Thiobencarb Degradation by TiO2 Photocatalysis: Parameter and Reaction Pathway Investigations

The present study deals with the photocatalytic degradation of the thiocarbamate herbicide, thiobencarb (TBC), in the presence of TiO2 particles and UV‐A (λ = 365 nm) radiation. Results show rapid and complete oxidation of TBC after 90 min, and slightly over 70% of TBC was mineralized after 32‐h treatment. Factors such as solution pH, TiO2 dosage, and the presence of anions are found to influence the degradation rate. The establishment of the reaction pathway is made possible by a thorough analysis of the reaction mixture identifying the main intermediate products generated. Results suggest that possible transformation pathways may include hydroxylation, dealkylation and C—S bond cleavage processes. The possible degradation pathways are proposed and discussed on the basis of the evidence of oxidative intermediate formation.