Facile Removal of Methylene Blue Using Carboxymethyl Cellulose Grafted Polyacrylamide/Carbon Black Nanocomposite Hydrogel

In the present work, novel pH-sensitive nanocomposite hydrogels were developed by grafting acrylamide onto carboxymethyl cellulose backbone (Hyd) using the free radical grafting polymerization method for the decontamination of methylene blue (MB) from an aquatic medium. Optimum values of weight percentage of acrylamide to total weight and content of carbon black nanoparticles based on removal efficiency were obtained at 75% and 7.5 wt%, respectively. The chemical structure, morphology, and thermal properties of synthesized adsorbents were characterized by FTIR, XRD, TGA, BET, and SEM methods. The removal efficiency under optimum conditions of pH 7, adsorbent dosage 1.5 g/L, contact time 60 min, dye initial concentration 10 mg/L, and temperature 25 °C were calculated to be 84.6 and 96.68% for Hyd and Hyd/CB, respectively. Kinetic and Equilibrium data were in good agreement with quasi-second-order and Langmuir models, respectively. With the rising temperature, the uptake of MB decreased, which implied the exothermic nature of the adsorption process.