Removal of Methylene Blue Dye from Wastewater Using Polydopamine Agave Americana Fibres-co-Poly(AAc)/Ag Nanocomposites

Abstract

In this research, efforts have been made to tailor the surface of Agave americana fibre by utilising a sequence of chemical techniques and their subsequent utilisation as adsorbents to remove methylene blue dye from wastewater. The surface modification of Agave americana cellulosic fibre was carried out by utilising a polydopamine (PDA) coating agent, which was subsequently graft copolymerized with vinyl monomer acrylic acid (AAc), and finally doped with silver nanoparticles (Ag NPs) to synthesise nanocomposites. Different characterisation techniques, such as SEM, FTIR and XRD were used to characterise the samples and UV-visible spectroscopy was utilised to assess their potential for the removal of dye from wastewater. The grafting of polydopamine, polyacrylic acid, and silver nanoparticles onto the cellulosic fibre resulted in morphological changes and the formation of new bonds, as confirmed by SEM images and FTIR spectra of the grafted samples, respectively. Further, during the dye adsorption/degradation study, among different surface-modified fibres, silver nanoparticles-doped Agave americana fibres graft copolymerized samples showed a maximum of 94.40% dye adsorption/degradation tendency and 85.20 mg/g adsorption capacity. Further, the adsorption was found to be close to Langmuir adsorption.

Keywords

• methylene blue
• wastewater
• polydopamine
• agave americana
• acrylic acid
• silver nanoparticle
• adsorption