Keynote Talk: Food Waste As a Sustainable Resource for the Production of Carbons for Purification and Catalytic Processes

Food waste can be considered as a renewable resource for energy and/or materials production. In this study, biochars were prepared via pyrolysis of food waste and then used as precursors for production of activated carbons via physical and chemical activation. Pyrolysis and activation conditions were varied to optimize the properties of biochar and activated carbons, respectively. Activated carbons were characterized by N₂ sorption-desorption, scanning electron microscope (SEM), energy-dispersive X-ray spectroscopy (EDX), elemental analysis, inductively coupled plasma atomic emission spectroscopy (ICP-OES), X-ray powder diffraction (XRD), ¹³C nuclear magnetic resonance (NMR), Fourier-transform infrared spectroscopy (FTIR) and Raman spectroscopy. Adsorption experiments of aromatic hydrocarbons were conducted to evaluate the feasibility of using biochars and activated carbons derived from food waste for the adsorption of aromatic hydrocarbons (benzene and naphthalene) from water. The activated carbon with the highest adsorption capacity was prepared via steam activation at 950⁰C/1 h. The BET surface area, micropore and total pore volume of the activated carbon were 745 m²/g, 0.185 cm³/g and 0.594 cm³/g, respectively. The benzene and naphthalene sorption capacity was 460 mg/g and 150 mg/g, respectively. The physicochemical properties and adsorption capacities of the activated carbons prepared from food waste were also compared to the corresponding properties and capacities of the activated carbons derived from miscanthus, as well as commercial carbons. Our study revealed that activated carbons prepared by physical activation of biochars derived from food waste are promising candidates for water purification with capacities for aromatic hydrocarbons similar to the ones observed using commercial activated carbons.