Capacitive deionization

Last updated
An illustration of capacitive deionization device. Capacitive Deionization.png
An illustration of capacitive deionization device.

Capacitive deionization (CDI) is a technology to deionize water by applying an electrical potential difference over two electrodes, which are often made of porous carbon. [2] In other words, CDI is an electro-sorption method using a combination of a sorption media and an electrical field to separate ions and charged particles. [3] Anions, ions with a negative charge, are removed from the water and are stored in the positively polarized electrode. Likewise, cations (positive charge) are stored in the cathode, which is the negatively polarized electrode.

Contents

Today, CDI is mainly used for the desalination of brackish water, which is water with a low or moderate salt concentration (below 10 g/L). [4] [5] [6] [7] Other technologies for the deionization of water are, amongst others, distillation, reverse osmosis and electrodialysis. Compared to reverse osmosis and distillation, CDI is considered to be an energy-efficient technology for brackish water desalination. [7] This is mainly because CDI removes the salt ions from the water, while the other technologies extract the water from the salt solution. [6] [8]

Historically, CDI has been referred to as electrochemical demineralization, "electrosorb process for desalination of water", or electrosorption of salt ions. It also goes by the names of capacitive desalination, or in the commercial literature as "CapDI".

History

In 1960 the concept of electrochemical demineralization of water was reported by Blair and Murphy. [9] In that study, it was assumed that ions were removed by electrochemical reactions with specific chemical groups on the carbon particles in the electrodes. In 1968 the commercial relevance and long term operation of CDI was demonstrated by Reid. [10] In 1971 Johnson and Newman introduced theory for ion transport in porous carbon electrodes for CDI and ion storage according to a capacitor mechanism. [11] From 1990 onward, CDI attracted more attention because of the development of new electrode materials, such as carbon aerogels and carbon nanotube electrodes. [12] In 1996, Farmer et al. also introduced the term capacitive deionization and used the now commonly abbreviation “CDI” for the first time. [2] In 2004, Membrane Capacitive Deionization was introduced in a patent of Andelman. [13]

Process

Adsorption and desorption cycles

The operation of a conventional CDI system cycles through two phases: an adsorption phase where water is desalinated and a desorption phase where the electrodes are regenerated. During the adsorption phase, a potential difference over two electrodes is applied and ions are adsorbed from the water. In the case of CDI with porous carbon electrodes, the ions are transported through the interparticle pores of the porous carbon electrode to the intraparticle pores, where the ions are electrosorbed in the so-called electrical double layers (EDLs). After the electrodes are saturated with ions, the adsorbed ions are released for regeneration of the electrodes. The potential difference between electrodes is reversed or reduced to zero. In this way, ions leave the electrode pores and can be flushed out of the CDI cell resulting in an effluent stream with a high salt concentration, the so-called brine stream or concentrate. Part of the energy input required during the adsorption phase can be recovered during this desorption step.

Adsorption of ions from the brackish water to desalinate it Capacitive deionization - Adsorption.pdf
Adsorption of ions from the brackish water to desalinate it
Desorption of ions from the brackish water to regenerate the electrodes Capacitive deionization - Desorption.pdf
Desorption of ions from the brackish water to regenerate the electrodes

Ion adsorption in Electrical Double Layers

Any amount of charge should always be compensated by the same amount of counter-charge. For example, in an aqueous solution the concentration of the anions equals the concentration of cations. However, in the EDLs formed in the intraparticle pores in a carbon-based electrode, an excess of one type of ion over the other is possible, but it has to be compensated by electrical charge in the carbon matrix. In a first approximation, this EDL can be described using the Gouy-Chapman-Stern model, which distinguishes three different layers: [14] [15] [16]

As the carbon matrix is charged, the charge has to be compensated by ionic charge in the diffuse layer. This can be done by either the adsorption of counterions, or the desorption of co-ions (ions with an equal charge sign as the one in the carbon matrix).

Electrical Double Layer (model according to the Gouy-Chapman-Stern theory) Electrical Double Layer -.pdf
Electrical Double Layer (model according to the Gouy-Chapman-Stern theory)

Besides the adsorption of ionic species due to the formation of EDLs in the intraparticle pores, ions can form a chemical bond with the surface area of the carbon particles as well. This is called specific adsorption, while the adsorption of ions in the EDLs is referred to as non-specific adsorption. [17]

Advantages of capacitive deionization

Scalable and simple to operate

CDI has low investment and infrastructure cost, as the process discussed above does not require high pressures or temperatures, unlike membrane or thermal processes.

Low energy cost for treatment of brackish water

In CDI, the energy cost per volume of treated water scales approximately with the amount of removed salt, while in other technologies such as reverse osmosis, desalination energy scales roughly with volume of treated water. This makes CDI a viable solution for desalination of low salt content streams, or more specifically, brackish water.

Membrane capacitive deionization

By inserting two ion exchange membranes, a modified form of CDI is obtained, namely Membrane Capacitive Deionization. [13] This modification improves the CDI cell in several ways:

Capacitive deionization during the adsorption cycle Capacitive deionization - Adsorption.pdf
Capacitive deionization during the adsorption cycle
Membrane capacitive deionization during the adsorption cycle Membrane CDI.pdf
Membrane capacitive deionization during the adsorption cycle

Constant voltage vs. constant current operation mode

A CDI cell can be operated in either the constant voltage or the constant current mode.

Constant voltage operation

During the adsorption phase of CDI using constant voltage operation, the salt effluent salt concentration decreases, but after a while, the effluent salt concentration increases again. This can be explained by the fact that the EDLs (in case of a carbon-based CDI system) are uncharged at the beginning of an adsorption step, which results in a high potential difference (electrical driving force on the ions) over the two electrodes. When more ions are adsorbed in the EDLs, the EDL potential increases and the remaining potential difference between the electrodes, which drives the ion transport, decreases. Because of the decreasing ion removal rate, the effluent concentration increases again. [22] [23]

Constant current operation

Since the ionic charge transported into the electrodes is equal to the applied electric current, applying a constant current allows a better control on the effluent salt concentration compared to the constant voltage operation mode. However, for a stable effluent salt concentration membranes should be incorporated in the cell design (MCDI), as the electric current does not only induce counter-ion adsorption, but co-ion depletion as well (see Membrane capacitive deionization vs. Capacitive deionization for an explanation). [22]

Cell geometries

Flow-by mode

The electrodes are placed in a stack with a thin spacer area in between, through which the water flows. This is by far the most commonly used mode of operation and electrodes, which are prepared in a similar fashion as for electrical double layer capacitors with a high carbon mass loading.

Flow-through mode

In this mode, the feed water flows straight through the electrodes, i.e. the water flows directly through the interparticle pores of the porous carbon electrodes. This approach has the benefit of ions directly migrating through these pores, hence mitigating transport limitations encountered in the flow-by mode. [24]

An illustration of flow-electrode capacitive deionization device Flowing Capacitive Water Deionization.png
An illustration of flow-electrode capacitive deionization device

Flow-electrode capacitive deionization

This geometrical design is comparable to the flow-by mode with the inclusion of membranes in front of both electrodes, but instead of having solid electrodes, a carbon suspension (slurry) flows between the membranes and the current collector. A potential difference is applied between both channels of flowing carbon slurries, the so-called flow electrodes, and water is desalinated. Since the carbon slurries flow, the electrodes do not saturate and therefore this cell design can be used for the desalination of water with high salt concentrations as well (e.g. sea water, with salt concentrations of approximately 30 g/L). A discharging step is not necessary; the carbon slurries are, after leaving the cell, mixed together and the carbon slurry can be separated from a concentrated salt water stream. [25] [26] [27] [28]

Capacitive deionization with wires

The freshwater stream can be made to flow continuously in a modified CDI configuration where the anode and cathode electrode pairs are not fixed in space, but made to move cyclically from one stream, in which the cell voltage is applied and salt is adsorbed, to another stream, where the cell voltage is reduced and salt is released. [29]

Flow-through CDI cell during the adsorption cycle Capacitive deionization - Flow through CDI cell during adsorption.pdf
Flow-through CDI cell during the adsorption cycle
Flow-electrode CDI cell during the adsorption cycle Capacitive deionization - Flow electrode CDI cell during adsorption.pdf
Flow-electrode CDI cell during the adsorption cycle

Electrode materials

For a high performance of the CDI cell, high quality electrode materials are of utmost importance. In most cases, carbon is the choice as porous electrode material. Regarding the structure of the carbon material, there are several considerations. As a high salt electrosorption capacity is important, the specific surface area and the pore size distribution of the carbon accessible for ions should be large. Furthermore, the used material should be stable and no chemical degradation of the electrode (degradation) should occur in the voltage window applied for CDI. The ions should be able to move fast through the pore network of the carbon and the conductivity of the carbon should be high. Lastly, the costs of the electrode materials are important to take into consideration. [30]

Nowadays, activated carbon (AC) is the commonly used material, as it is the most cost efficient option and it has a high specific surface area. It can be made from natural or synthetic sources. Other carbon materials used in CDI research are, for example, ordered mesoporous carbon, carbon aerogels, carbide-derived carbons, carbon nanotubes, graphene and carbon black. [6] Recent work argues that micropores, especially pores < 1.1 nm are the most effective for salt adsorption in CDI. [31] In order to mitigate the drawbacks associated with mass transfer and electric double layer overlapping, and simultaneously harness the benefits of higher surface area and higher electric fields that come with microporous structure, innovative ongoing efforts have attempted to integrate the advantages of micropores and mesopores by fabricating hierarchical porous carbons (HPCs) that possess multi levels of porosities. [32]

However, activated carbon, at only US$4/kg for commodity carbon and US$15/kg for highly purified, specially selected supercapacitor carbon, remains much cheaper than the alternatives, which cost US$50/kg or more. Larger activated carbon electrodes are much cheaper than relatively small exotic carbon electrodes, and can remove just as much salt for a given current. The performance increase from novel carbons is insufficient to motivate their use at this point, especially since virtually all CDI applications under serious near-term consideration are stationary applications, where unit size is a relatively minor consideration. [5]

Nowadays, electrode materials based on redox-chemistry are more and more studied, such as sodium manganese oxide (NMO) and prussian blue analogues (PBA).

Energy requirements

Since the ionic content of water is demixed during a CDI adsorption cycle, the entropy of the system decreases and an external energy input is required. The theoretical energy input of CDI can be calculated as follows:

where R is the gas constant (8.314 J mol−1 K−1), T the temperature (K), Φv,fresh, the flow rate of the fresh water outflow (m3/s), Cfeed the concentration of ions in the feed water (mol/m3) and Cfresh the ion concentration in the fresh water outflow (mol/m3) of the CDI cell. α is defined Cfeed/Cfresh and β as Cfeed/Cconc, with Cconc the concentration of the ions in the concentrated outflow.

In practice, the energy requirements will be significantly higher (20 times or higher) than the theoretical energy input. [33] Important energy requirements, which are not included in the theoretical energy requirements, are pumping, and losses in the CDI cell due to internal resistances. If MCDI and CDI are compared for the energy required per removed ion, MCDI has a lower energy requirement than CDI. [22]

Comparing CDI with reverse osmosis of water with salt concentrations lower than 20 mM, lab-scale research shows that the energy consumption in kWh per m3 freshwater produced can be lower for MCDI than for reverse osmosis. [6] [34]

Large-scale CDI facilities

In 2007, a 10,000 tons per day full-scale CDI plant was built in China for improving the reclaimed water quality by ESTPURE. [35] This project enables the reduction of total dissolved solids from 1,000 mg/L to 250 mg/L and turbidity from 10 NTU to 1 NTU, a unit indicating the cloudiness of a fluid. The water recovery can reach 75%. Electrical energy consumption level is 1 kWh/m3, and the cost for water treatment is 0.22 US dollars/m3. Some other large-scale projects can be seen from the table below.

Water sourceScale (m3/d)Water recovery rateSalt removal rateEnergy consumption (kWh/m3 produced water)Reference
Municipal wastewater being treated by first and second order processes + circulating water1000075%75%1.03 [36]
Cooling water12000075%85% of Cl−0.75 [37]
Wastewater240075%≥50%1.33 [35]

Related Research Articles

<span class="mw-page-title-main">Electrochemical cell</span> Electro-chemical device

An electrochemical cell is a device that generates electrical energy from chemical reactions. Electrical energy can also be applied to these cells to cause chemical reactions to occur. Electrochemical cells that generate an electric current are called voltaic or galvanic cells and those that generate chemical reactions, via electrolysis for example, are called electrolytic cells.

<span class="mw-page-title-main">Proton-exchange membrane fuel cell</span> Power generation technology

Proton-exchange membrane fuel cells (PEMFC), also known as polymer electrolyte membrane (PEM) fuel cells, are a type of fuel cell being developed mainly for transport applications, as well as for stationary fuel-cell applications and portable fuel-cell applications. Their distinguishing features include lower temperature/pressure ranges and a special proton-conducting polymer electrolyte membrane. PEMFCs generate electricity and operate on the opposite principle to PEM electrolysis, which consumes electricity. They are a leading candidate to replace the aging alkaline fuel-cell technology, which was used in the Space Shuttle.

Electrodialysis reversal (EDR) is an electrodialysis reversal water desalination membrane process that has been commercially used since the early 1960s. An electric current migrates dissolved salt ions, including fluorides, nitrates and sulfates, through an electrodialysis stack consisting of alternating layers of cationic and anionic ion exchange membranes. Periodically, the direction of ion flow is reversed by reversing the polarity of the applied electric current.

<span class="mw-page-title-main">Electrodialysis</span> Applied electric potential transport of salt ions.

Electrodialysis (ED) is used to transport salt ions from one solution through ion-exchange membranes to another solution under the influence of an applied electric potential difference. This is done in a configuration called an electrodialysis cell. The cell consists of a feed (dilute) compartment and a concentrate (brine) compartment formed by an anion exchange membrane and a cation exchange membrane placed between two electrodes. In almost all practical electrodialysis processes, multiple electrodialysis cells are arranged into a configuration called an electrodialysis stack, with alternating anion and cation-exchange membranes forming the multiple electrodialysis cells. Electrodialysis processes are different from distillation techniques and other membrane based processes in that dissolved species are moved away from the feed stream, whereas other processes move away the water from the remaining substances. Because the quantity of dissolved species in the feed stream is far less than that of the fluid, electrodialysis offers the practical advantage of much higher feed recovery in many applications.

<span class="mw-page-title-main">Osmotic power</span> Energy available from the difference in the salt concentration between seawater and river water

Osmotic power, salinity gradient power or blue energy is the energy available from the difference in the salt concentration between seawater and river water. Two practical methods for this are reverse electrodialysis (RED) and pressure retarded osmosis (PRO). Both processes rely on osmosis with membranes. The key waste product is brackish water. This byproduct is the result of natural forces that are being harnessed: the flow of fresh water into seas that are made up of salt water.

Nanofiltration is a membrane filtration process that uses nanometer sized pores through which particles smaller than about 1–10 nanometers pass through the membrane. Nanofiltration membranes have pore sizes of about 1–10 nanometers, smaller than those used in microfiltration and ultrafiltration, but a slightly bigger than those in reverse osmosis. Membranes used are predominantly polymer thin films. It is used to soften, disinfect, and remove impurities from water, and to purify or separate chemicals such as pharmaceuticals.

Nanotube membranes are either a single, open-ended nanotube(CNT) or a film composed of an array of nanotubes that are oriented perpendicularly to the surface of an impermeable film matrix like the cells of a honeycomb. 'Impermeable' is essential here to distinguish nanotube membrane with traditional, well known porous membranes. Fluids and gas molecules may pass through the membrane en masse but only through the nanotubes. For instance, water molecules form ordered hydrogen bonds that act like chains as they pass through the CNTs. This results in an almost frictionless or atomically smooth interface between the nanotubes and water which relate to a "slip length" of the hydrophobic interface. Properties like the slip length that describe the non-continuum behavior of the water within the pore walls are disregarded in simple hydrodynamic systems and absent from the Hagen–Poiseuille equation. Molecular dynamic simulations better characterize the flow of water molecules through the carbon nanotubes with a varied form of the Hagen–Poiseuille equation that takes into account slip length.

<span class="mw-page-title-main">Double layer (surface science)</span> Molecular interface between a surface and a fluid

In surface science, a double layer is a structure that appears on the surface of an object when it is exposed to a fluid. The object might be a solid particle, a gas bubble, a liquid droplet, or a porous body. The DL refers to two parallel layers of charge surrounding the object. The first layer, the surface charge, consists of ions which are adsorbed onto the object due to chemical interactions. The second layer is composed of ions attracted to the surface charge via the Coulomb force, electrically screening the first layer. This second layer is loosely associated with the object. It is made of free ions that move in the fluid under the influence of electric attraction and thermal motion rather than being firmly anchored. It is thus called the "diffuse layer".

Gas diffusion electrodes (GDE) are electrodes with a conjunction of a solid, liquid and gaseous interface, and an electrical conducting catalyst supporting an electrochemical reaction between the liquid and the gaseous phase.

Reverse osmosis (RO) is a water purification process that uses a semi-permeable membrane to separate water molecules from other substances. RO applies pressure to overcome osmotic pressure that favors even distributions. RO can remove dissolved or suspended chemical species as well as biological substances, and is used in industrial processes and the production of potable water. RO retains the solute on the pressurized side of the membrane and the purified solvent passes to the other side. It relies on the relative sizes of the various molecules to decide what passes through. "Selective" membranes reject large molecules, while accepting smaller molecules.

The lithium–air battery (Li–air) is a metal–air electrochemical cell or battery chemistry that uses oxidation of lithium at the anode and reduction of oxygen at the cathode to induce a current flow.

Carbide-derived carbon (CDC), also known as tunable nanoporous carbon, is the common term for carbon materials derived from carbide precursors, such as binary (e.g. SiC, TiC), or ternary carbides, also known as MAX phases (e.g., Ti2AlC, Ti3SiC2). CDCs have also been derived from polymer-derived ceramics such as Si-O-C or Ti-C, and carbonitrides, such as Si-N-C. CDCs can occur in various structures, ranging from amorphous to crystalline carbon, from sp2- to sp3-bonded, and from highly porous to fully dense. Among others, the following carbon structures have been derived from carbide precursors: micro- and mesoporous carbon, amorphous carbon, carbon nanotubes, onion-like carbon, nanocrystalline diamond, graphene, and graphite. Among carbon materials, microporous CDCs exhibit some of the highest reported specific surface areas (up to more than 3000 m2/g). By varying the type of the precursor and the CDC synthesis conditions, microporous and mesoporous structures with controllable average pore size and pore size distributions can be produced. Depending on the precursor and the synthesis conditions, the average pore size control can be applied at sub-Angstrom accuracy. This ability to precisely tune the size and shapes of pores makes CDCs attractive for selective sorption and storage of liquids and gases (e.g., hydrogen, methane, CO2) and the high electric conductivity and electrochemical stability allows these structures to be effectively implemented in electrical energy storage and capacitive water desalinization.

Electrochemical regeneration of activated carbon adsorbents such as granular activated carbon present an alternative to thermal regeneration or land filling at the end of useful adsorbent life. Continuous adsorption-electrochemical regeneration encompasses the adsorption and regeneration steps, typically separated in the bulk of industrial processes due to long adsorption equilibrium times, into one continuous system. This is possible using a non-porous, electrically conducting carbon derivative called Nyex. The non-porosity of Nyex allows it to achieve its full adsorptive capacity within a few minutes and its electrical conductivity allows it to form part of the electrode in an electrochemical cell. As a result of its properties Nyex can undergo quick adsorption and fast electrochemical regeneration in a combined adsorption-electrochemical regeneration cell achieving 100% regeneration efficiency.

Electrodeionization (EDI) is a water treatment technology that utilizes DC power, ion exchange membranes, and ion exchange resin to deionize water. EDI is typically employed as a polishing treatment following reverse osmosis (RO), and is used in the production of ultrapure water. It differs from other RO polishing methods, like chemically regenerated mixed beds, by operating continuously without chemical regeneration.

<span class="mw-page-title-main">Supercapacitor</span> High-capacity electrochemical capacitor

A supercapacitor (SC), also called an ultracapacitor, is a high-capacity capacitor, with a capacitance value much higher than solid-state capacitors but with lower voltage limits. It bridges the gap between electrolytic capacitors and rechargeable batteries. It typically stores 10 to 100 times more energy per unit volume or mass than electrolytic capacitors, can accept and deliver charge much faster than batteries, and tolerates many more charge and discharge cycles than rechargeable batteries.

<span class="mw-page-title-main">Pseudocapacitance</span> Storage of electricity within an electrochemical cell

Pseudocapacitance is the electrochemical storage of electricity in an electrochemical capacitor known as a pseudocapacitor. This faradaic charge transfer originates by a very fast sequence of reversible faradaic redox, electrosorption or intercalation processes on the surface of suitable electrodes. Pseudocapacitance is accompanied by an electron charge-transfer between electrolyte and electrode coming from a de-solvated and adsorbed ion. One electron per charge unit is involved. The adsorbed ion has no chemical reaction with the atoms of the electrode since only a charge-transfer takes place.

There are many water purifiers available in the market which use different techniques like boiling, filtration, distillation, chlorination, sedimentation and oxidation. Currently nanotechnology plays a vital role in water purification techniques. Nanotechnology is the process of manipulating atoms on a nanoscale. In nanotechnology, nanomembranes are used with the purpose of softening the water and removal of contaminants such as physical, biological and chemical contaminants. There are variety of techniques in nanotechnology which uses nanoparticles for providing safe drinking water with a high level of effectiveness. Some techniques have become commercialized.

A microbial desalination cell (MDC) is a biological electrochemical system that implements the use of electro-active bacteria to power desalination of water in situ, resourcing the natural anode and cathode gradient of the electro-active bacteria and thus creating an internal supercapacitor. Available water supply has become a worldwide endemic as only .3% of the Earth's water supply is usable for human consumption, while over 99% is sequestered by oceans, glaciers, brackish waters, and biomass. Current applications in electrocoagulation, such as microbial desalination cells, are able to desalinate and sterilize formerly unavailable water to render it suitable for safe water supply. Microbial desalination cells stem from microbial fuel cells, deviating by no longer requiring the use of a mediator and instead relying on the charged components of the internal sludge to power the desalination process. Microbial desalination cells therefore do not require additional bacteria to mediate the catabolism of the substrate during biofilm oxidation on the anodic side of the capacitor. MDCs and other bio-electrical systems are favored over reverse osmosis, nanofiltration and other desalination systems due to lower costs, energy and environmental impacts associated with bio-electrical systems.

Voltea is a water technology company based in Dallas, Texas.

The Iron Redox Flow Battery (IRFB), also known as Iron Salt Battery (ISB), stores and releases energy through the electrochemical reaction of iron salt. This type of battery belongs to the class of redox-flow batteries (RFB), which are alternative solutions to Lithium-Ion Batteries (LIB) for stationary applications. The IRFB can achieve up to 70% round trip energy efficiency. In comparison, other long duration storage technologies such as pumped hydro energy storage provide around 80% round trip energy efficiency.

References

  1. 1 2 Qi, Zhaoxiang; Koenig, Gary M. (July 2017). "Review Article: Flow battery systems with solid electroactive materials". Journal of Vacuum Science & Technology B, Nanotechnology and Microelectronics: Materials, Processing, Measurement, and Phenomena. 35 (4): 040801. Bibcode:2017JVSTB..35d0801Q. doi: 10.1116/1.4983210 . ISSN   2166-2746.
  2. 1 2 Biesheuvel, P.M.; Bazant, M.Z.; Cusick, R.D.; Hatton, T.A.; Hatzell, K.B.; Hatzell, M.C.; Liang, P.; Lin, S.; Porada, S.; Santiago, J.G.; Smith, K.C.; Stadermann, M.; Su, X.; Sun, X.; Waite, T.D.; van der Wal, A.; Yoon, J.; Zhao, R.; Zou, L.; Suss, M.E. (2017). "Capacitive Deionization -- defining a class of desalination technologies [OPEN ACCESS]". arXiv: 1709.05925 [physics.app-ph].
  3. ↑ D. Atoufi, Hossein; Hasheminejad, Hasti; Lampert, David J. (2020). "Performance of activated carbon coated graphite bipolar electrodes on capacitive deionization method for salinity reduction". Frontiers of Environmental Science & Engineering. 14 (6): 99. doi:10.1007/s11783-020-1278-1. ISSN   2095-221X. S2CID   219590425 – via Springer Nature.
  4. ↑ Suss, M.E.; Porada, S.; Sun, X.; Biesheuvel, P.M.; Yoon, J.; Presser, V. (2015). "Water desalination via capacitive deionization: what is it and what can we expect from it? [OPEN ACCESS]". Energy Environ. Sci. 8 (8): 2296. doi: 10.1039/C5EE00519A .
  5. 1 2 Weinstein, Lawrence; Dash, R. (2013). "Capacitive Deionization: Challenges and Opportunities". Desalination & Water Reuse.
  6. 1 2 3 4 Porada, S.; Zhao, R.; Wal, A. van der; Presser, V.; Biesheuvel, P.M. (2013). "Review on the science and Technology of Water Desalination by Capacitive Deionization [OPEN ACCESS]". Progress in Materials Science. 58 (8): 1388–1442. doi: 10.1016/j.pmatsci.2013.03.005 .
  7. 1 2 Anderson, M.A.; Cudero, A.L.; Palma, J. (2010). "Capacitive deionization as an electrochemical means of saving energy and delivering clean water. Comparing to present desalination practices: Will it compete?". Electrochimica Acta. 55 (12): 3845–3856. doi:10.1016/j.electacta.2010.02.012.
  8. ↑ "CDI & electrosorption".
  9. ↑ Blair, J.W.; Murphy, G.W. (1960). "Electrochemical demineralization of Water with Porous Carbon Electrodes of Large Surface Area". Advances in Chemistry. 27. Washington D.C.: U.S. Dept. of the Interior.
  10. ↑ Reid, G.W. (1968). "Field operation of a 20 gallons per day pilot plant unit for electrochemical desalination of brackish water". Research and development progress report. 293. Washington D.C.: U.S. Dept. of the Interior.
  11. ↑ Johnson, A.M.; Newman, J. (1971). "Desalting by means of porous carbon electrodes". Journal of the Electrochemical Society. 118 (3): 510–517. Bibcode:1971JElS..118..510J. doi:10.1149/1.2408094.
  12. ↑ Farmer, J.C.; Fix, D.V.; Mack, G.W.; Pekala, R.W.; Poco, J.F. (1996). "Capacitive deionization of NaCl and NaNO3 solutions with carbon aerogel electrodes". Journal of the Electrochemical Society. 143 (1): 159–169. Bibcode:1996JElS..143..159F. doi:10.1149/1.1836402.
  13. 1 2 USpatent 6709560,Marc D. Andelman&Gregory D. Walker,"Charge barrier flow-through capacitor", assigned to Voltea Ltd
  14. ↑ Kirby, B.J. "The diffuse structure of the electrical double layer". Archived from the original on 2019-08-27. Retrieved 2013-08-02.
  15. ↑ "Britannica - Electrical Double Layer".
  16. ↑ "TDA Research - Capacitive deionization". Archived from the original on 2012-03-05. Retrieved 2013-08-02.
  17. ↑ Ibach, H. (2006). Physics of Surfaces and Interfaces. Springer-Verlag.
  18. 1 2 3 Li, H.; Gao, Y.; Pan, L.; Zhang, Y.; Chen, Y.; Sun, Z. (2008). "Electrosorptive desalination by carbon nanotubes and nanofibres electrodes and ion-exchange membranes". Water Research. 42 (20): 4923–4928. doi:10.1016/j.watres.2008.09.026. PMID   18929385.
  19. 1 2 3 Kim, Y.; Choi, J. (2010). "Enhanced desalination efficiency in capacitive deionization with an ion-selective membrane". Separation and Purification Technology. 71 (1): 70–75. doi:10.1016/j.seppur.2009.10.026.
  20. 1 2 3 Zhao, R.; van Soestbergen, M.; Rijnaarts, H.H.M.; van der Wal, A.; Bazant, M.Z.; Biesheuvel, P.M. (2012). "Time-dependent ion selectivity in capacitive charging of porous electrodes". Journal of Colloid and Interface Science. 384 (1): 38–44. Bibcode:2012JCIS..384...38Z. doi:10.1016/j.jcis.2012.06.022. hdl: 1721.1/101160 . PMID   22819395. S2CID   12916467.
  21. ↑ Lee, J.B.; Park, K.; Eum, H.; Lee, C. (2006). "Desalination of a thermal power plant wastewater by membrane capacitive deionization". Desalination. 196 (1): 125–134. doi:10.1016/j.desal.2006.01.011.
  22. 1 2 3 Zhao, R.; Biesheuvel, P.M.; van der Wal, A. (2012). "Energy consumption and constant current operation in membrane capacitive deionization". Energy & Environmental Science. 5 (11): 9520–9527. doi:10.1039/c2ee21737f.
  23. ↑ Kim, T.; Dykstra, J.E.; Porada, S; van der Wal, A.; Yoon, J.; Biesheuvel, P.M. (2014). "Enhanced energy and charge efficiencies by increasing the discharge voltage in capacitive deionization". Journal of Colloid and Interface Science. 446: 317–326. Bibcode:2015JCIS..446..317K. doi:10.1016/j.jcis.2014.08.041. PMID   25278271.
  24. ↑ Suss, M.E.; Baumann, T.F.; Bourcier, W.L.; Spadaccini, C.M.; Rose, K.L.; Santiago, J.G.; Stadermann, M. (2012). "Capacitive desalination with flow-through electrodes". Energy & Environmental Science. 5 (11): 9511–9519. doi:10.1039/c2ee21498a.[ permanent dead link ]
  25. ↑ Jeon, S.; Park, H.; Jeo, Y.; Yang, S.; Cho, C.H.; Han, M.H.; Kim, D.K. (2013). "Desalination via a new membrane capacitive deionization process utilizing flow-electrodes". Energy & Environmental Science. 6 (5): 1471–1475. doi:10.1039/c3ee24443a.
  26. ↑ Hatzell, Kelsey; Iwama, Etsuro; Ferris, Anais; Daffos, Barbara; Urita, Koki; Tzedakis, Theodore; Chauvet, Fabien; Taberna, Pierre-Louis; Gogotsi, Yury; Simon, Patrice (2014). "Capacitive deionization concept based on suspension electrodes without ion exchange membranes" (PDF). Electrochemical Communications. 43 (43): 18–21. doi:10.1016/j.elecom.2014.03.003.
  27. ↑ Porada, S; Weingarth, D; Hamelers, H.V.M; Bryjak, M; Presser, V; Biesheuvel, P.M. (2014). "Carbon flow electrodes for continuous operation of capacitive deionization and capacitive mixing energy generation". Journal of Materials Chemistry A. 2 (24): 9313–9321. doi: 10.1039/c4ta01783h .
  28. ↑ Hatzell, Kelsey B.; Hatzell, Marta C.; Cook, Kevin M.; Boota, Muhammad; Housel, Gabrielle; McBride, Alex; Gogotsi, Yury (2015). "Effect of Oxidation of Carbon Material on Suspension Electrodes for Flow Electrode Capacitive Deionization". Environmental Science and Technology. 49 (5): 3040–3047. Bibcode:2015EnST...49.3040H. doi:10.1021/es5055989. OSTI   1265345. PMID   25633260.
  29. ↑ Porada, S.; Sales, B. B.; Hamelers, H. V. M.; Biesheuvel, P. M. (2012). "Water Desalination with Wires". The Journal of Physical Chemistry Letters. 3 (12): 1613–1618. doi:10.1021/jz3005514. PMID   26285717.
  30. ↑ Oren, Y. (2008). "Capacitive deionization (CDI) for desalination and water treatment — past, present and future (a review)". Desalination. 228 (1): 10–29. doi:10.1016/j.desal.2007.08.005.
  31. ↑ Porada, S.; Borchardt, L.; Oschatz, M.; Bryjak, M.; Atchison, J. S.; Keesman, K. J.; Kaskel, S.; Biesheuvel, P. M.; Presser, V. (2013). "Direct prediction of the desalination performance of porous carbon electrodes for capacitive deionisation [OPEN ACCESS]". Energy & Environmental Science. 6 (12): 3700. doi: 10.1039/c3ee42209g .
  32. ↑ Baroud, Turki N.; Giannelis, Emmanuel P. (November 2018). "High salt capacity and high removal rate capacitive deionization enabled by hierarchical porous carbons". Carbon. 139: 614–625. doi:10.1016/j.carbon.2018.05.053. ISSN   0008-6223. S2CID   103081318.
  33. ↑ Hemmatifar, Ali; Ramachandran, Ashwin; Liu, Kang; Oyarzun, Diego I.; Bazant, Martin Z.; Santiago, Juan G. (2018-08-24). "Thermodynamics of Ion Separation by Electrosorption". Environmental Science & Technology. 52 (17): 10196–10204. arXiv: 1803.11532 . Bibcode:2018EnST...5210196H. doi:10.1021/acs.est.8b02959. ISSN   0013-936X. PMID   30141621. S2CID   4683315.
  34. ↑ Zhao, R.; Porada, S.; Biesheuvel, P.M.; van der Wal, A. (December 2013). "Energy consumption in membrane capacitive deionization for different water recoveries and flow rates, and comparison with reverse osmosis". Desalination. 330: 35–41. doi:10.1016/j.desal.2013.08.017. S2CID   94423625.
  35. 1 2 ESPURE. "A chemical wastewater reuse and quality promotion project in Shanxi". Archived from the original on 2013-12-03.
  36. ↑ ESTPURE. "Inner Mongolia power group water recycling project". Archived from the original on 2013-12-03.
  37. ↑ ESTPURE. "A water reclaimed water plant upgrade project in Ningbo, Zhejiang". Archived from the original on 2013-12-02.
This page is based on this Wikipedia article
Text is available under the CC BY-SA 4.0 license; additional terms may apply.
Images, videos and audio are available under their respective licenses.