UASB Treatment Performance of Sulfate-Rich Wastewater from Ethanol-Related Chemical Industry

Abstract

 In this study, in order to evaluate the effect of COD loading rate on UASB reactor treating synthetic wastewater containing sulfate, acetate acid and ethanol, a continuous experiment was operated by shortening HRT stepwise from 48 to 2 h. The experiment results indicated that at COD loading rate 12.3 g-COD/L/d, the COD removal rate was maintained above 86.5%. With HRT in the range of 3-12 h, 47.5%-54.4% of the influent COD was converted into biogas methane, and 21.4%-28.0% was converted into sulfide. After this continuous operation of the UASB reactor, granular sludge with an average particle size of 1.8 mm and sedimentation velocity of 96.5 m/h was gained. In addition, the anaerobic degradation pathway of ethanol under sulfate-rich condition was investigated according to the test result of methane-producing activity (MPA) and sulfate-reducing activity (SRA).