Publication Type
Journal Article
Publication Date (Issue Year)
2022
Journal Name
Water Supply
Abstract
Capacitive deionization (CDI) is among the promising technologies employed for water purification. CDI has been studied for the removal of various ionic species from water including fluoride ion (F−) with promising results. However, there is no comprehensive literature that summarizes the use of CDI for water defluoridation applications. Therefore, this review paper critically analyzes different electrode materials that have been studied for water defluoridation, their electrosorption capacities and F− removal efficiencies. It further discussed the parameters that influence CDI efficiency during defluoridation and point out the issues of F− selectivity when co-existing with other ions in the solution. We can conclude that different electrode materials have shown different abilities in electrosorption of F−. The carbon-based materials possess high surface area and good electrical conductivity which is paramount for ion adsorption but gives lack selectivity for F− removal. Metal oxides and hydroxides have been reported with improved electrosorption capacity and high selectivity to F− due to the ion exchange between the F− and the hydroxyls surface of the metal oxides/hydroxides. Apart from the good performance of these materials for defluoridation, the discovery of actual practical use of the electrode materials for defluoridation for commercial scale is still a need.
Keywords
capacitive deionization, defluoridation, electrode materials, electrosorption
Rsif Scholar Name
Tusekile Alfredy
Thematic Area
Minerals, Mining and Materials Engineering
Africa Host University (AHU)
Nelson Mandela African Institution of Science and Technology (NM-AIST), Tanzania
Funding Statement
The International Centre of Insect Physiology and Ecology Icipe, Nairobi, Kenya, funded this study through the Partnership for Skills in Applied Sciences, Engineering, and Technology (PASET) Regional Scholarship and Innovation Fund (RSIF).
Recommended Citation
Alfredy, T., Elisadiki, J., & Jande, Y. A. (2022). Capacitive deionization: a promising technology for water defluoridation: a review. Water Supply https://doi.org/10.2166/WS.2021.287