Goethite-mediated transformation of bisphenol A

Bisphenol A (BPA) is an environmental endocrine disruptor widely present in the soil and sedimentary environment. In this study, we investigated the oxidative transformation of BPA by commercial and laboratory synthetic goethite. Both goethite samples effectively induced the transformation of BPA. The commercial goethite exhibited higher oxidation power towards BPA than the synthetic one. The transformation of BPA by goethite was pH dependent, showing that acidic conditions accelerated the reaction in the pH range of 4.0-8.5. Co-solutes such as Fe2+, Fe3+, and humic acid exhibited moderate to slight inhibitory effects on the reaction because of the reducing sorption of BPA on goethite surface in the presence of these co-solutes. Transformation of BPA by goethite was accompanied by the release of Fe2+. In addition, three reaction intermediates or products were identified and pathways of the transformation of BPA by goethite were proposed. Given that goethite is widespread in soils and sediments, results of this study suggest that goethite may play an important role in the abiotic attenuation of BPA in the natural environment. (C) 2012 Elsevier Ltd. All rights reserved.