Sorption of cesium and cobalt ions onto novel zirconium silicophosphate/polyacrylamide nanocomposite

Abstract

The ion exchange properties of a novel nanocomposite (nano zirconium silicophosphate/polyacrylamide) were tested against Cs + and Co 2+. Batches were constructed for kinetic and thermodynamic investigations. The highest achievable sorbed amounts of both metal ions were obtained within 120 min. Sorption kinetics of Cs + and Co 2+ followed the pseudo firstand second-order equations, respectively, and was controlled by the chemical sorption mechanisms. Diffusion of both metal ions into particles of the synthesized nanocomposite was the rate determining step. Both metal ions were weakly bonded to sorbent active sites where low values of activation energy (<42 kJ/mol) were obtained. Linear correlation of the sorption isotherm data to Langmuir and Freundlich equations confirmed the favorability of sorption processes. Raising temperature increased both of the monolayer and relative sorption capacities. The maximum sorbed amounts of Cs + and Co 2+ were calculated to be 2.06 and 8.75 mmol/g, respectively, with mean free energies reflecting the ion exchange mechanism. All sorption processes were endothermic and were occurred spontaneously where positive ΔH o and negative ΔG o quantities were obtained, respectively, with higher randomness of Cs + than of Co 2+ .

Synthesis and Application of MnO-Fe2O3 Nanocomposites for the Removal of 137Cs and 60Co Radionuclides from Artificial Radioactive Aqueous Waste

“…This is due to the fact that H3O + had a large concentration at lower pH values and com- The effect of different temperatures on the removal percentage and the amounts of both radioisotopes sorbed from their aqueous solutions was conducted at the optimal contact time and constant initial activity contents. The sorbed amounts and the associated removal of 60 Co were greater than those of 137 Cs, with a positive effect of temperature reflecting the endothermic natures of sorption [33]. During contact time at different temperatures, about 89% and 59% of the sorbed amounts were reached for 60 Co and 137 Cs, respectively.…”