National Engineering Laboratory for Hydrometallurgical Cleaner Production Technology, Beijing 100190, China.
Chemosphere. 2013 Aug;92(10):1294-300. doi: 10.1016/j.chemosphere.2013.04.071. Epub 2013 May 31.
The catalyzed removal of bisphenol A (BPA) by a horseradish peroxidase (HRP) cathode in the presence of humic acid (HA) was investigated. At an optimal condition, the removal of BPA achieved 100% within 2min reaction. In the electro-enzymatic process, products were analyzed by high performance liquid chromatography with diode array detector (HPLC-DAD) and high performance size exclusion chromatography (HPSEC). HPLC-DAD results showed that BPA was oxidized into self-polymers and then self-polymers as important intermediate products decreased and disappeared. HPSEC results showed the order of molecular weight (MW): HA+BPA cross-coupling products>HA self-coupling products>initial HA. According to above results, a novel mechanism of BPA transformation in the presence of HA was proposed in electro-enzymatic process. In summary, under oxidation of in situ hydrogen peroxide on HRP electrode, the BPA first are polymerized into self-polymers, and then, the polymers may be incorporated into HA matrix and finally larger MW of BPAn-HA might be formed. The presence of HA can provide chain reactions from BPA self-polymerization to cross-coupling oxidation. Therefore, in the presence of HA, the electro-enzymatic oxidation is an effective way to improve BPA removal.
辣根过氧化物酶（HRP）阴极在腐殖酸（HA）存在下催化去除双酚 A（BPA）的研究。在最佳条件下，BPA 在 2min 的反应时间内即可完全去除。在电酶过程中，采用二极管阵列检测器（HPLC-DAD）和高效尺寸排阻色谱（HPSEC）对产物进行了分析。HPLC-DAD 结果表明，BPA 被氧化成自聚物，然后作为重要的中间产物，自聚物减少并消失。HPSEC 结果表明分子量（MW）的顺序为：HA+BPA 偶联产物＞HA 自偶联产物＞初始 HA。根据以上结果，提出了电酶过程中 HA 存在下 BPA 转化的新机制。总之，在 HRP 电极原位生成的过氧化氢的氧化作用下，BPA 首先聚合形成自聚物，然后这些聚合物可能被掺入 HA 基质中，最终形成更大分子量的 BPAn-HA。HA 的存在可以提供从 BPA 自聚合到偶联氧化的链式反应。因此，在 HA 存在下，电酶氧化是提高 BPA 去除率的有效方法。
