Comparison of two excilamps and two reactor configurations in the UV-H2O2 removal process of amaranth

Abstract

Nowadays dyes are used in many industrial activities and their presence in wastewater is quite common and involves different environmental and health problems. In addition, dyes are usually recalcitrant compounds and conventional treatment are not appropriate for their removal. So there is great interest in finding alternative removal processes, as the one based on excimer lamp technology for the removal of amaranth dye described in the present work. Two excilamps and two reactor configurations have been tested: a batch reactor with KrCl or XeBr excilamp and a KrCl flow-through photoreactor. After comparing the results for both lamps in the batch reactor, the KrCl excilamp has proven to be more efficient both in terms of conversions achieved and energy consumption and, by this, it has been selected to be used in the flow-through photoreactor. For both reactor configurations, several experimental series were done to analyze the influence of the different operational variables on the photoprocess and the optimal mass ratio between hydrogen peroxide and dye has been established. Also, it has been proven that the use of Fenton reagent improves the process efficiency, particularly in the case of the XeBr lamp. In addition, a kinetic model, based on a previous one developed by the authors for a flow-through photoreactor and slightly modified to can also apply it to batch reactors, has been applied. The model has been validated with an excellent fitting of the experimental data for all series and both reactor configurations.