Fixation of various pollutants in a monolithic porous alumina.

Ultraporous monoliths of hydrated alumina, prepared at room temperature by atmospheric air oxidation of aluminium, dan fix various gaseous phases, for instance up to 1.25 kg hydrogen chloride per kg. The material porosity rem ains high after heating at 1200-1300 degreesC. Then, this alumina can be im pregnated by aqueous solutions of various salts, which result in oxides aft er drying and calcination. These oxides are confined within the material. F or instance, 1 kg monolith can contain more than 2 kg cerium oxide, which s erves as a model for the behaviour of transuranium element oxides (PuO2, Ac O2) contained in radioactive waste.