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Anaerobic treatment of wastewaters generated during grain fermentation and distillation of alcohol

Thesis/Dissertation ·
OSTI ID:5154005
Anaerobic treatment processes of grain fermentation wastewaters were investigated in this research. The study showed that bench-scale anaerobic stirred reactors were more applicable in treating the substrate than bench-scale anaerobic packed-bed reactors at a temperature of 35/sup 0/C. Results indicate that significant amounts of methane could be generated from the stabilization of the high strength (COD = 70,000 mg/L) acidic (pH less than or equal to4.2) grain fermentation wastewater. The study showed that anaerobic stirred reactors were applicable to the treatment of high strength wastewaters containing high suspended solids content. Anaerobic packed-bed reactors were applicable to soluble substrates. In terms of organic loading rates necessary for design purposes, stirred reactors were applicable at loading rates above 200 lb-COD/1000 ft/sup 3/-day while below this rate packed-bed reactors could be employed. Gas production yields were substantial for both the stirred and packed-bed reactors. Methane yields of 6.2 ft/sup 2/-CH/sub 4//lb-COD added and 6.4 ft/sup 3/-CH/sub 4//lb-COD added were observed for the stirred and packed-bed reactors operated at a theta/sub c/greater than or equal to30 days were 65% CH/sub 4/, 32% CO/sub 2/, and 3% N/sub 2/. Gas composition of packed-bed reactors operated at theta/sub h/greater than or equal to15 days were 65% CH/sub 4/, 32% CO/sub 2/ and 3% N/sub 2/.
OSTI ID:
5154005
Country of Publication:
United States
Language:
English