Mechanism and Process of Anaerobic Sludge Granulation in UASB Reactor with Aerobic Activated Sludge as Seed
LI Jianzheng1,2, ZHANG Liguo1, BAN Qiaoying1, XU Yiping1, AI Binling1
1. School of Municipal and Environmental Engineering, Harbin Institute of Technology, Harbin 150090, China;2. State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, China
Abstract：The mechanism and the process of the anaerobic sludge granulation of the aerobic flocculent sludge in an Upflow Anaerobic Sludge Blanket (UASB) reactor are studied in this paper. The sludge is obtained from a secondary sedimentation tank of an activated sludge plant for treating municipal wastewater. The results show that the anaerobic granular sludge is cultivated successfully after the continuous operation for 150 d and the Hydraulic Retention Time (HRT) is reduced from 24 h to 8 h. During the phase-shortening, the sludge load and the hydraulic load are increased from 0.25 kg COD/(kg(VSS)·d) and 0.1 m3/(m2·h) to 0.52kg COD/(kg(VSS)·d) and 0.3m3/(m2·h), respectively. The process of the granulation contains five stages, including the sludge acclimation, the microbial aggregates formation, the primary granular sludge formation, the secondary granular sludge formation and the mature granular sludge formation. During the mature granular sludge formation stage, the COD is removed approximately by 95%. The mechanism of the anaerobic sludge granulation of the aerobic flocculent sludge is consistent with the second nuclei theory as a whole. The primary granular sludge formation mechanism is consistent with the Extracellular Polymers (ECP) theory, while the secondary granular sludge formation mechanism is consistent with other reported theories. In this study, the secondary granular sludge is formed by the methane filamentous bacteria and other bacteria inserting or absorbing to the fragments while its inner nuclei are composed of primary granular broken fragments.
李建政;张立国;班巧英;许一平;艾斌凌. 好氧活性污泥在升流式厌氧污泥床反应器中的厌氧颗粒化过程及机制[J]. , 2012, 30(36): 19-23.
LI Jianzheng;ZHANG Liguo;BAN Qiaoying;XU Yiping;AI Binling. Mechanism and Process of Anaerobic Sludge Granulation in UASB Reactor with Aerobic Activated Sludge as Seed. , 2012, 30(36): 19-23.