Novel synthesis of GG-g-PAN based hydrolyzed products exclusion of congo red and methylene blue dyes undertaken aqueous medium for spectroscopic investigations

Abstract

Untreated industrial waste discharged to the surrounding water streams comprises of harmful contaminants which can harm the environment. In this work, GG-g-PAN and hydrolyzed grafted copolymers were tested for their ability to remove Congo-red (CR) and methylene blue (MB) dyes from water. GG was modified through graft copolymerization of acrylonitrile (AN) and subsequent hydrolysis to attain the GG-g-2HPAN and GG-g-4HPAN respectively. Physico-chemical changes and surface morphology were elucidated by x-ray diffraction (XRD), scanning electron microscopy (SEM), high-resolution scanning electron microscopy (HR-TEM), thermogravimetric analysis (TGA), energy dispersive x-ray spectroscopy (EDS), Fourier transform infrared spectroscopy (FTIR) and swelling. In relation to different process variables, the adsorption capacity for CR and MB dyes was investigated and modelled using suitable adsorption isotherms and kinetic models. The highest adsorption capacity exhibited by GG-g-4HPAN was 81% for congo red and 94.31% for methylene blue dye. The Langmuir isotherm, pseudo-second-order KM, Boyd’s KM, Elovich KM and WM IPD model were the best-fitted models for the adsorption equilibria and kinetic data respectively. Reusability studies were carried out for four consecutive cycles to comprehend environmental sustainability.