Testing a KrCl excilamp as new enhanced UV source for 4-chlorophenol degradation: Experimental results and kinetic model

Excilamps are new UV sources with great potential for application in wastewater treatment. In the present work, a KrCl excilamp emitting radiation at 222 nm has been used for the photodegradation of 4-chlorophenol within a range of concentrations from 50 to 500 mg L−1. The photodegradation process has been shown to form two main photoproduct intermediates, benzoquinone and hydroquinone. Total removal of 4-chlorophenol was shown for all concentrations assayed, and, for both main intermediates, residual concentrations of 20-30% of the initial concentration of 4-chlorophenol remained. Their increasing presence with increasing initial concentrations of 4-chlorophenol had the effect of decreasing the removal efficiency of the photoproducts. In order to simulate the process and scale-up a simplified kinetic model has been developed and validated from the experimental data.