Degradation of a Concentrated Sodium Ethylenediaminetetraacetate Aqueous Solution by Electric-Discharge Treatment

摘要

The disodium salt of ethylenediaminetetraacetic acid (Trilon B) is one of the most nondegradable components of surfactants used to clean up the structural elements of nuclear power plants. The spent solution (boiler chemical cleaning waste) contains organic compounds, basically Trilon B (COD of 3 g O/l or greater), sodium carbonate (50-500 g/l), and radioactive substances. The pH of the solution is 12-14. To utilize the solution, the radioactive substances are first isolated. The isolation is impeded by organic compounds present in the solution, since they form hardly extractable complexes with radioactive elements; thus, the utilization of chemical cleaning waste encounters the problem of lowering the COD to a level below 50 mg O/l [1].