文献类型：期刊文献

英文题名：Competitive enrichment of comammox Nitrospira in floccular sludge

作者：Hou, Jiaying[1];Zhu, Ying[1];Liu, Jinzhong[1];Lin, Limin[2];Zheng, Min[3];Yang, Linyan[4];Wei, Wei[5];Ni, Bing-Jie[5];Chen, Xueming[1]

机构：[1]Fuzhou Univ, Coll Environm & Safety Engn, Fuzhou 350116, Peoples R China;[2]Westlake Univ, Sch Engn, Hangzhou 310030, Zhejiang, Peoples R China;[3]Univ Queensland, Australian Ctr Water & Environm Biotechnol, St Lucia, Qld 4072, Australia;[4]East China Univ Sci & Technol, Sch Resources & Environm Engn, Shanghai 200237, Peoples R China;[5]Univ Technol Sydney, Ctr Technol Water & Wastewater, Sch Civil & Environm Engn, Sydney, NSW 2007, Australia

年份：2024

卷号：251

外文期刊名：WATER RESEARCH

收录：;WOS:【SCI-EXPANDED(收录号:WOS:001170033000001)】；

基金：This work was supported by the National Natural Science Foundation of China (Grant No.: 52100028) , Natural Science Foundation of Fujian Province (Grant No.: 2023J01065) and Fuzhou University (Grant No.: GXRC-20095) . B. -J. Ni acknowledges the Australian Research Council (ARC) through Discovery Project DP220101142. The authors declare that they have no known competing financial interests.

语种：英文

外文关键词：Complete ammonium oxidation (comammox); Floccular sludge; Sequencing batch reactor (SBR); Nitrous oxide(N2O)

摘要：The discovery of complete ammonium oxidation (comammox) has subverted the traditional perception of twostep nitrification, which plays a key role in achieving biological nitrogen removal from wastewater. Floccular sludge-based treatment technologies are being applied at the majority of wastewater treatment plants in service where detection of various abundances and activities of comammox bacteria have been reported. However, limited efforts have been made to enrich and subsequently characterize comammox bacteria in floccular sludge. To this end, a lab-scale sequencing batch reactor (SBR) in the step-feeding mode was applied in this work to enrich comammox bacteria through controlling appropriate operational conditions (dissolved oxygen of 0.5 +/- 0.1 g-O2/m3, influent ammonium of 40 g-N/m3 and uncontrolled longer sludge retention time). After 215-d operation, comammox bacteria gradually gained competitive advantages over counterparts in the SBR with a stable nitrification efficiency of 92.2 +/- 2.2 %: the relative abundance of Nitrospira reached 42.9 +/- 1.3 %, which was 13 times higher than that of Nitrosomonas, and the amoA gene level of comammox bacteria increased to 7.7 +/- 2.1 x 106 copies/g-biomass, nearly 50 times higher than that of conventional ammonium-oxidizing bacteria. The enrichment of comammox bacteria, especially Clade A Candidatus Nitrospira nitrosa, in the floccular sludge led to (i) apparent affinity constants for ammonium and oxygen of 3.296 +/- 0.989 g-N/m3 and 0.110 +/- 0.004 g-O2/m3, respectively, and (ii) significantly low N2O and NO production, with emission factors being 0.136 +/- 0.026 % and 0.023 +/- 0.013 %, respectively.