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

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.