Reactive Extraction of Metal Ion and Simultaneous Stripping Using Nanofibers-Supported Liquid Membrane in a Microchannel

Abstract

Heavy metals in wastewater resulting from industries have become a prime concern for both environmental and economic reasons. This work intends to recover ions of heavy metal from wastewater using reactive extraction by nanofibers-supported liquid membrane (NSLM) in a microchannel. The use of supported liquid membrane enables simultaneous extraction and stripping (i.e., recovery of the extractant) processes. In this study, the NSLM was applied in a microchannel to minimize mass transfer resistance, hence improving overall performance of the extraction. Copper (II) ion was used as a model ion, while di-2-ethylhexyl phosphoric acid (D2EHPA) dissolved in kerosene was used as the extractant. The extractant was supported by a thin layer of polyvinylidene fluoride (PVDF) nanofibers to form a thin immiscible layer. The experiment was conducted to identify the rate determining step in this process. The results show that the reactive stripping step was the rate determining step. The efficiency of extraction Cu(II) ions can be as high as 82% at 1 g/L of initial concentration of Cu(II) ion, microchannel thickness of 125 μm and flow rate of 9 ml/h.