Researchers with Institute of Process Engineering, Chinese Academy of Sciences investigated the catalyzed removal of bisphenol A (BPA) by a horseradish peroxidase (HRP) in the presence of humic acid (HA) in their recent work. A new mechanism of BPA removal during electro-enzymatic oxidative process was proposed. Chain reactions were changed from self-polymerization to cross-coupling oxidation.

 High performance liquid chromatography with diode array detector (HPLC-DAD) and high performance size exclusion chromatography (HPSEC) were used to test the products during the reaction. It was found that BPA was removed totally within 2 min reaction time under an optimal condition.

 The results showed that under the oxidation of in situ hydrogen peroxide on HRP electrode, the BPA first is polymerized into self-polymers, and then, the polymers may be incorporated into HA matrix and formed larger MW of (BPA)n-HA compound.

 Effect of experimental parameters on BPA removal was studied. The increase in electric current, enzyme dosage and HA concentration can improve BPA removal according to the results.

 The presence of HA can provide a chain pathway of BPA self-polymers incorporated into HA matrix. Therefore, the electro-enzymatic oxidation is an effective method to remove BPA in the presence of HA.

 The work has been published on Chemosphere, volume 92, issue10. And more details please see: http://www.sciencedirect.com/science/article/pii/S0045653513006930.