Particle and Interfacial Technology Group (PaInT), Ghent University, Belgium; Centre for Advanced Process Technology for Urban Resource Recovery (CAPTURE), Belgium.
Particle and Interfacial Technology Group (PaInT), Ghent University, Belgium; Centre for Advanced Process Technology for Urban Resource Recovery (CAPTURE), Belgium; European Centre of Excellence for Sustainable Water Technology (Wetsus), the Netherlands.
Water Res. 2023 Oct 15;245:120625. doi: 10.1016/j.watres.2023.120625. Epub 2023 Sep 12.
Capacitive electrodialysis (CED) is an emerging and promising desalination technology for decentralized drinking water production. Brackish water, often used as a drinking water source, may contain organic micropollutants (OMPs), thus raising environmental and health concerns. This study investigated the transport of OMPs in a fully-functional decentralized CED system for drinking water production under realistic operational conditions. Eighteen environmentally-relevant OMPs (20 µg L) with different physicochemical properties (charge, size, hydrophobicity) were selected and added to the feed water. The removal of OMPs was significantly lower than that of salts (∼94%), mainly due to their lower electrical mobility and higher steric hindrance. The removal of negatively-charged OMPs reached 50% and was generally higher than that of positively-charged OMPs (31%), whereas non-charged OMPs were barely transported. Marginal adsorption of OMPs was found under moderate water recovery (50%), in contrast to significant adsorption of charged OMPs under high water recovery (80%). The five-month operation demonstrated that the CED system could reliably produce water with low salt ions and TOC concentrations, meeting the respective WHO requirements. The specific energy consumption of the CED stack under 80% water recovery was 0.54 kWh m, which is competitive to state-of-the-art RO, ED, and emerging MCDI in brackish water desalination. Under this condition, the total OPEX was 2.43 € m, of which the cost of membrane replacement contributed significantly. Although the CED system proved to be a robust, highly adaptive, and fully automated technology for decentralized drinking water production, it was not highly efficient in removing OMPs, especially non-charged OMPs.
电容去离子（CED）是一种新兴的、有前途的海水淡化技术，可用于分散式饮用水生产。咸水通常被用作饮用水源，可能含有有机微污染物（OMPs），因此引发了环境和健康方面的担忧。本研究在实际运行条件下，考察了全功能分散式 CED 系统对饮用水生产中 OMPs 的传输情况。选择了 18 种具有不同物理化学性质（电荷、大小、疏水性）的环境相关 OMPs（20μg/L）并将其添加到进料水中。OMPs 的去除率明显低于盐类（约 94%），主要是由于其较低的电迁移率和较高的空间位阻。带负电荷的 OMPs 的去除率达到 50%，一般高于带正电荷的 OMPs（31%），而非带电的 OMPs 几乎没有被传输。在适度的水回收率（50%）下，发现 OMPs 有少量吸附，而在高水回收率（80%）下，带电荷的 OMPs 则有显著吸附。五个月的运行表明，CED 系统能够可靠地生产出低盐离子和 TOC 浓度的水，符合各自的世卫组织要求。在 80%水回收率下，CED 堆的比能耗为 0.54 kWh/m，在海水淡化方面与最先进的 RO、ED 和新兴的 MCDI 具有竞争力。在此条件下，总运营成本为 2.43 欧元/m，其中膜更换成本贡献显著。尽管 CED 系统被证明是一种用于分散式饮用水生产的稳健、高度适应和全自动技术，但去除 OMPs 的效率不高，尤其是非带电的 OMPs。
