| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a disposal method for carrying out reductive decomposition of nitric acid by an organic reducing agent, which can reduce a nitrogen concentration in the waste to a dischargeable level by decomposing nitrate-nitrogen and ammonium-nitrogen in the waste without using a catalyst. <P>SOLUTION: The disposal method carries out reductive decomposition of nitric acid ions by the organic reducing agent by adding the organic reducing agent to the nitric acid waste, and is characterized by that dissolved matter which inhibits decomposition reaction of the nitric acid ions is removed in advance, and/or action which inhibits decomposition reaction is suppressed to accelerate the reductive decomposition of the nitric acid ions. For example, the dissolved matter generating reductive elimination of nitrous acid is oxidized and removed in advance, and then the organic reducing agent is added, or an acid concentration of the whole waste is increased and generation of the nitrous acid is promoted. Thereby, a nitrate-nitrogen concentration exceeds an ammonium-nitrogen concentration so that the reductive decomposition of the nitric acid ions is promoted. <P>COPYRIGHT: (C)2012,JPO&INPIT</p> |
