Performance of a Pilot-Scale Hydrolysis Acidification and Improved UASB Process for the Treatment of Alcohol Wastewater: Sludge Granulation and Treatment Efficiency

Abstract

A system termed hydrolysis acidification-improved upflow anaerobic sludge blanket (HA-IUASB) was developed for alcohol wastewater treatment. The improvements of the UASB were that: a reflux pipe was set below the three-phase separator, and the mud mixture treated by the granular sludge bed returned into the water inlet.The improved UASB starts up completely after 61 days operation and the COD removal rate is between 70~96% during startup stage. The mature granule size reachs 3 mm and the methanogenic bacteria inside are mainly bacillus and cocci through Scanning Electron Microscope (SEM) observation. The treatment efficiency of the improved UASB is high and COD removal rate is 55%~80%. COD removal rate reachs 70%~87% by HA-UASB system under the condition of high concentration alcohol wastewater. CH4 is the main constituent and the percentage is 81.61% according to the gas composition analysis. This study proves that HA-IUASB is a feasible and practical means to treat alcohol wastewater.