Yu Lifang, Wang Yu, Li Ren, Zhang Ru, Zhang Xingxiu, Hua Sisi, Peng Dangcong
School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology #13, Yanta Road Xi'an 710055 China
Shaanxi Key Laboratory of Environmental Engineering, Xi'an University of Architecture and Technology Xi'an 710055 China.
RSC Adv. 2020 Jul 29;10(47):28277-28286. doi: 10.1039/d0ra05252c. eCollection 2020 Jul 27.
Nitrifier immigration from sewers to wastewater treatment systems is attracting increasing attention for understanding nitrifier community assembly mechanisms, and improving process modeling and operation. In this study, nitrifiers in raw sewage were cultivated and acclimated in a sequencing batch reactor (SBR) for 90 days to investigate the characteristics of the influent nitrifiers after immigration. During the experiment, specific nitrite utilization rate (SNUR) exceeded specific ammonia utilization rate (SAUR) when floc size reached 224 ± 46 μm, and nitrogen loss occurred at the same time. The ratio of nitrite oxidizing bacteria (NOB) to ammonia oxidizing bacteria (AOB) increased from 0.84 to 2.14 after cultivation. The Illumina MiSeq sequencing showed that the dominant AOB was sp. Nm84 and unidentified species, and the three most abundant were , , and unidentified spp. in both raw sewage and cultivated activated sludge. The shared reads of raw sewage and activated sludge were 48.76% for AOB and 89.35% for . These indicated that nitrifiers, especially NOB, immigrated from influent can survive and propagate in wastewater systems, which may be a significant hinder to suppress NOB in the application of advanced nitrogen remove process based on partial nitrification in the mainstream.
硝化细菌从下水道迁移至污水处理系统，这在理解硝化细菌群落组装机制、改进工艺模型和运行方面正吸引着越来越多的关注。在本研究中，将原污水中的硝化细菌在序批式反应器（SBR）中培养和驯化90天，以研究迁移后进水硝化细菌的特性。实验过程中，当絮体尺寸达到224±46μm时，亚硝酸盐比利用率（SNUR）超过氨比利用率（SAUR），同时发生氮损失。培养后，亚硝酸盐氧化细菌（NOB）与氨氧化细菌（AOB）的比例从0.84增加到2.14。Illumina MiSeq测序表明，优势AOB为Nm84菌属和未鉴定物种，在原污水和培养后的活性污泥中，三种最丰富的分别是、和未鉴定的菌属。原污水和活性污泥的共有序列，AOB为48.76%，为89.35%。这些表明，从进水迁移而来的硝化细菌，尤其是NOB，能够在废水系统中存活和繁殖，这可能是主流中基于部分硝化的深度脱氮工艺应用中抑制NOB的一个重大障碍。
