The influence of the catalyst on the CO formation during catalytic wet peroxide oxidation process

Herein, the formation of carbon monoxide as a harmful product upon the Catalytic Wet Peroxide Oxidation process is studied in presence of different solid catalysts: an iron supported activated carbon catalyst, a metal free catalyst based on Graphene Nanoplatelets, and 1.6 wt.% Fe containing Cr2AlC MAX phase catalyst. The CWPO performance and the evolution of the gas effluent have been compared to that obtained in a conventional Fenton process. Carbon monoxide yield released was significantly lower in Catalytic Wet Peroxide Oxidation process in relation to that obtained in the Fenton process, where CO concentration reaches a maximum of 6651 mg/Nm(3). By contrast, in presence of activated carbon-Fe catalyst and, notably, Graphene Nanoplatelets and Cr2AlC MAX phase catalysts, a more progressive phenol and aromatics intermediates oxidation resulted in a much lower CO maximum concentration in the gas phase at the exit of the reactor of 2454 mg/Nm(3), 170 mg/Nm(3) and 187 mg/ Nm(3), respectively. Hence, when compared to the homogeneous Fenton oxidation, Catalytic Wet Peroxide Oxidation process results be a more sustainable treatment for high-loaded phenolic wastewaters by decreasing the hazardous CO gaseous emissions avoiding this way a secondary pollution during the oxidation process.

Automated summary

The study showed that the formation of carbon monoxide in the Catalytic Wet Peroxide Oxidation process is significantly lower compared to the conventional Fenton process. Different solid catalysts can achieve a more gradual oxidation of phenol and aromatic intermediates, resulting in lower CO emissions.