FeOOH and derived phases: Efficient heterogeneous catalysts for clofibric acid degradation by advanced oxidation processes (AOPs)

Abstract In this study the degradation of an aqueous solution of clofibric acid was investigated during catalytic ozonation and Fenton-like process with FeOOH – derived catalysts. From the different calcination temperatures tested, it has been observed that the most active catalyst is the commercial FeOOH calcined at 200 °C, when maghemite and hematite are the predominant phases obtained. The best result, at room temperature, for CFA mineralization was observed over 0.5 wt% Pd on FeOOH (calcined at 200 °C) among all tested catalysts, achieving 68% and 81% mineralization degree, in 2 h and 6 h, respectively, in catalytic ozonation and 66% and 71% of mineralization degree within 2 h and 6 h, respectively for Fenton process. The efficiency of the Fenton-like process is enhanced at higher temperature (40–60 °C), reaching a mineralization degree up to 82% in 6 h. Furthermore, Pd impregnation on FeOOH increased the catalyst stability.