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Capacitive deionization (CDI) is a promising and cost-effective technology that is currently being widely explored for removing dissolved ions from saline water. This research developed materials based on activated carbon (AC) materials modified with zinc oxide (ZnO) nanorods and used them as high-performance CDI electrodes for water desalination. The as-prepared electrodes were characterized by cyclic voltammetry, and their physical properties were studied through SEM and XRD. ZnO-coated AC electrodes revealed a better specific absorption capacity (SAC) and an average salt adsorption rate (ASAR) compared to pristine AC, specifically with values of 123.66 mg/g and 5.06 mg/g/min, respectively. The desalination process was conducted using a 0.4 M sodium chloride (NaCl) solution with flow rates from 45 mL/min to 105 mL/min under an applied potential of 1.2 V. Furthermore, the energy efficiency of the desalination process, the specific energy consumption (SEC), and the maximum and minimum of the effluent solution concentration were quantified using thermodynamic energy efficiency (TEE). Finally, this work suggested that AC/ZnO material has the potential to be utilized as a CDI electrode for the desalination of saline water. [ABSTRACT FROM AUTHOR]

• Activated carbon derived from agriculture by-products obtain high surface area, high porosity, and low density. • Deionization efficiency of CDI, MCDI, and FCDI reached 80–90 % and water recovery rate 90 %. • The roller, spray coating, and mill ball grinding are useful to fabricate electrodes for industry applications. • The adsorption capacities of AC and AC-modified electrodes were 25–40 mg/g. • Life span and deionization efficiency of the flow electrode are higher than electrode plate. Capacitive deionization (CDI), membrane capacitive deionization (MCDI), and flow capacitive deionization (FCDI) are emerging technologies applied to remove ions from brackish water or saline wastewater based on electrode double layer (EDL) mechanisms. The electrode itself can be seen as the most important factor that determines the deionization efficiency of the CDI system. Electrode fabrication using activated carbon derived from agriculture byproducts is a useful solution to decrease cost, restrict environmental pollution, and enable agriculture waste recovery. In this review, the primary parameter's impact on activated carbon (AC) and the electrode fabrication process from the agriculture byproducts is detailed in a discussion to find the most optimal conditions. With excellent characteristics for the activated carbon such as a surface area of up to 2500 m2/g, it can be used to fabricate electrodes that have a high adsorption capacity of approximately 25 mg/g, able to be advanced to 40 mg/g with a modified AC. It can achieve a cycle performance of 95–97 %. The deionization efficiency of the CDI, MCDI, and FCDI systems can be up to 90 % with an input salt concentration from 2000 to 3000 mg/L where the water recovery ratio achieved is 50–90 %, alongside a salt rejection rate of about 7–75 %. AC can be modified to increase its special properties such as surface area, conductivity, and ion selectivity using different methods. The drawbacks and challenges of the CDI technology are also mentioned along with useful solutions such as electrode coating techniques using an anilox roller and a spray, for use in industry applications. [Display omitted] [ABSTRACT FROM AUTHOR]

[Display omitted] • Survey on biowaste material derived activated carbon (BMDAC) electrodes in CDI. • Applications of BMDAC electrodes for removal of pollutant ions are explained. • Systematic tabulation on BMDAC electrodes performance and parameters is presented. Capacitive deionization (CDI) is water desalination process used to remove pollutant ions and water purification. In present review contains current status biowaste material derived activated carbon (BMDAC) electrodes for pollutant ion removal using CDI. This review systematically present the fundamental about CDI, application of CDI, discusses the numerous BMDAC material, comparative tabulation on current status removal of pollutants ion using BMDAC electrodes by CDI and a future scope in present area. [ABSTRACT FROM AUTHOR]

The unequal distribution of the water resources warrants a search for more energy efficient water treatment technologies. In this regard, capacitive deionization (CDI) could play a leading role particularly in the case of brackish water desalination. In this work, inexpensive materials that are commercially available were investigated for being used as electrodes in CDI. After physical and electrochemical evaluation, activated carbon (AC) demonstrated superior performance compared to the different fabrics tested. Hereafter, a factorial design of experiments was used to investigate the effect of cell potential, mass of AC ( m AC ), carbon black, and interparticle porosity on ion removal, charge efficiency and energy consumption. The results showed that neither carbon black nor macroporosity had a single effect on electrode performance. An interaction effect of macroporosity and m AC was found to be beneficial in terms of ion electrosorption for thick electrodes. An additional evaluation concerning the role of electrode thickness revealed that an increase in thickness translated into an increase in the total salt removed and a reduction in ion removal per mass of electrode. In addition, while electrosorption kinetics were found to be independent of the AC thickness, slow desorption kinetics were detected for the thicker electrodes. [ABSTRACT FROM AUTHOR]