Degradation of Bisphenol A in an Aqueous Solution by a Photo-Fenton-Like Process Using a UV KrCl Excilamp.

Bisphenol A (BPA), a precursor to important plastics, is regarded as a common aquatic micropollutant with endocrine-disrupting activity. In the present study, we explored the capability of a UV KrCl excilamp (222 nm) to degrade BPA by a photo-Fenton-like process using persulfate under flow-through conditions. The first-order rate constants of degradation were obtained and the mineralization of dissolved organic carbon (DOC) was estimated. The results showed complete BPA degradation and high DOC mineralization (70-97%). A comparative analysis of degradation rates and DOC removal in the examined systems (UV, Fe(2+)/S(2)O(8)(2-), UV/S(2)O(8)(2-) and UV/Fe(2+)/S(2)O(8)(2-)) revealed a significant synergistic effect in the photo-Fenton-like system (UV/Fe(2+)/S(2)O(8)(2-)) without the accumulation of toxic intermediates. This indicated that the BPA was oxidized via the conjugated radical chain mechanism, which was based on the photo-induced and catalytic processes involving HO(•) and SO(4)(-•) radicals. The primary intermediates of BPA degradation in the UV/Fe(2+)/S(2)O(8)(2-) system were identified by HPLC/MS and the oxidation pathway was proposed. The high performance of the photo-Fenton-like process employing a quasi-monochromatic UV radiation of a KrCl excilamp offers promising potential for an efficient removal of such micropollutants from aqueous media.