Effect of electrode thickness variation on operation of capacitive deionization

Porada, S.; Bryjak, Marek; Wal, A. F. van der; Biesheuvel, P.M.

doi:10.1016/j.electacta.2012.04.083

Cited by 173 publications

(125 citation statements)

References 46 publications

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“…In commercial desalination technologies, such as reverse osmosis and multistage flash distillation, freshwater is produced at relatively high energy cost and often requires re-mineralization for human consumption. For brackish water or wastewater it can be advantageous to use a different type of technology, namely techniques where ions are removed from the feed water under the influence of electrical field effects, such as in electrodialysis [8,9], capacitive deionization [10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26][27][28], membrane capacitive deionization [29][30][31][32][33][34], desalination using microchannels [35], batteries [36], microbial desalination cells [37] and wires [38]. Such techniques have the potential to be energy-efficient as they focus on the removal of the (often relatively few) ions in the water to obtain freshwater in this way.…”

Section: Introductionmentioning

confidence: 99%

Time-dependent ion selectivity in capacitive charging of porous electrodes

Zhao

Soestbergen

Rijnaarts

et al. 2012

Journal of Colloid and Interface Science

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238

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In a combined experimental and theoretical study we show that capacitive charging of porous electrodes in multicomponent electrolytes may lead to the phenomenon of time-dependent ion selectivity of the electrical double layers (EDLs) in the electrodes. This effect is found in experiments on capacitive deionization of water containing NaCl/CaCl 2 mixtures, when the concentration of Na + ions in the water is 5 times higher than the Ca 2+ -ion concentration. In this experiment, after applying a voltage difference between two porous carbon electrodes, first the majority monovalent Na + cations are preferentially adsorbed in the EDLs, and later they are gradually replaced by the minority, divalent Ca 2+ cations. In a process where this ion adsorption step is followed by washing the electrode with freshwater under open-circuit conditions, and subsequent release of the ions while the cell is shortcircuited, a product stream is obtained which is significantly enriched in divalent ions. Repeating this process three times by taking the product concentrations of one run as the feed concentrations for the next, a final increase in the Ca 2+ /Na + -ratio of a factor of 300 is achieved. The phenomenon of timedependent ion selectivity of EDLs cannot be explained by linear response theory. Therefore, a nonlinear time-dependent analysis of capacitive charging is performed for both porous and flat electrodes. Both models attribute time-dependent ion selectivity to the interplay of the transport resistance for the ions in the aqueous solution outside the EDL, and the voltage-dependent ion adsorption capacity of the EDLs. Exact analytical expressions are presented for the excess ion adsorption in planar EDLs (Gouy-Chapman theory) for mixtures containing both monovalent and divalent cations.key-words: water desalination; porous electrode theory; capacitive (non-faradaic) electrochemical cells; electrostatic double layer theory.2

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Section: Introductionmentioning

confidence: 99%

Time-dependent ion selectivity in capacitive charging of porous electrodes

Zhao

Soestbergen

Rijnaarts

et al. 2012

Journal of Colloid and Interface Science

Self Cite

238

182

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“…Regarding the positive relationship between the increasing number of electrodes and the contacting distance for the influent (Porada et al 2012), the electrosorption kinetic was expressed in Eq. (6), where n represented the number of electrodes.…”

Section: Performance Of Electrosorption Treatment For Real Salinity Wmentioning

confidence: 99%

Electrosorption for organic pollutants removal and desalination by graphite and activated carbon fiber composite electrodes

Zhou

Wang

et al. 2015

Int. J. Environ. Sci. Technol.

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This paper investigates a new type of carbonbased electrodes, which were equipped with graphite and activated carbon fiber composite, to improve the performance of electrosorption. The results indicated that the highest desalination efficiency achieved 55 % and the optimal condition was 1.6 V voltage, 60 min retention time and 1.0 cm electrode distance. Freundlich isotherms successfully fitted with the respective behavior of the composite electrode and provided theoretical evidence for the desalination performance improvement. Applied in real black liquor of refined cotton, the graphite and activated carbon fiber composite electrodes achieved high removal efficiency for conductivity (59 %) and COD Cr (76 %). Similar removal performance was also observed in sodium copper chlorophyll wastewater, and removal efficiency was 37 % for conductivity and 14 % for COD Cr . For the first time, this research demonstrated the biodegradability improvement in real industrial wastewater via electrosorption treatment, suggesting a potential pretreatment technique for high-salinity wastewater.

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“…Despite activated carbon being widely studied as a material for CDI electrodes (Bouhadana et al, 2011;Choi, 2010;Hou and Huang, 2013;Hou et al, 2012;Huang et al, 2012;Mossad and Zou, 2012;Porada et al, 2012;Villar et al, 2010;Wang et al, 2012;Wang et al, 2013), one of the drawbacks associated with its use is the requirement for a polymeric binder. Typically hydrophobic polymers such as poly(tetrafluoroethylene) (PTFE) (Chang et al, 2012;Lee et al, 2009) or poly(vinylidene fluoride) (PVDF) (Zhang et al, 2012) are used to bind activated carbon powder.…”

Section: Introductionmentioning

confidence: 99%