Polycyclic aromatic hydrocarbons (PAHs) such as naphthalene recorded environmental concern that affects not only aquatic life but also human health. Naphthalene is widely wasted from different industries such as plastics, resins, fuels, and dyes. In this study, a low-cost and efficient technique for removing naphthalene from aqueous solutions will be introduced using graphene oxide (GO) and graphite (G) from rice husk as agricultural waste by the modified Hummer technique. The prepared GO and G were fully characterized by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and transmission electron microscope (TEM). The Brunauer­Emmett-Teller (BET) surface area for GO is higher than G. The adsorption capacity of the GO and G for naphthalene was investigated by adsorption experiments at different conditions (contact time, a dosage of GO and G, and pH). The maximum adsorption capacity of GO (256.0 µg/g) was found to be higher than G (141.4 µg/g), at a contact time of 60 min and dose of 0.075 g and 0.125 g for GO and G, respectively, at pH = 5. The experimental data for GO and G were analyzed using kinetic models and various isotherm models, including Langmuir, and Freundlich models. The results showed that the Langmuir isotherm is more favorable for naphthalene adsorption.

Overall, the results suggest that the synthesized graphene oxide from agricultural waste is an effective adsorbent for removing naphthalene from aqueous solutions. This study provides a sustainable and cost-effective approach for the synthesis of graphene oxide and its potential implementation in water treatment for the removal of organic pollutants.