The kinetics of biological reactions depends on the deuterium/protium (D/H) ratio in water. In this work, we describe the kinetic model of biocatalytic reactions in living organisms depending on the D/H ratio. We show that a change in the lifetime or other characteristics of the vital activity of some organisms in response to a decrease or increase in the content of deuterium in the environment can be a sign of a difference in taxons. For animals—this is a curve with saturation according to the Gauss’s principle, for plants—it is the Poisson dependence, for bacteria a weakly saturated curve with a slight reaction to the deuterium/protium ratio toward increasing deuterium. The biological activity of the aquatic environment with reduced, elevated, and natural concentrations of deuterium is considered. The results of the study are presented in different vital indicators of some taxons: the bacteria kingdom—the colony forming units (CFU) index (Escherichia coli); animals—the activation energy of the death of ciliates (Spirostomum ambiguum), embryogenesis of fish (Brachydanio rerio); plants—germination and accumulation of trace elements Callisia fragrans L., sprouting of gametophores and peptidomics of moss Physcomitrella patens. It was found that many organisms change their metabolism and activity, responding to both high and low concentrations of deuterium in water.

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The results of the comparative study of the effect of the method for structured packing pretreat ment (CY type Sulzer packing and rolled ribbon screw packing) on the effectiveness of mass exchange in the course of hydrogen isotope exchange in water rectification and its phase isotope exchange (PIE) are given. The latter process is used for the removal of tritiated water vapors from gases and its difference from rectifi cation involves that the irrigation density of packing by water is 50-150 times less under other comparable process conditions. This difference leads to the fact that, for the packings prepared from stainless steel, the coefficient of mass transfer ratio for two boundary cases, namely, its preliminary flooding by water or launch of column with dry packing, is nearly 50 for PIE and 2 for rectification. The use of CY type Sulzer packing for PIE process prepared from oxidized copper yields that this ratio for PIE becomes identical with rectifica tion. Based on the obtained results, the recommendations for the optimization of PIE column startup are given.

Counter-current processes, based on heterogeneous isotope-exchange reactions in a gas-liquid system, have become widely used for separating the isotopes of light elements [1]. However, considerable thermodynamic isotope effects are also observed in a system with a solid phase. They can be explained both by chemical isotope exchange reactions between two different substances and by physical sorption, which leads to thermodynamic nonequivalence of the isotopes in gas molecules and in such molecules adsorbed by the solid phase. The first case is characteristic for hydrogen isotope exchange in systems consisting of molecular hydrogen and hydride-forming metals or their intermetallic compounds with transition metals [2]. Irrespective of the nature of the isotope effect, the ways of achieving the counter-current separation of isotopes in systems with a solid phase and the fundamental factors that govern the efficiency of the operation of separatioa equipment are common to both.The purpose of this paper is to investigate isotope effects and the physical features of the thermodynamics of isotope exchange in gas-solid-phase systems, and also the factors which govern the efficiency of the counter-current separation of isotopes using a method we have proposed, which can be realized both under laboratory conditions and on a pilot-plant scale.The system considered in this paper is the most interesting for solving the ecological problems of tritium in nuclear power, and also for setting up fuel cycles in thermonuclear reactors.When separating mixtures of hydrogen isotopes containing tritium, one needs to use working materials which are not subjected to radiolysis due to the action of tritium radiation. The choice of the gaseous phase in such a system is obviousit is molecular hydrogen, characterized by high radiation stability and also having the greatest relative mass difference of isotopic varieties. Note that tritium in the form of molecular hydrogen is approximately 400 times less toxic than in the form of water vapor (in the air of working environments DK A is equal to 7.4.104 and 1.8" 102 Bq/liter for HT and HTO, respectively [3]).For a system with molecular hydrogen the solid phases that are stable to radiolysis, which reversibly absorb hydrogen, are of the greatest interest as the other working substance. Such materials are primarily hydride-forming metals and intermetallic compounds.The Concentrational Dependence of the Separation Factor, The quantitative characteristic of thermodynamic isotope effects is the separation factor, defined by the ratio c~ = x(1 -y)/y(1 -x), where x and y are the atomic fraction of the heavy isotope in the solid and the gaseous phase, respectively. In the majority of cases the solid phase is enriched with the heavy isotope. Some metals (Pd and Ti) and intermetallic compounds (TiCo, TiFe, TiNi, Mg2Ni), are an exception.The formation of the hydride phase of a metal or of intermetallic compounds is usually accompanied by dissociation of the hydrogen molecules on the surface and the implantati...

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