Degradation of Oxalic Acid by Catalytic Ozonation

Abstract

Wastewater treatment processes leads to the formation of refractory compounds which are resistant to conventional treatment processes. Total mineralization of refractory compounds is not possible by conventional oxidation processes hence some ozone based advanced oxidation processes have been developed. Typical refractory compound oxalic acid has been used to treat by ozonation processes in this study. Degradation of oxalic acid was studied with ozonation and catalytic ozonation. The catalyst used was Mn-Cu(5%-5%)/Al2O3. The catalyst was able to adsorb the model compound. The mineralization of oxalic acid was more with the catalytic ozonation as compared to non-catalytic ozonation. The removal% was 62% and 87% for non-catalytic and catalytic ozonation processes respectively. The kinetics of the system was also developed. For non-catalytic ozonation the rate constant was 5.03Ms-1. Langmuir Hinshelwood model has been used to describe the kinetics of heterogeneous catalytic ozonation. Experimental kinetics for overall process gave the rate constant as 3.69x107 M-2s-1. Future scope of the research is to use these processes on the commercial scale for the removal of oxalic acid from wastewater treatment.