PURPOSE: To well separate and recover an acid and alkali without damaging an anion exchange membrane by successively treating an alkaline waste solution of sulfate by an ion exchange membrane electrodialytic apparatus using an alkali-resistant monovalent anion permselective membrane and an ion exchange membrane electrodialytic apparatus using a bipolar membrane.
CONSTITUTION: In an ion exchange membrane electrodialytic apparatus A constituted by combining a cation exchange membrane 1 and an alkali-resistant monovalent anion permselective membrane 2, an alkaline waste solution of sulfate is treated to remove alkali. Next, in an ion exchange membrane electrodialytic apparatus B constituted by successively combining a cation exchange membrane 11, a bipolar membrane 10 and an anion exchange membrane 12, the alkali removed waste solution of sulfate is treated to separate and recover an acid and alkali. As a result, an acid and alkali can be well separated and recovered from the alkaline waste solution of sulfate without disposing said waste solution.
HANADA FUMIO
HIRAYAMA HIROKI
