STUDY ON THE CATALYTIC ACTIVITY OF COBALT AND IRON-COBALT MIXED OXIDES FOR THE OXIDATIVE DEGRADATION OF ACID ORANGE 7 IN AQUEOUS SOLUTION
Iva A. Slavova, Maria K. Stoyanova, Stoyanka G. Christoskova, Vanina V. Ivanova
Pages: 469-478 Published: 1 Jun 2014
Views: 2,736 Downloads: 1,472
Abstract: The oxidative degradation of Acid Orange 7 (AO7) by nanosized cobalt and iron-cobalt spinel oxides activated Oxone has been performed in this study. It was found that the as-prepared catalysts could effectively catalyze decomposition of oxidant to generate sulfate radicals to degrade AOR in aqueous solution. Co3O4 catalyst exhibited better catalytic activity than cobalt ferrites; however the latter are more relevant catalysts considering environmental and practical aspects. Kinetic studies showed that heterogeneous oxidation of AO7 in catalyst/Oxone systems followed first order kinetics. The effects of several parameters on the degradation efficiency of the process were investigated. Furthermore, the scavenging effect was examined by using ethanol and tert-butyl alcohol which indicated that sulfate radicals were the dominating reactive species responsible for the degradation process.