Integrating Diffusion Dialysis with Membrane Electrolysis for Recovering Sodium Hydroxide from Alkaline Sodium Metavanadate Solution

Here, an energy-saving and efficient method is proposed for the clean and sustainable production of typical metal oxide (vanadium pentoxide as a case) by integrating diffusion dialysis with membrane electrolysis via cation-exchange membranes. This integrated process can achieve alkali recycle with less energy consumption. In addition, the gases—H 2 and O 2 —produced in the membrane electrolysis process can be used as byproducts. Results indicate that the total alkali recovery ratio and the vanadium rejection ratio can be as high as ∼100% and ∼92.56%, respectively. Moreover, preliminary economic evaluation indicates that the running cost can be significantly decreased from $24.52/(m 3 feed) (traditional method) to $–24.18/(m 3 feed) (proposed method).