Cadmium removal using vegetable oil based emulsion liquid membrane (ELM): membrane breakage investigation

The aim of this research is to quantify the occurrence of membrane breakage in vegetable oil based Emulsion Liquid Membrane (ELM). Basically, ELM consists of three main phasesinternal, external and membrane. In this work, the membrane phase was prepared by dissolving Span 80 as surfactant and Aliquat 336 as carrier in commercial grade corn oil. As a way to promote sustainable development, vegetable oil which is environmentally benign diluent was incorporated in the formulation of ELM. The influence of several important parameters towards membrane breakage were studied. They are carrier and surfactant concentration, W/O volume ratio, emulsification time, internal phase concentration as well as stirring speed. Based on the data obtained, emulsion prepared using 4 wt% Aliquat 336 and 3 wt% Span 80 resulted in the most stable emulsion with only 0.05% membrane breakage. The emulsion was produced using W/O volume ratio of 1/3 and it was homogenized with the assistance of ultrasound for 15 min. Moreover, emulsion produced able to provide a fair balance between emulsion stability and Cd(II) permeability as it able to remove 98.20% Cd(II) ions from the external phase