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

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.

KEYWORDS:

• Adsorption
• metal ion removal
• thin-film nanocomposite membrane
• cellulose nanoparticles

Acknowledgments

The authors are grateful to the Hamedan Branch, Islamic Azad University for providing facilities to conduct and complete this study.

Author contributions

All authors contributed to the study conception and design. Material preparation, data collection and analysis were performed by [Keivan Farokhi], [Mehrdad Cheraghi], [Soheil Sobhan Ardakani], [Bahareh Lorestani] and [Daryoush Emadzadeh]. The first draft of the manuscript was written by [Daryoush Emadzadeh] and [Keivan Farokhi] and all authors commented on previous versions of the manuscript. All authors read and approved the final manuscript.

Disclosure statement

The authors declare that they have no conflict of interest regarding the publication of this article.

Additional information

Funding

This research did not receive any grant from public, commercial or non-profit agencies.