Novel magnetic bio-sorbent hydrogel beads based on modified gum tragacanth/graphene oxide: Removal of heavy metals and dyes from water

New magnetic bio-sorbent hydrogel beads were prepared based on modified biopolymer gum tragacanth (GT), polyvinyl alcohol (PVA), and graphene oxide (GO) by using gelation method in the acetone solution of boric acid. The magnetic beads were fully characterized and used as an effective adsorbent for removal of both cationic (crystal violet, CV) and anionic (Congo red, CR) dyes and heavy metal ions such as Pb(II) and Cu(II) from aqueous solution. The adsorption rates were described by the pseudo-second-order kinetic model and the experimental data were fitted well with the Langmuir isotherm model with the maximum adsorption of 81.78, 69.67, 94.0, and 101.74 mg g(-1) for Pb(II), Cu(II), CV, and CR, respectively. The reusability of the beads showed no significant loss of activity after three cycles. These magnetic recyclable beads can be considered as an efficient and low-cost adsorbent for the removal of dyes (cationic and anionic) and heavy metal ions from water, and column applications. (C) 2016 Elsevier Ltd. All rights reserved.