流动电极型电吸附装置中的电荷传递调控及应用

This proposal aims to produce reclaimed water with low energy consumption, high pollutant removal and phosphorus recovery efficiency based on flow electrodes capacitive deionization (FCDI). Two regulation methods, including electron transfer regulation through adding conductive additive and ions transfer regulation by coupling concentration difference dialysis, will be utilized to improve the ions transfer、ions selectivity and removal. The mechanism of charge transfer in FCDI system will be investigated. The suspended electrodes modification, conductive additive and different current collector designs will be used to optimize the charge transfer and improve the adsorption performance of FCDI. The ions distribution on the suspended electrodes and electrolyte will be determined and the fluorescent probe will be utilized to investigate the influence of inert ions on the transfer of target ions. The concentration of inert ions in the electrolyte will be enhanced to realize the selectivity of target ions based on concentration difference dialysis. An FCDI with combined cathode and anode chamber will be constructed to improve the selectivity. The NO3- concentrated in the anode chamber will be reduced on the cathode, while the negatively charged EfOM will be oxidized on the anode in this newly designed FCDI. The phosphorus concentrated in the electrode chamber will be removed by precipitation through reaction with iron oxide and separated by magnetic methods. The mechanisms of the adsorption, reaction and magnetic separation will be analyzed. The optimized FCDI configuration and operation will be applied in long term experiment to propose the strategy for maintaining long-term stability in FCDI.

以低耗高效处理城市污水厂二级出水、并回收有用物质为目标，基于流动电极型电吸附(FCDI)装置开发高效选择性富集-反应/回收水处理技术，实的硝酸盐、有机物去除高效去除及磷回收。突破流动电极电子导电性弱的瓶颈，建立流动电极电子传递阻力的测试方法，模拟电极和集电体碰撞，从力学和电化学角度阐释流动电极电子传导机制，从优选电极材料、固体导电剂、集电体设计及运行参数多方面提升流动电极电子导电性。针对FCDI对离子选择性富集不足，利用扩散渗析提高FCDI电极液中非目标离子浓度，构建电极循环型FCDI，利用流动电极表面发生氧化-还原反应，实现有机物和NO3-有效去除，同时利用磁性氧化铁回收磷，对目标离子实现选择性富集-去除/回收。在此基础上连续运行循环型FCDI，提出稳定运行的技术方案。

针对流动电极型电容去离子（FCDI）系统中流动电极电荷传递阻力大等问题，基于传输线理论，构建流对电极内电荷传递模型，提出系列测试方法，获得流动电极中电子、离子在不同空间传递的阻力，比较流动电极参数（活性炭含量、盐浓度和电极流速）对电子和离子阻力的影响；通过电极材料导电性优化、添加导电剂、构建新型膜电极（集电体）、提出SC运行模式，系统提升流动电极脱盐性能，脱盐速率提升2~3倍，运行能耗下降40%；利用流动电极表面发生氧化-还原反应，实现有机物和NO3-有效去除，同时利用FCDI实现单质铜的高效回收。完成“构建方法-系统优化-污水处理及资源化”三个环节的目标。项目执行过程中，发表多篇SCI论文，授权发明专利1项，3名研究生获得硕士/博士学位。