| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a method for treating a nitric acid waste solution where the high decomposition rate of nitrate nitrogen can be attained under relatively mild conditions without requiring expensive catalysts and severe treating conditions such as high temperature-high pressure. <P>SOLUTION: The method for decomposing the component of nitric acid by adding an organic reducing agent to a nitric acid waste solution is characterized in that inorganic acid is added, and reaction is progressed in such a manner that the concentration of the acid upon the end of the decomposition treatment lies in the range from 0.3N to 1.0N, preferably, from 0.3N to 0.5N. It is preferable that the amount of the organic reducing agent to be added lies in the range from an amount equivalent to 1.0 time the amount of nitrate nitrogen in the waste solution to an amount equivalent to 1.5 times that, the inorganic acid is added before the treatment or under the treatment, heating is performed to a temperature at which boiling is not caused under ordinary pressure, and the organic reducing agent is gradually added in accordance with the generating conditions of gaseous nitrogen oxide, so as to decompose the component of nitric acid. <P>COPYRIGHT: (C)2006,JPO&NCIPI</p> |
