Transport of metal ions across bulk liquid membrane with macrocycle compounds

Abstract EN

The transport experiments of Pb2+, Cd2+ and Zn2+ metal cations were performed by dibenzo-18- crown -6, dicyclo18-crown-6, kryptofix 2.2.2 and diaza 18-crown -6 using 1,2- Dichtoro ethane, chloroform and carbon tetra chloride as liquid membrane, The aqueous source phase consisted of 10-3M of Metals nitrate in 10 ml of double distilled deionized water at PH = 5.2–5.5 and the receiving phases consisted of 10 ml double distilled deionizer water at PH = 3.2-3.7.

The effects of operating conditions, stirring speed, type of carrier structure and solvents in the feed and strip phase were studied.

From the results that the transport rate of Pb2+, Cd2+ and Zn2+ metal cations can be enhanced by increasing stirring speed but not very high, dicyclohexyl-18-crown-6 is the best carrier structure and du to the effect cyclohexhl which is electron donating group, 1,2- di chloro ethane was found the best set solvent according to permeability and flux data du to its polarity constants Also, the transport rate efficiency observed of cations the selectivity of cations is Pb2+ , Cd2+ and Zn2+ which are appreciable with the value of its hydration energy and the Pearson’s Hard Soft Acid Base principle (HSAB).