The Coupling Use of Weak Magnetic Field and Fe⁰/H₂O₂ Process for Bisphenol a Abatement: Influence of Reaction Conditions and Mechanisms

The coupling use of the heterogeneous Fenton-like process (zero-valent iron (Fe0)/H2O2) and weak magnetic field (MWF) for bisphenol A (BPA) abatement was systematically investigated in this study. Though both the Fe0/H2O2 and WMF-Fe0/H2O2 processes are sensitive to pH, WMF remarkably enhanced BPA removal under the pH range of 3.0–6.0 by 0.5–9.5 times. The characterization of Fe0 confirmed the role of WMF in promoting the corrosion of Fe0. Radicals, rather than Fe intermediates, were responsible for BPA degradation. Due to the presence of Cl– as the background ions and its reactivity towards HO•, reactive chlorine species (RCS, i.e., Cl• and Cl2•−) were produced and considerably contributed to BPA degradation. In addition, ~37% and 54% of degraded BPA was ascribed to RCS in the presence of 2 and 100 mM of Cl−, respectively. However, 1.9 mg/L of ClO3− was detected in the presence of 2 mM of Cl− in the WMF- Fe0/H2O2 process. HCO3− could diminish ClO3− generation significantly through transforming RCS. The concentration of ClO3− decreased by 74% and 82% with dosing 1 and 10 mM HCO3−, respectively. The results of this study suggest that the WMF-Fe0/H2O2 process is a promising approach for BPA removal.