Electrochemical Oxidation in Aqueous Solutions of Organic Complexing Agents and Surfactants

The electrochemical oxidation (ECO) of aqueous solutions of organic complexing agents [ethylenediaminetetraacetic acid (EDTA), nitrilotriacetic acid (NTA), diethylenetriaminepentaacetic acid (DTPA)] and surfactants [sodium dodecylbenzenesulfonate (anionic surfactant) and OP-10 (nonionic surfactant)] was studied using a flow-through modular electrochemical element MB-11T-06. It is shown that the degree of their oxidation reaches 95% during the ECO of complex ions solutions. The introduction of chloride ions up to 1 g/dm 3 into the initial solutions increases the ECO rate of complex ions by about 3 times. ECO of surfactant solutions in the presence of 1 g/dm 3 chloride ions removes more than 99% of anionic surfactants and about 85% of nonionic surfactants. Electrochemical treatment of solutions containing complex ions and chloride ions increases the efficiency of sorption purification of solutions from 137 Cs radionuclides on the FNS ferrocyanide sorbent by 1–2 orders of magnitude and from 152 Eu on sulfonic acid cation exchange resin by 4–5 orders of magnitude. The efficiency of 152 Eu co-precipitation with iron(III) hydroxide after ECO increases by 3 orders of magnitude. The conclusion was drawn that the ECO method is highly promising for removing various organic complexing agents and surfactants from aqueous solutions, as well as from liquid radioactive waste.