Fabrication And Properties Of TFC Nanofiltration Membrane By Interfacial Polymerization For High Water Flux

Thin film composite nanofiltration?TFC?membranes are frequently used to remove the residual salts from industrial wastewater.However,these nanofiltration membranes often have relatively low fluxes that limit their practical applications.To solve the problem,sodium bicarbonate and ammonium bicarbonate were introduced intothecompositenanofiltrationmembranesrespectivelyviainterfacial polymerization of piperazine?PIP?and 1,3,5-benzenetricarbonyl trichloride?TMC?and the effects of sodium bicarbonate and ammonium bicarbonate were compared.The membrane surfaces were characterized by scanning electronic microscopy?SEM?,attenuated total reflection Fourier transform infrared spectroscopy?ATR-FTIR?,electro kinetic analyzer,and contact angle goniometer.The results showed that the addition of sodium bicarbonate generated more tiny cracks on membrane surface and decreased the zeta potential of the membrane,which improved the permeation properties of the membrane without significantly decreasing the rejection against four kinds of salts?Na₂SO₄,MgSO₄,NaCl,MgCl₂?;While the addition of ammonium bicarbonate generated deeper cracks on the surface and the increase of flux and the decrease of rejection against salts were more significant.When the addition of sodium bicarbonate is 1.5 wt%and the addition of ammonium bicarbonate is 0.5 wt%,the membrane showed the best properties.The addition of sodium bicarbonate and ammonium bicarbonate provided a new possibility to improve the permeation properties of TFC nanofiltration membranes in seperating salts such as Na₂SO₄ and MgSO₄ from industrial waste water.