| 摘要 |
PURPOSE:To separate and recover efficiently high concn. acid and alkali from an aqueous salt soln. by electrolyzing the soln. with an anion exchange membrane contg. fluorine and having a special structure and a cation exchange membrane contg. fluorine. CONSTITUTION:An aqueous salt soln. such as industrial waste liquor is electrolyzed in an electrolytic cell provided with an anion exchange membrane and a cation exchange membrane as diaphragms to produce an aqueous acid soln. in the anode chamber and an aqueous alkali soln. in the cathode chamber. When the acid and alkali are separated from the aqueous salt soln. as mentioned above, a cation exchange membrane contg. fluorine is used as the cation exchange membrane and an anion exchange membrane contg. fluorine and made of a copolymer having repeating units represented by the formula is used as the anion exchange membrane. In the formula, X is F or CF3, l is 0 or an integer of 1-5, m is 0 or 1, n is an integer of 1-5, each of p and q is a positive number, the ratio of p/q is 2-16 and Y is a quat. ammonium group. The durability of the anion exchange membrane is increased and restrictions on the kind of salt, the concn. of acid and the electrolytic temp. are eliminated. |
