Coconut Shell-Derived Activated Carbon: A Promising Electrode for High-Performance Capacitive Deionization (CDI) System

摘要

Capacitive deionization (CDI) is a potential technique for water treatments such as brackish water desalination, seawater desalination, wastewater remediation, and water softening. CDI has more advantages over other desalinating processes: (i) the technique works by the process of electroabsorption, and is even more energy-efficient, as it does not require any high-pressure pumps; (ii) as the module works in 0.8-2.0 V. An ideal electrode for CDI system requires the following characteristics: (i) large surface area; (ii) high porosity (both meso and micropores); (iii) high electrical conductivity; (iv) electrochemical stability; (v) bio-inertness; (vi) fast adsorption-desorption kinetics; (vii) good wetting behavior; (viii) low cost; and (ix) scalability. In Vietnam, coconut shell-derived activated carbon is produced by a calcinated process under nitrogen gas, which exhibits a high surface area (800-1000 m~2/g). In this work, we prepared the CDI composite electrode based on coconut shell-derived activated carbon and high conductive carbon like CNTs or carbon black in the pilot scale. CDI systems with a capacity of 1 m~3 per day were fabricated and monitored the desalination performance in Mekong Delta.