Efficient ozonation of reverse osmosis concentrates from petroleum refinery wastewater using composite metal oxideloaded alumina

摘要

Novel Mn–Fe–Mg-and Mn–Fe–Ce-loaded alumina(Mn–Fe–Mg/Al_2O_3 and Mn–Fe–Ce/Al_2O_3) were developed to catalytically ozonate reverse osmosis concentrates generated from petroleum refinery wastewaters(PRW-ROC). Highly dispersed 100–300-nm deposits of composite multivalent metal oxides of Mn(Mn^(2+)), Mn^(3+),and Mn^(4+), Fe(Fe^(2+))and Fe^(3+) and Mg(Mg^(2+)), or Ce(Ce^(4+)) were achieved on Al_2O_3 supports. The developed Mn–Fe–Mg/Al_2O_3 and Mn–Fe–Ce/Al_2O_3 exhibited higher catalytic activity during the ozonation of PRW-ROC than Mn–Fe/Al_2O_3, Mn/Al_2O-3, Fe/Al_2O_3, and Al_2O_3. Chemical oxygen demand removal by Mn–Fe–Mg/Al_2O_3-or Mn–Fe–Ce/Al_2O_3-catalyzed ozonation increased by 23.9% and23.2%, respectively, in comparison with single ozonation.Mn–Fe–Mg/Al_2O_3 and Mn–Fe–Ce/Al_2O_3 notably promoted áOH generation and áOH-mediated oxidation. This study demonstrated the potential use of composite metal oxide-loaded Al_2O_3 in advanced treatment of bio-recalcitrant wastewaters.