Pollution Minimization by using Gain Based Fermentation ProcessAuthor(s): Lalit M. Pandey, D. S. Kharat and A. B. Akolkar
Distillery sector has been identified as one of the highly water polluting category and grouped under “Red” category and amongst the 17 categories of highly polluting industries. It involved the fermentation of sugars (sucrose) by yeast S. cerevisiae and distillation of fermented broth. Molasses is being used as main raw material for carbon source, which contains about 40-50% sugars. Molasses also contains caramelize sugars i.e. Caramel which are non-fermentable and imports color in final effluent. Recently, grains are also being used as raw material in place of molasses, which contains about 65-70% starch. Starch is converted to fermentable sugars i.e. glucose, sucrose etc. by liquefaction and saccharification process using α-amylase and amyloglucosidase enzymes respectively. This results high sugar content in raw material and further saccharification and fermentation take place simultaneously. These enables to achieve 12-14% alcohol in fermented broth as compare to 8-10% alcohol in case of molasses based distilleries. This results in low volume of effluent generation with lesser organic loads (low BOD/COD values) and absence of Caramel in the effluent.