Adsorptive removal of benzo(ghi)perylene from vehicle-wash wastewater using eucalyptus wood waste-derived biochar

This study reports the preparation of eucalyptus waste-derived biochar (EWB) and its application in the sustainable removal of benzo[ghi]perylene (B[ghi]P) from vehicle wash wastewater (VWW). The EWB was prepared by pyrolysis under a nitrogen atmosphere, followed by activation with 1 M HCl to improve its adsorption performance. The prepared EWB was characterized by surface area analysis (SAA), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). Batch adsorption experiments were conducted to evaluate the effects of initial B[ghi]P concentration, contact time, pH, temperature, and adsorbent dosage on the adsorption process. The optimal adsorption conditions were: initial B[ghi]P concentration of 40 mg L -1 , contact time of 120 min, temperature of 60 °C, adsorbent dosage of 0.8 g, and pH of 6. Under these conditions, the maximum removal efficiency of EWB reached 98%. The adsorption process best fits the pseudo-second-order kinetic model, while the Langmuir isotherm model provides the best statistical fit for the equilibrium adsorption data. Furthermore, the EWB maintained an initial adsorption efficiency of over 84% after six consecutive adsorption-desorption cycles, indicating its potential for reusability. The observed adsorption efficiency and reusability suggest that the EWB may have the potential to treat wastewater contaminated with PAHs. However, further research is needed to determine its practical and sustainable applications, addressing issues such as energy requirements, production costs, environmental impact, and scalability.