Treatment of textile wastewater containing acid dye using novel polymeric graphene oxide nanocomposites (GO/PAN,GO/PPy, GO/PSty)

Water pollution by synthetic dyes and other organic contaminants is a serious issue of the present days for both mankind and scientists. From the past few years, much attention has been given to the graphene oxide nanocomposites due to their greater ability to adsorb and degrade the industrial pollutants and greater suitability to the environment. In the present research, polymeric graphene oxide (GO) nanocomposites such as GO/polyaniline (PAN), GO/polypyrrole (PPy) and GO/polystyrene (PS) were utilized as promising adsorbents for removal of actacid orange RL (AO-RL) dye. Characterization of synthesized nanocomposites was done by Fourier transform infrared spectroscopy and scanning electron microscopy techniques. Higher adsorption rates were achieved at pH values 2, 6 and 3 for all three nanocomposite GO/PAN, GO/PPy, and GO/PSty. Maximum removal 39.54, 44.76 and 21.43 mg/g were achieved, respectively when optimum adsorbent dose of 0.01 g was used at 35 °C. The maximum adsorption of 39.65, 43.99, and 21.10 mg/g for all three nanocomposites were obtained at the equilibrium contact time of 60 min. For GO/PAN and GO/PPy the maximum adsorption rates were attained when 150 mg/L of initial dye concentration was used and for GO/PSty nanocomposite the maximum removal 54.34 mg/g was obtained when 100 mg/L of initial dye concentration was used. Obtained results showed that removal of AO-RL dye was best fit by the pseudo 2nd order kinetic model and Langmuir adsorption isotherm with R2 values 0.99, 0.997, and 0.986, respectively. Negative values of enthalpy variation: −40.95,-62.95 and −55.52 kJ/mol, respectively, show the spontaneity and exothermic nature of the reaction. So, results indicated that the synthesized polymeric GO nanocomposites have a good perspective for the treatment of wastewater.