| 摘要 |
<p>This invention aims at providing a method of treating a waste liquor from a final water washing tank used in the cation electrodeposition painting, which method is capable of reutilizing the waste liquor as final water washing water by recovering the waste liquor without discarding the same. A method of treating a waste liquor from a final water washing tank, characterized by the steps of separating the waste liquor, which is discharged from the final water washing tank, into a raw painting material-containing condensed liquid and a filtrate by using a semi-permeable membrane while maintaining the waste liquor pH not higher than 6.4 at all times in a condensation tank, returning the whole or a part of the filtrate to the final water washing tank, and reusing this filtrate as final water washing cleaning water.</p> |
