The recovery of phosphorus (P) from wastewaters is a worthy goal considering the potential environmental and economic benefits. Flow-electrode capacitive deionization (FCDI), which employs flowable carbon electrodes instead of the static electrodes used in conventional CDI, has been demonstrated to be a promising P recovery technology. FCDI outperforms CDI and other competitive technologies in a number of aspects including (i) large salt adsorption capacity and (ii) extremely high water recovery rate. In this study, magnetic (Fe₃O₄ impregnated) activated carbon particles were prepared and applied as FCDI electrodes. The magnetic carbon electrodes were found to have a strong affinity towards P, facilitating the selective adsorption of P to the magnetic particles through a ligand exhange mechanism. Continuous operation of the FCDI system could be achieved with only three minutes required to separate the electrode particles from the brine stream on application of an external magnetic field. A P-rich stream was produced on regeneration of the exhausted magnetic electrodes using alkali solution. We envision that the use of magnetic carbon enhanced flow-electrodes will pave the way for efficient operation of FCDI as well as the preferential recovery of P.

考虑到潜在的环境和经济效益，从废水中回收磷（P）是一个值得追求的目标。流电极电容去离子（FCDI）技术是一种有前途的P回收技术，该技术采用可流动的碳电极代替常规CDI中使用的静电电极。在许多方面，FCDI优于CDI和其他竞争技术，其中包括（i）大型盐吸附能力和（ii）极高的水回收率。在这项研究中，磁性（Fe ₃ O ₄制备经浸渍的）活性炭颗粒并将其用作FCDI电极。发现磁性碳电极对P具有很强的亲和力，有助于通过配体交换机理将P选择性吸附到磁性颗粒上。在施加外部磁场的情况下，只需三分钟即可将电极颗粒从盐水流中分离出来，从而实现了FCDI系统的连续运行。使用碱溶液再生耗尽的磁性电极时会产生富P的物流。我们设想使用磁性碳增强型流电极将为FCDI的有效运行以及P的优先回收铺平道路。