Photodegradation of Bisphenol A and Triclosan using ZnCl2(6OMeQ)2 complex as photosensitizer under homogeneous conditions

Abstract

The complexes derived from 6-methoxyquinoline ZnCl2(6OMeQ)2 have been shown to be effective as singlet molecular oxygen photosensitizers, which can be interesting for the removal of microcontaminants such as Bisphenol A (BPA) and Triclosan (TCS). Photodegradation with eosin Y (EOY) was also carried out as standard photosensitizer. Due to the physicochemical characteristics of these synthesized photosensitizers, the analysis was carried out in a homogeneous system in simulated effluents. An experimental design was made, based on previous studies and supporting literature. It was established that, at pH 5 and at 0.00104 mM EOY concentration, 20% removals were obtained in the case of BPA. Then, using the same photosensitizer with TCS it was possible to establish photodegradation up to 56% at the same pH but at a temperature of 50 °C, associating this result with the increase in temperature generated, and an increase in speed being reflected in the results obtained. Photodegradation using the coordinated compound, at pH 5.0, and 0.00119 mM photosensitizer concentration, a 26.7% of BPA photodegradation was obtained and, at 50 °C and pH 6, a 52.3% of TCS photodegradation was obtained. This photosensitizer is comparable for the removal this kind of the micropollutant. The experiments were made with UV/VISIBLE Lamps and monitored for HPLC, and some subproducts were analyzed for GC/MS.