In this work the photo-Fenton process for removing organic substances from wastewater was studied by utilizing LaFeO3 perovskites supported on corundum monoliths. The results showed that the heterogeneous photo-Fenton process, based on structured catalysts, allows the total mineralization of acetic acid, giving CO2 and H2O. By adding H2O2 in one time at the beginning of the reaction, it was possible to attain a degree of total organic carbon (TOC) removal between 50 to 70%. With H2O2 dosage during irradiation time, 97% of TOC removal was achieved on structured catalyst containing 10.64 wt% of LaFeO3, coupled to a best utilization of H2O2 at parity of acetic acid conversion. On the same catalyst and with similar operative conditions, by changing the model pollutant in solution, an increased TOC removal was observed after 4 hours of irradiation time, resulting 53, 62 and 95% passing from ethanol to acetaldehyde and finally to oxalic acid, respectively. These results show that suitable heterogeneous catalyst permits the removal of a wide range of substances and suggest that, starting from ethanol, a progressive oxidation occurs, in agreement with the mechanism reported for the homogeneous photo-Fenton degradation of ethanol. Nanoperovskites, well anchored to the monolithic support, permitted to conjugate the improved catalytic activity to their easy and safely manipulation and direct separation from treated effluents. The catalysts can be reutilized, and no metal leaching from the structured catalyst was observed.
Heterogeneous Photo-Fenton Oxidation of Organic Pollutants onStructured Catalysts
SANNINO, Diana;VAIANO, VINCENZO;CIAMBELLI, Paolo
2012-01-01
Abstract
In this work the photo-Fenton process for removing organic substances from wastewater was studied by utilizing LaFeO3 perovskites supported on corundum monoliths. The results showed that the heterogeneous photo-Fenton process, based on structured catalysts, allows the total mineralization of acetic acid, giving CO2 and H2O. By adding H2O2 in one time at the beginning of the reaction, it was possible to attain a degree of total organic carbon (TOC) removal between 50 to 70%. With H2O2 dosage during irradiation time, 97% of TOC removal was achieved on structured catalyst containing 10.64 wt% of LaFeO3, coupled to a best utilization of H2O2 at parity of acetic acid conversion. On the same catalyst and with similar operative conditions, by changing the model pollutant in solution, an increased TOC removal was observed after 4 hours of irradiation time, resulting 53, 62 and 95% passing from ethanol to acetaldehyde and finally to oxalic acid, respectively. These results show that suitable heterogeneous catalyst permits the removal of a wide range of substances and suggest that, starting from ethanol, a progressive oxidation occurs, in agreement with the mechanism reported for the homogeneous photo-Fenton degradation of ethanol. Nanoperovskites, well anchored to the monolithic support, permitted to conjugate the improved catalytic activity to their easy and safely manipulation and direct separation from treated effluents. The catalysts can be reutilized, and no metal leaching from the structured catalyst was observed.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
