Heterogenous Photocatalysis Treatement of Azo Dye Methyl Orange by Nano Composite TiO2/Diatomite

摘要

The objective of this work is to study the removal of an azo dye methyl orange (MeO) by dioxide titanium supported on the surface of diatomite, as a new nano-composite by an advanced oxidation method as heterogeneous Photocatalysis. The titanium oxide (Degussa-25) was immobilized on the powder of diatomaceous earth with a very simple method and low expensive. Diatomite used in this study has porosity more 72%; was thermal activated at temperatures of 800 ° c and 900 ° c and 1000 ° C for 2 h and chemically by sulfuric acid at reflux. Photocatalytic degradation of methyl orange use, was studied in the presence of the materials prepared in solution aqueous with different compositions, M1 (1 g diatomite + 0.5 g Ti02) and M2 (5 g diatomite + 0.5 g Ti02). The photocatalytic activity of the prepared catalysts was tested in a single reactor followed by pH analyzes conductivity and the absorbance. The prepared materials exhibit a very porous morphology, which has been confirmed by several methods DRX, SEM and IR.The results of the photocatalytic treatment of water synthetically polluted with MeO at initial concentration 10 ppm showed a good performance for four nano composite prepared: M1TA is composed by material M1 with diatomite treated by sulfuric acid, and M1TT is composed by material M1 with diatomite calcined at 1000 ° C, and M2TA is M2 material with diatomite treated by sulfuric acid, and M2TT is M2 material with diatomite calcined at 1000 ° c. Maximum efficiency of removing MeO that reaches 84% and 72% for M2TA, M1TT. According to the kinetic study reveals that the phenomenon is mixed resulting in a rapid response that is established after 30 minutes, the reaction kinetics of the methyl orange photodegradation following the model of the first order.