Modelling the electrodialytic recovery of sodium lactate

The recovery of sodium lactate from model solutions by ED (electrodialysis) was studied using a sequential experimental procedure so as to assess the main engineering parameters (i.e. ion transport numbers in solution and electro‐membranes, effective solute and water transport numbers, effective membrane surface area, surface resistances and limiting current intensity) affecting ED stack design and/or optimization. Of the major factors that determine the performance of this ED process, Ω (the current efficiency) was about 88% in the constant‐current region, while ε (the specific energy consumption) increased from 0.14 to 0.31 kWh·kg −1 for a solute recovery yield of 95% and j (current density) increasing from 112 to 337 A·m −2 . The specific‐resistance values of the anion‐ or cation‐exchange membranes were found to be five or two times greater respectively than those extracted from literature and measured in aqueous NaCl solutions.