Recovery of hydrochloric acid from simulated chemosynthesis aluminum foils wastewater: An integration of diffusion dialysis and conventional electrodialysis

Diffusion dialysis (DD) and conventional electrodialysis (CED) were integrated to recover hydrochloric acid from simulated chemosynthesis aluminum foil wastewater. Effects of dialysate flow rate, DD pre-running duration (t1), CED current were investigated. Results showed that the integration of DD and CED was a feasible and effective approach to recover the hydrochloric acid. The dialysate flow rate and CED current are adjustable to achieve a compatibility and operational uniformity between DD and CED. When the dialysate flow rate was 0.60 L/(h m2), t1 was 10 min, and CED current was 2 A, the average acid recovery ratio and average aluminum leakage ratio were 74.9% and 12.2% respectively, while the energy consumption was only 0.41 kw h. The results confirm that such integration process is not only a cost-effective process compared with an individual DD process, but also an environment friendly process with little water consumption. Especially, due to the concentrating by CED, the recovered acid can be reused in the productive cycle directly.

► Diffusion dialysis (DD) and conventional electrodialysis were integrated to recover HCl.
► Such integration is compared with individual DD.
► The integration is a cost-effective process.
► The recovered acid can be reused directly.