Aerobic sludge granulation under horizontal mechanical agitation in a SBR with lower ratio of height to diameter
QU Xin-yue, FAN Wen-wen, YUAN Lin-jiang, ZHANG Rui-huan, WEI Ping
Key Laboratory of Environmental Engineering, Shaanxi Province, Key Laboratory of Northwest Water Resources, Environment and Ecology, Ministry of Education, Xi'an University of Architecture and Technology, Xi'an 710055, China
Aerobic sludge granulation was investigated in a horizontal mechanical stirred and aerated SBR with lower ratio of height to diameter (H/D) of 1.2. The average shear rate that granules suffered was calculated and the effect of horizontal agitation on the granulation process was discussed. The results show, the aerobic sludge was granulated in the reactor with a mean diameter of 1.12mm and settling velocity of 21.41m/h finally. The average shear rate of granules was calculated out as 27.25s-1, and the shear force 3.38×10-2N/m2. The average shear rate acted on the surface of the granules positively related to mechanical agitation speed and superficial gas upflow velocity, of which the mechanical agitation speed contributed more to the shear rate, about 37.48times of that the superficial gas upflow velocity did. It was considered that the eddy secondary flow pattern with appropriate shear force caused by transverse rotation of stirrer was essential to aerobic sludge granulation in the reactor with lower ratio of height to diameter.
曲新月, 范文雯, 袁林江, 张瑞环, 魏萍. 水平搅拌下低高径比SBR中好氧活性污泥的颗粒化[J]. 中国环境科学, 2018, 38(9): 3358-3366.
QU Xin-yue, FAN Wen-wen, YUAN Lin-jiang, ZHANG Rui-huan, WEI Ping. Aerobic sludge granulation under horizontal mechanical agitation in a SBR with lower ratio of height to diameter. CHINA ENVIRONMENTAL SCIENCECE, 2018, 38(9): 3358-3366.
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