Research On Separation Effect Of Process Integration Of Membrane Separation And Foam Separation

Membrane separation and foam separation are two kinds of widely-used separation techniques.However,they have their own disadvantages,such as concentration polarization and fouling for membrane,low efficiency for foam separation.In order to exert respective advantages,membrane separation and foam separation were integrated to dispose of wastewater with surfactant.At the PFOA concentration 450mg·L^-1,gas flowrate 35L·h^-1,liquid flowrate 5L·h^-1,ratio of the heights of foam and bubbling region 1.0,pressure 0.5Mpa,the results of external integration method indicated that PFOA concentration in foam that overflowed from foam separation column reached 3690mg·L^-1,and the content of PFOA in the residual bulk solution was reduced to 37.5mg·L^-1,the removal efficiency reached 91.7%.Three kinds of internal integration experiments indicated that they reduced concentration polarization and membrane fouling.Besides,these methods reduced back-mixing phenomenon of foam separation and increased the concentration of bulk liquid phase for foam separation. Therefore,internal integrated separation promoted mass transfer rate and improved separation efficiency,especially for tubular and hollow fiber membrane modules.Advantages of both external and internal integration methods included their high efficiency, mechanical and operational simplicity,low capital and maintenance costs,and lower energy consumption.