The ZETA Potential Test Method And Application Research Of Organic Separation Membrane Surface

With the development of membrane separation technology,more and more organic separation membranes are used in water treatment,medicine and biological engineering fields.However,chargeability of organic separation membrane will affect membrane flux,retention rate and anti-pollution ability.In this paper,the standard method and application of Zeta potential measurement of organic separation membrane surface were studied by using Zeta Potential Analyzer of SurPASS made by Anton Paar in Austria.The main contents and conclusions are as follows:Flat polyamide nanofiltration membrane and cellulose acetate hollow fiber nanofiltration membrane were taken as research object to establish a method for testing Zeta potential of membrane surface.The first study of Zeta potential test for cellulose acetate hollow fiber nanofiltration membrane was also proposed.Experimental results show that using 1×10-3 mol/L KCl solution as electrolyte solution and membrane samples need to be immersed in ultrapure water for more than 2 h before measurements;the best test pressure of membrane is 3 kPa.In process of flat membrane test,adjustable gap sample cell is selected.The best streaming channel is between 100 and 110?m and best flow is between 80 mL/min and 120 mL/min.Hollow fiber nanofiltration test process,use of plexiglass made of cylindrical sample cell,by adjusting the tightness of the sample filling control test flow rate of 80?120 mL/min.In addition,test method of flat membrane laid the foundation for the standard of "Nanofiltration membrane surface Zeta potential test method-Flow potential method".Influence of membrane material,membrane pore size,membrane shape and hydrophilicity and hydrophobicity on Zeta potential of membrane surface was investigated by the established test method.Besides,changes of Zeta potential in adsorption of NF membrane in seawater were also studied.Experimental results show that different functional groups contained in membrane material have a greater influence on Zeta potential of membrane surface.Pore size does not change the trend of Zeta potential on membrane surface with pH,but slightly affects the absolute value of Zeta potential,membrane pore size increases,the absolute value of the Zeta potential of membrane surface is slightly larger.Shape of membrane has no effect on Zeta potential of membrane surface.Hydrophobic of membrane has a great influence on Zeta potential of membrane surface which is essentially effect of change of functional groups in membrane material.In adsorption seawater,changes of Zeta potential in three NF membrane surfaces are different.therefore,in the practical application,It is necessary to select the proper membrane according to the chargeability of the membrane surface and the amount of charge.