Efficient microfiltration of oil-water emulsion using ACF-supported and GO-dispersed RF membrane

Abstract

A graphene oxide (GO)-dispersed resorcinol–formaldehyde (RF) film coated on an activated carbon fabric (ACF) is synthesized for the first time as a microfiltration (MF) membrane for an efficient separation of oil-water emulsion. Physicochemical characterization of the prepared GO-RF/ACF membrane showed that the material contained pores of an average size 0.553 µm. The membrane contained an asymmetric internal structure, with the relatively narrower sized pores at the top surface of the membrane, conducive for retaining oil droplets, and the larger sized internally connected pores, conducive for water permeation. Inclusion of GO increased hydrophilic characteristics of GO-RF/ACF, attributed to the oxygen containing functional groups in the material. The contact angle measurements confirmed the hydrophilic (contact angle 56.15°) and oleophobic (contact angle 135.05°) characteristics of the material. Tested against a 10% (v/v) oil-water emulsion with the oil droplet size in the range 420–1200 nm, the dead-end MF tests showed the rejection efficiency of ~99.99% and permeate flux of ~158 L/m2-h with the oil droplet size in the range 5–130 nm. The data clearly indicate an efficient separation of oil-water emulsion by MF using the GO-RF/ACF membrane prepared in this study, and its extended application in the membrane separation processes including the recovery of bioactive compounds from wastewater of the food- and agro-industries.