’Emulsion locks’ for the containment of hydrocarbons during surfactant flushing

作     者：Kristine Lamont Alejandro GMarangoni Erica Pensini Kristine Lamont;Alejandro G.Marangoni;Erica Pensini

作者机构：University of GuelphSchool of Engineering50 Stone Road EastGwelph ONNIG 2W1Canada University of GuelphFood Science Department50 Stone Road EastGuelph ONNIG 2WlCanada 

出 版 物：《Journal of Environmental Sciences》 (环境科学学报（英文版）)

年 卷 期：2020年第32卷第4期

页      面：98-109页

核心收录：

学科分类：0830[工学-环境科学与工程（可授工学、理学、农学学位）] 07[理学] 0713[理学-生态学] 

基　　金：funded by the Natural Sciences and Engineering Research Council of Canada through a Discovery Grant awarded to Dr.Erica Pensini(No.RGPIN-2018-04636) 

主　　题：Remediation Emulsion Hydrocarbons Surfactant Rheology Langmuir trough 

摘      要：Reversible double water in oil in water(W/O/W)emulsions were developed to contain subsurface hydrocarbon spills during their remediation using surfactant flushing.Double emulsions were prepared by emulsifying CaCl2 solutions in canola oil,and subsequently by emulsifying the W/O emulsions in aqueous sodium alginate solutions.The formation of double emulsions was confirmed with confocal and optical microscopy.The double emulsions reversed and gelled when mixed with the surfactants sodium dodecyl sulfate(SDS)and cocamidopropyl betaine(CPB).Gels can act as’emulsion locks’to prevent spreading of the hydrocarbon plume from the areas treated with surfactant flushing,as shown in sand column tests.Shear rheology was used to quantify the viscoelastic moduli increase(gelation)upon mixing the double emulsion with SDS and CPB.SDS was more effective than CPB in gelling the double emulsions.CPB and SDS could adsorb at the interface between water and model hydrocarbons(toluene and motor oil),lowering the interfacial tension and rigidifying the interface(as shown with a Langmuir trough).Bottle tests and optical microscopy showed that SDS and CPB produced W/O and O/W emulsions,with either toluene or motor oil and water.The emulsification of motor oil and toluene in water with SDS and CPB facilitated their flow through sand columns and their recovery.Toluene recovery from sand columns was quantitated using Gas-Chromatography MassSpectroscopy(GC-MS).The data show that SDS and CPB can be used both for surfactant flushing and to trigger the gelation of’emulsion locks’.Ethanol also gelled the emulsions at100 mL/L.