MINERAL ADSORBENT OF TRITIUM BASED ON SAPONITE AND ZEOLITE А
The paper is a result of the experimental research which was performed on the potential usage of saponite-zeolite composites as mineral membranes for adsorption of tritium out of tritiated water. It was found that the rate of filtration of the aqueous solution through a saponite-zeolite membrane decreased slightly during the first thirteen days. Afterwards the filtration process stabilized at a rate of 0.5-0.4 cm per day. A decrease of specific radioactivity of tritium in the filtration product by 17% after 41 days of filtration through an 80 mm saponite-zeolite membrane was observed. The filtration process happened in stages. Initially superficially adsorbed H2O moved into the aqueous solution from the membrane and was replaced by HTO, thus reducing specific radioactivity of the solution. Then the molecular exchange between HTO and H2O in the inter-layer space and isotope-hydrogen exchange in the structural position of OH-groups of the clay material came into effect. After 41 days of filtration the saturation of tritium in the composite was not observed. The researched composite can be used to decrease of specific radioactivity of tritium aqueous solutions by filtering it through a saponite-zeolite membrane. Keywords: saponite-zeolite composite, tritiated water, membrane, filtration, adsorption.