Department of Chemical and Materials Engineering, The University of Auckland, 20 Symonds Street, Auckland 1042, New Zealand.
Water Res. 2012 Mar 1;46(3):873-81. doi: 10.1016/j.watres.2011.11.066. Epub 2011 Dec 6.
Estrone is a representative steroid estrogen contaminant that has been detected in effluents from sewage treatment facilities, as well as in surface and ground waters. Our study shows that estrone can be readily removed from water via a unique chemisorption mechanism using nylon microfiltration membranes. Experiments on a laboratory in-line filtration system showed instant removal of estrone from 200 μg/l aqueous solutions by 0.45-μm nylon membranes (ca. 35 L per m(2) membrane). Comparisons with 0.45-μm PVDF, PTFE and glass microfiber membranes suggested that the significant estrone adsorption in nylon membrane should be predominately driven by a different mechanism rather than common physical adsorption. Fourier transform infrared spectroscopy study on nylon membranes and a model compound, N-methylacetamide, showed that the significant adsorption originated from the hydrogen bonding between terminal -OH groups on estrone molecules and nucleophile -C=O groups in amide groups of nylon 6,6. The saturated nylon membrane showed very low leachability in ambient water, while it could be effectively regenerated in alkaline or ethanol solutions. Preliminary reusability study showed that the membrane maintained a consistent adsorption capacity for estrone during ten cycles of reuse. The chemisorption-based polymeric adsorption may provide a new alternative approach for removing estrone and potentially other trace organic contaminants from water.
雌酮是一种具有代表性的甾体雌激素污染物，已在污水处理设施的废水中以及地表水和地下水中被检测到。我们的研究表明，雌酮可以通过使用尼龙微滤膜的独特化学吸附机制从水中轻易去除。在实验室在线过滤系统上的实验表明，0.45-μm 尼龙膜（约 35 升/平方米膜）可立即从 200μg/L 的水溶液中去除雌酮。与 0.45-μm 的聚偏二氟乙烯（PVDF）、聚四氟乙烯（PTFE）和玻璃微纤维膜的比较表明，尼龙膜中显著的雌酮吸附主要是由不同的机制驱动的，而不是常见的物理吸附。对尼龙膜和模型化合物 N-甲基乙酰胺的傅里叶变换红外光谱研究表明，显著的吸附源于雌酮分子末端-OH 基团与尼龙 6,6 中酰胺基团的亲核-C=O 基团之间的氢键。饱和的尼龙膜在环境水中的浸出率非常低，而在碱性或乙醇溶液中可以有效地再生。初步的可重复使用性研究表明，在十次重复使用过程中，该膜对雌酮的吸附容量保持一致。基于化学吸附的聚合物吸附可能为从水中去除雌酮和潜在的其他痕量有机污染物提供一种新的替代方法。
