New composite hydrogels were synthesized based on gum tragacanth (GT) carbohydrate andgraphene oxide (GO). GT was sulfonic acid-functionalized and cross-linked by using 2-acrylamido-2-methylpropanesulfonic acid (AMPS) and N,N’-methylenebisacrylamide (MBA) monomers and cericammonium nitrate (CAN) as an initiator. The prepared hydrogels were characterized by Fourier trans-form infrared spectrum (FT-IR), field emission scanning electron microscope (FE-SEM), energy dispersiveX-ray spectroscopy (EDS), X-ray diffraction (XRD) and thermogravimetric analysis (TGA). Adsorption pro-cess for removal of heavy metal ions has followed the pseudo-first-order kinetic model and fitted wellwith the Langmuir model. The maximum adsorption capacity (Qm) was 142.50, 112.50 and 132.12 mg g−1for Pb(II), Cd(II), and Ag(I), respectively. The removal percentage decreased slightly after several adsorp-tion/desorption cycles. The adsorbed Ag(I) ions in hydrogel were transformed to Ag0nanoparticles (witha narrow distribution and mean size of 13.0 nm) by using Achillea millefolium flower extract. The antibac-terial performance of the Ag0nanocomposite hydrogel was also investigated.
