Removal of butyl xanthate and Cr(Ⅵ) using FeNi-biochar

The magnetic FeNi-biochar (FeNi-BC) is prepared for butyl xanthate (BX) and Cr(Ⅵ) wastewater purification, which occurs via the adsorption and activation peroxodisulfate (PDS) degradation. The physical and chemical properties of FeNi-BC are analyzed by characterization technology, which is loaded on an FeNi alloy. According to Langmuir model calculation, the BX and Cr(Ⅵ) adsorption capacities of FeNi-BC are 366.21 and 29.56 mg/g, respectively. Adsorption mechanism analysis demonstrates that the functional groups on the surface of FeNi-BC contribute to BX and Cr(Ⅵ) removal. FeNi-BC can also be used for activating peroxysulphate (PDS) to remove BX and Cr(Ⅵ) with 100% and 97% removal, respectively. According to degradation mechanism analysis, the generated reactive oxygen species, such as SO4•– and 1O2 can transform BX into inorganic molecules. Cr(Ⅵ) is reduced to Cr(Ⅲ) by Fe(III)/Fe(II) and Ni(III)/Ni(II) cycles based on electron donors. The formation of FeNi on FeNi-BC changes the electronic structure, improving electron transfer ability and achieving excellent PDS activation performance for FeNi-BC.