Popis: |
As a part of the fundamental research work for radioactive iodine removal in the reprocessing of spent fuel from a nuclear reactor, the reduction reaction of iodate ion by nitrous acid was experimentally examined in an aqueous acidic solution with a spectrophotometer. The overall reaction is as follows: 2IO3-+5HNO2+2H+→I2+5HNO3+H2O. In this reaction, there exists an induction period when production of iodine is very slow. The reaction is accelerated by the produced iodine, and finally the whole iodate ion is converted into iodine, though the rate is fairly small. The overall auto-catalytic production rate of iodine was formulated and the temperature dependency of the reaction rate constant was determined. The resulting activation energy was 61.6kJ·mol-1. |