New material of polyacrylic acid-modified graphene oxide composite for phenol remediation from synthetic and real wastewater

In this study, new material of polyacrylic acid-modified graphene oxide (GO-PAA) composite for phenol remediation from synthetic and real wastewater was investigated. The graphene oxide (GO) and GO-PAA were physically and chemically characterized using scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), energy dispersive X-ray analysis (EDX), and Brunauer–Emmet–Teller (BET). The effects of various experimental factors including pH, temperature, and initial phenol concentration were examined. Results showed that the optimum adsorption occurred at pH 2 and temperature 25 °C. The adsorption capacity of GO-PAA was double of the case of un-modified GO, indicating the importance of surface modification and the introduction of (C=O) groups in the enhancement of the adsorption process. Moreover, the Langmuir adsorption isotherm was found to be the most suitable isotherm to describe the adsorption process of phenol, and thermodynamics studies confirmed the spontaneity and the exothermic nature of the adsorption process. GO-PAA was capable of removing 75% and 18% of phenol from synthetic and real wastewater, respectively under optimum conditions of pH 2 and 25 °C. These results indicate that adsorption of phenolic compounds using GO-PAA could be an effective and simple method to remediate pollution, especially in acidic conditions.