Removal characteristics of anionic metals by micellar-enhanced ultrafiltration

Surfactant-based separation of Fe(CN)(6)(3-) and CrO42- using regenerated cellulose membrane was studied in order to assess the potential of micellar-enhanced ultratiltration for the remediation of wastewater or groundwater polluted with ferriccyanide and chromate. In the ferriccyanide/octadecylamine acetate (ODA) and chromate/ODA systems, removal of ferriccyanide increased from 73 to 92% and to 98%, and that of chromate from 64 to 97% and to >99.9% as the molar ratio of ODA to ferriccyanide and to chromate increased from 1 to 2 and to 3, respectively. In the ferriccyanide/chromate/ODA system, while the removal of ferriccyanide increased from 62 to 72% and to 93%, the removal of chromate from 20 to 38% and to 68% as the molar ratio of ferriccyanide: chromate: ODA increased from 1: 1: 1 to 1: 1:2 and to 1: 1:4, respectively. With the molar ratio of 1:1:6, the removal was >99.9 and 98% for chromate and ferriccyanide, respectively. Ferriccyanide ions were more easily bound to ODA micelles because the binding power of ferriccyanide was greater than that of chromate. (C) 2003 Elsevier Science B.V All rights reserved.