METHOD OF REDUCING AMMONIA CONCENTRATION IN LIQUID RADIOACTIVE WASTES Russian patent published in 2015 - IPC G21F9/00 

FIELD: chemistry.

SUBSTANCE: invention relates to means of treating liquid radioactive wastes, specifically to processing ammonia-containing liquid radioactive wastes. The disclosed method of reducing ammonia concentration in liquid radioactive wastes includes stripping radioactive wastes in alkaline conditions and secondary stripping of the formed condensate in acidic conditions in the presence of a nitrite. The nitrite solution is used in concentration of 150-800 g/dm³ and in an amount which is 10-50% higher than the stoichiometric amount on the reaction for oxidising ammonia to nitrogen, fed into a container with ammonia-containing liquid radioactive wastes, followed by holding for 3-24 hours. The condensate fed for secondary stripping is additionally fed into a container with an ammonia condensate. The liquid radioactive wastes and the ammonia condensate with nitrite are mixed.

EFFECT: high efficiency of removing ammonia from liquid radioactive wastes, low consumption of reagents for filter regeneration, low amount of liquid radioactive wastes, low volumes of re-evaporated solutions and energy resources and reagents spent on evaporation.

3 cl, 1 dwg