Fe(3+)-饱和蒙脱石表面催化 17β-雌二醇的氧化寡聚
Surface catalyzed oxidative oligomerization of 17β-estradiol by Fe(3+)-saturated montmorillonite.
出版信息
Environ Sci Technol. 2015 Jan 20;49(2):956-64. doi: 10.1021/es504815t.
With widespread detection of endocrine disrupting compounds including hormones in wastewater, there is a need to develop cost-effective remediation technologies for their removal from wastewater. Previous research has shown that Fe(3+)-saturated montmorillonite is effective in quickly transforming phenolic organic compounds such as pentachlorophenol, phenolic acids, and triclosan via surface-catalyzed oligomerization. However, little is known about its effectiveness and reaction mechanisms when reacting with hormones. In this study, the reaction kinetics of Fe(3+)-saturated montmorillonite catalyzed 17β-estradiol (βE2) transformation was investigated. The transformation products were identified using liquid chromatography coupled with mass spectrometry, and their structures were further confirmed using computational approach. Rapid βE2 transformation in the presence of Fe(3+)-saturated montmorillonite in an aqueous system was detected. The disappearance of βE2 follows first-order kinetics, while the overall catalytic reaction follows the second-order kinetics with an estimated reaction rate constant of 200 ± 24 (mmol βE2/g mineral)(−1) h(–1). The half-life of βE2 in this system was estimated to be 0.50 ± 0.06 h. βE2 oligomers were found to be the major products of βE2 transformation when exposed to Fe(3+)-saturated montmorillonite. About 98% of βE2 were transformed into βE2 oligomers which are >10(7) times less water-soluble than βE2 and, therefore, are much less bioavailable and mobile then βE2. The formed oligomers quickly settled from the aqueous phase and were not accumulated on the reaction sites of the interlayer surfaces of Fe(3+)-saturated montmorillonite, the major reason for the observed >84% βE2 removal efficiency even after five consecutive usages of the same of Fe(3+)-saturated montmorillonite. The results from this study clearly demonstrated that Fe(3+)-saturated montmorillonite has a great potential to be used as a cost-effective material for efficient removal of phenolic organic compounds from wastewater.
随着内分泌干扰化合物（包括废水中的激素）的广泛检测，需要开发具有成本效益的修复技术来去除废水中的这些化合物。先前的研究表明，Fe(3+)-饱和蒙脱石通过表面催化聚合可有效快速转化五氯苯酚、酚酸和三氯生等酚类有机化合物。然而，对于其与激素反应的有效性和反应机制知之甚少。在这项研究中，研究了 Fe(3+)-饱和蒙脱石催化 17β-雌二醇（βE2）转化的反应动力学。使用液相色谱-质谱联用技术鉴定转化产物，并使用计算方法进一步确定其结构。在水溶液中存在 Fe(3+)-饱和蒙脱石的情况下，检测到快速的 βE2 转化。βE2 的消失遵循一级动力学，而整体催化反应遵循二级动力学，估计反应速率常数为 200±24（mmol βE2/g 矿物）(-1) h(-1)。在该系统中，βE2 的半衰期估计为 0.50±0.06 h。当暴露于 Fe(3+)-饱和蒙脱石时，βE2 被发现是βE2 转化的主要产物。约 98%的βE2 转化为βE2 低聚物，其水溶性比βE2 低>10(7)倍，因此，其生物可利用性和迁移性比βE2 低得多。形成的低聚物迅速从水相中沉淀出来，并且不会在 Fe(3+)-饱和蒙脱石的层间表面的反应位点上积累，这是即使在使用相同的 Fe(3+)-饱和蒙脱石连续五次后仍观察到>84%βE2 去除效率的主要原因。这项研究的结果清楚地表明，Fe(3+)-饱和蒙脱石具有很大的潜力，可以用作从废水中有效去除酚类有机化合物的经济有效的材料。
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