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

Abstract

Hexavalent chromium Cr(VI) causes serious damage to human health. In this study, food waste (FW) was used as raw material to prepare the food waste-derived biochar (FWB), which was further modified using Ce and Fe 2+ /Fe 3+ co-precipitation to obtain Ce dopped magnetic waste-derived biochar (Ce/Fe3O4/FWB ) material for the efficient Cr(VI) adsorption. The morphology, structure, and characteristics of Ce/Fe3O4/FWB composite were thoroughly investigated, and its Cr(VI) uptake behavior was explored. Ce/Fe3O4/FWB showed the best Cr(VI) adsorption of 20.4 mg/g at pH 2.Additionally, the adsorption suited the pseudo-second-order kinetic equation and the Langmuir equation, and the intra-particle diffusion the main step limited the Cr(VI) adsorption by Ce/Fe3O4/FWB. The thermodynamic investigation discovered that the adsorption owned a spontaneous and endothermic nature. With increasing concentrations of Cl -, SO4 2and PO4 3-, the Cr(VI) uptake was weakened in the sequence of Cl -＜SO4 2-＜PO4 3-.Adsorbent preparation for Cr(VI) removal utilizing FW as a raw material is a sustainable and environmentally beneficial technology for FW reclamation and Cr(VI)-bearing wastewater treatment.

A novel sludge-based biochar composite adsorbent CS/SBC-H3PO4 for efficient Cr(vi) removal from aqueous solution

“…Among these, Cl − , SO 4 2− and PO 4 3− inhibit the removal of Cr( vi ) by the adsorbent probably because they compete with Cr( vi ) for adsorption. 36 The order of the inhibition effect of these three anions is PO 4 3− > SO 4 2− > Cl − . This is because PO 4 3− has the highest charge number, followed by SO 4 2− and Cl − , which makes the inhibition effect of PO 4 3− stronger than that of SO 4 2− , and SO 4 2− stronger than that of Cl − .…”