Patent EA-000170-B1 (EA)
Title: Method for processing oils and solvents contaminated by radioactive substances and device therefor
IPC: G21F9/10
Filed: 1996-02-12
Abstract: 1. Method for processing oils and solvents contaminated by radioactive substances comprising a step of influencing by selected micro organisms upon said oils and solvents in the presence of air and excessive amount water towards the volume said oils and solvents to be treated, wherein said micro-organisms are able to destroy organic molecules, in particular, to transform them into CO2 and H2O, characterized in that the process additionally includes the following steps: a) a predetermined volume of water is provided which has predetermined characteristics as to the content of dissolved oxygen, pH and REDOX potential; b) to said water volume is added a predetermined charge of oils and solvents contaminated by radioactive substances, said charge corresponding to a volume of oils and solvents which is a predetermined fraction of the predetermined water volume; c) said charge is subjected to the action of micro-organisms at a predetermined temperature and duration; d) at least part of the effluent obtained is taken; e) the water is separated from the materials contained in such effluent; f) the materials separated from said water are recycled or evacuated; g) the water free of materials contained in the effluent is regenerated so that it recovers said predetermined characteristics; h) at least part of said regenerated water is recycled; i) the cycle from the step a) is repeated. 2. Method according to Claim 1,characterized in that the predetermined volume of regenerated water is taken, actually corresponding to the volume of a new charge of oils and solvents, contaminated by radioactive substances. 3. Method according to Claim 1 or 2, characterized in that mineral supports are used for micro organisms to fix at least part of metals, present in the charge, using ion exchange. 4. Method according to Claim 3, characterized in that said mineral supports comprise alumosilicate, zeolites, or calcium carbonate. 5. Method according to any of the preceding Claims, characterized in that the sediment, obtained at step e), is recycled to step c). 6. Method according to any of the preceding Claims, characterized in that water from said effluent is evaporated, and water, regenerated after evaporation and condensation is used at step g). 7. Method according to Claim 6, characterized in that the residue after evaporation is regenerated and dried in a fluidized bed. 8. Method according to Claim 3,or other depending on it Claim characterized in that at the end of the operation mineral supports (4), comprising radioactive metals are separated. 9. Method according to any of the preceding Claims characterized in that micro organism and the required for them nutritious substances are fed into water, having a predetermined temperature and characteristics so as to provide reactivation and development of said micro organisms in water, and said water is fed to step c). 10. Method according to any of the preceding Claims characterized in that at step g) water, from which substances, present in said effluent, are taken out, further regenerated to restore the following characteristics: dissolved oxygen - about 3 mg/l pH - about from 6.9 to 7.1 REDOX potential - more -150 mv, preferably positive (to 70 mv). 11. Device (1) to realize said method according to any of the preceding Claims characterize in that said device comprises: storage tank (3) for receiving and storing of predetermined water volume and predetermined charge of oils and solvents, contaminated by radioactive substances, and means for air injection into said storage tank (3); means (11, 5) for taking out and receiving at least part of obtained effluent; means (7) for water separation from substances contained in said effluent; means (14, 25) for recycling or evacuation of said substances contained in said effluent; means (19) for water regeneration, from which said substances, contained in said effluent, are taken out; means for recycling of at least part of regenerated water; 12. Device according to Claim 11 characterized in that means for water separation from substances, contained in effluent, comprise means (7) of said effluent clarification by flocculation. 13. Device according to Claim 11 or 12 characterized in that said device comprises means (8) of water vacuum evaporation from said effluent. 14. Device according to any Claims of 11-13 characterized in that said device comprises: preliminary mixer (2) for receiving a predominated water volume, a predominated charge of oils and solvents and also micro organisms; first reactor (3) for receiving at least part of mixture from said mixer (2) and micro organisms; second reactor (5) for receiving said mixture from said first reactor (3) means (6, 20, 21) for air injection into said preliminary mixer (2) and into each of reactors (3, 5); a clarifier (7) for separation of substances, contained in said mixture coming out from said second reactor (5); an evaporator (8) and a condenser (9) for water regeneration from effluent, coming out from said clarifier. 15. Device according to any Claims of 11-14 characterized in that said device comprises means for drying of said substance, using said fluidized bed. 16. Device according to any Claims of 11-15 characterized in that all components of said device are installed in a hermetically sealed reservoir (28). 17. Device according to Claim 16 characterized in that said reservoir (28) is covered by a hermetically sealed casing (29), and provided with a system (30) of ventilation and filtering of air taken out from said device to maintain slightly lowered pressure.