| 摘要 |
PURPOSE:To easily and efficiently carry out a 2nd treatment by adding a barium salt to the titled waste solution, and by effecting a solid-liquid separation to separate a liquid and a precipitate, followed by carrying out the 2nd treatment of the separated solution. CONSTITUTION:The barium salt is added to the titled waste solution, and the solid-liquid separation is carried out to separate the precipitate and the liquid, and the separated liquid is carried out the 2nd treatment. Namely, if the barium salt such as BaCl2, etc. is added to the titled solution, an org. acid contd. in the photographic processing waste solution is reacted with for example, sodium thiosulfate to form a salt, and precipitates for example, barium thiosulfate, barium silver thiosulfate, barium sulfate and barium carbonate, etc. The component which does not react with the barium salt or the component which does not form a precipitatable salt, even in case of reacting, is separated as a liquid (a supernatant) having low BOD value and COD value in a dissolved state. The usable barium salt is exemplified by preferably BaCl2, Ba(NO3)2, BaBr2, BaI2, and BaO, etc. |
