Oxidative Reaction of the Herbicide 2,4-Dichlorophenoxyacetic Acid Employing Ozone and UVC Radiation

M. E. LOVATO, M.B. GILLIARD, C. A MARTIN, A. E. CASSANO

Porto

Congreso; 7th European Meeting on Solar Chemistry and Photocatalysis: Environmental Applications - SPEA7; 2012

This work describes the degradation of herbicide 2,4-Dichlorophenoxyacetic Acid (2,4-D) in aqueous solution employing Ozone (O3) based Advanced Oxidation Process (AOP). The mayor objective was to find a comprehensive reaction pathway, identifying the contribution of both reactive species that coexist in this AOP, namely molecular ozone and OH radical, formed in the decomposition and photolysis. The analysis of samples with and without tertiary butanol (t-BuOH) revealed the influence of OH radical reactions. A comparative study was performed, for dissolved O3 (molecular+OH), O3/UV (OH enhancement) and O3+t-BuOH (OH inhibition) processes, taking into account three criteria: (a) percentage conversion of 2,4-D, (b) mineralization rate, and (c) release of chloride ion.