E-Waste Management via Liquid Emulsion Membrane (LEM) Process: Enrichment of Cd(II) from Lean Solution

E-waste management via liquid emulsion membrane (LEM) process for the extraction and enrichment of cadmium(II) has been studied using di-2-ethylhexyl phosphoric acid (D2EHPA) dissolved in n-dodecane as carrier and methane sulfonic acid (MSA) as a strip phase. The complexation stoichiometric coefficient (n) and equilibrium constant (K ex) were determined by carrying out conventional liquid−liquid extraction studies. The factorial design method was used to see the importance of parameters. Emulsion preparation parameters such as carrier concentration, surfactant concentration, and internal strip phase (MSA) concentration were determined to get maximum extraction and enrichment. The influence of operating process parameters on the performance of LEM process, i.e., residence time, speed of agitation, and treat ratio, has been studied. A realistic simple model to aid the process design of LEM process has been developed.