Ferric iron enhanced chloramphenicol oxidation in pyrite (FeS2) induced Fenton-like reactions

In this study, the novel combination of Fe 3+ and FeS 2 /H 2 O 2 system was used to enhance the degradation of chloramphenicol (CAP) by promoting the synergetic effect between the Fe 3+ and the FeS 2 , and the kinetic models to elucidate the reaction mechanisms were validated. Raw pyrite samples were pretreated and characterized by X-ray diffraction, scanning electron microscope, transmission electron microscopy and Brunauer–Emmett–Teller surface area analyzer. Studies on the effects of buffer solution and phosphate on the kinetics of CAP degradation revealed that the autocatalytic effect was associated with the dissolution and generation of Fe 3+ . As confirmed by the experiment to examine the Fe 3+ mediated oxidation of FeS 2 , the catalytic improvement was due to the release of Fe 2+ by the reaction between the FeS 2 and the Fe 3+ at zero-order rate when the Fe 3+ was excessively present. Kinetic models including surface-controlled activation and homogeneous Fenton reactions were responsible for the degradation of CAP.