The Impact of Surfactant-Driven Emulsion Droplet Size on Lead (Pb) Recovery Efficiency in Emulsion Liquid Membrane Systems

Abstract. The emulsion liquid membrane (ELM) extraction technology offers significant perspectives into the extraction and recovery of lead (Pb) from aqueous solutions. In this study, ELM stability was investigated using ELM components consist of bis(2-ethylhexyl) phosphate (D2EHPA) as an extractant, kerosene as diluent, nitric acid (HNO3) as stripping agent and polysorbate 80 (Tween 80) as surfactant. These components were prepared and formulated at 2000 rpm and 5 minutes emulsification time. The size of emulsion droplet and the effect of surfactant concentration on the breakage/swelling effect for ELM stability and extraction efficiency were studied. The results show that, at 0.5 M D2EHPA, 0.5 M HNO3 and 5 % w/v Tween 80 was enough to perform stable emulsion with 1.5 µm droplet size and the highest extraction efficiency of Pb removal was 96.16 %. ELM approach has significant potential to facilitate extraction process efficiently.