Oxidarea şi mineralizarea catecolului din soluţii apoase utilizând procese omogene [Articol]

Abstract

Catechol is widely used in industrial applications such as photographic de-velopers, lubricants, polymerization inhibitors, and pharmaceuticals. Due to its toxicity and persistence, its removal from wastewater is essential. This study investigated the degradation and mineralization of catechol using homogeneous advanced oxidation processes—specifical-ly, Fenton and Photo-Fenton. Key operational parameters, including pH, reagent concentra-tions, UV type, and molar ratios, were systematically optimized. Optimal performance was observed at pH 2.6-3.2, with 0.1 mM H2O2 and Fe2+, and a molar ratio of H2O2 : Fe2+ : catechol of 10 : 1 : 2. UV-C radiation significantly enhanced the Photo-Fenton process by promoting Fe²⁺ regeneration. Kinetic analysis showed pseudo-first-order behavior, with the highest rate constant (0.00347 min-1) and a degradation rate of 9.23·10-8 mol/L·s. The proposed degradati-on mechanism involves hydroxyl radical attack, ring cleavage, and mineralization to CO2 and H2O. Among the systems tested, the UV-C assisted Photo-Fenton process achieved the highest catechol removal and COD reduction. These results highlight the potential of homogeneous AOPs for efficient treatment of phenolic pollutants in industrial wastewater.