Brewery Wastewater Treatment in UASB Reactor at Ambient Temperature

Abstract

Granulation was examined in the 12.3 L upflow anaerobic sludge blanket reactor at the average ambient temperature of 21.8°C. Brewery wastewater with an average chemical oxygen demand (COD) of 2,030 mg/L and biochemical oxygen demand of 1,150 mg/L was used as substrate, and anaerobic digested sludge as inoculum. During start-up, the sludge loading rate was gradually increased when 80% of soluble COD removal efficiency was achieved. The granules were initially developed after 4-month operation and fully grown after 6-month operation. At 21.8°C, the influent alkalinity seemed to have played a positive role in the granulation process by improving the biogas release from the sludge, with the appropriate value of 1,200 mgCaCO3/L. The granules cultivated ranged from 0.4 mm to 1.5 mm in diameter, with specific methanogenic activity of 0.92 gCH4-COD/gVSS⋅d and sludge volume index of 14 mL/g of suspended solids. After granulation, the upflow anaerobic sludge blanket reactor performed stably with soluble COD and biochemical oxygen demand removal efficiencies of 89.1% and 91.3%, respectively, under the volumetric loading rate of 12.2 gCOD/L⋅d and hydraulic retention time of 4 h.