A new substrate and by-product kinetic model for the photodegradation of 4-chlorophenol with KrCl exciplex UV lamp and hydrogen peroxide

4-chlorophenol removal has been studied with many different methods. One of these methods is their UV oxidation. Among chemical oxidation, excimer and exciplex lamps are attractive alternatives to commonly used mercury lamps, mainly because they are free of elemental mercury, present long life and geometric freedom. It has been described that the first step in 4-chlorophenol photodegradation process is the break of the CCl bond leading to the formation of primary photoproducts after further reactions. Besides, it is described that the photodegradation of 4-chlorophenol in the presence of hydrogen peroxide improve the formation of oxygenated products increasing their removal. In previous studies the kinetics of these reactions has been described by pseudo-first order reaction models but none of these studies has taking into account the photoproducts in the kinetic equations. In this work, a new kinetic model that considers 4-chlorophenol and the photoproducts has been formulated. The validation of the model has been done with previously obtained experimental data.

► 4-chlorophenol photodegradation with KrCl exciplex UV lamp is improved using H2O2.
► A new kinetic model has been proposed.
► This model includes 4-chlorophenol degradation and primary photoproducts formation.
► The model fits to the experimental data with a good degree of approximation.