Manser Reto, Gujer Willi, Siegrist Hansruedi
Swiss Federal Institute of Aquatic Science and Technology, Eawag, and Swiss Federal Institute of Technology, ETH, CH-8600 Dübendorf, Switzerland.
Water Res. 2006 Jul;40(12):2416-26. doi: 10.1016/j.watres.2006.04.019. Epub 2006 Jun 6.
A knowledge of the decay rates of autotrophic bacteria is important for reliably modeling nitrification in activated sludge plants. The introduction of nitrite to activated sludge models also requires the separate determination of the kinetics of ammonia- and nitrite-oxidizing bacteria. Batch experiments were carried out in order to study the effects of different oxidiation-reduction potential conditions and membrane separation on the separate decay of these bacteria. It was found that decay is negligible in both cases under anoxic conditions. No significant differences were detected between the membrane and conventional activated sludge. The aerobic decay of these two types of bacteria did not diverge significantly either. However, the measured loss of autotrophic activity was only partly explained by the endogenous respiration concept as incorporated in activated sludge model no. 3 (ASM3). In contrast to nitrite-oxidizing bacteria, ammonia-oxidizing bacteria needed 1-2 h after substrate addition to reach their maximum growth rate measured as a maximum OUR. This pattern could be successfully modeled using the ASM3 extended by enzyme kinetics. The significance of these findings on wastewater treatment is discussed on the basis of the extended ASM3.
了解自养细菌的衰减速率对于在活性污泥厂中可靠地模拟硝化作用非常重要。将亚硝酸盐引入活性污泥模型还需要分别测定氨氧化细菌和亚硝酸盐氧化细菌的动力学。为了研究不同氧化还原电位条件和膜分离对这些细菌分别衰减的影响，进行了批次实验。结果发现，在缺氧条件下，两种情况下的衰减都可以忽略不计。膜分离活性污泥和传统活性污泥之间未检测到显著差异。这两种类型细菌的好氧衰减也没有明显差异。然而，所测量的自养活性损失仅部分地由活性污泥模型3（ASM3）中纳入的内源呼吸概念来解释。与亚硝酸盐氧化细菌不同，氨氧化细菌在添加底物后需要1 - 2小时才能达到以最大OUR测量的最大生长速率。使用通过酶动力学扩展的ASM3可以成功地模拟这种模式。基于扩展的ASM3讨论了这些发现对废水处理的意义。
