Oxidative removal of bisphenol A using zero valent aluminum–acid system

Abstract

Bisphenol A (BPA), a controversial endocrine disruptor, is ubiquitous in the aquatic environment. In this study, the oxidative degradation of BPA and its mechanism using zero valent aluminum (ZVAl)–acid system under air-equilibrated conditions was investigated. Under pH <3.5 acidic conditions, ZVAl demonstrated an excellent capacity to remove BPA. More than 75% of BPA was eliminated within 12 h in pH 1.5 reaction solutions initially containing 4.0 g/L aluminum and 2.0 mg/L BPA at 25 ± 1 °C. The removal of BPA was further accelerated with increasing aluminum loadings. Higher temperature and lower initial pH also facilitated BPA removal. The addition of Fe 2+ into the ZVAl–acid system significantly accelerated the reaction likely due to the enhancing transformation of H 2O 2 to HO via Fenton reaction. Furthermore, the primary products or intermediates including monohydroxylated BPA, hydroquinone, 2-(4-hydroxyphenyl)propane and 4-isopropenylphenol, were identified and a possible reaction scheme was proposed. The remarkable capacity of the ZVAl–acid system in removing BPA displays its potential application in the treatment of organic compound–contaminated water.