Keywords: catalytic wet oxidation, CWO, wet air oxidation, pulp and paper mills, industrial effluent, ferulic acid, transition metal catalysts, wastewater treatment, high-pressure reactors, organic removal
Catalytic wet oxidation of ferulic acid
Catalytic Wet Oxidation (CWO) of aqueous ferulic acid (a lignin model compound) was carried out under mild conditions (100?150?C, ~300 kPa PO2). Significant removal of ferulic acid (in terms of Total Organic Carbon (TOC)) (81% at 100?C and 95% at 150?C after 2 hr) was obtained using a CuNiCe/Al2O3 catalyst. A considerable portion of this TOC was removed during the heat-up period prior to oxygen addition (40% at 100?C and 62% at 150?C). This was most likely due to oxidation of organics by the catalysts' lattice oxygen, catalytic decarboxylation or adsorption. No TOC removal occurred in the absence of the catalyst during the heat-up period at 150?C. The catalytic mechanism in the presence of oxygen was also investigated using various techniques (FTIR, GC-MS and Electrospray-MS). Based on the data obtained an adsorption/desorption/oxidation mechanism is proposed.