Catalytic degradation (decolourization) of methylene blue with metal oxide catalysts.

Abstract

Due to increasingly stringent environmental regulations on harmful and nonbiodegradable dyes like methylene blue (MB), there is an imperative need to develop efficient and effective technological systems for the complete removal of these organic pollutants from wastewaters. Over the years, advanced oxidation processes (AOP) have emerged as a destructive technology leading to the total mineralization of most organic pollutants. However, several challenges still need to be met before the full potential of this technology can be realized. The most important being shorter treatment times for sizeable amounts of organic pollutants. This report presents the catalytic performances of different supported nano-catalyst on degrading MB via heterogeneous oxone activation.Catalyst parameters were optimized based on the catalyst displaying the highest kinetic performance in MB degradation. Parameters investigated include cobalt loading, support preparation methods and calcination temperatures. The synergetic effect between oxone, Co3O4 and the support, as well as the stability of the catalyst displaying optimum performance was also evaluated. It is believe that MgO support prepared by thermal decomposition of Mg(OH)2 at 600oC for 3h shows potential in solving the challenge to the complete mineralization of MB in shorter duration, displaying capabilities of completely mineralizing MB within a short reaction time of 3 minutes. Nonetheless, the optimization of preparation parameters so that the catalyst is stable, effective and display high catalytic performance still poses certain level of difficulties.