Application of external electric field to enhance the permeate flux during micellar enhanced ultrafiltration

Removal of dye from aqueous solution using electric field assisted micellar enhanced ultrafiltration (MEUF) has been studied in a rectangular cross-flow channel over a wide range of operating conditions. Sodium dodecyl sulfate (SDS) and methylene blue (MB) have been taken as anionic surfactant and cationic dye, respectively. An ultrafiltration membrane (polyphenylene ethersulfone) of molecular weight cut-off (MWCO) 10 kDa, has been used in the experiment. The effects of operating conditions, e.g., electric field, surfactant to dye concentration ratio, transmembrane pressure and cross-flow velocity on the permeate flux and retention of MB have been investigated in detail. Experimental results confirm that by applying d.c. electric field (1000 V m−1), permeate flux increases by about 33% with approximately 99% removal of MB. An expression for the prediction of limiting flux in ultrafiltration is developed in this study. The predictions of permeate flux are in good agreement with the experimental results.