Kinetic & Thermodynamic Studies on Uranium Ions Recovery Using Magnetite- Dowex 50WX8 composite

Document Type : Original Article

Author

NMA, P.O. Box 530 El Maadi, Cairo, Egypt

Abstract

Batch Experiments on synthesized "Magnetite-Dowex 50WX8" composite were conducted to characterize its capability towards uranium adsorption. The effect of pH, contact time, composite dose, initial uranium concentration and temperature on uranium adsorption rate was investigated to optimize operation conditions of the synthesized composite. Thermodynamic and kinetic parameters have been studied. The maximum sorption capacity from Langmuir reached up to 200 mg/g at room temperature, pH 4, 25 mg of composite and 30 min. contact time. Uranium adsorption kinetics is well fitted to pseudo second order kinetic model at 500 mg/L uranium concentration. The change in thermodynamic parameters (ΔG, ΔH and ΔS) indicates that the adsorption process is a spontaneous exothermic random process. Loaded hexavalent uranium ions were stripped from the loaded composite using 0.25M nitric acid. Optimum conditions were applied to purify dissolved uranium content from a leaching solution of a granite sample from El-Missikat area, Central Eastern Desert, Egypt.

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