URANIUM SEPARATION FROM WASTEWATER BY ELECTRODIALYSIS

Uranium is a toxic and radioactive heavy metal found in nuclear effluents and should be treated by considering economic and environmental aspects. In this study, uranium separation from synthetic effluents by electrodialysis was investigated. Taguchi method was used to plan a minimum number of experiments. An orthogonal L9 array (three factors in three levels) was employed to evaluate the effects of flow rate (5, 15 and 30 mL/min), voltage (10, 20 and 30 V) and feed concentration (200, 500 and 1000 mg/L) on performance of uranium separation. ANOVA method was applied to evaluate the relative effect of each factor. Results showed that increasing voltage and decreasing flow rate improves performance, and initial concentration does not affect it considerably. The effect of flow rate was more significant. Electrodeionization was applied for final treatment of dilute solutions. The effect of magnesium ions in the feed solution caused a decrease in uranium removal. The relation between current and voltage was linear. A comparison between actual and theory energy consumption showed a considerable difference due to concentration polarization. Based on the results, electrodialysis was found to be very effective for uranium removal from wastewaters.