ammonia , particularly aqueous ammonia is sequestered in unexpected large amounts on zeolite molecular sieves having high proportions of silica with respect to alumina in their crystal frameworks . while conventional adsorption mechanisms are to some degree involved , it is apparent from the fact that the characteristic odor of ammonia is not detectable by the human sense of smell over the ammonia - loaded adsorbents indicates that other mechanisms are operable . these properties provide the basis for processes and products which are useful in removing ammonia from an environment to alleviate health hazards or unpleasant odor .