To prevent clogging of fine holes due to reaction of a solid material by installing a pH adjusting means in a regenerating system of waste water for separating into the solid material and the water by passing the waste water in which the solid material is incorporated through the fine holes.
In the system, the pH adjusting means 12 for measuring the pH of waste water and controlling to the desired pH is attached. The waste water measured in the pH is controlled to the desired pH by adding a chemical showing alkalinity or acidity corresponding to the pH value of the waste water. Particularly in scrap of silicon, the waste water is adjusted to a neutral side or acidic side to prevent generation of a gel-like or colloidal material to prevent the clogging of the filter.
IINUMA HIROFUMI
TAKAGAWA TEIJI
