Research On Oil-Containing Water Treatment By Flotation Column Using Microporous Tube To Generate Microbubbles

A lot of oil-containing water is produced from oilfield exploit and industrial production. It will form oil-water emulsion with the oil content of 0.5-4wt.%, and it's difficult to be separated. In recent years, flotation has been deeply explored as a kind of oil-water separation technology.This paper mainly discussed about oil-containing water treatment and oil recovery through flotation column in which bubbles were generated by microporous tube, and explored the optimal conditions for flotation and the influence of flotation agents. Then FLUENT software was used to establish gas-liquid model of flotation column. Diesel and water phacoemulsification was used to simulate the industry oil-containing water as raw material liquid. The flotation column was designed to be 0.9m high. Firstly, it was found that the flotation agent PDA was more effective for the separation of oil-water emulsion through flotation agents evalution. Secondly, using PDA as the flotation agent, the influence on flotation was investigated about the factors to optimize operational conditions. Then the performance of synthetic flotation agent was examined. Finally, the effect of flotation dosage quantity and mixed flotation agent was analyzed through experiments.Experimental results showed that oil removal rate of diesel-water emulsion after flotation can reach 80.03%, when microporous tube pore size was 0.3～2μm, PDA dosage quality was 20mg/L, the liquid flow rate was 5L/h from the top feed position, and the air flow rate was 0.25m3/h.6～12g oil phase can be recovered from 30L processed feed solution, and the moisture content was 40～55%. The enrichment of oil was significant. The study results showed that the longer the gas-liquid contact time, the smaller the bubble size, the bigger the flotation agent dosage, the higher the oil removal rate, and the better the flotation effect will be. Meanwhile, the simulation results of gas holdup distribution were close with experimental results.Compared with traditional methods, this flotation process has some advantages, such as large handling capacity, simple equipment, low operation cost. It can effectively solve the shortage of covering too large area, and will have broad application prospects.