Dual‐Zinc Electrode Electrochemical Desalination. Issue 10 (19th March 2020)

• Record Type: Journal Article
• Authors: Dai, Jinhong; Wang, Jian; Hou, Xianhua; Ru, Qiang; He, Qingyu; Srimuk, Pattarachai; Presser, Volker; Chen, Fuming
• Is Part Of: ChemSusChem. Volume 13:Issue 10(2020)
• Page Start: 2792
• Page End: 2798
• Publication Date: 2020-03-19
• Subjects: deionization -- dual-zinc electrode -- electrochemical desalination -- redox mediators -- water remediation; Green chemistry -- Periodicals; Sustainable engineering -- Periodicals; Chemistry -- Periodicals; Chemical engineering -- Periodicals; 660
• DOI: 10.1002/cssc.202000188
• Languages: English
• ISSNs: 1864-5631

Abstract

Abstract: Continuous and low‐energy desalination technologies are in high demand to enable sustainable water remediation. Our work introduces a continuous desalination process based on the redox reaction of a dual‐zinc electrode. The system consists of two zinc foils as redox electrodes with flowing ZnCl2 electrolyte, concentrated and diluted salt streams with three anion‐ and cation‐exchange membranes (AEM and CEM) separated configuration (AEM|CEM|AEM). If a constant current is applied, the negative zinc electrode is oxidized, and electrons are released to the external circuit, whereas the positive zinc electrode is reduced, causing salt removal in the dilution stream. The results showed that brackish water can be directly desalted to 380.6 ppm during a continuous batch‐mode process. The energy consumption can be as low as 35.30 kJ mol −1 at a current density of 0.25 mA cm −2, which is comparable to reverse osmosis. In addition, the dual‐zinc electrode electrochemical desalination demonstrates excellent rate performance, reversibility, and batch cyclability through electrode exchange regeneration. Our research provides a route for continuous low‐energy desalination based on metal redox mediators. Abstract : Continuous desalination ! A novel dual‐zinc electrode electrochemical desalination process allows continuous desalination at low energy consumption. Brackish water is directly desalted from 2000 to 380.6 ppm during a continuous batch‐mode process. The energy consumption is as low as 35.30 kJ mol −1 at a current density of 0.25 mA cm −2, which is comparable to reverse osmosis.