Modular desalination concept with low-pressure reverse osmosis and capacitive deionization: Performance study of a pilot plant in Vietnam in comparison to seawater reverse osmosis

Optimization and Evaluation for the Capacitive Deionization Process of Wastewater Reuse in Combined Cycle Power Plants

“…Water is demineralized in an adsorption phase and the electrodes are regenerated in a desorption phase [ 8 , 50 , 53 ]. MCDI combines an ion exchange membrane on the electrode surface, reducing the influence of ions of the same charge and reducing the possibility of electrode fouling, resulting in better deionization performance [ 25 , 54 , 55 ]. CDI in this paper refers to MCDI.…”

“…Capacitive deionization (CDI) is an alternative to conventional deionization because it can effectively remove a wide range of ions, including dissolved salts, heavy metals, and other contaminants [ 23 , 24 ]. CDI requires relatively low energy consumption and maintenance, making it a cost-effective option [ 25 , 26 , 27 ]. Because of these advantages, CDI has been used to treat feed water that contains less than 2.0 g/L of total dissolved solids (TDS) [ 28 ].…”

Optimal Management Strategy for Salt Adsorption Capacity in Machine Learning-Based Flow-Electrode Capacitive Deionization Process

“…Therefore, brackish or seawater desalination was suggested as an alternative for sustainable freshwater sources. , Capacitive deionization (CDI) has been proposed for the purpose of brackish water desalination or post-treatment for seawater desalination, with extensive research underway due to its environmentally benign nature and relatively simple operating conditions. − Since CDI removes ions from the brackish water and seawater based on an electrochemical process, CDI can be assessed by calculating the salt adsorption rate or capacity. , Salt adsorption capacity (SAC) presents the amount of salt removal by CDI and is a versatile performance assessment metric. , Therefore, the optimization of CDI parameters aims to increase SAC. , For the maximization of SAC, various structures of CDI have been explored, with CDI, membrane CDI (MCDI), and flow-electrode CDI (FCDI) currently being suggested. , Among these desalination processes, the FCDI technology was developed to overcome the difficulties of continuous processing, which are the limitations of conventional CDI and MCDI processes. , Conventional CDI and MCDI have disadvantages in practical continuous operation since they require high energy demand. Low energy efficiency driven by insufficient specific surface area leads to such results. , The diverse studies attempt to overcome the above-mentioned problem by combining photovoltaic energy generation or reverse osmosis systems. − In contrast, FCDI has the advantage of enabling long-term operation by maximizing ion adsorption capacity and operational sustainability by using an ion exchange membrane and a flow-electrode (i.e., slurry materials). ,− Nevertheless, due to the presence of a flow-electrode, the system’s performance is significantly influenced by the electrode material and the physical and chemical properties of the electrolyte, necessitating optimization distinct from existing CDI and MCDI. Consequently, various studies are currently being conducted to optimize FCDI.…”

Comparison of Pilot-Scale Capacitive Deionization (MCDI) and Low-Pressure Reverse Osmosis (LPRO) for PV-Powered Brackish Water Desalination in Morocco for Irrigation of Argan Trees

“…However, the main challenges of MCDI are its low salinity ranges and higher investment costs, which are the main reasons why an application of MCDI on a large and industrial scale has not yet been achieved [ 22 , 24 ]. Studies have shown the long-term use of MCDI in different applications [ 25 , 26 , 27 , 28 ]. However, operation at larger operational scale is necessary to validate lab-scale and small-scale results and to better understand the effect of operational parameter interactions.…”

“…Another study compared the use of reverse osmosis with MCDI and LPRO in a modular system for the desalination of brackish river water (17 g/L) in Vietnam to produce drinking water, showing that both pilot plants resulted in similar energy requirements (ca. 5 kWh/m 3 ) [ 28 ]. In the field of agriculture, one study evaluated the feasibility of MCDI in the desalination of brackish groundwater for the irrigation of selected crops at prices below AUD 1/m 3 , showing the profitability compared to irrigation with brackish water [ 31 ].…”