Che G H, Yip W K, Mo H K, Liu Y
Department of Civil Engineering, Hong Kong University of Science & Technology, Clear Water Bay, Kowloon.
Water Res. 2001 Mar;35(4):1029-37. doi: 10.1016/s0043-1354(00)00346-8.
Reduction of excess sludge in an oxic-settling-anoxic (OSA) activated sludge process might be attributed to a "sludge fasting (insufficient food under an anoxic condition)/feasting (sufficient food under an oxic condition)" treatment. This paper was to examine this explanation by investigating both the sludge fasting/feasting phenomenon and the effect of a fasting/feasting treatment on sludge growth. In this study, five different activated sludge cultures cultivated using synthetic wastewater composed of mainly glucose and other necessary nutrients: (1) an aerobic batch culture, (2) an intermittently aerated batch culture, (3) an anoxic batch culture, (4) a continuous aerobic culture, and (5) an OSA culture, were employed. It was found that only the aerobic batch culture and the aerobic continuous culture are fastable when the oxidation reduction potential (ORP) level is below 100 mV under no-food condition during a 2-h fasting treatment, showing that both the biomass and carbohydrate storage of these two cultures were reduced after the treatment. When the fasted cultures were treated in a feasting environment, an accumulation of carbohydrate storage did not occur, while specific oxygen uptake rates (SOUR) showed a sharp increase. Both the substrate utilization and biomass growth rates were also accelerated. It was therefore confirmed that a sludge feasting did occur after a fasting treatment for the fastable cultures. However, an increase in sludge ATP content was not brought about by the feasting treatment. The sludge fasting/feasting treatment in this paper could not induce a reduction of the observed growth yield (Y(obs)) in all the cultures cultivated with glucose-based synthetic wastewater.
在好氧-沉淀-缺氧（OSA）活性污泥工艺中，剩余污泥的减少可能归因于“污泥禁食（缺氧条件下食物不足）/进食（好氧条件下食物充足）”处理。本文旨在通过研究污泥禁食/进食现象以及禁食/进食处理对污泥生长的影响来检验这一解释。在本研究中，使用主要由葡萄糖和其他必需营养物质组成的合成废水培养了五种不同的活性污泥培养物：（1）好氧间歇培养物，（2）间歇曝气间歇培养物，（3）缺氧间歇培养物，（4）连续好氧培养物，以及（5）OSA培养物。研究发现，在2小时禁食处理的无食物条件下，当氧化还原电位（ORP）水平低于100 mV时，只有好氧间歇培养物和连续好氧培养物可以禁食，这表明这两种培养物的生物量和碳水化合物储存量在处理后均有所减少。当对禁食后的培养物进行进食处理时，碳水化合物储存量没有积累，而比氧摄取率（SOUR）却急剧增加。底物利用率和生物量生长速率也都加快了。因此证实，对于可禁食的培养物，禁食处理后确实发生了污泥进食。然而，进食处理并未导致污泥ATP含量增加。本文中的污泥禁食/进食处理并不能使所有以葡萄糖为基础的合成废水培养的培养物中观察到的生长产率（Y(obs)）降低。
