Maximizing Volumetric Removal Capacity in Capacitive Deionization by Adjusting Electrode Thickness and Charging Mode

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 m2/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.

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Efficiency Improvement of a Capacitive Deionization (CDI) System by Modifying 3D SWCNT/RVC Electrodes Using Microwave-Irradiated Graphene Oxide (mwGO) for Effective Desalination

Journal of Nanomaterials ◽

10.1155/2020/5165281 ◽

2020 ◽

Vol 2020 ◽

pp. 1-14

Author(s):

Ali Aldalbahi ◽

Mostafizur Rahaman ◽

Mohammed Almoiqli ◽

Al Yahya Meriey ◽

Govindasami Periyasami

Keyword(s):

Graphene Oxide ◽

Dip Coating ◽

Vitreous Carbon ◽

Capacitive Deionization ◽

Feed Concentration ◽

Removal Capacity ◽

Coating Method ◽

3D Electrodes ◽

Dip Coating Method ◽

Adsorption Desorption

This work is aimed at improving the electrosorption capacity of carbon nanotube/reticulated vitreous carbon- (CNT/RVC-) based 3D electrodes and decreasing the duration of electrosorption-desorption cycles by facilitating the ions’ adsorption and desorption on the electrode surface. This was achieved by preparing composites of microwave-irradiated graphene oxide (mwGO) with CNT. All composite materials were coated on RVC by the dip-coating method. The highest loading level was 50 mg. This is because it exhibited the maximum electrosorption capacity when tested in terms of geometric volume. The results showed that the 9-CNT/mwGO/RVC electrode exhibited 100% capacitive deionization (CDI) cyclic stability within its 1st five cycles. Moreover, 27.78% time was saved for one adsorption-desorption cycle using this electrode compared to the CNT/RVC electrode. In addition, the ion removal capacity of NaCl by the 9-CNT/mwGO/RVC electrode with respect to the mass of the electrode (3.82 mg/g) has increased by 18.27% compared to the CNT/RVC electrode (3.23 mg/g) when measured at the optimum conditions. In a complete desalination process, the water production per day for the 9-CNT/mwGO/RVC electrode was increased by 67.78% compared to the CNT/RVC electrode when measured within the same CDI cell using NaCl solution of concentration less than 1 mg/L. When considered volume of 1 m3, this optimum 9-CNT/mwGO/RVC electrode produces water 29,958 L per day. The highest electrosorption capacity, when measured experimentally at 500 mg/L NaCl feed concentration, was 10.84 mg/g for this optimum electrode, whereas Langmuir isotherm gave the theoretically calculated highest value as 16.59 mg/g. The results for the 9-CNT/mwGO/RVC composite electrode demonstrate that it can be an important electrode material for desalination in CDI technology.

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Promoting the Chloride Ions Uptake by ZnCo-Cl Layered Double Hydroxide Electrodes towards the Enhanced Capacitive Deionization

Environmental Science Nano ◽

10.1039/d1en00350j ◽

2021 ◽

Author(s):

Zehao Zhang ◽

Haibo Li

Keyword(s):

Layered Double Hydroxide ◽

Chloride Ions ◽

Capacitive Deionization ◽

Removal Capacity ◽

Double Hydroxide ◽

Research Domain

Hybrid capacitive deionization (HCDI) has gained a lot attentions in desalination research domain due to the remarkable salt removal capacity. In this work, the ZnCo-Cl layered double hydroxide (LDH) has...

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Effect of electrode thickness variation on operation of capacitive deionization

Electrochimica Acta ◽

10.1016/j.electacta.2012.04.083 ◽

2012 ◽

Vol 75 ◽

pp. 148-156 ◽

Cited By ~ 111

Author(s):

S. Porada ◽

M. Bryjak ◽

A. van der Wal ◽

P.M. Biesheuvel

Keyword(s):

Thickness Variation ◽

Capacitive Deionization ◽

Electrode Thickness

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

Applied Sciences ◽

10.3390/app10020683 ◽

2020 ◽

Vol 10 (2) ◽

pp. 683 ◽

Cited By ~ 6

Author(s):

Nayeong Kim ◽

Jiho Lee ◽

Seonghwan Kim ◽

Sung Pil Hong ◽

Changha Lee ◽

...

Keyword(s):

Continuous Process ◽

Short Review ◽

Water Desalination ◽

Current Status ◽

Future Research ◽

Capacitive Deionization ◽

Ion Removal ◽

Removal Capacity ◽

Desalination Technology ◽

Further Development

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.

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