Adsorptive Removal of Drimarene Brilliant Blue by Thermo Stable, Eco-friendly Graphene Oxide Reinforced Polyvinyl Alcohols Hydrogels With High Reusability Potential

Abstract

In this study graphene oxide (GO) reinforced polyvinyl alcohol (PVA) composites hydrogels were synthesized and used as efficient adsorbents for Drimarene Brilliant Blue K-4BL. GO nanoparticles (NPs) were synthesized by modified Hummer’s method. The composites were characterized by Fourier transform infrared spectroscopy (FT-IR), Thermo-gravimetric analysis (TGA), Scanning electron microscopy (SEM) and X-ray diffraction (XRD). The results showed homogeneous dispersion of reinforcement in the synthesized composites. Moreover thermal stability of the composites was significantly enhanced by the addition of graphene oxide nanoparticles. The synthesized composites were used for the removal of Drimarene brilliant Blue from model waste water. The effect of pH, content of GONPs and initial concentration of Drimarene Brilliant Blue K-4BL on the adsorption capacity of synthesized GO/PVA composites were investigated. The equilibrium isothermal data were studied by applying Langmuir and Freundlich isotherm models. Results demonstrated that the adsorption process is well described by the Langmuir adsorption isotherm. According to the Langmuir model, maximum adsorption capacity i.e. 32mg/g was obtained at 0.7% GO/PVA composite. From the kinetic study it was concluded that pseudo-second-order model is the best fitted. Synthesized composites showed excellent reusability (almost 95 %) for the adsorption of Drimarene Brilliant Blue K-4BL after four successive cycles of adsorption and desorption. Thus, the GO/PVA composites demonstrated a great potential in terms of cost effectiveness, efficiency and reusability for the removal of Drimarene Brilliant Blue K-4BL dye.