New combination of pulsed light and iron (II) for carbonate radical production to enhanced degradation of bisphenol A: Parameter optimization and degradation pathway.

Bisphenol A(BPA) is a common industrial chemical with significant adverse impacts on Environment and human health. The present work evaluates the efficacy of pulsed light (PL) and Fe2+ ions in activation of sodium percarbonate (SPC) to produce hydroxyl (OH•) and carbonate (CO3•-) radicals for efficient degradation of BPA. The effects of operational parameters such as solution pH, SPC and Fe2+ dose as well as the mixture composition were analyzed and the decomposition pathway of BPA proposed. The BPA was successfully degraded at the initial concentration of 15.0 mg/L and optimized conditions by the PL/Fe2+/SPC process (99.67 ± 0.29%). A rapid reduction in the degradation of BPA was observed with increasing pH due to OH• radicals quenching and also the precipitation of Fe2+. Under the optimized conditions, degradation of BPA by PL/Fe2+/SPC process was five-times faster than the individual process. The quenching experiments revealed that radical and non-radical pathways on BPA degradation was accomplished with OH•, CO3•-, O2•-, and 1O2, while OH• and CO3•- radicals (as a dominant radicals) have the contributions of 80.23% and 8.30%, respectively. Based on the detected byproducts, ring cleavage can be considered as the main transformation mechanism of BPA by the PL/Fe2+/SPC process.