Biogenic silver nanocomposite TFC nanofiltration membrane with antifouling properties

Abstract

Biofouling is still a major obstacle hindering wider application of thin-film composite (TFC) nanofiltration membranes in the water industry. One of the practical strategies to reduce biofouling is to develop novel antibiofouling membrane materials. Well-dispersed biogenic silver nanoparticles with a diameter of ~6 nm (Bio-Ag0-6) were first immobilized in the selective layer of TFC nanofiltration membranes. Different dosages of Bio-Ag0-6 were added in the aqueous solution during the interfacial polymerization of tetraethylenepentamine and 1,3,5-benzenetricarbonyl trichloride (TMC). Improved properties of Bio-Ag0-6 /TFC membranes were systematically investigated. When the concentration of Bio-Ag0-6 increased from 0 to 0.05 wt.% in aqueous solution, the water flux of TFC membranes increased from 7.31 to 13.76 Lm−2 h−1 while maintaining the rejection of Na2SO4 at a relatively high level. The addition of Bio-Ag0-6 also enhanced the hydrophilicity of Bio-Ag0-6/TFC membranes in comparison with the bare TFC membranes. All Bio-Ag0-6/TFC membranes exhibited an obvious antibacterial ability to inhibit the growth of Pseudomonas aeruginosa. Moreover, the Bio-Ag0-6/TFC membranes showed the property of a low silver leaching rate in both the static immersion and the filtration systems. It demonstrated that the embedded Bio-Ag0-6 in TFC membrane via interfacial polymerization improved the performance of the TFC nanofiltration membrane.