Document Type : VSI: Women in Membr.
Ege University, Faculty of Engineering, Chemical Engineering Department, 35100 Izmir, Turkey
Ege University, Graduate School of Science, Division of Environmental Sciences, Izmir, Turkey
Ege University, Faculty of Science, Chemistry Department, 35100 Izmir, Turkey
In this research, effect of operational parameters on removal and recovery of lithium simultaneously from brine by electrodialysis (ED) method with bipolar ion exchange membranes (BM) having 10 membrane triplets of cation exchange membranes (CEMs), anion exchange membranes (AEMs) and bipolar membranes (BMs) was investigated. The Mega EDR-Z-Full-V4 model BMED system was employed in order to produce lithium hydroxide from brine containing lithium ions. Four different concentrations of LiCl solutions were used in the sample compartment as 34, 68, 170, 340 mg Li+/L. Also, effects of concentrations of acid (HCl) and base (NaOH) solutions as 0.003 M and 0.05 M in the acid and base compartments, respectively in addition to the electrical potentials (20 and 25 V) were investigated. A NaOH solution with 0.1 M concentration was used as the electrode solution for all tests run. As a result of the study operated with 0.05 M HCl and 0.05 M NaOH solutions at 20 V, the lithium removal percentages were obtained as 98.6, 99.2, 99.7 and 99.6% while the lithium recoveries were 75.5, 54.5, 55.4, 51.2% at four different concentrations of LiCl as 34, 68, 170, 340 mg Li+/L, respectively. When lithium concentration of sample solution increased, the lithium removal remained constant. But the lithium recovery decreased and the lithium concentration in the base recovery compartment increased. The mass transfer coefficient of lithium was high when the electrical potential applied is high but it decreased with an increase in lithium concentration.