Study of Reaction Parameters that Influence Photocatalytic Degradation of Orange Acid 7 (AO7) using MCM-41 materials modified with Cr and Ti

Abstract

The AO7 is an organic synthetic dye, and due to its characteristics, is considered a toxic, non-biodegradable substance, resistant to conventional physicochemical treatments. In this work, the heterogeneous photocatalysis was used as an efficient Advanced Oxidation Process (AOP) to AO7 degradation, using materials MCM-41 modified with Cr and Ti as photocatalysts.
The influence of the following parameters on the photodegradation was studied: initial concentration of AO7 and catalyst and pH of the solution. The results obtained for a degradation of AO7 close to 86% after 5 h of irradiation, could set as optimized conditions of reaction: 20 ppm of AO7, 1 g/l of TiO2/Cr/MCM-41 working at natural pH. In addition the colored solution biodegradability was evaluated by measuring the BOD5/COD ratio. The value obtained at 20 h ofirradiation was 0,52, so the biodegradability of the solution could be reach using the optimized AOP.