Ma Zhi-Bo, Li Zhi-Hua, Yang Cheng-Jian, He Chun-Bo, Qiu Liang, Zhang Jing
Key Laboratory of Northwest Water Resource, Environment and Ecology, Ministry of Education, School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, China.
Department of Civil and Environmental Engineering, Norwegian University of Science and Technology, Trondheim 7050, Norway.
Huan Jing Ke Xue. 2017 Sep 8;38(9):3801-3806. doi: 10.13227/j.hjkx.201701082.
The current research on filamentous bulking focuses on the effluent quality and the settling properties but the reports on the microbial physiology under filamentous bulking conditions are seldom. In this study, the variations in the respirogram of microorganisms and affinity coefficient during filamentous bulking were explored in a sequence batch reactor. Low dissolved oxygen, regarded as the typical reason for filamentous bulking, was applied as the stimulation method. The results showed that microorganisms entered the physiological adaptation stage in the early period of low DO. The following properties were observed in the system:① a sudden increase in the endogenous specific oxygen uptake rate (SOUR) of activated sludge, ② an abrupt decrease in the specific oxygen uptake rate (SOUR) of autotrophic bacteria, ③ a rapid increase after a slight decline in the specific oxygen uptake rate (SOUR) of heterotrophic bacteria and a sudden increase in the oxygen affinity coefficient (O). However, maintaining the low DO levels would deteriorate the effluent quality and sedimentation properties, but the SOUR and SOUR could recover to higher levels after a while and the COD affinity coefficient (S) and O would decrease gradually. In low DO conditions, a sufficient hydraulic retention time will benefit the effluent quality from a theoretical point of view. Moreover, microorganisms could adapt to low DO conditions, which verifies the feasibility of "low oxygen aeration theory" from the respiration and kinetic parameters. The results from this study provide a theoretical support for energy savings of sewage treatment plant operations.
目前关于丝状菌膨胀的研究主要集中在出水水质和沉降性能方面，而关于丝状菌膨胀条件下微生物生理学的报道却很少。在本研究中，在序批式反应器中探讨了丝状菌膨胀过程中微生物呼吸图和亲和系数的变化。低溶解氧被视为丝状菌膨胀的典型原因，并被用作刺激方法。结果表明，微生物在低溶解氧的早期进入生理适应阶段。系统中观察到以下特性：①活性污泥的内源比氧摄取率（SOUR）突然增加，②自养细菌的比氧摄取率（SOUR）急剧下降，③异养细菌的比氧摄取率（SOUR）在略有下降后迅速增加，且氧亲和系数（O）突然增加。然而，维持低溶解氧水平会使出水水质和沉降性能恶化，但SOUR和SOUR一段时间后会恢复到较高水平，而化学需氧量亲和系数（S）和O会逐渐降低。在低溶解氧条件下，从理论角度来看，足够的水力停留时间将有利于出水水质。此外，微生物能够适应低溶解氧条件，这从呼吸和动力学参数方面验证了“低氧曝气理论”的可行性。本研究结果为污水处理厂运行的节能提供了理论支持。
