Mahendraker Venkatram, Mavinic Donald S, Rabinowitz Barry, Hall Kenneth J
Sustainability Program, Pulp and Paper Research Institute of Canada, 570 Blvd. St-Jean, Pointe-Claire, Quebec H9R 3J9, Canada.
Biotechnol Bioeng. 2005 Jul 5;91(1):22-42. doi: 10.1002/bit.20471.
In this investigation, a laboratory-scale enhanced biological phosphorus removal (EBPR) process was operated under controlled conditions to study the impact of varying the influent ratio of chemical oxygen demand (COD), total Kjeldahl nitrogen (TKN) and total phosphorus (TP), and the consequential biochemical reactions on oxygen transfer parameters. The data showed that the experiment with high influent phosphorus relative to nitrogen (COD/TP = 51 and TKN/TP = 3.1) achieved higher alpha and oxygen transfer efficiency (OTE(f)). On the other hand, the experiment with high influent nitrogen relative to phosphorus (TKN/TP = 14.7 and COD/TP = 129) resulted in approximately 50% reduction in alpha and OTE(f) under similar organic loading. This suggested that the intracellular carbon storage and the enhanced biological P removal phenomenon associated with the phosphorus-accumulating organisms (PAOs) had a positive influence on OTE(f) in the high phosphorus experiment compared to an active population of nitrifying and denitrifying organisms in the high nitrogen experiment. The intracellular carbon storage by the glycogen-accumulating organisms also appeared to have had a positive effect on oxygen transfer efficiency, although to a lesser extent in comparison to the PAOs. It was also found that oxygen uptake rate (OUR) was not a good indicator of the measured alpha and OTE(f), because it was a combined effect of several biochemical reactions, each having a varying degree of influence. It is difficult to underestimate the crucial role of flocs in mass transfer of oxygen, because microorganisms associated with flocs carry out the biochemical reactions. It seems that the combination of influent characteristics and biochemical reactions in each experiment produced a unique biomass quality (determined by the biomass N to P ratio), ultimately affecting the mass transfer of oxygen. A theoretical explanation for the observed oxygen transfer efficiency under the process conditions is also proposed in this article.
在本研究中，在可控条件下运行实验室规模的强化生物除磷（EBPR）工艺，以研究改变进水化学需氧量（COD）、总凯氏氮（TKN）和总磷（TP）的比例以及随之而来的生化反应对氧传递参数的影响。数据表明，进水磷相对于氮含量较高（COD/TP = 51且TKN/TP = 3.1）的实验获得了更高的α值和氧传递效率（OTE(f)）。另一方面，进水氮相对于磷含量较高（TKN/TP = 14.7且COD/TP = 129）的实验在相似有机负荷下导致α值和OTE(f)降低了约50%。这表明，与高氮实验中活跃的硝化和反硝化生物群体相比，在高磷实验中，聚磷菌（PAO）的细胞内碳储存和强化生物除磷现象对OTE(f)有积极影响。糖原积累菌的细胞内碳储存似乎也对氧传递效率有积极作用，尽管与PAO相比程度较小。还发现氧摄取率（OUR）不是所测α值和OTE(f)的良好指标，因为它是几种生化反应的综合效应，每种反应的影响程度不同。很难低估絮凝物在氧传质中的关键作用，因为与絮凝物相关的微生物进行生化反应。似乎每个实验中进水特性和生化反应的组合产生了独特的生物质质量（由生物质氮磷比决定），最终影响了氧的传质。本文还针对工艺条件下观察到的氧传递效率提出了理论解释。
