| 摘要 |
PROBLEM TO BE SOLVED: To evade the problem of the closure of an oxidizing agent supply port in the lower part of a reaction column and to enable the stable continuous operation for a long period of time by using the sodium hydrogencarbonate existing in the state of liquid at around a decomposition treatment temp. as a catalyst when PCB (polychlorinated biphenyl) is subjected to a decomposition treatment. SOLUTION: In the case of the hot hydrolysis of the PCB, the sodium hydrogencarbonate is formed by reacting sodium hydroxide and the PCB is subjected to the decomposition treatment by using the catalyst system contg. the sodium hydrogencarbonate. Other catalyst components contributing to the PCB decomposition reaction, such as sodium carbonate, may be incorporated in addition to the sodium hydrogencarbonate into the catalyst system. At the time of the decomposition treatment, the amt. of the sodium hydroxide is so regulated as to attain 6.0 to 11.0 in pH at ordinary temp. and the sodium hydroxide is preferably supplied in this amt. to the reaction column. As a result, the changing of the main catalyst is made possible simply by regulating the pH to change the prescribed equi. conditions and, therefore, there is no need for changing a supply material even when the method is switched from a method using the sodium carbonate as the main catalyst.
|
