Selective separation of gold and palladium using the improved Gemini Micellar-Enhanced ultrafiltration

The aim of this study was to selectively separate precious metals such as gold and palladium from a binary solution using the Gemini micellar-enhanced ultrafiltration (GMEUF) process. The selectivity of this process was improved by adding the chelating agent ethylene diamine tetra-acetic acid (EDTA) to the solution. It means that one of these two metals can interact with the surface of Gemini micelles and reject by the membrane. The other metal must tend to bind to the ligand and enter the permeate stream. The effect of various parameters such as solution pH, operating pressure, flow rate, molar concentration ratio of the surfactant to the metal (S/M) and molar concentration ratio of the chelating agent to the metal (C/M) was investigated on the selective separation of these metals by a commercial polyethersulfone (PES) membrane and two Gemini surfactants. The rejection of gold and palladium in the optimal conditions of the above parameters reached the values of 90.2% and 21.4%, respectively, for the solutions containing N1-dodecyl-N1,N1,N2,N2-tetramethyl-N2-octylethane-1,2-diaminium bromide (CG12) micelles. In the presence of pentanediyl-1,5-bis (dimethyl cetyl ammonium bromide) (G5) micelles, these rejection values changed to 91.7% and 27.1%, respectively. The obtained results indicated a good selectivity in the separation of gold and palladium by the improved GMEUF process.

Automated summary

The aim of this study was to selectively separate precious metals such as gold and palladium from a binary solution using the Gemini micellar-enhanced ultrafiltration (GMEUF) process. The results showed that the improved GMEUF process achieved good selectivity in the separation of gold and palladium.