Insights into the mechanism of peroxydisulfate activated by magnetic spinel CuFe2O4/SBC as a heterogeneous catalyst for bisphenol S degradation

Abstract The CuFe2O4 catalyst in advanced oxidation processes had received much attention, while the leaching metal ions and its agglomeration limited its application prospect. The conversion of waste activated sludge (WAS) into sludge-derived biochar (SBC) through pyrolysis could not only be the option of reducing the environmental burden but also converted to be the value-added environmental remediation materials. Hence, the present study prepared as a CuFe2O4/SBC heterogeneous catalyst to degrade new environmental pollutants (bisphenol S, BPS). To our best knowledge, CuFe2O4/SBC as a heterogeneous catalyst activating peroxydisulfate to degrade BPS in solution is rarely reported, and the catalytic performances and degradation mechanism of CuFe2O4/SBC need to be comprehensively investigated. The synergistic effect between CuFe2O4 and SBC enhanced catalytic performances and alleviated agglomeration. The CuFe2O4/SBC was greatly ameliorated metal ions leaching, but the synthetic strategy could better optimize to further reducing Cu ion leaching. The dominant role of heterogeneous catalysis by CuFe2O4/SBC also have been elucidated. It was proposed that radical ( OH and SO4 −) and non-radical (1O2) oxidation processes worked together for BPS degradation, but surface-bound radical pathways played more crucial roles. Some intermediate products with higher toxicity may be produced due to the non-completely mineralized, thus future attention should be paid to their environmental risks. Hence, the detoxification efficiency of CuFe2O4/SBC needs to be further strengthened via improving the reaction conditions. Overall, this study provided a new strategy to simultaneously solve the problems of WAS disposal and leaching metal ions of CuFe2O4.