Highly efficient removal of hexavalent chromium by magnetic Fe–C composite from reed straw and electric furnace dust waste

Abstract

Reed straw and electric furnace dust (EFD) waste were used to prepare magnetic Fe-C composite (EFD&C) by co-precipitation and high-temperature activation method to remove Cr(VI) from water. The magnetic EFD&C owned a large speci c surface (536.61 m 2 /g) and a porous structure (micropores and mesopores), and had an e cient removal capacity for Cr(VI). Under conditions of pH ( 2), the addition amount of EFD&C (1 g/L), the adsorption time (760 min), and the temperature (45 o C), the maximum adsorption capacity reached 111.94 mg/g. The adsorption mechanism mainly attributed to chemical adsorption (redox), Cr(VI) reduced to Cr(III) by Fe(II) and Fe(0) (from Fe 3 O 4 and Fe components in EFD) and surface functional groups of -OH, C = C, C-C and O-C = O (from biochar), and secondary attributed to physical adsorption, Cr(VI) and Cr(III) (from reduced Cr(VI)) adsorbed into the porous structure of EFD&C.This study provided guidance for the recycling of iron-containing metallurgical solid and biomass waste.