Environ Technol. 2014 May-Jun;35(9-12):1525-31. doi: 10.1080/09593330.2013.872196.
An urban wastewater treatment plant (WWTP) with two different parallel lines of treatment and located in the north of Portugal was studied during four months, following recurrent episodes of filamentous bulking caused by Sphaerotilus natans and eventual occurrences of Nocardioforms and Type 1863. An aerobic selector was introduced in both lines in the beginning of the studied period, suppressed in one of the lines during six weeks, and then put into operation again until the end of the study. A total of 14 filamentous bacteria morphotypes were identified. The results showed that the presence of an aerobic biological selector in continuous operation prevented the overgrowth of the filamentous Type 1863, of Nocardioforms and, in particular, of S. natans. Simultaneously, it allowed lowering the oxygen levels in the aeration tanks without negative consequences in the overall performance of the WWTP, namely bulking occurrence. Dissolved oxygen (DO) in the aeration tank varied initially between 2 and 3 mg/L, but the introduction of the selector enabled to lower it to 1-1.5 mg/L in the aeration tank and around 0.5 mg/L in the selector. A significant energy save was allowed, even considering the aeration of the selector. The results are more relevant if one considers the fact that the main cause of the bulking problems in this WWTP was the overgrowth of S. natans, a filamentous bacterium known to be stimulated by low DO levels.
本研究针对葡萄牙北部的一家城市污水处理厂（WWTP），该污水处理厂有两条不同的平行处理线，在四个月的时间里，反复出现由 Sphaerotilus natans 引起的丝状菌膨胀问题，最终还出现了诺卡氏菌和 1863 型菌。在研究开始时，两条处理线都引入了好氧选择器，其中一条处理线在六周内被停用，然后再次投入使用，直至研究结束。共鉴定出 14 种丝状菌形态。结果表明，连续运行的好氧生物选择器可防止 1863 型丝状菌、诺卡氏菌，特别是 S. natans 的过度生长。同时，它还可以降低曝气池中的含氧量，而不会对 WWTP 的整体性能（即膨胀发生）产生负面影响。曝气池中的溶解氧（DO）最初在 2 至 3mg/L 之间波动，但选择器的引入可将其降低至曝气池中的 1-1.5mg/L 和选择器中的约 0.5mg/L。即使考虑到选择器的曝气，也可以节省大量能源。如果考虑到导致该 WWTP 膨胀问题的主要原因是 S. natans 的过度生长，那么这些结果就更加重要了，因为 S. natans 是一种已知会被低 DO 水平刺激的丝状菌。
