Nutrient conditions and reactor configuration influence floc size distribution and settling properties.
Nutrient conditions and reactor configuration influence floc size distribution and settling properties.
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DOI：
10.2166/wst.2011.849
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发表时间：
2011-12
期刊：
影响因子：
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通讯作者：
G. A. Ehlers;D. Wagachchi;S. Turner
中科院分区：
文献类型：
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作者：
G. A. Ehlers;D. Wagachchi;S. Turner
在许多废水处理过程中，絮体的形成和沉降性对于有效的固液分离是至关重要的。本研究旨在探讨不同生物反应器结构中颗粒分布与营养条件的关系。在相同的营养条件下，对连续(B1)、连续加澄清器、回流污泥(B2)和SBR(B3)反应器中形成的絮体的粒度分布进行了研究。合成乳制品加工废水的进水COD稀释了8倍，导致了对生物量和絮凝特性的显著影响。反应器MLSS的絮体尺寸分析表明，当投加最低(饥荒)COD废水进水(0.61g L(-1))时，反应器的絮体尺寸发生了变化。在最小COD进水期间，所有反应器的絮体尺寸分布都在增加，尽管不同的反应器配置观察到了不同的尺寸模式。这些增长与聚集和EPS数量的变化相对应。当运行在两种进水中时，SBR产生的絮体相对较大，如d(0.9)值所示(90%的颗粒≤d大小)。总体而言，结果表明，絮体的形成和大小受营养物质浓度的调节，代表着朝着改进固液分离迈出的重要一步。
Floc formation and settleability is critical for effective solid-liquid separation in many wastewater treatment processes. This study aimed to investigate the relationship between particle size distribution and nutrient conditions in different bioreactor configurations. Size distribution profiles of flocs that formed in continuous (B1), continuous with clarifier and return sludge (B2) and SBR (B3) reactors were investigated in parallel under identical nutrient conditions. An eight-fold dilution of the influent COD of a synthetic dairy processing wastewater resulted in a 'feast and famine' regime that triggered significant effects on the biomass and flocculation characteristics. Floc size analysis of reactor MLSS revealed a shift in floc sizes when reactors were fed with the minimum (famine) COD wastewater feed (0.61 g L(-1)). Increasing floc size distributions were detected for all reactors during the minimum COD feed although different size patterns were observed for different reactor configurations. These increases corresponded with variations in aggregation and EPS quantities. The SBR yielded comparatively larger flocs when operated under both COD feeds as indicated by d(0.9) values (90% of particles ≤ d in size). Overall the results indicated that floc formation and floc size are mediated by nutrient concentrations and represents an important step towards improved solid-liquid separation.