Abstract
Micellar-enhanced ultrafiltration (MEUF) of zinc cations (Zn super(2+)) from aqueous solutions using anionic surfactant sodium dodecyl sulfate (SDS) at low concentrations was investigated. The Zn super(2+) adsorption to SDS micelle reached equilibrium after 3h. When the initial concentration of Zn super(2+) was constant and the initial concentration of SDS was below the critical micelle concentration, not only the dosage of SDS could be reduced but also the of Zn super(2+) and the permeate flux were high. The retention rate of Zn super(2+) is a function of the SDS concentration at the surface of the membrane. With the increases of the initial SDS concentration, the permeate flux decreased gradually and the permeate concentration of SDS increased. Whatever was the concentration of SDS in the feed, the SDS concentration in the permeate was lower than CMC. Consequently the loss of SDS was small. The retention rate of Zn super(2+) decreased with the increases of the initial Zn super(2+) concentration. The removal