A win-win strategy for the reclamation of waste acid and conversion of organic acid by a modified electrodialysis

In view of some inherent problems, such as the high mobility of protons and low dissociation degrees of organic acid, the conventional electrodialysis technology must be improved before being applied widely in the related fields. In this work, a win-win strategy for simultaneously reclaiming industrial waste acid and producing organic acid by ion substitution electrodialysis (ISED) was put forward. Above all, the ISED technology was further investigated, including its universality and work performance influenced by the membrane selection. Subsequently, a modified ISED was developed and applied in the conversion of acetic acid using the simulated waste acid effluent as proton source. The experiments indicated that a much better work performance, including improved current efficiency and conversion rate and reduced energy consumption, can be achieved when compared to the conventional technology. Especially, it was observed that the content of electro-migrated metal ions in the produced organic acid was so low that a high purity organic acid product can be easily obtained after a simple post-treatment.