Decolorization of Direct Blue 71 solutions using tannic acid/polysulfone thin film nanofiltration composite membrane; preparation, optimization and characterization of anti-fouling

The objective of this research was to use tannic acid (TA) as polyphenol monomer and trimesoyl chloride (TMC) to synthesize the nano-composite membranes and its application for dye removal from water. The combined effects of factors were studied by response surface methodology (RSM). Synthesized membrane was characterized by field emission scanning electron microscopy (FESEM), atomic force microscopy (AFM), attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR) and water contact angle measurement. The results showed that monomer concentrations and post treatment (time and temperature) had a significant effect on the membrane synthesis. The predicted optimum operational conditions were initial direct blue 71 concentration of 30.31 mg/L; time of 16.96 min, applied pressure of 1.16 bar. Fouling mechanism was pore sealing (n=1.96). The excellent antifouling properties and resistance ability to organic and chemical reagents of the prepared composite nanofiltration membranes caused to suggest this membrane for water treatment.