TAÏP CHÍ PHAÙT TRIEÅN KH&CN, TAÄP 19, SOÁ K6- 2016 Trang 155 Capacitive deionization (CDI) for desalisation using carbon aerogel electrodes  Le Khac Duyen  Pham Quoc Nghiep  Le Anh Kien Institute for Tropicalisation and Environment, ITE, Ho Chi Minh City, Vietnam (Manuscript Received on July, 2016, Manuscript Revised on September, 2016) ABSTRACT Capacitive deionization (CDI) is an electrochemical water treatment process that holds the promise of not only being a commercially viable alternative for treating water but for saving energy as well. Carbon aerogel electrodes for CDI process with high specific surface area (779.04 m 2 /g) and nano- pore (2-90 nm) have been prepared via pyrolyzing RF organic aerogel at 800oC in nitrogen atmosphere. The CDI characteristics of carbon aerogel electrodes were investigated for the NaCl absorption into a CDI cell at variation conditions. Experiments data showed that the maximum NaCl removal capacity was 21.41 mg/g in 500 mg/L NaCl solution, higher than for other carbon-based materials in the literature. It was evaluated that the CDI process using carbon aerogel electrodes promising to be an effective technology for desalination. Keywords: Capacitive deionization, carbon aerogel, aerogel electrodes, desalination, electrosorption. 1. INTRODUCTION Capacitive deionization (CDI) is a technology for removing ionic materials from aqueous solution using an electrostatic adsorption reaction on the electric double layer (EDL) created on the electrode surface interface when a potential is applied on porous carbon electrodes [1, 2]. The technique is mainly applicable for brackish water and offers advantage of easy regeneration, low voltage, and ambient operational conditions. Salty water is passed through the electrode surface with an applied charge. Cations and anions are drawn toward the cathode and anode, respectively. Salts from water are removed by the electrosorption of ions on the porous surface of electrodes [3]. After the electrode becomes saturated, it can easily be regenerated by cancelling or changing the electrical potential of the electrodes, the regeneration of the electrode is not only very simple, but is also recognized as an environmentally friendly process [4, 5].