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Anaerobic treatment of a sorghum-based alcohol production wastewater

Thesis/Dissertation ·
OSTI ID:5190290

An alcohol production wastewater was treated anaerobically to evaluate the effects of reactor configuration, hydraulic retention time and influent organic concentration. Laboratory-scale experiments were conducted at 35/sup 0/C using conventional and modified completely mixed and packed bed reactors, totalling 6 in all. Both single-stage and two-stage systems were studied. Influent organic COD concentrations of 107,450 mg/l and 44,000-46,000 mg/l were used. A 6-liter single-stage upflow plug/packed bed reactor operating at a hydraulic retention time (HRT) of 6 days and an organic load rate of 7.4 kgCOD/cu m-day was evaluated as the optimal treatment system. The total COD removal efficiency averaged 64% and the gas production averaged 19.8 liters/day. The two-stage systems were limited by poor hydrolysis in the first-stage, and attained a maximum organic loading rate of 3.86 kgCOD/cu m-day at an overall HRT of 11.5 days. The conventional and modified completely mixed reactors were each operated at an optimum organic loading rate of 3.05 kgCOD/cu m-day and at a HRT of 15 days. The gas production and COD removal efficiency increased with increase in the influent COD concentration. The anaerobic degradation process was substrate limited in single-stage reactors at hydraulic retention times higher than a critical HRT, and was rate limited at lower HRT. A minimum HRT was identified and varied between 10.3 to 11.1 days for different single-stage completely mixed reactors, and represented the HRT below which stable operation was not possible.

Research Organization:
Texas Univ., Austin (USA)
OSTI ID:
5190290
Country of Publication:
United States
Language:
English