Catechin as a new improving agent for a photo-Fenton-like system at near-neutral pH for the removal of inderal

Abstract

Photodegradation of inderal in a photo-Fenton like system at near-neutral pH modified with catechin, a natural catecholate siderophore, was investigated under simulated sunlight. The main factors influencing the process, such as Fe(III)–catechin complexes, pH, and catechin concentration were examined. Photodegradation of inderal was strongly dependent on pH, following the order pH 3.0 < 5.0 < 7.0 < 6.0. Formation of the Fe(III)–catechin complex resulted in the stabilization of ferric iron and generation of ˙OH under irradiation at near-neutral pH values. The removal of inderal was about 75% under optimal conditions (50 μmol L⁻¹ Fe(III) and 200 μmol L⁻¹ catechin at pH 6.0). The photodegradation products of inderal were identified by LC-ESI-MS and GC-MS, and the photodegradation pathway was proposed. Iron in the Fe(III)–catechin system was reused by simple addition of catechin to the reaction mixture. Results of this study suggest that the Fe(III)–catechin complex may be used in the photo-Fenton like process, an advanced approach to the removal of organic pollutants at near-neutral pH.