Removal of Ag ﴾I﴿ ions using potassium nickel hexacyanoferrate ion exchanger incapsulated barium alginate from aqueous solutions.
Abdel- Fattah Fadel Shaaban ,Mohammed Morsy Azab, Asmaa Said
Spherical beads of potassium nickel hexacyanoferrate ion exchanger incapsulated barium alginate (KNiHCF-Ba-alginate) have been prepared by ionotropic gelation of nickel chloride, potassium ferrocyanide with sodium alginate in the presence of BaCl2 solution. The composition, properties and morphology of the resulting ion exchanger have been characterized by Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), x-ray diffraction (XRD) and thermogravimetric analysis (TGA). Batch technique was employed to examine the effects of different parameters such as solution pH, concentration of metal ions, contact time and medium temperature on silver ion uptake. The results indicated that the barium–alginate ion exchanger have high affinity towards silver ions. The ion exchange data have been perfectly described by Freundlich isotherm rather than other isotherms such as Langmuir and Temkin. Kinetics data have been analyzed using pseudo-first order, pseudo-second order and intra-particle diffusion equations. The resulted showed that pseudo-second-order kinetic model was best fit with the obtained data. Also, thermodynamic data proved the spontaneity of sorption process. Furthermore, the removal of silver ions using KNiHCF-Ba-alginate has been studied using column technique as well.
Keywords: Potassium nickel hexacyanoferrate