Long-lasting, monovalent-selective capacitive deionization electrodes
Autor: | Chen Yinke, Eric N. Guyes, Amit N. Shocron, Charles E. Diesendruck, Matthew E. Suss |
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Jazyk: | angličtina |
Rok vydání: | 2021 |
Předmět: |
Water supply for domestic and industrial purposes
Capacitive deionization Chemistry Portable water purification 02 engineering and technology 010501 environmental sciences Management Monitoring Policy and Law 021001 nanoscience & nanotechnology 01 natural sciences Pollution Membrane Chemical engineering Electrode medicine Ionic conductivity Water treatment 0210 nano-technology Selectivity Waste Management and Disposal TD201-500 0105 earth and related environmental sciences Water Science and Technology Activated carbon medicine.drug |
Zdroj: | npj Clean Water, Vol 4, Iss 1, Pp 1-11 (2021) |
ISSN: | 2059-7037 |
Popis: | Emerging water purification applications often require tunable and ion-selective technologies. For example, when treating water for direct use in irrigation, often monovalent Na+ must be removed preferentially over divalent minerals, such as Ca2+, to reduce both ionic conductivity and sodium adsorption ratio (SAR). Conventional membrane-based water treatment technologies are either largely non-selective or not dynamically tunable. Capacitive deionization (CDI) is an emerging membraneless technology that employs inexpensive and widely available activated carbon electrodes as the active element. We here show that a CDI cell leveraging sulfonated cathodes can deliver long-lasting, tunable monovalent ion selectivity. For feedwaters containing Na+ and Ca2+, our cell achieves a Na+/Ca2+ separation factor of up to 1.6. To demonstrate the cell longevity, we show that monovalent selectivity is retained over 1000 charge–discharge cycles, the highest cycle life achieved for a membraneless CDI cell with porous carbon electrodes to our knowledge, while requiring an energy consumption of ~0.38 kWh/m3 of treated water. Furthermore, we show substantial and simultaneous reductions of ionic conductivity and SAR, such as from 1.75 to 0.69 mS/cm and 19.8 to 13.3, respectively, demonstrating the potential of such a system towards single-step water treatment of brackish and wastewaters for direct use in irrigation. |
Databáze: | OpenAIRE |
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