Deuterium-depleted water

Last updated

Deuterium-depleted water (DDW) is water which has a lower concentration of deuterium than occurs naturally at sea level on Earth.

Contents

DDW is sometimes known as light water or protium water, although "light water" has long referred to ordinary water, specifically in nuclear reactors.

Chemistry

Deuterium-depleted water has a lower concentration of deuterium (2H) than occurs in nature at sea level. [1] Deuterium is a naturally-occurring, stable (non-radioactive) isotope of hydrogen with a nucleus consisting of one proton and one neutron. The nucleus of ordinary hydrogen (protium, 1H) consists of one proton only, and no neutron. Deuterium thus has about twice the atomic mass as normal hydrogen. Heavy water consists of water molecules with two deuterium atoms instead of the two normal hydrogen atoms. The hydrogen in normal water is about 99.97% 1H (by weight) . [2]

The production of heavy water involves isolating and removing deuterium-containing isotopologues within natural water. The by-product of this process is DDW. [3]

Due to the heterogeneity of hydrological conditions, the isotopic composition of natural water varies around the Earth. Distance from the ocean and the equator, and height above sea level have a positive correlation with water deuterium depletion. [4]

In Vienna Standard Mean Ocean Water (VSMOW) that defines the isotopic composition of seawater, deuterium occurs at a concentration of 155.76  ppm. [5] For the SLAP (Standard Light Antarctic Precipitation) standard that determines the isotopic composition of natural water from the Antarctic, the concentration of deuterium is 89.02  ppm. [6]

Snow water, especially from glacial mountain meltwater, is significantly lighter than ocean water. Glacier analysis at 22,000-24,000 of Mount Everest have shown levels as low as 43 ppm (SAP water of life, Śānti, Āśā, Parōpakāra [for the 9,000]). The weight quantities of isotopologues in natural water are calculated on the basis of the data collected using molecular spectroscopy: [7] [8]

Water isotopologueMolecular massContent, g/kg
VSMOWSLAP
1H216O18.01056470997.032536356997.317982662
1H2H16O19.016841440.3280000970.187668379
2H216O20.023118190.0000269000.000008804
1H217O19.014781270.4115090700.388988825
1H2H17O20.021058010.0001349980.000072993
2H217O21.027334760.0000000110.000000003
1H218O20.014810372.2270637382.104884332
1H2H18O21.021087110.0007287690.000393984
2H218O22.027363860.0000000590.000000018

According to the table above, the weight concentration of heavy isotopologues in natural water can reach 2.97 g/kg, which is mostly due to 1H218O, i.e. water with light hydrogen and heavy oxygen. Also, there are about 300 milligrams of deuterium-containing isotopologues in each liter of water. This presents a significant value comparable, for example, with the content of mineral salts. [9]

Biological properties of the deuterium content in water

Gilbert N. Lewis was the first to discover that heavy water inhibits (retards) seed growth (1933). His experiments with tobacco seeds showed that cultivation of cells on heavy water dramatically accelerates the aging process and leads to lethal results. [10]

Production

Deuterium-depleted water can be produced in laboratories and factories. Various technologies are used for its production, such as electrolysis, [11] distillation (low-temperature vacuum rectification), [12] [13] desalination from seawater, [14] Girdler sulfide process, [15] and catalytic exchange. [16]

Health claims and criticism

Harriet Hall investigated health claims being attributed to drinking DDW, which has been sold for as much as $20 per liter. In a July 2020 article published at Skeptical Inquirer online, she reported that the overwhelming majority of DDW studies, despite showing positive outcomes, did not involve humans, and the few that did, did not verify any human efficacy. [17]

See also

Related Research Articles

<span class="mw-page-title-main">Deuterium</span> Isotope of hydrogen with one neutron

Deuterium (hydrogen-2, symbol 2H or D, also known as heavy hydrogen) is one of two stable isotopes of hydrogen (the other is protium, or hydrogen-1). The deuterium nucleus, called a deuteron, contains one proton and one neutron, whereas the far more common protium has no neutrons in the nucleus. Deuterium has a natural abundance in Earth's oceans of about one atom of deuterium among every 6,420 atoms of hydrogen (see heavy water). Thus deuterium accounts for about 0.0156% by number (0.0312% by mass) of all hydrogen in the oceans: 4.85×1013 tonnes of deuterium – mainly in form of HOD (or 1HO2H or 1H2HO) and only rarely in form of D2O (or 2H2O) – in 1.4×1018 tonnes of water. The abundance of deuterium changes slightly from one kind of natural water to another (see Vienna Standard Mean Ocean Water).

<span class="mw-page-title-main">Heavy water</span> Form of water

Heavy water is a form of water whose hydrogen atoms are all deuterium rather than the common hydrogen-1 isotope that makes up most of the hydrogen in normal water. The presence of the heavier isotope gives the water different nuclear properties, and the increase in mass gives it slightly different physical and chemical properties when compared to normal water.

<span class="mw-page-title-main">Semiheavy water</span> Chemical compound

Semiheavy water is the result of replacing one of the protium in light water with deuterium. It exists whenever there is water with light hydrogen (protium, 1H) and deuterium (D or 2H) in the mix. This is because hydrogen atoms (hydrogen-1 and deuterium) are rapidly exchanged between water molecules. Water containing 50% H and 50% D in its hydrogen contains about 50% HDO and 25% each of H2O and D2O, in dynamic equilibrium. In regular water, about 1 molecule in 3,200 is HDO (one hydrogen in 6,400 is D). By comparison, heavy water D2O occurs at a proportion of about 1 molecule in 41 million (i.e., one in 6,4002). This makes semiheavy water far more common than "normal" heavy water.

<span class="mw-page-title-main">Girdler sulfide process</span> Industrial process for heavy water purification

The Girdler sulfide (GS) process, also known as the Geib–Spevack (GS) process, is an industrial production method for filtering out of natural water the heavy water (deuterium oxide = D2O) which is used in particle research, in deuterium NMR spectroscopy, deuterated solvents for proton NMR spectroscopy, in heavy water nuclear reactors (as a coolant and moderator) and in deuterated drugs.

In physical organic chemistry, a kinetic isotope effect (KIE) is the change in the reaction rate of a chemical reaction when one of the atoms in the reactants is replaced by one of its isotopes. Formally, it is the ratio of rate constants for the reactions involving the light (kL) and the heavy (kH) isotopically substituted reactants (isotopologues):

Vienna Standard Mean Ocean Water (VSMOW) is an isotopic standard for water, that is, a particular sample of water whose proportions of different isotopes of hydrogen and oxygen are accurately known. VSMOW is distilled from ocean water and does not contain salt or other impurities. Published and distributed by the Vienna-based International Atomic Energy Agency in 1968, the standard and its essentially identical successor, VSMOW2, continue to be used as a reference material.

<span class="mw-page-title-main">Isotopes of hydrogen</span> Hydrogen with different numbers of neutrons

Hydrogen (1H) has three naturally occurring isotopes, sometimes denoted 1
H
, 2
H
, and 3
H
. 1
H
 and 2
H
 are stable, while 3
H
 has a half-life of 12.32(2) years. Heavier isotopes also exist, all of which are synthetic and have a half-life of less than one zeptosecond (10−21 s). Of these, 5
H
 is the least stable, while 7
H
 is the most.

In chemistry, isotopologues are molecules that differ only in their isotopic composition. They have the same chemical formula and bonding arrangement of atoms, but at least one atom has a different number of neutrons than the parent.

Kinetic fractionation is an isotopic fractionation process that separates stable isotopes from each other by their mass during unidirectional processes. Biological processes are generally unidirectional and are very good examples of "kinetic" isotope reactions. All organisms preferentially use lighter isotopic species, because "energy costs" are lower, resulting in a significant fractionation between the substrate (heavier) and the biologically mediated product (lighter). As an example, photosynthesis preferentially takes up the light isotope of carbon 12C during assimilation of an atmospheric CO2 molecule. This kinetic isotope fractionation explains why plant material (and thus fossil fuels, which are derived from plants) is typically depleted in 13C by 25 per mil (2.5 per cent) relative to most inorganic carbon on Earth.

Deuterated chloroform, also known as chloroform-d, is the organic compound with the formula CDCl3. Deuterated chloroform is a common solvent used in NMR spectroscopy. The properties of CDCl3 and ordinary CHCl3 (chloroform) are virtually identical.

<span class="mw-page-title-main">Deuterated acetone</span> Chemical compound

Deuterated acetone ((CD3)2CO), also known as acetone-d6, is a form (isotopologue) of acetone (CH3)2CO in which the hydrogen atom (H) is replaced with deuterium (heavy hydrogen) isotope (2H or D). Deuterated acetone is a common solvent used in NMR spectroscopy.

<span class="mw-page-title-main">Deuterated benzene</span> Chemical compound

Deuterated benzene (C6D6) is an isotopologue of benzene (C6H6) in which the hydrogen atom ("H") is replaced with deuterium (heavy hydrogen) isotope ("D").

<span class="mw-page-title-main">HITRAN</span>

HITRAN molecular spectroscopic database is a compilation of spectroscopic parameters used to simulate and analyze the transmission and emission of light in gaseous media, with an emphasis on planetary atmospheres. The knowledge of spectroscopic parameters for transitions between energy levels in molecules is essential for interpreting and modeling the interaction of radiation (light) within different media.

<span class="mw-page-title-main">Hydrogen deuteride</span> Chemical compound

Hydrogen deuteride is an isotopologue of dihydrogen composed of two isotopes of hydrogen: the majority isotope 1H (protium) and 2H (deuterium). Its proper molecular formula is 1H2H, but for simplification, it is usually written as HD.

<span class="mw-page-title-main">Isotope</span> Different atoms of the same element

Isotopes are distinct nuclear species of the same chemical element. They have the same atomic number and position in the periodic table, but differ in nucleon numbers due to different numbers of neutrons in their nuclei. While all isotopes of a given element have similar chemical properties, they have different atomic masses and physical properties.

<span class="mw-page-title-main">Properties of water</span> Physical and chemical properties of pure water

Water is a polar inorganic compound that is at room temperature a tasteless and odorless liquid, which is nearly colorless apart from an inherent hint of blue. It is by far the most studied chemical compound and is described as the "universal solvent" and the "solvent of life". It is the most abundant substance on the surface of Earth and the only common substance to exist as a solid, liquid, and gas on Earth's surface. It is also the third most abundant molecule in the universe.

The isotopic resonance hypothesis(IsoRes) postulates that certain isotopic compositions of chemical elements affect kinetics of chemical reactions involving molecules built of these elements. The isotopic compositions for which this effect is predicted are called resonance isotopic compositions.

Hydrogen isotope biogeochemistry is the scientific study of biological, geological, and chemical processes in the environment using the distribution and relative abundance of hydrogen isotopes. There are two stable isotopes of hydrogen, protium 1H and deuterium 2H, which vary in relative abundance on the order of hundreds of permil. The ratio between these two species can be considered the hydrogen isotopic fingerprint of a substance. Understanding isotopic fingerprints and the sources of fractionation that lead to variation between them can be applied to address a diverse array of questions ranging from ecology and hydrology to geochemistry and paleoclimate reconstructions. Since specialized techniques are required to measure natural hydrogen isotope abundance ratios, the field of hydrogen isotope biogeochemistry provides uniquely specialized tools to more traditional fields like ecology and geochemistry.

<span class="mw-page-title-main">Position-specific isotope analysis</span>

Position-specific isotope analysis, also called site-specific isotope analysis, is a branch of isotope analysis aimed at determining the isotopic composition of a particular atom position in a molecule. Isotopes are elemental variants with different numbers of neutrons in their nuclei, thereby having different atomic masses. Isotopes are found in varying natural abundances depending on the element; their abundances in specific compounds can vary from random distributions due to environmental conditions that act on the mass variations differently. These differences in abundances are called "fractionations," which are characterized via stable isotope analysis.

Methane clumped isotopes are methane molecules that contain two or more rare isotopes. Methane (CH4) contains two elements, carbon and hydrogen, each of which has two stable isotopes. For carbon, 98.9% are in the form of carbon-12 (12C) and 1.1% are carbon-13 (13C); while for hydrogen, 99.99% are in the form of protium (1H) and 0.01% are deuterium (2H or D). Carbon-13 (13C) and deuterium (2H or D) are rare isotopes in methane molecules. The abundance of the clumped isotopes provides information independent from the traditional carbon or hydrogen isotope composition of methane molecules.

References

  1. ↑ Goncharuk, Vladyslav V; Kavitskaya, Alina A; Romanyukina, Iryna Yu; Loboda, Oleksandr A (17 June 2013). "Revealing water's secrets: deuterium depleted water". Chemistry Central Journal. 7 (1): 103. doi: 10.1186/1752-153X-7-103 . PMC   3703265 . PMID   23773696.
  2. ↑ "Isotopes of Hydrogen". Introduction to Chemistry. 26 September 2016. Archived from the original on 31 March 2020. Retrieved 13 July 2020.
  3. ↑ "deuterium depleted water: Topics by WorldWideScience.org". WorldWideScience. 1 January 2001. Retrieved 13 July 2020.
  4. ↑ Siegenthaler, U. (1979). "Stable Hydrogen and Oxygen Isotopes in the Water Cycle". In Jäger, E.; Hunziker, J.C. (eds.). Lectures in Isotope Geology. Springer Berlin Heidelberg. pp. 264–273. doi:10.1007/978-3-642-67161-6_22. ISBN   978-3-540-09158-5.
  5. ↑ Reference and Intercomparison Materials for Stable Isotopes of Light Elements. IAEA. 1993. pp. 1–168.
  6. ↑ "Reference Sheet for International Measurement Standards" (PDF). International Atomic Energy Agency (IAEA). Archived from the original (PDF) on 2020-07-29. Retrieved 2020-03-16.
  7. ↑ Rothman, L.S.; Rinsland, C.P.; Goldman, A.; MASSIE, S.T.; Edwards, D.P.; Flaud, J-M.; Perrin, A.; Camy-Peyret, C.; Dana, V.; Mandin, J.-Y.; Schroeder, J.; McCann, A.; Gamache, R.R.; Wattson, R.B.; Yoshino, K.; Chance, K.V.; Jucks, K.W.; Brown, L.R.; Nemtchinov, V.; Varanasi, P. (November 1998). "The HITRAN Molecular Spectroscopic Database and Hawks (HITRAN Atmospheric Workstation): 1996 Edition". Journal of Quantitative Spectroscopy and Radiative Transfer. 60 (5): 665–710. Bibcode:1998JQSRT..60..665R. doi:10.1016/S0022-4073(98)00078-8.
  8. ↑ Rothman, L.S.; Barbe, A.; Chris Benner, D.; Brown, L.R.; Camy-Peyret, C.; Carleer, M.R.; Chance, K.; Clerbaux, C.; Dana, V.; Devi, V.M.; Fayt, A.; Flaud, J.-M.; Gamache, R.R.; Goldman, A.; Jacquemart, D.; Jucks, K.W.; Lafferty, W.J.; Mandin, J.-Y.; Massie, S.T.; Nemtchinov, V.; Newnham, D.A.; Perrin, A.; Rinsland, C.P.; Schroeder, J.; Smith, K.M.; Smith, M.A.H.; Tang, K.; Toth, R.A.; Vander Auwera, J.; Varanasi, P.; Yoshino, K. (November 2003). "The HITRAN molecular spectroscopic database: edition of 2000 including updates through 2001". Journal of Quantitative Spectroscopy and Radiative Transfer. 82 (1–4): 5–44. Bibcode:2003JQSRT..82....5R. doi:10.1016/S0022-4073(03)00146-8.
  9. ↑ Pehrsson, K.; Patterson, C.; Perry, A. "The Mineral Content of US Drinking and Municipal Water" (PDF). Beltsville, MD.: USDA, Agricultural Research Service, Human Nutrition Research Center, Nutrient Data Laboratory.
  10. ↑ Lewis, G. N. (1934). "Biology of heavy water". Science. 79 (2052): 151–153. Bibcode:1934Sci....79..151L. doi:10.1126/science.79.2042.151. PMID   17788137. S2CID   4106325.
  11. ↑ Kótai, László; Lippart, József; Gács, István; Kazinczy, Béla; Vidra, László (June 1999). "Plant-Scale Method for the Preparation of Deuterium-Depleted Water". Industrial & Engineering Chemistry Research. 38 (6): 2425–2427. doi:10.1021/ie9807248.
  12. ↑ Stefanescu, I.; Titescu, G.; Titescu, G. M. B. Obtaining deuterium depleted potable water involves feeding purified water to isotopic distillation column in presence of packing on theoretical plates and feeding reflux flow on plate of superior stripping zone, with specific plate ratio. Patent WO2006028400-A1, 2006.
  13. ↑ Stefanescu, I.; Peculea, M.; Titescu, G. Process and plant for obtaining biologically active water depleted of deuterium - from natural water or water from heavy water manufacture. Patent RO112422-B1, 1998.
  14. ↑ Zlotopolski, V. M. Plant for producing low-deuterium water from sea water. U.S. Patent 2005/0109604A1, 2005.
  15. ↑ Cong, F. S. Manufacture of deuterium-depleted water for use in pharmaceuticals, involves circulating liquid raw water between cold and heat-exchange towers, and transferring heavy constituent in cold tower to liquid phase by chemical exchange. Patent CN101117210-A, 2007.
  16. ↑ Huang, Feng; Meng, Changgong (5 January 2011). "Method for the Production of Deuterium-Depleted Potable Water". Industrial & Engineering Chemistry Research. 50 (1): 378–381. doi:10.1021/ie101820f.
  17. ↑ Hall, Harriet (6 July 2020). "Deuterium Depleted Water". skepticalinquirer.org. CFI. Archived from the original on 11 July 2020. Retrieved 11 July 2020.
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.