Photodecomposition of sodium dodecyl sulfate under high-intensity pulsed UV radiation of continuous spectrum and hydrogen peroxide

Surfactants are widely used in industry and households, although they are typically non-toxic, their self-degradation products could have potential health and environmental effects. Therefore, the improvement of water purification technology from these substances is an essential problem. Within this paper, the features of the photochemical decomposition of an anionic surfactant (sodium dodecyl sulfate) under the combined effect of high-intensity pulsed UV radiation of continuous spectrum and hydrogen peroxide are investigated. All experiments were conducted with an initial pollutant concentration of 10 mg L–1. Direct photolysis has proven to be an extremely inefficient method due to the low process rate and high energy consumption. However, the addition of hydrogen peroxide to a solution irradiated by polychromatic light drastically enhances the photodecomposition rate. The decomposition efficiency rises from 90% to more than 99% and the energy consumption significantly decreases with an increase in the molar ratio of hydrogen peroxide and sodium dodecyl sulfate concentrations. The obtained values of electrical energy per order in conjunction with other process aspects demonstrate that the use of UV/H2O2 technology with a xenon flashlamp as a radiation source is advantageous for the purification of solutions from the investigated contaminant.