission electron microscopy, scanning electron microscopy, and Fourier transform infrared spectroscopy. The hysteresis loop of the nanocomposite, obtained by the vibrating sample magnetometer, shows a soft magnetic behavior with a saturation magnetization of about 6.96 emu/g. The optimum pH for the sorption of Y(III) and Sr(II), studied by the batch mode, was found to be 4.7 and that ion exchange is not the only mechanism in the sorption process. The obtained kinetic data of Y(III) and Sr(II) was analyzed using the reaction rate and diffusion models and it was found that the pseudo-second-order fits well the data with a high correlation coefficient > 0.99. The isotherm study revealed that the sorption of Y(III) was well described by the Freundlich model, whereas the Langmuir model provided the best fit for the sorption of Sr(II).The maximum sorption capacity of the nanocomposite was 78.22 mg/g for Y(III) and 47.5 mg/g for Sr(II). Furthermore, Y(III) and Sr(II) were recovered from the loaded nanocomposite with a high desorption percentage using 1.0 mol/L of HNO3 demonstrating its reusability. It can be concluded based on the results that the Alg-CoFe2O4 nanocomposite has good sorption potential of Y(III) and Sr(II).