UNSW Water Research Centre, School of Civil and Environmental Engineering, University of New South Wales, Sydney, NSW 2052, Australia.
Beijing Origin Water Membrane Technology Company Limited, Huairou, Beijing, 101400, P. R. China.
Water Res. 2021 Feb 1;189:116653. doi: 10.1016/j.watres.2020.116653. Epub 2020 Nov 16.
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 (FeO 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.
从废水中回收磷（P）是一个值得关注的目标，因为这具有潜在的环境和经济效益。流动电极电容去离子（FCDI）采用可流动的碳电极代替传统 CDI 中使用的静态电极，已被证明是一种很有前途的 P 回收技术。FCDI 在许多方面优于 CDI 和其他竞争技术，包括（i）较大的盐吸附容量和（ii）极高的水回收率。在这项研究中，制备了磁性（FeO 浸渍）活性炭颗粒并将其用作 FCDI 电极。磁性碳电极对 P 具有很强的亲和力，通过配体交换机制促进 P 选择性地吸附到磁性颗粒上。在外加磁场的作用下，仅需 3 分钟即可将电极颗粒从盐水中分离出来，从而实现 FCDI 系统的连续运行。使用碱溶液对耗尽的磁性电极进行再生，可产生富含 P 的溶液。我们设想，使用磁性碳增强流动电极将为 FCDI 的高效运行以及 P 的优先回收铺平道路。
