Predicting pharmaceutical degradation by UV (MP)/H2O2 processes: A kinetic model

• Published in: Chemical engineering journal (Lausanne, Switzerland : 1996) Switzerland : 1996), 2015-03, Vol.263, p.336-345
• Main Authors: Wols, B.A., Harmsen, D.J.H., Beerendonk, E.F., Hofman-Caris, C.H.M.
• Format: Article
• Language: English
• Subjects: Advanced oxidation process; Hydrogen peroxide; Modelling; Pharmaceuticals; Water treatment
• ISSN: 1385-8947; 1873-3212
• DOI: 10.1016/j.cej.2014.10.101

•(Photo)kinetic model of polychromatic (MP) UV advanced oxidation processes.•Degradation pathways via direct photolysis, OH radical reactions and carbonate radical reactions.•Validation of model with large group of pharmaceuticals.•Validation of model in different water matrices.•Sensitivity analysis for the chemical reactions involved, including nitrate reactions. A kinetic model for the degradation of organic micropollutants (OMPs) by MP UV lamps has been developed. The model includes (photo)chemical reactions of hydrogen peroxide and nitrate; reactions with the most important water matrix components; changes in pH; and transient radical concentrations. Three pathways of organic micropollutant degradation are involved: direct photolysis, hydroxyl radical reactions and carbonate radical reactions. The model was validated using collimated beam experiments for a group of 35 pharmaceuticals in synthetic and natural water matrices. For MP UV with 10mg/L H2O2, good agreement between the modelled and measured degradation rates was found. For MP UV without H2O2, most of the pharmaceuticals were well predicted, except for the sulphonamides. A sensitivity analysis on different water matrix constituents was performed for MP UV with H2O2, NO3- and both H2O2 and NO3-. Also, the most important chemical reactions for the degradation of OMPs are identified for different water matrices.