A special surfactant can make thermodynamically stable microemulsion liquid change to thermodynamically unstable state

and its complex with a polymer can do the microemulsion separation into a mixture of oil and water.It is found by transmission electron microscopy(TEM)analysis that size of particles dispersed in transparent deinking paper wastewater containing insoluble organic matter is much smaller than visible light wave-length

and this wastewater is at microemulsion state.So

the transparent deinking paper wastewater was taken as test sample

and treated with this complex(a mixture of special surfactant cBPE-2030 and polymer LYPW-301).The chemical oxygen demand(COD)was determined. The results showed that COD value after treatment with this complex was significantly reduced.The mechanism of oil and water separation was explored by TEM analysis for microscopic state change of microemulsion and emulsion liquids.The method separating oil and water of microemulsion could be effectively applied to other transparent wastewater from papermaking and oilfield

whose separation

in general

is difficult.