Membrane separation and foam separation are widely used separation techniques.To make use of their advantages,membrane separation and foam separation were integrated to dispose waste water with low concentration of linear alkylbenzene sulfonate(LAS).A method of forcing bubbles through a single hollow fiber ultrafiltration tube was put forward to study the separation efficiency of the integrated process.The effects of pressure,gas-liquid ratio and LAS concentration on the separation efficiency were investigated.Under the conditions of pressure 0.03—0.1 MPa,gas-liquid ratio 0—0.9,and LAS concentration 0—70 mg·L-1,the membrane permeate flux was raised from 26.5 to 38.6 L·m-2·h-1,increased by 48.6%,and the retention rate was raised from 37.0% to 64.9%,increased by 75.5%.The results show that the integrated process can reduce the concentration polarization and membrane fouling.Moreover,this method reduces the back-mixing of foam separation and increases the concentration of bulk liquid phase for foam separation.Therefore,the integrated separation promotes mass transfer and improves separation efficiency.
