Deuterium content of natural waters

In the heavy-water plants constmcted at Savannah River and at Dana, these considerations led to designs in which the relatively economical GS process was used to concentrate the deuterium content of natural water to about 15 mol %. Vacuum distillation of water was selected (because there is Httle likelihood of product loss) for the additional concentration of the GS product from 15 to 90% D2O, and an electrolytic process was used to produce the final reactor-grade concentrate of 99.75% D2O. 

Friedman 1. (1953) Deuterium content of natural waters and other substances. Geochim. Cosmochim. Acta 4, 89-103. 

Friedman I., Redfield A. C., Schoen B., and Harris J. (1964) The variation of the deuterium content of natural waters in the hydrologic cycle. Rev. Geophys. 2, 177-224. 

The deuterium content of natural waters varies from place to place and from time to time because of isotopic fractionation which occurs when water evaporates from land or sea or is condensed from the air. The deuterium content of natural waters relative to standard water samples has been determined by a number of investigators representative results of two workers are abstracted in Table 13.1. The percent differences from standards have been converted to atom percent deuterium by using the indicated deuterium content of the standards, which, however, are less accurately known than the differences. 

The examples of this table have been selected to illustrate the variability of the deuterium content of natural waters. Actually, over large parts of the earth where conditions of precipitation are comparatively uniform and evaporation of groundwater unimportant, the variability is much less. For example, the deuterium content of river and lake waters in the... 

These relationships are independent of the yeast strain and of the fermentation temperature, within normal limits. Typical values of the parameters for natural wines are (D/H), 102 ppm, (D/H)n 131 ppm, (D/H), 160 ppm, (D/H)w — 155 ppm. The deuterium content of methyl and methylene sites is greatly reduced with respect to glucose and starting water, but (D/H), is about 5 times more sensitive to the (D/H) ratio of the glucose than to the starting water, whereas (D/H)n depends almost entirely on the starting water. 

Analysis of the increased deuterium production made possible through use of supplementary hot water feed will be made by reference to Fig. 13.35. Here it is assumed that the flow rate of supplementary feed F to the top of stage number of the hot tower and the product rate P are so adjusted that the deuterium content of water flowing from stage rtg -I-1 to stage ng equals that of natural water feed Xp, to prevent mixing loss at the supplementary... 

Figure 13.40 Material flow sheet for first stage of Sulzer dual-temperature methylamine-hydrogen exchange heavy-water process. [AT] = deuterium content of hydrogen relative to natural water containing 135 ppm. Flow quantities, kg-mol/h.

Because the variation in equilibrium ratio is rather small, there is only a small difference in deuterium concentrations between the feedwater entering the top of the cold tower and the water leaving the hot tower. In practice, about 17% of natural water s deuterium content can be extracted, compared with the 50% that would be possible if a monothermal process were practicable. This further raises the already large mass of water that a G-S plant must process to about 37,000-times the product, including allowance for heavy water being 10% heavier than normal water. In consequence, G-S plants are very large (Figure 4.7). 

HEAVY WATER. Winer in which the hydrogen of the water molecule consists entirely of the heavy hydrogen isotope of muse 2 (deuterium I. Wrinen D>0 Density, 1.1076 at 20 degrees C. It is used us a moderator in certain types of nuclear reactors. The term is someiiines applied to water whose deuterium content is greater than natural water See uko Nuclear Power Technology. 

Fishman and Erdmann (1971) have recently reviewed the topic of water analysis. Among the infrared methods mentioned were the following the use of internal reflection spectroscopy for the analysis of optically opaque samples the determination of total carbon in waste waters the quantitative determination of total CO2 in sea water the determination of the deuterium content in water the use of spectra of hydrocarbon fractions from the acid part of organic substances in natural waters and the use of infrared for the identification of organic substances in water. 

In vivo deuterium ( H) MRS has been used to characterize amino acid metabolism, body iron content, brain and kidney metabolism and body fat utilization rates in rodents. These studies rely on the use of deuterium labelling or the existence of natural-abundance deuterium in water or lipids. For example, deuterium-labelled methionine was used to confirm the dominant contribution of the glycine/ sarcosine shuttle to the metabolism of excess methionine, while deuterium-labelled glucose was used to show that systemic glucose level influences brain... 

---