活性污泥中硝化螺菌(Nitrospira)的富集及其动力学参数

Enrichment of Nitrospira in Activated Sludge and Kinetic Characterization

采用连续进水的进水方式对污水处理厂活性污泥系统中的Nitrospira富集培养并对其相关动力学参数进行研究.结果表明,在控制反应器亚硝酸盐浓度不高于2 mg·L^(-1)的条件下可以成功富集出以Nitrospira为优势种属的活性污泥,其最大比亚硝酸盐氧化速率(以N/VSS计)为48.72 mg·(g·h)^(-1).荧光原位杂交结果显示Nitrospira占活性污泥总微生物量的75%左右,而Nitrobacter仅占总微生物的0.1%.此外通过对Nitrospira在20℃时的动力学参数进行测定,结果表明Nitrospira的最适生长温度为30~35℃,温度修正系数τN为1.046,其基质半饱和常数KS和氧半饱和常数KO分别为(0.32±0.03)mg·L^(-1)和(1.52±0.09)mg·L^(-1).Nitrospira动力学参数的研究为污水处理厂的设计运行及工艺优化提供理论参考.

Nitrospira was enriched from activated sludge by using fed-batch cultivation, and its related kinetic characterization was studied. The results showed that Nitrospira could be successfully enriched from the activated sludge for a controlled nitrite concentration no higher than 2 mg·L - 1 . The maximum nitrate oxidation rate was 48. 72 mg·（g·h） - 1 . The fluorescence for the in situ hybridization results showed that Nitrospira accounted for about 75% of the total biomass, while Nitrobacter accounted for only 0. 1% . In addition, the kinetic parameters of Nitrospira at 20℃ were also investigated. The results showed that the optimum growth temperature for Nitrospira was 30-35℃. The temperature correction coefficient TN was 1. 046. The nitrite half-saturation constant KS and oxygen half-saturation constant KO were （0. 32 ± 0. 03）mg·L - 1 and （1. 52 ± 0. 09）mg·L - 1 , respectively. This study on the kinetic characterization of Nitrospira provided a theoretical foundation for the treatment plant design and process optimization.