Adsorption Behaviors of Polycyclic Aromatic Hydrocarbons and Oxygen Derivatives in Wastewater on N-Doped Reduced Graphene Oxide

Abstract

In this study, nitrogen-doped reduced graphene oxide (NRGO) was synthesized by a hydrothermal method and then applied to remove polycyclic aromatic hydrocarbons (PAHs) and their oxygen derivatives (OPAHs) in a water solution. NRGO exhibited high mesoporosity (72.9%) and hydrophobicity, a partly graphitized structure and remarkable adsorption efficiency to anthracene (ANT) and 2-methylanthraquinone (2-MAQ). The adsorption capacity of NRGO was 5.77 mg/g for ANT and 9.29 mg/g for 2-MAQ, corresponding to increases in adsorption of more than 2.76- and 2.29-fold compared with graphene oxide (GO), respectively, and 1.4-fold compared with reduced graphene oxide (RGO) at 298 K and pH 7 and an initial concentration of 1 mg/L. It was possible that intraparticle diffusion, hydrophobic effects and π-π interactions were simultaneously involved in the adsorption process based on the characterization results and adsorption experiments. Furthermore, NRGO could be effectively regenerated by ethanol. This work provides ideas for the environmental application of NRGO and its potential use in the removal of low concentrations of PAHs and OPAHs from wastewater.