ammonification - impregnation with ammonia or a compound of ammonia

carbonation - saturation with carbon dioxide (as soda water)

diffusion - (physics) the process of diffusing; the intermingling of molecules in gases and liquids as a result of random thermal agitation

saturation, impregnation - the process of totally saturating something with a substance; "the impregnation of wood with preservative"; "the saturation of cotton with ether"