Development of an strategy for industrial wastewater treatment from yeast industry

In this work we present experimental results of a sequential biological treatment of yeast industry effluents. These effluents are composed by two equal streams originated in the centrifugation stage (vinasse and cream washing). The sequential system consisted of a dissolved air flotation, as a primary treatment, followed by an UASB anaerobic reactor and a final polishing lagoon. It was found that the dissolved air flotation removed up to 60% of fatty compounds present in the effluent. Addition of FeCL(3) sol. allowed to drive out more than 95% of anion sulfates. When the organic loading of the UASB reactor increased from 0.3 to 10 Kg COD/m(3).d it was obtained. 50 to 70% COD removal. It was possible to operate the UASB reactor with a pH kept constant among 6.5-7.5. The AGV/alkalinity ratio remained less than 0.3 and the alkalinity ranged from 1800 to 2800 mg CaCO3/L. A 29% average removal of COD was obtained in the polishing lagoon. Finally, the sequential system showed of 70% COD and 95% degradation of BOD.