Porous adsorbent derived from acid activation of food waste biochar: A sustainable approach for novel removal chlorophenol in wastewater

In this study, porous biochar (PBC) was prepared by acid activation of biochar derived from food waste (FWBC) and used as a suitable approach for the removal of 4-chlorophenol (CP) in wastewater. The characterization of PBC and the influent of different experimental conditions are determined. After the acid activation process, the surface area, porosity, and functional groups of PBC were developed. The removal performances of CP (1 mg/L) by PBC and FWBC were archived at 97.8 and 82.1%, respectively. Adsorption kinetics and isotherms of CP were followed by the second-order and Langmuir models, respectively. The maximum capacities of CP uptake onto mono-layer of FWBC and PBC based on the Langmuir model were determined at 79.8 and 108.7 mg/g, respectively. Besides, PBC could remove more than 89% CP from wastewater within 45 min of reaction time and it is suitable to reuse 8 times with over 60% adsorption efficiency of CP. In addition, the adsorption mechanism and environmental impact were discussed in detail. This work could bring a sustainable approach to the treatment of CP in wastewater as well as the management of food waste in Vietnam.