Dégradation d’un polluant organique persistant par photo activation du chlore

Abstract

The advanced oxidation process using ultraviolet radiation combined with chlorine (UV/Chlore) is a promising technique for the treatment of complex organic pollutants, due to its ability to generate highly reactive free radicals such as HO• and Cl•, which can degrade recalcitrant organic compounds. This study aims to evaluate the efficiency of this process in removing the synthetic dye Basic Yellow 28 (YB 28), widely used in the textile industry and classified as a hazardous pollutant. Experiments were conducted in a photochemical reactor equipped with a UV lamp emitting at 254 and 365 nm, by examining the influence of several operational parameters : pH (5 to 9), chlorine concentration (100 – 1000 μM), initial dye concentration (10 – 40 mg/L), and the nature of the water matrix (seawater, river water, tap water, etc.). Results showed that the maximum removal efficiency (>90%) was achieved at pH 9, with 254 nm irradiation and 500 μM chlorine, within just a few minutes. Radical scavenging experiments confirmed that the hydroxyl radical HO• is the main oxidizing species, followed by Cl•. Moreover, total organic carbon (TOC) analysis indicated significant mineralization of organic compounds, thus confirming the effectiveness of the UV/Cl₂ process for treating water contaminated with industrial dyes.