METHOD FOR CLEANING LIQUID WASTES FROM IONS OF HEAVY METALS AND THEIR RADIOACTIVE ISOTOPES Russian patent published in 1999 - IPC

FIELD: decontamination and recovery of liquid wastes containing toxic and radioactive pollutants to prevent their emission into surrounding atmosphere. SUBSTANCE: method involves electrochemical treatment of liquid wastes by oxidizing complex compounds of heavy metals and radioactive isotopes contained in them by means of electrodes using nonconsumable electrode as anode and gas-diffusion one, as cathode, this procedure being followed by joint sedimentation of ions of heavy metals and their radioactive isotopes with collectors, separation of slurry phase, and production of clean solution. Collectors are produced by electrochemical treatment of solution obtained due to oxidation of wastes using consumable anode and gas-diffusion cathode. Electrochemical treatment is effected at anode current density of at least 0.1 A/sq.dm and at oxygen partial pressure across gas-diffusion cathode not lower than 0.2. Liquid wastes having salt content of 5 to 500 g/cu.dm can be effectively cleaned of heavy metals and their radioactive isotopes in the environment of organic and inorganic complexing agents. EFFECT: improved degree of decontamination; provision for eliminating unwanted electrochemical reactions causing emission of explosive and fire-hazard electrolytic gases and nonproductive power consumption. 3 cl, 4 tbl, 3 ex