Photocatalytic Oxidation of Oxalic Acid with Oxygen and Ozone in an Aqueous Solution

Abstract—An experimental study has been carried out on the mineralization of oxalic acid H2C2O4 and other oxidation-resistant organic compounds in aqueous solutions under the influence of oxygen, ozone, and ultraviolet radiation. It was found that in acidic solutions H2C2O4 does not oxidize under the influence of ozone or UV irradiation in the presence of oxygen; when exposed simultaneously to O3 + UV it has a low rate of oxidation. The possibility of photocatalysis of the mineralization process by Mn2+, MnO $$_{4}^{ - }$$ , Fe3+, Co2+, BrO $$_{3}^{ - }$$ , or IO $$_{3}^{ - }$$ ions was studied The most effective photocatalysts are Fe3+ ions: in their presence and under UV irradiation, a fairly rapid oxidation of oxalic acid to CO2 occurs, as under the influence of O3 and O2. The conditions for maximum ozone conversion during photomineralization of oxalic acid have been found. The possibility of oxidative destruction of a more oxidation-resistant substrate, acetic acid, is shown during ozonation and UV irradiation of solutions with Fe(III) and H2C2O4 additives.