Food Azo-Dyes Removal from Water by Heterogeneous Photo-Fenton with LaFeO3 Supported on Honeycomb Corundum Monoliths

Heterogeneous photo-Fenton process with structured catalyst was investigated in the removal of two typical food azo dyes, red allura (RED) and tartrazine (TRZ). The influence of LaFeO3 loading (with and without Pt) on corundum honeycombs monolithic support was evaluated in the discoloration and mineralization of the target azo dyes. The results for discoloration were reported for different experimental conditions: UV, UV+H2O2, UV+H2O2+structured catalysts. In the case of UV alone the discoloration occurs very slowly and not completely (approximately 36 and 20% in 120 min of irradiation for RED and TRZ, respectively); but the process efficiency has been enhanced in the presence of H2O2 (approximately 77 and 80% in 5 min of irradiation for RED and TRZ, respectively). The best efficiency in RED dye discoloration and mineralization by heterogeneous photo-Fenton process was observed for a LaFeO3 loading equal to 4.5% by weight (complete discoloration and 95% of TOC removal in 60 min of irradiation time...