| 摘要 |
PURPOSE:To efficiently remove polyalkylene oxide from liquid waste, by adding an excess amount of a salt to the liquid waste of a chemical plating solution containing polyalkylene oxide to liberate said polyalkylene oxide. CONSTITUTION:An excess amount of a salt, e.g. sulfate, cupric salt or chloride, is added to the liquid waste of a chemical plating solution containing polyalkylene oxide in addition to Cu, Ni, Au, Ag, Pd, Sn or the like, to separately liberate said polyalkylene oxide by salting out. The salt to be added to the liquid waste of the chemical plating solution is pref. an inorganic one from a standpoint on COD and BOD, esp. sulfate such as sodium or potassium sulfate. The addition amount of said salt is 400g sodium sulfate, for instance, based on 1l of the chemical plating solution to form a saturated solution. Hence, most of the polyethylene glycol is liberated.
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