Research On Separation Diesel Oil-in-Water Emulsion From Oil-Containing Water By Flotation Column

A lot of oil-containing water is discharged in crude oil mining and processing. And oil-in-water emulsion is difficult to remove from oil-containing water because its droplet diameter is very small. Therefore the technology and equipment of oil-water separation should be explored. If we make good use of the oil that recovered by separation technology and equipment, it is beneficial to economy and environment.In this paper, oil-in-water emulsion produced by ultrasound was separated from oil-containing water by flotation column. First, the stability of diesel oil-in-water emulsion produced by ultrasound was studied. Second, the effect of operation conditions on oil removal rate was explored, especially the cation concentration of PDA. Third, the mechanism of flotation based on the experimental results above was investigated. Fourth, the kinetics of flotation under different operation conditions were investigated. Meanwhile the flotation kinetics constant with different operation conditions was fitted.Experimental results show that when PDA cationic degree is92, PDA dosage is5mg/L, liquid flow rate is lOL/h from the top feed position, and the air flow rate is0.25m3/h, the oil removal rate could reach68.08%; besides, with increase of PDA cationic concentration, the oil removal rate increase firstly and then decrease. The results also show that the more the time and opportunities between bubbles and floes contact, the higher the oil removal rate will be. And the oil removal rate is determined by contact, attachment, separation of bubbles and flocs. Only when bubbles and flocs share the same sizes, the bubbles and flocs could form aerated flocs, will the oil removal rate be higher. In the end, the formulation below was used to simulate the kinetics of flotation. In addition, the relationship of flotation kinetics constant k and different operation conditions was concluded with below formulation. κ＝0.05h0.44m0.44g0.97q-0.44It is proved that the flotation column was good in separating oil-in-water from oil-containing water, and also had a good potential application in industry.