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Objective: Micellar properties of sodium dodecyl sulfate (NaDS) was examined in the presence of cetylpyridinium chloride (CPC) by means of surface tension, viscosity, dye solubilization, cloud point (CP) measurements.Antimicrobial activities of single and binary systems were also investigated. Results: A decrease in critical micelle concentration (CMC) and increase in solubilizing power for NaDS was observed with increasing CPC concentration. At the highest CPC concentration studied (0.1 M), the surface tension decreased up to 51 mN / m.Also, viscosity results showed growth in NaDS micelles (50 mM) up to the 0.1 M CPC concentration. Antimicrobial activity of NaDS, CPC and NaDS in presence of CPC was investigated against ten different strains of bacteria and ayeast which was not investigated up to now. The susceptibilities of the microorganism were determined by the agar diffusion method. The results showed that NaDS and CPC have a antimicrobial activity but NaDS in presence of CPC has not antimicrobial activity on the bacterial and yeast.

In the present study, the optimum conditions have been investigated for the separation of Zn 2+ ions from aqueous solution by micellar enhanced ultrafiltration (MEUF). For this purpose, the best conditions for the concentration of surface active agent in the feed solution (sodium dodecyl sulfate, SDS), cetyltrimethylammonium bromide (CTAB), triton-X-100 (TX100)), filtering pressure, stirring rate, and for the membrane porosity have been determined. It was found that the filtering pressure has a significant effect on the permeate flux but a relatively insignificant impact on rejection of Zn 2+. Permeate flux increased linearly with increasing pressure, ranging from 0.32 mLmin-1 m-2 at 3 bar to 0.72 mLmin-1 m-2 at 4 bar. The results showed that by adding SDS anionic surfactant, the permeate flux and the removal efficiency of zinc increased. Best results in terms of zinc rejection coefficient is 97.5 % at 5.0 x 10-4 M zinc concentration, 1.0 x 10-2 M SDS concentration (~x 8 cmc), stirring rate 500 rpm and transmembrane pressure 4 bar.