# The Impact of Tritium in the Environment
## 5 Isotopic Effects of Hydrogen in Living and Inanimate Matter
### The Phenomenon of Isotope Osmosis  
Osmosis is the phenomenon of the spontaneous movement of a solvent towards equalization of concentrations across a semipermeable membrane separating solutions of different concentrations. The normal functioning of the cells of living organisms occurs thanks to osmotic processes. For the first time, the phenomenon of isotope osmosis was observed through a clay membrane that separated light (protium) and super-heavy (tritiated) water (Figure 11). Even though the mass difference between the molecules of protonated (H\({}_{2}\)O) and tritiated (HTO) water is small (m\({}_{\text{H2O}}\)/m\({}_{\text{HTO}}\) = 0.9), an equilibrium distribution of tritium was established between the liquid and gaseous phases of water, which is different from uniform. This distribution was temperature-dependent and was determined by the difference in vapor pressure between the tritium and protium water. Subsequently, an isotope-osmotic effect was found for other membranes [109]. The isotope osmosis processes studied in greenhouse experiments on plants growing in tritiated water led to a significant (up to 40%) fractionation of hydrogen isotopes in solutions separated by wildlife membranes (Figure 12). At the same time, the heavy isotope was  
Figure 11: Visualization of isotopic osmosis effect: 1—protium water, 2—bentonite membrane, 3—tritiated water, 4—level of the isotope osmosis pressure. removed from the system, i.e., the processes of \"isotope osmosis\" through plant membranes contributed to the purification of the water environment from tritium. The isotope-osmotic effects of the separation of protium and tritium through membranes made from living matter open perspectives for the development of biotechnology for the phytoremediation of semi-natural reservoirs from tritium contamination. The phytoremediation technique uses plants to remediate contaminated environments, including soil and water, by utilizing biochemical processes that can transform or decompose toxic compounds (rhizo-degradation, phytodegradation), accumulate chemical elements (phytoextraction, rhizo-filtration), disperse compounds (phyto-vaporization), and immobilize compounds (hydraulic control and phyto-stabilization) [110]. Given that the aqueous form of tritium (HTO, with an absolute content of the superheavy isotope orders of magnitude less than nano concentrations) is the most abundant and migrating substance on the planet in both the gaseous and liquid phases, effective, environmentally safe, and economical methods of tritium remediation are still unknown. A lot of literature data show that the content of tritium in living matter and the surrounding liquid and gaseous aquatic environment is strongly correlated [89; 90]. Most sources claim that the main specie of tritium in living matter (75-95%) is HTO. However, in areas affected with a direct impact of tritiated water vapor emissions into the atmosphere and discharges into the hydrosphere, the effect of tritium accumulation in an organically bound form can often be observed. For the first time, such an anomaly was observed in the biotic components of an aquatic ecosystem receiving liquid wastewater from complex nuclear facilities located in Mol (BE). The specific activity of tritium incorporated in organic matter was 20 times that observed in river water. This unexpected observation contradicts the results of experiments in laboratory aquariums, in which tritium was present in the form of HTO [89]. The study of the tritium content in biotic levels of a wetland ecosystem near the \"Radon\" radioactive waste storage facility in Kiev (UKR) showed a similar effect: the \({}^{3}\)H/\({}^{1}\)H fractionation ratio reached 18.3 [46]. Subsequently, in a greenhouse experiment, it was demonstrated this discrepancy was explained by the kinetics of tritium assimilation and dissimilation in the tissues of living organisms.