Reducing the potential for migration of radioactive waste: Aqueous thermal degradation of the chelating agent disodium edta

摘要: Abstract Ethylenediaminetetraacetic acid (EDTA), a common component of cleaning solutions used for decontamination radioactive equipment, has been associated with increased migration radionuclides into local groundwaters at some radwaste disposal sites. It proposed that predisposal thermal degradation EDTA-containing aqueous may reduce the potential chelate-enhanced mobilization these Aqueous experiments disodium EDTA have shown compound degrades rapidly 200°C (half-life 1.1 ± 0.41 hours), an activation energy 114.3 7.87 kJ/mol, and forms decomposition product methyliminodiacetic (MIDA). A comparison values stability constants transition metal actinide complexes EDTA, MIDA, two other reported products, iminodiacetic (IDA) hydroxyethyliminodiacetic (HEIDA), indicates chelating efficiency products is 6 to 22 orders magnitude lower than 25°C. In addition, researchers primary decarboxylate 265°C, which should eliminate their capability. concluded significantly overall solutions.