Sludge reduction during brewery wastewater treatment by hydrolyzation-food chain reactor system

During brewery wastewater treatment by a hydrolyzation-food chain reactor (FCR) system, sludge was recycled to the anaerobic segment. With the function of hydrolyzation acidification in the anaerobic segment and the processes of aerobic oxidation and antagonism, predation, interaction and symbiosis among microbes in multilevel oxidation segment, residual sludge could be reduced effectively. The 6-month dynamic experiments show that the average chemical oxygen demand (COD) removal ratio was 92.6% and average sludge production of the aerobic segment was 8.14%, with the COD of the influent at 960–1720 mg/L and hydraulic retention time (HRT) of 12 h. Since the produced sludge could be recycled and hydrolyzed in the anaerobic segment, no excess sludge was produced during the steady running for this system.