Abstract
Micellar enhanced ultrafiltration (MEUF) has been extensively applied to the separation of organic solutes or heavy metal ions from water, but the feasibility and efficiency of removing them simultaneously via MEUF have been seldom researched. In this study, simultaneous removal of methylene blue (MB) and cadmium ion (Cd2+) with MEUF by the binary mixture of sodium dodecylsulfate (SDS) and polyoxyethylene octyl phenyl ether (TritonX-100) was investigated. The critical micelle concentration (CMC) of mixed surfactants was considered. Retentions of MB and Cd2+, flux decay, and three parameters, namely distribution coefficient (D), micelle loading (L), and micelle binding constant (K) were discussed to assess the efficiency of MEUF process. The higher mole ratio of TritonX-100 exhibited lower CMC value but more intensified flux decay. Within a certain range, the addition of TritonX-100 was in favor of MB and Cd2+ removal. The presence of Cd2+ could promote the rejection of MB by increasing the micelles in the retentate but had no influence on the unit binding capacity of micelles and the relative affinity of MB for micelles. The presence of MB could also increase Cd2+ rejection with little influence on the unit binding capacity of micelles. (C) 2014 Elsevier B.V. All rights reserved.