| 摘要 |
<p>PURPOSE:To recover sulfurous acid and sulfite from bisulfite as the aq. soln. respectively by using an electrodialyzer in which a bipolar membrane and an anion-exchange membrane are alternately arranged. CONSTITUTION:Compartments separated by a bipolar membrane B and an anion-exchange membrane A are formed between an anode 1 and a cathode 2, aq. sulfurous acid soln. 6 is supplied to the compartment as an acid compartment 3 with the bipolar membrane B on the anode 1 side, and aq. bisulfite soln. 5 is supplied to the compartment as an alkali compartment 4 with the bipolar membrane B on the cathode 2 side. The bisulfite ion in the compartment 4 is permeated through the membrane A and moved into the acid compartment 3, and the bisulfite ion reacts with the hydrogen ion supplied from the membrane B in the acid compartment 3 according to equation I to form sulfurous acid. The residual bisulfite ion not permeated through the membrane A reacts with the hydroxide ion supplied from the membrane B in the compartment 4 according to equation II to form sulfite ion. The sulfurous acid is recovered as aq. sulfurous acid soln. 7 and the sulfite ion as aq. sulfite soln 8.</p> |
