III International Conference

PP-III-38HETEROGENEOUS-CATALYTIC DECOMPOSITION OF EDTA ON CARBONICMATERIALS IN NITRATE MEDIUMJeleznov V.V., Avramenko V.А., Dobrzansky V.G., Dmitrieva E.E., Mashkovsky A.,Sokolnickay T.A.Institute of Chemistry, Far-Eastern Branch Russian Academy of Science, Vladivostok, RussiaE-mail: kafitul@ich.dvo.ruThe research of degradation of EDTA on carbonic materials - Sibunite and carbonactivated fibres ANM is carried out. The influence on degradation of temperature and acidityof medium is studied. The rate constants and activation energy of reactions are determined.The problems of processing liquid radioactive wastes often require preliminary removalof a number of organic and inorganic compounds - activated complexons, oxalic acid,hydrazine, hydronitric and nitric acids. Use of catalytic oxidation - reduction processes ismore preferable to their removal, as they do not increase volumes of radioactive waste. In thereview [1] the example of use of activated charcoals and Pt/Si as catalysts of decompositioncomplexons is given.Work is directed on definition of ANM catalytic properties for process of EDTAoxidation in cube residue with the purpose of extraction of radioactive nuclides, and alsocomparison ANM with known catalysts (BAC, Sibunite).As a result of research it is stated, that for temperatures 50, 60 and 72 ºС rate constants onANM are 0,0653, 0,1469, 0,283 min -1 , respectively. Upon the comparison of these rateconstants with constants for the activated carbon of mark - BAC [2], it is obvious, that theyare similar: so for BAC at 60 0 С the rate constant is equal 0,138 min -1 , and for ANM thisvalue is equal to 0,147 min -1 .For Sibunite rate constants of reaction for the same temperatures have values muchlower: 0,0131, 0,0264, 0,0774 min -1 . Thus mass ratio solid/liquid (S/L) for ANM and forSibunite is two orders lower, than for BAC. For Sibunite the presence of a latent site ismarked, when degradation of EDTA is not fixed. The size of a latent site depends fromacidity of medium.Dependences of the rate constants of reaction for ANM and Sibunite from temperatureare given in figures 1, 2.541