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

本研究将六氰高铁酸镍（NiHCF）薄膜沉积在碳纤维和/或三维碳毡上，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。优化了薄膜的制备条件，得到了结构稳定、不溶性好的ESIX薄膜。结果表明，膜上吸附了98%以上的铯离子，通过改变外加电压，90%以上的铯离子被有效解吸。这一过程重复了200多次，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具有较高的选择性。阐明了分离机理以及分离因素与操作条件的关系。该方法有望作为一种有前途的污水处理技术。

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.