The experimental and mechanism study of novel heterogeneous Fenton-like reactions using Fe3−xTixO4 catalysts for Hg0 absorption

Novel heterogeneous Fenton-like Fe3−xTixO4 catalysts prepared by co-precipitation method were used for Hg0 absorption in a self-designed bubbling reactor system. Characterization by X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) showed that Ti successfully entered the structure of Fe3−xTixO4 catalysts and was enriched on the surface of Fe3−xTixO4. Important factors affecting Fe3−xTixO4 catalysts activity toward Hg0 absorption, such as H2O2 concentration and Ti content in Fe3−xTixO4, were considered. Results showed that Fe3−xTixO4 can effectively decompose H2O2 to generate highly reactive OH radicals, and oxidize Hg0 to Hg2+ in Fenton-like solutions. The mechanism model of Hg0 absorption by heterogeneous Fenton-like reaction was preliminarily established. Theoretically calculated results using the model well agreed with the experimental results, indicating that Hg0 absorption is simultaneously controlled by solid-liquid surface oxidation and gas-liquid film oxidation. These findings can help investigations on the mechanism of Hg0 absorption by the heterogeneous Fenton-like reaction.