Polyester Thin Film Composite Nanofiltration Membranes Prepared by Interfacial Polymerization Technique for Removal of Humic Acid

Abstract

Nanofiltration (NF) polyester thin film composite membranes have been prepared through interfacial polymerization using a microporous polyethersulfone membrane as support. The thin polyester layer formed on the top surface of the microporous support layer was produced by the reaction of 6 %w/v of triethanolamine (TEOA) in aqueous solution and a solution containing trimesoyl chloride (TMC) for different reaction times (15, 25, and 35 min). The performance of the membranes was then characterized using permeation experiments with 0.001–0.1 M of salt solutions (NaCl and Na2SO4) and 15 mg/l of humic acid solution as a model for natural organic matter (NOM), normally found in surface water. This study has shown that through the interfacial polymerization technique, the variation of reaction time at a constant monomer concentration of 6 % w/v can affect the properties of the membrane produced and indirectly influences the membrane performance. Increasing the reaction time resulted in decreasing water permeabilities. However, a higher removal of humic acid was observed.