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Enhanced electrosorption selectivity of phosphate using an anion-exchange resin-coated activated carbon electrode.
- Source :
-
Journal of Colloid & Interface Science . Oct2021, Vol. 600, p199-208. 10p. - Publication Year :
- 2021
-
Abstract
- [Display omitted] Regenerable methods for phosphate (P) recycling have received intense attention due to their potential environmental and economic benefits. In this study, to improve the electrosorptive removal of P in membrane capacitive deionization, an activated carbon (AC) electrode was coated with a heterogeneous anion-exchange resin layer, and named the AE-AC composite electrode. It was shown that the AE-AC electrode exhibited a good capacitive behavior for electrical double-layer charging. The batch-mode experiments indicted that when the solution pH changed from 5 to 8, the predominant P species shifted from monovalent H 2 PO 4 − to divalent HPO 4 2− that was preferentially electroadsorbed for competitive electrosorption with Cl−. Importantly, the AE-AC composite electrode significantly increased the selectivity coefficient of P over Cl− to 0.56 that was 2.24-fold greater than that of the uncoated AC electrode, at 1.2 V in single-pass mode operation. This improvement can be ascribed to the preferential transport of P through the thin coating layer containing quaternary amine functional groups. The permselectivity of the coating also significantly increased the electrosorption capacity of P from 0.031 to 0.101 mmol/g with a high charge efficiency (97%) by the reduction in the co-ion repulsion effect. When the reverse voltage (−1.2 V) was applied, electroadsorbed P was reversibly desorbed from the AE-AC electrode in repeated operation. This work suggests that coating an anion-exchange resin layer on the surface of a carbon electrode shows great potential to improve the selective removal of P through electrosorption. [ABSTRACT FROM AUTHOR]
- Subjects :
- *DEIONIZATION of water
*CARBON electrodes
*PHOSPHATES
*FUNCTIONAL groups
*ELECTRODES
Subjects
Details
- Language :
- English
- ISSN :
- 00219797
- Volume :
- 600
- Database :
- Academic Search Index
- Journal :
- Journal of Colloid & Interface Science
- Publication Type :
- Academic Journal
- Accession number :
- 151122915
- Full Text :
- https://doi.org/10.1016/j.jcis.2021.04.129