Selective recovery of palladium from a simulated industrial waste water by liquid surfactant membrane process

摘要

The selective recovery of palladium from an acidic solution of high iron concentration with liquid surfactant membranes (LSMs) containing di-2-ethylhexyl monothiophosphoric acid (commercial name MSP-8) as a carrier has been conducted in a batch and a continuous system using a mixer-settler. In the batch operation, the effects of several chemical species and their concentrations on the recovery of palladium were discussed. Using a relatively low concentration of PX100, stable emulsions were obtained and a high degree of palladium recovery was performed by a LSM technique. The concentration of thiourea employed as a stripping agent greatly affected the efficiency of palladium recovery. Under optimum conditions, palladium ions were separated from a large amount of iron ions and they were concentrated from the external feed aqueous solution into the inner receiving phase of W/O emulsions. Furthermore, an effective recovery of palladium could be achieved in a continuous operation using a mixer-settler under the optimum conditions for the batch system.