Degradation of bisphenol A in aqueous environment using peroxymonosulfate activated with carbonate: Performance, possible pathway, and mechanism

Abstract

In the current study, bisphenol A (BPA) removal in water environment by carbonate-activated peroxymonosulfate (CO32-/PMS) oxidation process is reported for the first time. The CO32-/PMS system showed excellent catalytic activity by degrading 100% BPA within 40 min reaction time. BPA degradation showed pseudo-first-order kinetics with rate constant (k) value of 0.0918 min−1. The effects of initial concentration of CO32-, PMS, BPA, pH, and inorganic anions, including nitrate (NO3-), sulfate (SO42-), chloride (Cl-), phosphate (PO4-), and humic acid (HA) were studied. The addition of NO3-, SO42-, and PO4- in the CO32-/PMS system decreased BPA degradation %, whereas a high concentration of Cl− and HA addition promoted BPA degradation %. Electron paramagnetic resonance and radical scavenging experiments verified that both the SO4•– and HO• were generated in the CO32-/PMS system. According to liquid chromatography-mass spectrometry results, the possible degradation pathways for BPA were suggested. Toxicity experiments revealed that BPA metabolites were not toxic. It could be concluded that the CO32-/PMS system is a promising process for removing BPA in different types of water (ultrapure, lake, and wastewater)