title: Destabilization of emulsions by natural minerals.
abstract: This study developed a novel method to destabilize emulsions and recycle oils, particularly for emulsified wastewater treatment. Natural minerals were used as demulsifying agents, two kinds of emulsions collected from medical and steel industry were treated. The addition of natural minerals, including artificial zeolite, natural zeolite, diatomite, bentonite and natural soil, could effectively destabilize both emulsions at pH 1 and 60 °C. Over 90% of chemical oxygen demand (COD) can be removed after treatment. Medical emulsion can be even destabilized by artificial zeolite at ambient temperature. The mechanism for emulsion destabilization by minerals was suggested as the decreased electrostatic repulsion at low pH, the enhanced gathering of oil microdroplets at elevated temperature, and the further decreased surface potential by the addition of minerals. Both flocculation and coalescence were enhanced by the addition of minerals at low pH and elevated temperature.
authors.affiliation: State Key Lab of Biogeology and Environmental Geology, China University of Geosciences, Wuhan 430074, PR China. yuansonghu622@hotmail.com
authors.forename: Songhu
authors.initials: S
authors.lastname: Yuan
authors.forename: Man
authors.initials: M
authors.lastname: Tong
authors.forename: Gaoming
authors.initials: G
authors.lastname: Wu
mesh_terms: D002623:Chemistry Techniques, Analytical; D004655:Emulsions; D005427:Flocculation; D006863:Hydrogen-Ion Concentration; D007221:Industry; D008903:Minerals / Q000032:analysis*; D009821:Oils; D010100:Oxygen / Q000737:chemistry*; D055672:Static Electricity; D013696:Temperature; D014865:Waste Disposal, Fluid / Q000379:methods; D014874:Water Pollutants, Chemical / Q000032:analysis*; D018508:Water Purification / Q000379:methods*; D017641:Zeolites / Q000737:chemistry
chemical_list: D004655:Emulsions; D008903:Minerals; D009821:Oils; D014874:Water Pollutants, Chemical; D017641:Zeolites; D010100:Oxygen