Redox Flow Deionization Using Prussian Blue and Functionalized Ion Exchange Membrane for Enhanced Selective Lithium Recovery

Redox flow deionization using Prussian blue and functionalized ion exchange membrane for enhanced selective ion recovery

Selective and continuous ion recovery using flow electrode capacitive deionization with polymer multilayers functionalized ion exchange membrane

Equivalent film-electrode model for flow-electrode capacitive deionization: Experimental validation and performance analysis

Enhanced capacitive deionization for Cr(VI) removal from electroplating wastewater: Efficacy, mechanisms, and high-voltage flow electrodes

Selective Lithium separation from Li/Co/Ni mixtures using optimized flow-electrode capacitive deionization

While flow-electrode capacitive deionization (FCDI) is recognized as an attractive desalination technology, its practical implementation has been hindered by the ease of scaling and energy-intensive nature of the single-cell FCDI system, particularly when treating brackish water with elevated levels of naturally coexisting SO42- and Ca2+. To overcome these obstacles, we propose and design an innovative ion-selective metathesis FCDI (ISM-FCDI) system, consisting of a two-stage tailored cell design. Results indicate that the specific energy consumption per unit volume of water for the ISM-FCDI is lower (by up to ∼50%) than that of a conventional single-stage FCDI due to the parallel circuit structure of the ISM-FCDI. Additionally, the ISM-FCDI benefits from a conspicuous disparity in the selective removal of ions at each stage. The separate storage of Ca2+ and SO42- by the metathesis process in the ISM-FCDI (46.25% Ca2+, 14.25% SO42- in electrode 1 and 4.75% Ca2+, 35.25% SO42- in electrode 2) can effectively prevent scaling. Furthermore, configuration-performance analysis on the ion-selective migration suggests that the properties of the ion exchange membrane, rather than the carbon species, govern the selectivity of ion removal. This work introduces system-level enhancements aimed at enhancing energy conservation and scaling prevention, providing critical optimization of the FCDI for brackish water softening.

A novel four-chamber flow electrode capacitive deionization system for continuous recovery of heavy metal ions from wastewater

Construction of MS-Ti3C2TX MXene continuous conductive structure for highly efficient fluoride removal in flow-electrode capacitive deionization

Membrane-spacer assembly for flow-electrode capacitive deionization

Efficient capacitive deionization with hierarchical porous carbon flow electrodes

Influence of particle size distribution on carbon-based flowable electrode viscosity and desalination efficiency in flow electrode capacitive deionization

This study demonstrates the efficacy of a symmetrically designed flow-electrode capacitive deionization (FCDI) system for the electrochemical defluorination of photovoltaic (PV) wastewater, with a systematic investigation conducted to optimize operational parameters and analyze key factors influencing system performance, offering valuable insights into enhancing FCDI efficiency. The results revealed that an optimal applied voltage of 1.2 V yielded a fluoride removal efficiency of 92.9% with an energy consumption of 6.49 kWh/mol. Increasing the electrode content to 0.75 wt% enhanced the removal efficiency to 98.3%; however, further increases in electrode content led to higher energy consumption due to elevated viscosity. Optimizing the flow rate to 45 mL/min resulted in a removal efficiency of 98.6%, accompanied by improved adsorption rates and reduced energy consumption. Adding 1 g/L of electrolyte substantially enhanced system performance, achieving a fluoride removal efficiency of 92.9%. In mixed-ion wastewater, competitive adsorption between NO 3 − and F⁻ was observed. Doubling the NO 3 − concentration relative to F⁻ decreased the F⁻ removal efficiency from 96.2% to 87.3%. Nonetheless, the FCDI system demonstrated robust fluoride removal performance under high ion concentrations and complex matrix conditions, offering an efficient and sustainable approach for industrial wastewater treatment.

In situ potential measurement in a flow-electrode CDI for energy consumption estimation and system optimization

Towards long-term operation of flow-electrode capacitive deionization (FCDI): Optimization of operating parameters and regeneration of flow-electrode

Enhanced salt removal performance using nickel hexacyanoferrate/carbon nanotubes as flow cathode in asymmetric flow electrode capacitive deionization