Efficient catalytic degradation of sulfamethazine in aqueous solution by activation of peroxydisulfate with CuFeO2

In this work, the bimetallic oxide CuFeO 2 was synthesized by simple hydrothermal synthesis and utilized to activate peroxydisulfate (PDS) for the sulfamethazine (SMT) degradation in water. The influence of some key factors such as CuFeO 2 dose, PDS concentration and initial pH on the degradation of SMT was investigated. In particular, the CuFeO 2 /PDS system was capable of effectively degrading SMT under neutral and weak alkaline conditions. The mechanism of the CuFeO 2 /PDS system was revealed by quenching experiments and ESR tests. It involves a combined radical and non-radical mechanism with multiple active species (SO 4 •− , HO•, O 2 •− and 1 O 2 ) acting together. A synergistic interaction between iron and copper on the CuFeO 2 surface accelerated the conversion of Fe(III) to Fe(II), which is one of the advantages of CuFeO 2 over monometallic oxides. Furthermore, simulated experiments for the SMT degradation were conducted in different water matrices, and the effects of some inorganic ions (e.g. Cl - , SO 4 2- and HCO 3 - ) and humic acid were also explored. Exceptionally, HCO 3 - played a facilitating role for the removal of SMT. Finally, the CuFeO 2 /PDS system still exhibited superior performance after five cycles of testing. Overall, this study provided a cost-effective and promising strategy for the removal of antibiotics from the aqueous environment.