[Synergistic Enhancement on Oxidation of Phenol by Fenton Processes by Adding Ce3+ and Cu2+ Ions].

Synergistic effect of Ce3+ and Cu2+ on the oxidation efficiency of phenol in different initial pH and H2O2 concentrations by Fenton processes was studied. The experiment results illustrated that Ce3+/Cu2+/Fe2+/H2O2 system had a wider scope of application than Fenton process in the aspect of pH and H2O2 concentration. Phenol was still efficiently degraded by Ce3+/Cu2+/Fe2+/H2O2 at a higher pH (pH=5.0) and a higher H2O2 concentration (2.0 mmol·L-1). In addition, Cu2+ could react with quinone-like substrates, the oxidation intermediates of phenol, to produce Cu+, which could catalyze the decomposition of H2O2 to form·OH, while Ce3+ could accelerate the formation of quinone-like substrates and facilitate the cycling of Fe3+ and Fe2+, to enhance the decomposition of H2O2 to form·OH, the mechanism analysis illuminated the synergy of Ce3+ and Cu2+. The reactive species in Ce3+/Cu2+/Fe2+/H2O2 system was still proved to be·OH, resulting from the scavenging experiments by adding different radical scavengers.