Effect of pH and Temperature on Vinasse Decolorization by Lactic Acid Bacteria in Batch Processes.

The waste-free policy is part of the process of sugar production from beets in which the resulting molasses are used for ethanol production. However, during this process another byproduct, namely vinasse, is created. Therefore, there is a problem with the utilization of wastewater, which cannot be disposed to the environment without being treated. Melanoidins, caramels, and hexoses alkaline degradation products contained in the vinasse give it a dark brown color. The aim of the study was to investigate the effect of the pH and the temperature on the decolorization of vinasse by lactic acid bacteria (Lactobacillus plantarum, L. case), and Pediococcus parvulus). Experiments were performed in batch mode in a BioStatB bioreactor for 72 hrs. The medium consisted of 25% v/v sugar beet molasses vinasse, 77.34 gdm(-3) of glucose, and 2.24 gdm(-3 )of yeast extract. The maximum decolorization was 25.14% and was achieved at non-controlled pH 6.5 and at 30 degrees C. (C) 2019 Water Environment Federation