Study of Fe₃O₄/PS System in Degrading BPA in Aqueous Solution

The degradation of bisphenol A (BPA) by Fe₃O₄/persulfate system was investigated in aqueous solution. The influences of the initial concentrations of Fe₃O₄, persulfate (PS) and BPA, pH value, and initial reaction temperature on BPA removal were studied. The radical species was investigated by adding excessive dose of scavenger (methanol (MeOH) and tert-butanol (TBA)) into Fe₃O₄/PS system for the purpose of radical scavenging. The degradation products of BPA were detected by gas chromatography-mass spectrometry (GC-MS). The recyclability of Fe₃O₄ was also evaluated. The BPA removal rate of 80.7% was achieved under the following conditions: [BPA]₀ = 1 mg L^-1, [PS]₀ = 0.2 mM, [Fe₃O₄]₀ = 0.1 g L^-1, T₀ = 20 ± 1 ºC, pH₀ = 6.8 ± 0.2. The results confirmed that the main free radicals in the reaction process were sulfate radicals, followed by hydroxyl radicals. Some intermediate products of BPA degradation, such as phenols, benzoquinones and benzoic acid were identified by GC-MS.

Keywords:
sulfate radicals; Fe₃O₄; bisphenol A; hydroxyl radicals; advanced oxidation processes