Competitive bind of anionic metals with cetylpyridinium chloride micelle in micellar-enhanced ultrafiltration

Competitive binding characteristics of anionic metals, chromate and ferriccyanide, with cetylpyridinium chloride micelles were investigated in micellar-enhanced ultrafiltration (MEUF). In MEUF process, removal of pollutants depends on the bind of pollutants to surfactant micelles which increases with the valence of anions. The valence for chromate is -2, while that for ferriccyanide is -3. In chromate/CPC and ferriccyanide/CPC system, the removal of ferriccyanide was higher than that of chromate at the same molar ratio of surfactant due to the difference of valence. In the chromate/ferriccyanide/CPC system, the removal of chromate was inhibited by the ferriccyanide at the low molar ratio of CPC (<chromate: ferriccyanide: CPC = 1:1:4) because of preferential bind of ferriccyanide to chromate.