Treatment of brewery wastewater using upflow anaerogic sludge blanket proces

Abstract

This study aimed at assessing the feasibility of using upflow anaerobic sludge blanket (UASB) process for treatment of brewery wastewater averaging 2000 g/m3 COD. The continuous experiments were carried out in a UASB pilot-plant with an inner diameter of 0.3 m and height of 4.7 m, at mesophilic temperature range. The granular sludge was cultivated by using brewery wastewater adjusted to have approximately 1000 gCOD/m3.The granules were formed in about 2 weeks in the reactor which controlled organic loading was 1 - 2 KgCOD/m3 –d and the hydraulic loading was 0.1 - 0.3 m3/m2-h. After reaching steady state operation, the reactor could handle the organic loading rates between 2.2 - 12.4 Kg COD/m3-d when the hydraulic retention time was decreased from 24 to 4 hours. The treatment efficiency of 90 - 94 % COD removal and 94 - 97 % BOD removal were obtained. During the 310 days of investigation, the average concentration of sludge blanket formed as high as 37KgSS/m3 or 20 Kg VSS/m3 was found to remain in the reactor. At 4 - 6 h HRT there was very few sludge loss and the process did not show any sign of failure. Methane production was in the range of 188 - 316 1 (STP)/KgCOD removed and its content varied between 74.0 to 80.9 % of the biogas produced. The effluent COD ranged from 95 to 180 g/m3. The experimental result indicated that the UASB process should be used for pre-treatment of the brewery wastewater, because of its high treat capability and energy saving.