Strategies for maximizing removal of lactic acid from acid whey – Addressing the un-processability issue

Abstract

Maximum removal of lactic acid (LA) from acid whey (AW) is essential for further processing of the AW waste stream. Hence, one and two step nanofiltration (NF) and nano diafiltration (NDF) approaches were applied to evaluate the removal efficiency of LA from AW at low and high pH, respectively. NDF at pH 3.0 achieved removal of ∼50–55% LA with a diafiltration factor (DF) of 4. Addition of diafiltration water with adjusted pH to prevent the pH fluctuations with dilutions had no significant impact on the extent of LA permeation. Adjusting pH of AW to pH 7.3 or 10.5 resulted in formation of precipitates which were removed by centrifugation, bringing about ∼22% removal of LA. The resultant super..