Preparation of Ce/ferroferric oxide/food waste-derived biochar for aqueous Cr(VI) adsorption

BACKGROUND Cr(VI) in aqueous solution is a serious concern that can harm human health by accumulating in the food chain. Meanwhile, the most common form of food waste (FW) disposal by landfill takes up a lot of area and pollutes the environment. As a consequence, FW was employed as a raw material in the production of food waste-derived biochar (FWB), which was then modified to produce a Ce/Fe3O4/FWB composite for high-efficiency Cr(VI) removal RESULTS The structure, morphology, and properties of the Ce/Fe3O4/FWB composite were thoroughly investigated, as well as its Cr(VI) adsorption ability. The composite exhibited the highest Cr(VI) adsorption of 20.4 mg/g at pH 2. Furthermore, the adsorption fitted the pseudo-second-order kinetic model and the Langmuir model, with intra-particle diffusion acting as the rate-controlling step. The thermodynamic investigation demonstrated that Cr (VI) adsorption by Ce/Fe3O4/FWB was a spontaneous endothermic process. With increasing concentrations of Cl-, SO42- and PO43-, the Cr(VI) adsorption was weakened in the sequence of Cl-, SO42- and PO43-. CONCLUSION Adsorbent preparation utilizing FW as raw material is a sustainable and environmentally beneficial method for FW reclaimation and Cr(VI)-bearing wastewater treatment. (c) 2022 Society of Chemical Industry (SCI).