METHOD OF TREATING WASHING AQUEOUS SOLUTION AND METHOD OF WASHING METAL SUBSTRATE USING THE AQUEOUS SOLUTION

摘要

PROBLEM TO BE SOLVED: To provide a method of treating a washing aqueous solution for removing metal ions eluted into the washing aqueous solution from the piping of a washing apparatus without specifying eluted ions and replacing the piping, in the treatment of the aqueous solution used for washing a metal substrate, especially an aluminum substrate used for manufacturing magnetic recording medium. SOLUTION: This treatment method is performed so as to bring the washing aqueous solution into contact with the same member as the metal substrate to remove metal ions contained in the aqueous solution eluted from piping. That is, the washing aqueous solution is brought into contact with a metal member to precipitate metal ions having an ionization tendency smaller than the member included in the aqueous solution on the surface of the member to remove them. COPYRIGHT: (C)2004,JPO