Soybean peroxidase-catalyzed treatment and removal of BPA and bisphenol derivatives from aqueous solutions

Abstract

The systematic studies were carried out to determine the optimum process parameters, such as the hydrogen peroxide (H₂O₂) concentration, concentration and molar mass of poly(ethylene glycol) (PEG) as an additive, pH value, temperature, and enzyme dose for treatment of bisphenol A (BPA) with soybean peroxidase (SBP). The SBP-catalyzed treatment of BPA was effectively enhanced by adding PEG in the presence of H₂O₂. BPA was completely treated by SBP of 0.50 U/cm³ and water-insoluble oligomers were generated. The optimum conditions for SBP-catalyzed treatment of BPA at 0.3 mM were determined to be 0.3 mM of H₂O₂ and 0.10 mg/cm³ of PEG with molar mass of 1.0 × 10⁴ g/mol in a pH 7.0 buffer at 30°C. A variety of bisphenol derivatives were completely or effectively treated by SBP under the optimum conditions determined for treatment of BPA, although the SBP dose was further increased as necessary for some of them. The aggregation of water-insoluble oligomers generated was enhanced by decreasing the pH values of the solutions to 4.0 with HCl after the enzymatic treatment, and BPA and bisphenol derivatives were removed from aqueous solutions by filtering off the oligomer precipitates. © 2010 American Institute of Chemical Engineers Environ Prog, 2011