Evaluation of Photocatalysis Based on Ozone/Goethite/Ultraviolet C for Caffeine Degradation

Abstract

Caffeine is found in significant concentrations in the environment due to bioaccumulation and high resistance to conventional and biological treatments. It has critical effects on aquatic species and human health. Intensification of photocatalysis based on ozone (O3)/ultraviolet (UV) radiation type C/goethite (GHT) was applied in the degradation and mineralization of caffeine in solution by using a heterogeneous stirred‐tank photoreactor with artificial light. O3 dose and GHT charge were established as perturbation variables, and the effects of speed of agitation, pH, initial caffeine concentration, and UV light were evaluated before intensification to find the best conditions. With the O3/UV/GHT process, a degree of degradation of ca. 99.97 % for caffeine in water was reached in less than 20 min. The degree of mineralization achieved was 38.02 %.