Investigation On Microemulsion Solubilization Properties And Oily Sludge Treatment

Microemulsion is a kind of multiphase system with ultra low interfacial tension, which has a wide range of applications. The oil solubilization ability of microemulsions provides ideas for the treatment of organic pollutant like oily sludge.Microemulsion systems consist of surfactant, inorganic salt, oil, water and cosurfactant, each component having important influence to the microemulsions. According to the results of HLB value calculating and solubilization ability evaluating, SDS and SDS/AEO-7(1:1) mixed surfactants have been chosen as the raw material to dispose the oily sludge. By the method of high-speed centrifugation, conductivity Test, particle size determination, formation of microemulsion system was confirmed.The Winsor phase diagram and ε-β fish-like phase diagram were used to study the effects of cosurfactants and inorganic salts on microemulsion phase inversion and solubilization capacity. Through the study on SDS-oil-water-butanol-inorganic salt microemulsion system using Winsor phase diagram, it was found that all the microemulsion systems experienced the phase inversion from Winsor type Iâ†'IIIâ†'II with the increase of concentration of various salts or butanol, but different salts have different effects. for the SDS-kerosene-watern-butanol- inorganic salt microemulsion system, under the conditions of the same cationic charge concentration, the effeciency of salt cation shows a rule of Al3+>Ca2+>Na+ and K+>Na+, while the effeciency of salt anion shows SO42-=CO32-. However, in AEO-7/SDS-octanewater-n-butanol-inorganic microemulsion system, under the conditions of the same cationic charge concentration, the effeciency of salt cation shows a rule of Al3+>Ca2+>K+>Na+, while the effeciency of salt anion shows SO42-<CO32. Through the phase diagram study, it was found that Na Cl microemulsion has very high solubilization capacity. Considering the efficiency of salt, stability of microemulsion, environmental protection and other factors, Na Cl was selected to prepare for microemulsion using in oily sludge treatment.Through the experiment on treatment of oily sludge, it was found that the microemulsion showed a good treatment effect. For the single SDS surfactant microemulsion, under the condition of 10.0ml kerosene, 20.0ml water, 0.9g Na Cl, 1.52 g SDS, and 5.0ml n-butyl alcohol, the strongest elution effect could reach to 94.7%. For the SDS/AEO-7(1:1) mixed surfactant microemulsion system, containing 15.0ml kerosene, 20.0ml water, 1.0g Na Cl, 1.52 g SDS/AEO-7 and 6.5 ml n-butyl alcohol, the strongest elution effect reached 98.48%. After the treatment by microemulsion, the oily sludge can be separated from the oil phase under the action of gravity.