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KMID : 1024519930020010061
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Journal of the Environmental Sciences
1993 Volume.2 No. 1 p.61 ~ p.72
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Separation of the Heavy Metals by macrocycles- mediated Emulsion Liquid Membrane Systems
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Jung Oh-Jin
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Abstract
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Result of this study indicate that two criteria must be met in order to have effective macrocycle-mediated transport in these emulsionsystem. First, one must effective extraction of the post transition metals, . and , into toluene membrane. The effectiveness of this extraction is greatest if log K values for the metal-macrocycle interaction is large. Second, the ratio of the log K values for the metal ion-receiving phase to the metal ion-macrocycle interaction must be large enough to ensure quantitative stripping of the metal ion at the toluene phase interface. Control of the first step can be obtained by appropriate selection of macrocycle donor atom, substituents, and cavity radius. The second step can be controlled by selecting the proper complexing agent for inclusion in the receiving phase. The order of the transport, when using the several species such as , , and is the order of the changing degree of solvation for and the transport of the metals is also affected by the control of concentration for receiving species because of solubility-differences. In this study, we can seperate each single metal ion from the mixture of , , and ions by using the toluene membranes controlled by optimized conditions. Transport of the single metal is also very good, and alkaline and alkaline earth metals as interferences ions did not affect the seperation of the metals in this macrocycle-liquid membrances but transition metal ions were partially affected as interferences for the post transition metal ions.
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KEYWORD
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Heavy metals, Macrocycle-emulsion Liquid membrane, Transport, Seperation, Concentration
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