A method for increasing the removal efficiency of radio nuclides using acetic acid and sodium acetate on dicomtaminating the soil contaminated radio nuclides by electrokinetic method

摘要

PURPOSE: A method for removing radioactive species is provided which enables remediation of soil contaminated with radionuclides as well as contaminated soil of heavy metal mine and chemical plants by using buffer solution of acetic acid and sodium acetate in electrokinetics, thereby suppressing increase of pH and improving decontamination efficiency. CONSTITUTION: In remedying soil contaminated with radionuclides by electrokinetics, the method comprises the processes of injecting the mixture into cylindrical soil column having a ratio of cross sectional diameter to column length of 1:5 to 7 by hardening the mixture in the soil column so that pores are not generated after preparing a mixture by injecting a buffer solution of 0.01 to 0.05 M of acetic acid (CH3COOH) and sodium acetate (CH3COONa) into contaminated soil and mixing the buffer solution and contaminated soil; installing filter paper at both front ends of the soil column; injecting 0.01 to 0.05 M of sodium acetate solution into the anode reservoir at one side of the soil column, and agitating the acetic acid solution and mixture of contaminated soil and buffer solution as continuously injecting 5 to 15 M of acetic acid solution into the cathode reservoir at the other side of the soil column from the upper side so that soil cleaning waste liquid and solution are discharged to the lower part of the cathode reservoir into which acetic acid solution is flown; and supplying current of 0.05 to 0.5 mA into the soil column to move the radionuclides to the cathode reservoir by ion migration and electro-osmosis, thereby lowering pH inside the soil column to 5 or less so that formation of hydroxide precipitate is prevented so as to improve removal efficiency of the radionuclides.