Degradation of anti-inflammatory drug diclofenac using cobalt ferrite as photocatalyst

Abstract

Emerging pollutants, among them pharmaceutical compounds, are found in surface and ground waters, suggesting their ineffective removal by conventional wastewater treatment technologies. In this paper, the removal of sodium diclofenac, a widely used non-steroidal anti-inflammatory drug, was explored by a heterogeneous Photo-Fenton process using CoFe2O4, H2O2 and Uv germicide radiation (254nm). Cobalt ferrites, were obtained by Pechini method and calcined at 600°C and 800°C. They were characterized by X-ray diffraction, Uv visible spectroscopy, Mössbauer and X-ray photoelectron spectroscopy, temperature-programmed reduction and specific surface area. The inverse spinel structure was obtained, and both materials presented good performance in the photo-Fenton reaction. A degradation mechanism based on the generation of OH groups is suggested. The complete sodium diclofenac degradation and 86% of mineralization of the total organic carbon were obtained using cobalt ferrite calcined at 800°C. This catalyst was used in three cycles, without activity loss showing a negligible Fe leaching.