Micro- and nano-sized bentonite filled composite superabsorbents of chitosan and acrylic copolymer for removal of synthetic dyes from water

Abstract Bentonite clay, chitosan and acrylic copolymer gels have been separately reported for the adsorption of dyes. In the present work these three kinds of adsorbents were combined to make composite hydrogels. The hydrogels were characterized by FTIR, XRD, DTA–TGA and SEM. The swelling, diffusion and network parameters of the hydrogels were also evaluated. These composite hydrogels were used for the removal of malachite green and methyl violet dyes from water. The composite hydrogels showed high adsorption and removal% of both of these dyes. The mass transfer coefficient, diffusion coefficient and thermodynamic parameters of the dye adsorption were also determined.