气候变化领域集成服务门户(CCPortal): Electrochemical removal of amphoteric ions

CCPortal

DOI	10.1073/pnas.2108240118
	Electrochemical removal of amphoteric ions
	Shocron A.N.; Guyes E.N.; Rijnaarts H.H.M.; Biesheuvel P.M.; Suss M.E.; Dykstra J.E.
发表日期	2021
ISSN	0027-8424
卷号	118 期号:40
英文摘要	Several harmful or valuable ionic species present in seawater, brackish water, and wastewater are amphoteric, weak acids or weak bases, and, thus, their properties depend on local water pH. Effective removal of these species can be challenging for conventional membrane technologies, necessitating chemical dosing of the feedwater to adjust pH. A prominent example is boron, which is considered toxic in high concentrations and often requires additional membrane passes to remove during seawater desalination. Capacitive deionization (CDI) is an emerging membraneless technique for water treatment and desalination, based on electrosorption of salt ions into charging microporous electrodes. CDI cells show strong internally generated pH variations during operation, and, thus, CDI can potentially remove pH-dependent species without chemical dosing. However, development of this technique is inhibited by the complexities inherent to the coupling of pH dynamics and ion properties in a charging CDI cell. Here, we present a theoretical framework predicting the electrosorption of pH-dependent species in flow-through electrode CDI cells. We demonstrate that such a model enables insight into factors affecting species electrosorption and conclude that important design rules for such systems are highly counterintuitive. For example, we show both theoretically and experimentally that for boron removal, the anode should be placed upstream and the cathode downstream, an electrode order that runs counter to the accepted wisdom in the CDI field. Overall, we show that to achieve target separations relying on coupled, complex phenomena, such as in the removal of amphoteric species, a theoretical CDI model is essential. © 2021 National Academy of Sciences. All rights reserved.
英文关键词	Amphoteric ions; Boron removal; Capacitive deionization; Electrochemical water treatment; PH modeling
语种	英语
来源期刊	Proceedings of the National Academy of Sciences of the United States of America
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/238354
作者单位	Faculty of Mechanical Engineering, Technion–Israel Institute of Technology, Haifa, 3200003, Israel; Environmental Technology, Wageningen University, Wageningen, 6708 WG, Netherlands; Wetsus, European Centre of Excellence for Sustainable Water Technology, Leeuwarden, 8911 MA, Netherlands; Grand Technion Energy Program, Technion–Israel Institute of Technology, Haifa, 3200003, Israel; Wolfson Department of Chemical Engineering, Technion–Israel Institute of Technology, Haifa, 3200003, Israel
推荐引用方式 GB/T 7714	Shocron A.N.,Guyes E.N.,Rijnaarts H.H.M.,et al. Electrochemical removal of amphoteric ions[J],2021,118(40).
APA	Shocron A.N.,Guyes E.N.,Rijnaarts H.H.M.,Biesheuvel P.M.,Suss M.E.,&Dykstra J.E..(2021).Electrochemical removal of amphoteric ions.Proceedings of the National Academy of Sciences of the United States of America,118(40).
MLA	Shocron A.N.,et al."Electrochemical removal of amphoteric ions".Proceedings of the National Academy of Sciences of the United States of America 118.40(2021).