Sulfonamides degradation assisted by UV, UV/HO and UV/KSO: Efficiency, mechanism and byproducts cytotoxicity.

The objective of this study was to analyze the effectiveness of UVC, UVC/HO and UVC/KSO on the degradation of SAs. Rate constant values increased in the order SMZ < SDZ < SML and showed the higher photodegradation of sulfonamides with a penta-heterocycle. Quantum yields were 1.72 × 10 mol E, 3.02 × 10 mol E, and 6.32 × 10 mol E for SMZ, SDZ and SML, respectively, at 60 min of treatment. R values show that the dose habitually utilized for water disinfection is inadequate to remove this type of antibiotic. The initial sulfonamide concentration has a major impact on the degradation rate. The degradation rates were higher at pH 12 for SMZ and SML. SMZ and SML photodegradation k values are higher in tap versus distilled water. The presence of radical promoters generates a greater increase in the degradation rate, UVC/KSO cost less energy, a mechanism was proposed, and the degradation by-products are less toxic than the original product.