State Key Laboratory of Environmental Aquatic Chemistry, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, 18, Shuangqing Road, Beijing 100085, China.
Water Res. 2011 Jan;45(1):145-54. doi: 10.1016/j.watres.2010.08.017. Epub 2010 Aug 17.
Technology for immobilization of biomass has attracted a great interest due to the high sorption capacity of biomass for sequestration of toxic metals from industrial effluents. However, the currently practiced immobilization methods normally reduce the metal sorption capacities. In this study, an innovative ion-imprint technology was developed to overcome the drawback. Copper ion was first imprinted onto the functional groups of chitosan that formed a pellet-typed sorbent through the granulation with Sargassum sp.; the imprinted copper ion was chemically detached from the sorbent, leading to the formation of a novel copper ion-imprinted chitosan/Sargassum sp. (CICS) composite adsorbent. The copper sorption on CICS was found to be highly pH-dependent and the maximum uptake capacity was achieved at pH 4.7-5.5. The adsorption isotherm study showed the maximum sorption capacity of CICS of 1.08 mmol/g, much higher than the non-imprinted chitosan/Sargassum sp. sorbent (NICS) (0.49 mmol/g). The used sorbent was reusable after being regenerated through desorption. The FTIR and XPS studies revealed that the greater sorption of heavy metal was attributed to the large number of primary amine groups available on the surfaces of the ion-imprinted chitosan and the abundant carboxyl groups on Sargassum sp. Finally, an intraparticle surface diffusion controlled model well described the sorption history of the sorbents.
由于生物质对工业废水中有毒金属的高吸附容量，固定化生物质的技术引起了极大的关注。然而，目前实践的固定化方法通常会降低金属的吸附容量。在这项研究中，开发了一种创新的离子印迹技术来克服这一缺点。首先将铜离子印迹到壳聚糖的功能基团上，壳聚糖通过与马尾藻属形成颗粒状吸附剂；然后通过化学方法将印迹的铜离子从吸附剂上分离下来，形成一种新型的铜离子印迹壳聚糖/马尾藻属（CICS）复合材料吸附剂。发现 CICS 对铜的吸附高度依赖于 pH 值，在 pH 4.7-5.5 时达到最大吸附容量。吸附等温线研究表明，CICS 的最大吸附容量为 1.08mmol/g，远高于非印迹壳聚糖/马尾藻属吸附剂（NICS）（0.49mmol/g）。用过的吸附剂在经过解吸再生后可以重复使用。FTIR 和 XPS 研究表明，重金属的大量吸附归因于印迹壳聚糖表面上大量的伯胺基团和马尾藻属上丰富的羧基基团。最后，内扩散表面扩散控制模型很好地描述了吸附剂的吸附历史。
