Fabrication of novel electrically switched ion exchange films on three dimensional carbon electrodes for the continuous separation of metal ions

本研究在碳纤维和/或三维碳毡上制备了铁氰化镍（NiHCF）膜，并将其作为电开关离子交换（ESIX）材料用于废水中有毒金属离子的分离。优化了成膜条件，得到了结构稳定、不溶的ESIX膜。结果表明，98%以上的铯离子被吸附在薄膜上，90%以上的吸附离子通过改变外加电压从薄膜上有效地脱附。重复该过程超过200次，但膜的分离能力几乎保持不变。此外，该膜对铈离子的分离比其他共存的金属离子显示出高的选择性。并阐明了分离机理及分离因子与操作条件的关系。该方法可望成为一种有前途的实际废水处理技术。

In this study, nickel hexacyanoferrate (NiHCF) film was deposited on carbon fiber and/or three dimensional carbon felt and used as electrically switched ion exchange(ESIX) materials for the separation of toxic metal ions fron wastewater. The film fabrication conditions were optimized and the ESIX film with stable and insoluble structure were obtained. It is found that over 98% of cesium ions was adsorbed on the film and over 90% of the adsorbed ions was effectively desorbed from the film by changing the applied voltage. This process was repeated for over 200 times but the separation ability of the film was almost remained. Furthermore, the film showed high selectivity for the separation of cerium ions over other co-existed metal ions. The separation mechanism and the relationship between the separation factor and the operation conditions were also clarified. It is expected that this developed method can be taken as a promising technology for actual wastewater treatment.