Enhanced phosphate removal under an electric field via multiple mechanisms on MgAl-LDHs/AC composite electrode
| Autor: | K. N. Hui, Enhao Zhu, Kwan San Hui, Xiaoting Hong, Zhuoliang Ye |
|---|---|
| Rok vydání: | 2019 |
| Předmět: |
Supercapacitor
Ion exchange Chemistry Capacitive deionization General Chemical Engineering Layered double hydroxides Langmuir adsorption model 02 engineering and technology engineering.material 010402 general chemistry 021001 nanoscience & nanotechnology Phosphate 01 natural sciences 0104 chemical sciences Analytical Chemistry chemistry.chemical_compound symbols.namesake Adsorption Chemical engineering Electrode Electrochemistry engineering symbols 0210 nano-technology |
| Zdroj: | Journal of Electroanalytical Chemistry. 836:16-23 |
| ISSN: | 1572-6657 |
| Popis: | Phosphorus removal is essential to avoid eutrophication in water bodies. Layered double hydroxides (LDHs) are widely used to scavenge phosphate through intercalated ion exchange or surface complexation. Moreover, LDHs have attracted increasing attention as electrode modifiers for supercapacitors. Researchers have begun to re-delve the electrosorption technology according to the fundamental principle of electrical double layers. Herein, we propose a new phosphate removal method inspired by the adsorption characteristic and electrical double-layer capacitive properties of LDHs through electrosorption via capacitive deionization. We present a series of experiments to study the enhanced phosphate removal under an electric field via multiple mechanisms on the MgAl-LDHs/AC electrode. The uptake of phosphate by MgAl-LDHs/AC was investigated as a function of phosphate concentration, applied voltage, electrode materials, and temperature. The MgAl-LDHs/AC electrode possessed a salt removal capacity of 67.92 mg PO43−·g−1 (1.2 V, 250 mg·L−1 KH2PO4, 30 °C). The electrosorption kinetics of phosphate ions onto the capacitive deionization electrode followed the pseudo-second-order kinetics model rather than the pseudo-first-order kinetics model. Furthermore, the adsorption isotherms of phosphate on the MgAl-LDHs/AC electrode fitted the Freundlich model better than the Langmuir model. The proposed method could be used for phosphate removal. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|
Full Text from ScienceDirect