SOLID CATALYSTS FOR WET OXIDATION OF NITROGEN-CONTAINING ORGANIC-COMPOUNDS

Several solid catalysts (Co3O4/gamma-Al2O3, Fe2O3/gamma-Al2O3, Mn2O3/g amma-Al2O3, Zn-Fe-Mn-Al-O, Pt/gamma-Al2O3, Ru/CeO2, Ru/C) have been pr epared and used to remove N-containing organic contaminants while proc essing toxic and hazardous industrial waste waters using wet oxidation by air (WAO). The autoclave tests of catalysts were done to reveal th e main advantages of catalysts in water presence at high pressures and temperatures. Catalyst activity was determined with regard to oxygen interaction with model mixtures (water-organic contaminant: acetonitri le, carbamide, dimethyl formamide, or multicomponent mixture of alipha tic alcohols). Activity tests were done in a static reactor under idea l mixing regime. Reagents and products were monitored using gas chroma tograph Cvet-560, Millichrom-1 HPLC, and routine chemical analysis. Op timum process conditions for the best catalyst (Ru/graphite-like carbo n) are as follows: partial oxygen pressure - 1.0 MPa, temperature - 47 3-513 K. At 0.5-5.0 MPa total pressure and 433-523 K catalysts show hi gh water-resistance and high activity level (residual content of toxic compounds is less than 1%, and no NOx and NH3 are detected). There ar e no legal restrictions on catalysts operation, since they are harmles s to environment. (C) 1998 Elsevier Science B.V. All rights reserved.