Abstract
The global concern over water pollution caused by contaminants of emerging concern has been the subject of several studies due to the complexity of treatment. Here, the synthesis of a graphene oxide-based magnetic material (GO@Fe(3)O(4)) produced according to a modified Hummers' method followed by a hydrothermal reaction was proposed; then, its application as a photocatalyst in clonazepam photo-Fenton degradation was investigated. Several characterization analyses were performed to analyze the structure, functionalization and magnetic properties of the composite. A 2(3) factorial design was used for the optimization procedure to investigate the effect of [H(2)O(2)], GO@Fe(3)O(4) dose and pH on clonazepam degradation. Adsorption experiments demonstrated that GO@Fe(3)O(4) could not adsorb clonazepam. Photo-Fenton kinetics showed that total degradation of clonazepam was achieved within 5 min, and the experimental data were better fitted to the PFO model. A comparative study of clonazepam degradation by different processes highlighted that the heterogeneous photo-Fenton process was more efficient than homogeneous processes. The radical scavenging test showed that O2·- was the main active free radical in the degradation reaction, followed by hydroxyl radicals ((•)OH) and holes (h(+)) in the valence layer; accordingly, a mechanism of degradation was proposed to describe the process.