Method for separating and recovering an acid.

摘要

A method for separating and recovering an acid, which comprises contacting to one side of a diffusion dialysis membrane an acid solution containing an acid having an acid radical with a formula weight of at most 200 and impurities and to the other side of the membrane water or a dilute acid solution, to separate and recover the acid in the solution, wherein the diffusion dialysis membrane comprises a cation exchange membrane having certain specific properties or comprises a main layer of an anion exchanger and a surface layer of the cation exchange membrane having certain specific properties formed on the main layer at the side of which is contact with the acid solution.