Transport of ions of pyrophosphoric acid through chemically different anion-exchange membranes

Characteristics of mass transport of the anions of pyrophosphoric acid are investigated during electrodialysis through MA-40 and MA-41 anion-exchange membranes. It is established that the rate of mass transport for counterions is greater through the MA-41 membrane than the MA-40 membrane, and thus the former can be used for demineralizing solutions with salts of pyrophosphoric acid. Higher selectivity to pyrophosphate ions is found for the MA-40 membrane compared to the MA-41 membrane in the electrodialysis of mixtures of pyrophosphate and hydropyrophosphate ions, and thus the MA-40 membrane can be regarded as promising for the separation of such mixtures.