Adsorption-capacitive deionization hybrid system with activated carbon of modified potential of zero charge

Omari Sufiani; Joyce Elisadiki; Hideki Tanaka; Katsuya Teshima; Mtabazi G Sahini; Revocatus L Machunda; Yusufu A C Jande

doi:10.1016/j.envres.2022.115114

Adsorption-capacitive deionization hybrid system with activated carbon of modified potential of zero charge

Environ Res. 2023 Feb 15:219:115114. doi: 10.1016/j.envres.2022.115114. Epub 2022 Dec 24.

Authors

Omari Sufiani¹, Joyce Elisadiki², Hideki Tanaka³, Katsuya Teshima³, Mtabazi G Sahini¹, Revocatus L Machunda⁴, Yusufu A C Jande⁵

Affiliations

¹ Department of Chemistry, College of Natural and Mathematical Sciences, The University of Dodoma, P.O. Box 338, Dodoma, Tanzania.
² Physics Department, College of Natural and Mathematical Sciences, The University of Dodoma, P.O. Box 338, Dodoma, Tanzania.
³ Research Initiative for Supra-Materials, Shinshu University 4-17-1, Wakasato, Nagano, 380-8553, Japan.
⁴ Department of Water and Environmental Sciences and Engineering, Nelson Mandela African Institution of Science and Technology, P.O. Box 447, Arusha, Tanzania.
⁵ Water Infrastructure and Sustainable Energy Futures (WISE-Futures) African Centre of Excellence, The Nelson Mandela African Institution of Science and Technology, Nelson Mandela Road, Tengeru, P.O. Box 9124, Nelson Mandela, Arusha, Tanzania. Electronic address: yusufu.jande@nm-aist.ac.tz.

PMID: 36574800
DOI: 10.1016/j.envres.2022.115114

Abstract

In this study water solutions are desalinated with carbon electrodes of modified surface charges. The idea is to endow the electrodes with the ability to physically adsorb salt ions without applying potential so as to save energy. The modification enhanced to decrease the energy consumption of a newly invented adsorption-CDI hybrid system by 19%, since modified activated carbon cell consumed 0.620 (relative error 3.00%) kWh/m³ compared to pristine activated carbon cell which consumed 0.746 (relative error 1.20%) kWh/m³. Further analysis revealed high adsorption capacity of the modified activated carbon electrode cell which exhibited 9.0 (relative error 2.22%) compared to activated carbon cell with 5.3 (relative error 5.66%) mg g^-1. These results show the potential of surface modification in adding value to low cost activated carbons for application in CDI.

Keywords: Activated carbon; Adsorption; Capacitive deionization; Energy consumption; Oxygen functional groups; Surface charges.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Adsorption
Charcoal*
Electrodes
Sodium Chloride
Water Purification* / methods

Substances

Charcoal
Sodium Chloride