Short Review of Multichannel Membrane Capacitive Deionization: Principle, Current Status, and Future Prospect

Abstract

Capacitive deionization (CDI) has gained a lot of attention as a promising water desalination technology. Among several CDI architectures, multichannel membrane CDI (MC-MCDI) has recently emerged as one of the most innovative systems to enhance the ion removal capacity. The principal feature of MC-MCDI is the independently controllable electrode channels, providing a favorable environment for the electrodes and enhancing the desalination performance. Furthermore, MC-MCDI has been studied in various operational modes, such as concentration gradient, reverse voltage discharging for semi-continuous process, and increase of mass transfer. Furthermore, the system configuration of MC-MCDI has been benchmarked for the extension of the operation voltage and sustainable desalination. Given the increasing interest in MC-MCDI, a comprehensive review is necessary to provide recent research efforts and prospects for further development of MC-MCDI. Therefore, this review actively addresses the major principle and operational features of MC-MCDI along with conventional CDI for a better understanding of the MC-MCDI system. In addition, the innovative applications of MC-MCDI and their notable improvements are also discussed. Finally, this review briefly mentions the major challenges of MC-MCDI as well as proposes future research directions for further development of MC-MCDI as scientific and industrial desalination technologies.

A Review of the Water Desalination Technologies

“…A schema of a Hydration plant is reported in Figure 26 [18]. According to the literature, this technology requires a lower energy consumption for the desalination of brackish water and lower maintenance operations than the electrodialysis reversal units [56]. Despite these advantages, CDI is a process under investigation, as it is a recent introduction in the context of saltwater desalination [54,57].…”

Desalination Technology in South Korea: A Comprehensive Review of Technology Trends and Future Outlook

“…In the same manner as a capacitor, energy can be partially recovered during the electrode regeneration step [56][57][58]. The energy consumption in the CDI process strongly depends on the salt concentration of the feed water because CDI desalinates ions by electrosorption [59]. Thus, it has been suggested that CDI is more energy-efficient than RO for brackish water desalination when the feed salinity is lower than 3.5 g/L, and the product water salinity is 1 g/L [60].…”

Progress and Perspectives of Desalination in China

“…On another hand, novel membrane material synthesis, module design and processing approaches have been broadly explored, rendering the membranes chlorine-resistant, antifouling, stable, and highly efficient in terms of desalination and separation performance. Interested readers are referred to the excellent research and review articles [ 38 , 39 , 40 , 41 , 42 , 43 , 44 , 45 , 46 ]. In a recent work by ISDMU and Shandong University of Science and Technology, aminophenyl-modified mesoporous silica NPs were used to fabricate RO membranes, enabling enhanced water flux by 21% while maintaining high NaCl rejection of 98.97%, only slightly decreased by 0.29% compared with that of the pristine membrane [ 47 ].…”