Lactic acid recovery from model solutions and fermentation broth by electrodialysis

The effect of current density, initial concentration of diluting solution o n lactic acid (LA) recovery by electrodialysis from both model solutions an d real fermentation broth was investigated. In model solutions, LA recovery efficiency was 93-96% and it was independent of both, current density and initial concentration of diluting solution. The recovery rates at 33, 66 an d 100 A . m(2) were 76, 175 and 272 g . m(2) . h(1) respectively and, clear ly were linearly depended on current (tensity. In the first stage of the pr ocess, both model solution and real fermentation broth showed similarities in the dynamic of LA recovery and water flux. With real fermentation broth, at current density of 100 A . m(2) and 41.8g/l initial lactate concentrati on of diluting solution, the LA recovery rate and the water flux were 279.5 and 679g.m(2).h(-1), respectively. However, the recovery efficiency was de creased front a 93-96% range to 71%, compared to that in model solutions. T he reason probably was that anion-exchange membrane was fouled by protein f rom broth.