Removal of Herbicides from Water Using Heterogeneous Photocatalysis Case Study: MCPA Sodium Monohydrate

Abstract

In this study, the herbicide MCPA sodium salt monohydrate (sodium (4-chloro-2 methylphenoxy) acetate has been studied as are presentative compound used in the agricultural field. Accordingly, direct photolysis and photocatalytic experiments under artificial irradiation simulating solar light in laboratorial conditions were performed. Photocatalytic experiments were performed using TiO 2 dispersed powder and as an immobilized thin layer on the surface of blue glasses. The obtained results of photolysis showed a poor efficacy toward degradation of MCPA sodium monohydrate, with half-life (t 1/2 ) 6931.5 min. While, the addition of TiO 2 dispersed powder to the photocatalytic process enhances the process dramatically with (t 1/2 ) equal to 36.5 min; furthermore, complete mineralization had been reached after approximately 4 hours, whereas the addition of TiO 2 through immobilized system led to enhance the degradation rate with 2236 min. as t 1/2 . In spite of this, using TiO 2 supported on glass substrates with more improvements could be a promising alternative to conventional TiO 2 suspension, and provides a clean treatment method.