화학공학소재연구정보센터
Separation and Purification Technology, Vol.183, 1-10, 2017
Mn-Fe-Mg-Ce loaded Al2O3 catalyzed ozonation for mineralization of refractory organic chemicals in petroleum refinery wastewater
There is great interest in designing a cost-efficient catalytic ozonation system for refractory wastewater treatment. A novel Mn-Fe-Mg-Ce loaded Al2O3 (Mn-Fe-Mg-Ce/Al2O3) was developed to catalytically ozonate real petroleum refinery wastewater (PRW). The loadings, calcination temperature and impregnation sequence of metals significantly influenced the catalytic performance. An optimized catalyst was consisted of 2.2% MnO, 2.2% Fe2O3, 0.9% MgO and 0.9% CeO2. Mg and Ce were co-impregnated and then calcinated at 550 degrees C, followed by Mn and Fe co-impregnation and calcination at 550 degrees C. Mg and Ce oxides pre-loaded on the catalyst promoted an even surface distribution of multivalent Mn (Mn4+, Mn3+ and Mn2+) and Fe oxides (Fe3+ and Fe2+). Such evenly distributed Mn, Fe, Mg and Ce oxides greatly facilitated the hydroxyl radical generation, thus promoted mineralization of refractory organic chemicals in PRW. The Mn-Fe-Mg-Ce/Al2O3 catalyzed ozonation doubled removal of total organic carbon in PRW relative to single ozonation. About 54% polar chemicals were removed, and 60% naphthenic acids and naphthenic acid esters were eliminated, indicating a high degree of mineralization. This study illustrates a potential of Mn-Fe-Mg-Ce/Al2O3 catalyzed ozonation for advanced treatment of refractory wastewaters. (C) 2017 Elsevier B.V. All rights reserved.