3.2.3. Influence of by-products
Table 7 presents the average values of the by-products of the
broth in the feed analyzed by HPLC. The results for the centrifuged
broth were compared with those for the standard mixture to determine
the influence of by-products on the permeate flux, the
enrichment factor and the concentration of the permeate.
According to Table 7, the glycerol concentration in the fermentation
broth in the present study was 1.67% by weight. Chovau
et al. (2011) have reported that the presence of glycerol in low concentrations does not significantly affect the permeate flux parameter
or the coefficient of enrichment. In addition, the effect of carboxylic
acids on the process of pervaporation was studied, and the
presence of lactic acid at a concentration of 10.9 mmol L1 was
observed to increase both permeate and water flux; however, the
coefficient of enrichment was reduced to 12.2%.