LAUSR

Liquid membranes (LMs), such as bulk liquid membrane (BLM), supported liquid membrane (SLM), emulsion liquid membrane, and polymer inclusion membrane (PIM) coupled with variety of carriers such as crown ethers, organo-phosphorous compounds, carboxylic acids and calixarenes, have been investigated for the transport of Pb(II) ions from different aqueous media. The effects of the chemical compositions and LM configurations on the transport selectivity and the recovery yield of Pb(II) ions have been reviewed in this paper. The comparison among the selectivities of these carriers showed that crown ether-mediated LMs can be efficiently used in analytical laboratories for high selective preconcentration of trace amounts of Pb(II) ions. On the other hand, D2EHPA-mediated LMs could be the mostly suitable for simultaneous removal and recovery of the other heavy metal ions including Pb(II) ions from wastewater. For the potential applicability of the existing LM configurations in the areas of metal ion separation processes, it seems that BLM, SLM, and PIM are sufficient enough on the laboratory scale at high selective preconcentration step. The other configurations such as hollow fiber or emulsion LMs would be the most suitable to apply on large scale of heavy metal ions removal from wastewater.