Water-soluble metalworking fluids such as cutting fluids and quenching fluids are frequently renewed. This is because such fluids are generally used in the environment in which oxidation and corruption are likely to occur, causing the deterioration of their performance, an offensive odor, etc. Since these metalworking fluids contain environment load substances, the costly waste disposal is necessary. Therefore, the establishment of such recycling and life-lengthening technologies is required to reduce the waste liquid quantity. The offensive odor given with the corruption of water-soluble cutting fluids is often caused by the organic acid that the bacteria discharges. Also, the accumulation of the organic acid by the corruption of the fluids is estimated to cause the deterioration in the quenching performance of the quenching fluids. Noticing the usefulness of the electrodialysis method, we have developed a system which removes the organic acid efficiently using the anion exchange membrane. At the same time as the dialysis, this system allows complete disinfection of the corruption bacteria, making it possible to recycle the water-soluble metalworking fluids and lengthen their life. In the future, its application to various kinds of manufacturing processes is expected to diminish the waste fluid of water-soluble metalworking fluids.
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