Electrodialysis for water desalination: A critical assessment of recent developments on process fundamentals, models and applications

Current to Clean Water – Electrochemical Solutions for Groundwater, Water, and Wastewater Treatment

“…Increased electrical and hydraulic resistance and, therefore, higher energy consumption is the consequence . Apart from pretreatment of the influent, e.g., by filtering and adjustment of pH, or in‐place cleaning procedures, reversing the polarity of the electrodes for short intervals, the so‐called EDR, proved to be an effective strategy to avoid fouling and scaling and to enhance the lifetime of membranes .…”

“…Heavy metals in sediments, soils, fly ash, and sludge can be removed by electrodialytic remediation (EDRem) . The separation of monovalent or divalent ions of saline water by monovalent or divalent membranes is done in selective electrodialysis, also named SElectroDialysis (SED) , . It is applied for the production of irrigation water from brackish groundwater with preservation of a certain level of hardness ions (divalent ions) , and for industrial applications like recovering lithium from brines .…”

“…Other authors also report high removal efficiency of heavy metals with ED treatment [37 -41] and for desalination [41,42] The ED process depends on several parameters, e.g., applied voltage or current, conductivity, pH, and concentration of the electrolyte [53]. The performance and lifetime of ED modules are affected by scaling and fouling phenomena of IEMs due to low solubility of some salts, organic substances, and colloidal particles of the influent [17]. Increased electrical and hydraulic resistance and, therefore, higher energy consumption is the consequence [54].…”

Ion transfer modeling based on Nernst–Planck theory for saline water desalination during electrodialysis process

“…Electrodialysis technique is based on ion transportation through selective membranes driven by the electrical field. In an electrodialysis stack, cation‐ and anion‐exchange membranes (AEMs) are placed alternatively between the cathode and the anode commonly . The applied potential difference between electrodes makes cations move toward the cathode, migrating through the cation‐exchange membrane (CEM) with negative fixed groups, and retained by the AEM with positive fixed groups, as shown in Figure .…”

“…To date, the state‐of‐the‐art transfer model is based on irreversible thermodynamic theory, which is relatively accurate to describe transport phenomena occurring in the electrodialysis process compared with other semiempirical models . A limitation of this approach is the very long computational time required to solve the model equations, thus making the tool unsuitable for practical applications . Recently, Gu et al reported that simulation of a three‐dimensional periodic domain of a spacer‐filled channel takes more than 3 hr by a RAM‐96GB workstation .…”