▎ 摘　　要

NOVELTY - Method for removing emulsified oil in a surfactant stabilized oil-in-water emulsion involves (1) preparing a magnetic adsorbent by (i) taking graphene oxide, a mixed salt solution of iron (III) chloride and iron (II) sulfate, and a magnesium aluminum layered double hydroxide (LDHs), dispersing graphene oxide (GO) in a three-necked flask containing deionized water, adding mixed salt solution, heating, (ii) adding sodium hydroxide solution to obtain a mixture, heating, filtering to obtain a filter cake, washing, vacuum drying to obtain a black magnetic graphene oxide hybrid (MGO), (iii) mixing magnesium-aluminum layered double hydroxide and magnetic graphene oxide, stirring, filtering to collect precipitate, washing and drying to obtain the magnetic adsorbent, (2) adjusting the emulsion to an ionic strength of 0.001-0.1 mol/L with a regulator, and (3) performing an adsorption process by adding the magnetic adsorbent to the emulsion to adsorb emulsified oil. USE - Method for removing emulsified oil in surfactant stabilized oil-in-water emulsion for sewage treatment. ADVANTAGE - The method is safe and easy to control, has low investment in equipment, small area occupancy and high removal efficiency, and being suitable for continuous and large-scale treatment of oil-contained wastewater. DETAILED DESCRIPTION - Method for removing emulsified oil in a surfactant stabilized oil-in-water emulsion involves (1) preparing a magnetic adsorbent by (i) taking graphene oxide, a mixed salt solution of iron (III) chloride and iron (II) sulfate, and a magnesium aluminum layered double hydroxide (LDHs), dispersing 0.15 g graphene oxide (GO) in a three-necked flask containing 200 mL deionized water, adding 20 mL mixed salt solution, and heating under nitrogen to 80-90° C, (ii) adding 1.5 mol/L sodium hydroxide solution to obtain a mixture, adjusting the mixture to a pH of 10-11, heating under nitrogen to 80-90° C, stirring for 30-40 minutes, filtering to obtain a filter cake, washing the filter cake with deionized water and vacuum drying at 50-65° C for 20-24 hours to obtain a black magnetic graphene oxide hybrid (MGO), (iii) fixing the concentration of MGO at 5 mg/L, and mixing magnesium-aluminum layered double hydroxide and magnetic graphene oxide in a mass ratio of 5:1-1:5, stirring continuously at 10-40° C for 1-2 hours, filtering to collect precipitate, washing the precipitate and drying to obtain the magnetic adsorbent (MGO/magnesium-aluminum-LDH), (2) adjusting the surfactant-stabilized oil-in-water emulsion to an ionic strength of 0.001-0.1 mol/L with a regulator, and (3) performing an adsorption process by adding the magnetic adsorbent to the surfactant-stabilized oil-in-water emulsion to adsorb emulsified oil, stirring at 10-40° C for 15-25 minutes, and separating the resulting mixture by magnetic separation under the action of an external magnetic field. The magnetic adsorbent has a concentration of 0.1-0.4 g/L. The surfactant stabilized oil-in-water emulsion has a pH value of 6-8 and an ionic strength of 0.001-0.1 mol/L.