Studying Of The Surfactant Compound System On Oil Wastewater Treatment In Flotation Process

Flotation is a highly efficient and rapid method of solid-liquid separation, and widelyused for mineral separation, wastewater treatment, oil exploitation and so on. Flotationusually applies chemosynthetic surface-active reagent. Due to the chemical surfactant is noteasy to degrade. So, more and more people are pay attention to produced by the plants andanimals, or microorganisms which has the same effect with chemical surfactant biosurfactant.The Paper mainly for complex a variety of chemical surfactants with biosurfactant, and totest the surface activity, research the effect of all kinds of surface active agent to remove oilwastewater system.The paper using two kinds of biosurfactants which is rhamnolipid and tea saponin.Determination of various single surfactant and the mixed surfactant under differentconcentration gradient of surface tension and CMC values. The result show surfactant CMCvalue: SDS is0.0088mol/L, rhamnolipid is0.0068mol/L, tea saponin is0.0012mol/L,CTAB is0.0008mol/L.In the distribution system, rhamnolipid/SDS mole ratio is6:1, tea saponin/SDSmole ration is7:1,tea saponin/CTAB mole ration is6:1,which is achieve their critical micelleconcentration distribution system.Secondly, through the stokes method determine the average diameter of bubble sizeunder different dissolving tank pressure group. Through the liquid level rise methoddetermines the gas content under different pressure, and the optimal condition of gas-liquidmixing pump was determined. The result show: when dissolving tank pressure is0.15MPa，the micro bubbles around the average diameter is35um,this is gas-liquid mixing pump can beproduce minimum diameter of the bubbles. When dissolving tank pressure is0.1MPa, thehighest overall gas hold is5.2%.The best condition of gas-liquid mixing pump is: when thedissolving tank pressure is0.15MPa, waster water salinity is1.0g/L, the chitosan content is1.0mg/L,the water flow rate is0.1m3/h,water oil content within the scope of the1500mg/L,gas-liquid mixing pump air flotation effect is the best.Thirdly, under the best working condition of gas-liquid mixing pump, using a variety ofsingle surfactant and mixing surfactant. The result show: SDS molar concentration is0.00032mol/L, the removal rate is96%; Rhamnolipid molar concentration is0.00016mol/L, the removal rate is94%; Tea saponin molar concentration is0.00016mol/L，the removal rateis93%;CTAB molar concentration is0.00064mol/L,the removal rate is90%;Rhamnolipid/SDS molar concentration rate is5:1,the removal rate is97.15%;Teasaponin/SDS molar concentration rate is5:1,the removal rate is93.3%;Tea saponin/CTABmolar concentration rate is3:1,the removal rate is91%.In conclusion, oil removal rate ofwastewater reached the maximum when the rhamnolipid/SDS mixed system been produced.Mixed system on purification efficiency of wastewater is greater than the single surfactantsystem, it show that the compound have the better efficiency.