Oil-water separation process based on microbubble air flotation membrane device and scale-up research

The treatment of oily wastewater is of great significance to oilfield production and ecological environment protection. A microbubble air flotation membrane device integrating air flotation separation and membrane separation is proposed, and a purely physical process of wastewater treatment is designed, which has significant advantages in the treatment of oily wastewater, especially in the treatment of polymer-driven oily wastewater. In this paper, we studied the oil-water separation mechanism and the removal effect of suspended solids of the microbubble air flotation membrane device, examined the handling capacity, reflux ratio, dissolved air water gas-liquid ratio on the oil removal rate, and determined the optimal parameters of the process for the handling volume of 7.8m3/h, reflux ratio of 15.57%, dissolved air water gas-liquid ratio of 1:10. The oily wastewater is discharged from the device and filtered by special quartz sand can be achieved with the oil content and suspended solids content were below 20mg/L, and the oil removal rate was over 95%, which reached the reinjection standard. This study can help the treatment and utilization of oilfield wastewater, and realize the water resources, energy, energy saving, and emission reduction.