Enhanced separation performance of microfiltration carbon membranes for oily wastewater treatment by an air oxidation strategy

Abstract

An air oxidation strategy was developed for the first time to modify the microstructure and separation performance of microfiltration carbon membranes (MFCMs) for oily wastewater treatment. The structure and property of MFCMs were characterized by the techniques of Fourier transform infrared spectroscopy, scanning electron microscope, pore size distribution, porosity, X-ray diffraction, nitrogen adsorption and water contact angle. The results have shown that the oxidation can effectively modulate the porous structure, surface property and separation performance of MFCMs by varying air oxidation temperature and holding time. The optimal separation performance was respectively achieved to 554.5 kg m−2 h−1 for water permeation flux and 99.0% for oil rejection when MFCMs were oxidized at 80 °C for 30 min. Meanwhile, the anti-fouling ability of MFCMs was substantially improved by two-fold for the flux recovery ratio after oxidation modification. In brief, the work has been proved that the air oxidation is one of the most promising strategies for tailoring MFCMs to efficiently remove the emulsified oil from wastewater.