Recovery of Lactic Acid from Sodium Lactate Using Ion-exchange Membrane Electrodialysis

Lactic acid was recovered from sodium lactate solution by ion-exchange membrane electrodialysis with three compartments.The experiment results of using ion-exchange membrane JM-1 and DF-120 were compared.The influence of sodium lactate initial concentration on lactic acid recovery and electric energy consumption was investigated.It indicated that both lactic acid recovery and electric energy consumption were affected by sodium lactate initial concentration obviously.Selective character of membrane JM-1 was better than that of membrane DF-120,so the lactic acid recovery of membrane JM-1 was higher.Under the condition of operating current at 4 A,sodium lactate initial concentration about 1.0 mol·L-1,the recovery of lactic acid was 95% and the corresponding electric energy consumption was 0.78 W·h·g-1 lactic acid.Ion-exchange membrane electrodialysis had the advantage of bipolar membrane electrodialysis in electric energy consumption.