Salem S, Berends D H J G, Heijnen J J, Van Loosdrecht M C M
Kluyver Laboratory for Biotechnology, Department of Biochemical Engineering, Delft, University of Technology, Julianalaan 67, 2628 BC, The Netherlands.
Water Res. 2003 Apr;37(8):1794-804. doi: 10.1016/S0043-1354(02)00550-X.
Bio-augmentation can be used to obtain nitrification in activated sludge processes that operate at sub-optimal solid retention times. In this study, we evaluated the potential of augmenting the endogenous nitrifying bacteria, by implementing a nitrification reactor in the sludge return line. This reactor can be fed with an internal N-rich flow (e.g. effluent from the sludge treatment) or with an external ammonium source. A mathematical model based on ASM1 was developed and used to evaluate the potential of this technique. The bio-augmentation studied here aimed to enhance the nitrification process of highly loaded activated sludge systems. A calibrated simulation model of a high loaded wastewater treatment plant in The Netherlands was used for this study. A side stream process (the named BABE process) was included in the simulation. This process was fed with the ammonia-rich water generated by sludge digestion and subsequent thickening by centrifugation (the so-called rejectwater). An external source (artificial) of ammonium was also considered to evaluate the differences between the two origins of ammonium. The results showed that with the augmentation process, high loaded activated sludge systems can achieve nitrification even at low winter temperatures. The best effect is obtained for systems operating at approximately 50% of the minimal SRT without augmentation. The use of an internal ammonia source is more effective than an external source. The results of this study give a quantitative basis for the design of process internal bio-augmentation processes and the effect on the N-removal capacity of the treatment plant.
生物强化可用于在固体停留时间未达最佳的活性污泥工艺中实现硝化作用。在本研究中，我们通过在污泥回流管线中设置一个硝化反应器，评估了强化内源性硝化细菌的潜力。该反应器可以采用内部富含氮的水流（如污泥处理的出水）或外部铵源作为进料。开发了一个基于活性污泥1号模型（ASM1）的数学模型，并用于评估该技术的潜力。此处研究的生物强化旨在增强高负荷活性污泥系统的硝化过程。本研究使用了荷兰一个高负荷污水处理厂的校准模拟模型。模拟中纳入了一个侧流工艺（即所谓的BABE工艺）。该工艺采用污泥消化以及随后通过离心浓缩产生的富氨废水（即所谓的回流污泥）作为进料。还考虑了铵的外部（人工）来源，以评估两种铵来源之间的差异。结果表明，通过强化工艺，高负荷活性污泥系统即使在冬季低温时也能实现硝化作用。对于在未强化时最小固体停留时间约50%的条件下运行的系统，效果最佳。使用内部氨源比外部氨源更有效。本研究结果为工艺内部生物强化工艺的设计及其对污水处理厂氮去除能力的影响提供了定量依据。
