Incorporation of modified cellulose nanocrystals to polyamide nanofiltration membrane for efficient removal of Cr(III) and Pb(II) ions from aqueous solutions

Abstract

ABSTRACT In this study, thin-film nanocomposite nanofiltration (TFN) membranes were fabricated using interfacial polymerisation by incorporating modified cellulose nanoparticles (mNCs). In the first place, cellulose nanoparticles were modified by AAPTES, and were then dispersed in an organic solvent with the aim of reaction with the polyamide layer of TFC membrane. The resulting membranes were then tested for the removal of Cr(III) and Pb(II) heavy metals ions from wastewater. Modified nanoparticles and nanocomposite membranes were characterised by FTIR, TEM, AFM, SEM, and zeta potential. FTIR results showed the proper mNCs deposition on the surface of membranes. Also, SEM analyses demonstrated that the incorporation of mNCs to TFC membranes led to higher surface roughness. The performance results indicated that the water flux of TFN membranes increased from 42 L·m−2 h−1 to 125 L.m−2 h−1, which might have been due to the higher surface hydrophilicity of TFN membranes, while the rejection rates of Cr(NO3)3 and Pb(NO3)2 were over 99% at and 88%, respectively, showing a competitive and efficient removal of toxic heavy metal ions Pb(II) and Cr(III). Besides, regarding pH of the membranes, rejection performance of the membrane increased with increased pH so that at pH 8.5, the removal rates of Pb(II) and Cr(III) were 93% and 100%, respectively.