Removal of crystal violet dye using grafted guar gum along with nanoclay and MWCNT

Abstract

The present study is aimed to remove toxic crystal violet dye from aqueous solutions. In this study guar gum (GG) has been grafted with acrylic acid (AA) by following microwave assisted grafting method. Two different nanomaterials i.e., nanoclay (NC) and multiwalled carbon nanotubes (MWCNT) has been incorporated either alone or in combination during the grafting reaction. The synthesized nanocomposites have been used for removal of crystal violet dye from aqueous solutions. Study showed higher dye adsorption capacity of the synthesized composites after addition of nanomaterials. The adsorption isotherm followed both Langmuir and Freundlich model. It was found that GG grafted AA composite with MWCNT showed highest crystal violet dye adsorption compared to others. Swelling behaviour of the synthesized composites in acidic, neutral and alkaline medium has been studied. The swelling kinetics in acidic, neutral and alkaline medium was found to follow pseudo second order kinetic model with value more than 0.98. Fourier transform infrared spectroscopy (FTIR) showed efficient grafting of AA on GG. X-ray diffraction (XRD) and morphological characteristics depicted enhanced dispersion of nanomaterials in GG matrix.