Removal of emulsified oil by ferrite-coated ceramic membranes†
Abstract
This research was conducted to investigate the removal effect and mechanisms of emulsified oil by ferrite-coated ceramic membranes. Three kinds of ferrite-coated ceramic membranes (CuFe2O4, CoFe2O4 and Co0.5Cu0.5Fe2O4) were prepared by the sol–gel method. The structure and valence state confirmed the presence of spinel ferrite on the surface of the ceramic membrane. The coated form of ferrite retained the porous structure of the ceramic membrane surface. The coated ceramic membrane has been shown to effectively improve the removal rate of emulsified oil and improve the antifouling ability of the ceramic membrane. When the influent concentration of emulsified oil was 45 ± 5 mg L−1, the removal rate of emulsified oil reached 87–93% after 2 hours, and the normalized flux after 2 hours was increased from 0.08 of the blank ceramic membrane to 0.17 of the copper ferrite-coated ceramic membrane. The generation of free radicals proved that the ferrite-coated ceramic membrane can catalyze the degradation of emulsified oil by H2O2. The low metal ion leaching concentration also met the sewage discharge requirements. Therefore, the ferrite-coated ceramic membrane is an option in improving the removal rate of emulsified oil, strengthening the antifouling ability of the ceramic membrane, avoiding the generation of iron sludge, reacting at room temperature without additional UV light and solving the recovery of spinel ferrite.