Use of chitosan for removal of bisphenol a from aqueous solutions through quinone oxidation by polyphenol oxidase

In this study, a combined use of biopolymer chitosan and oxidoreductase polyphenol oxidase (PPO) was applied to the removal of bisphenol A (BPA) as an endocrine disrupting chemical from aqueous solutions. The optimum conditions for the enzymatic quinone oxidation of BPA were determined to be pH 7.0 and 40 degrees C. Quinone derivatives generated were chemisorbed on chitosan beads, and BPA was completely removed at 47 h. The removal time was shortened with an increase in the amount of dispersed chitosan beads or the PPO concentration. In addition, the initial velocity of quinone oxidation increased with an increase in the amount of chitosan beads. The use of chitosan in the form of porous beads was more effective than the use of chitosan in the form of solutions or powder. It was found that an important factor for this procedure was a high-specific surface area of chitosan beads and heterogeneous reaction of quinone derivatives enzymatically generated with chitosan. (C) 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012