Efficient activation of persulfate by FeO@β-cyclodextrin nanocomposite for removal of bisphenol A.

Experimental studies were conducted to investigate the degradation of bisphenol A (BPA) by using persulfate (PS) as the oxidant and FeO@β-cyclodextrin (β-CD) nanocomposite as a heterogeneous activator. The catalytic activity was evaluated in consideration of the effect of various parameters, such as pH value, PS concentration and FeO@β-CD load. The results showed that 100% removal of BPA was gained at pH 3.0 with 5 mM PS, 1.0 g L FeO@β-CD, and 0.1 mM BPA in 120 min. Further, the catalytic activity of FeO@β-CD nanocomposite was observed as much higher when compared with FeO nanoparticles alone. The sulfate and hydroxyl radicals referred to in the FeO@β-CD/PS system were determined as the reactive species responsible for the degradation of BPA by radical quenching and electron spin resonance (ESR) tests. In addition, the catalyst also possessed with accepted reusability and stability. On the basis of the results of the effect of chloride ions (Cl), β-CD was found to play a crucial role in reducing interference from Cl ions, and lead to achieve higher removal efficiency for BPA in FeO@β-CD/PS system. A possible mechanistic process of BPA degradation was proposed according to the identified intermediates by gas chromatography-mass spectroscopy (GC-MS).