Nanostructured ceramic membranes for hydrogen isotope separation

Methods and systems directed to the separation of a heavy hydrogen isotope, e.g., tritium, from an aqueous stream are described. The methods and systems incorporate a separation media that includes a proton conducting ceramic that at low temperatures preferentially adsorbs heavy hydrogen isotopes and at high temperature preferentially adsorbs lighter heavy hydrogen isotopes. The methods can be temperature controlled to sequentially purify a contaminated stream and regenerate the separation media. The separation media can be free of traditional hydrogen isotope exchange catalyst materials.