Oxidation of NH3 Wastewater in Supercritical Water over Mn-M-O/TiO2-Al2O3 Catalyst
HU Zi-Fang1，2, JIANG Hao-Xi1，2, LI Gui-Ming1，2
1R&D Center for Petrochemical Technology, Tianjin University, Tianjin 300072, China; 2Key Laboratory for Green Chemical Technology of Ministry of Education， Tianjin University, Tianjin 300072, China
Abstract：
Ammonia is one of the most refractory pollutants in coking wastewater. The degradation effect of traditional biochemical methods is not obvious. However, supercritical water oxidation technology as a novel and highly efficient method can completely remove ammonia in coking wastewater after the introduction of manganese based catalysts. In this work, supported manganesebased catalysts doped with additives Mn-M-O/TA of three different Mn/M molar ratio were prepared separately by incipient impregnation with oxides of Mn and M(Ce, Co, Cu) as active components and TiO2-Al2O3 (TA) as the support. The oxidation reaction of NH3 in supercritical water was carried out in a continuous flow reactor at 460 ℃, 26 MPa, and the residence time of 4—5 s with the oxidant dose of 3 times the stoichiometric amount. The results showed that the Mn-Cu-O/TA catalysts had a preferable performance of ammonia degradation, Mn-Cu-O/TA-55 exhibited the highest activity and the conversion of ammonia was 55.8%. The catalysts were characterized by XRD, XPS, TPR and other methods. The results showed that the reduction properties of the catalysts after adding Cu improved fast, which was good for the increase of conversion of ammonia.
HU Zi-Fang, JIANG Hao-Xi, LI Gui-Ming.Oxidation of NH3 Wastewater in Supercritical Water over Mn-M-O/TiO2-Al2O3 Catalyst[J]. Chemcial Industry and Engineering, 2014,31(6): 13-17
2014, Vol. 31 
