| 摘要 |
PROBLEM TO BE SOLVED: To shorten the processing time required for disposal of solution having been used for forming a ferrite film. SOLUTION: A film forming device is connected to a pipe system for film formation. Chemistry decontamination of the pipe inner surface of the pipe system is carried out. After the completion of the decontamination, film forming aqueous solution to be used for ferrite film formation (containing organic acid solution containing iron (II) ion, oxidizer, and pH adjustor) is adjusted in temperature, and the ferrite film is formed on the pipe inner surface. The method for treating the used film forming aqueous solution (waste liquid) after the ferrite film formation is as follows. Solid particles contained in the waste liquid is removed by a filter. A pH adjustor (hydrazine) is injected into the waste liquid so that the pH of the waste liquid circulating in a place for film formation (for example, recirculating system pipe). Iron (II) ions contained in the waste liquid are removed by cation-exchange resin while the pH is maintained and organic acid (formic acid) contained in the waste liquid is decomposed using the oxidizer and catalyst. COPYRIGHT: (C)2009,JPO&INPIT
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