Characterization of magnetic guar gum-grafted carbon nanotubes and the adsorption of the dyes

► GG was covalently grafted on MWCNT. ► GG improved the dispersion of MWCNT in water. ► Iron oxide nanoparticles were synthesized on the GG-MWCNT to prepare magnetic composite. ► GG acted as the template for nanoparticle growth. ► The composites possessed magnetic separation and good adsorption for MB and NR.