A heterogeneous fenton-like system with green iron nanoparticles for the removal of bisphenol A：Performance, kinetics and transformation mechanism.

Green synthesized iron nanoparticles have been received increasing attention due to its advantages of a simple, rapid and cost-effective synthesis. In this study, green iron nanoparticles by grape seed extracts (GS-Fe-NPs) were used as a heterogeneous catalyst of Fenton-like system to degrade bisphenol A (BPA) in the aqueous solution. The properties of GS-Fe-NPs before and after reaction were characterized by Scanning electron microscopy, Fourier transform infrared spectroscopy and X-ray diffraction respectively. Effect factors, including initial pH value, initial BPA concentration, GS-Fe-NPs dosage, HO dose and temperature on the degradation were investigated systematically. Good performances on the BPA degradation were observed over the wider pH range (3.0-11.0) in the GS-Fe-NPs/HO system. At solution initial pH 6.9 (not adjusted), the BPA degradation efficiency could achieve 96.4% with GS-Fe-NPs 0.30 g/L and HO 1.0 mol/L at 308 K. Furthermore, quenching experiments confirmed that OH was the main free radical and its contribution to the BPA degradation varied with the initial pH. The kinetics behavior of BPA degradation had good agreements with the pseudo-first-order model (R 0.9710-0.9997), suggesting that the degradation of BPA is dominated by redox process. Based on the identified intermediates by liquid chromatography/mass spectrometry, the possible degradation pathways and BPA removal mechanism in the GS-Fe-NPs/HO system were proposed. It provides a simple and effective water treatment method for BPA contaminated water.