Effect of ammonium to nitrite ratio on reactor performance and microbial population structure in anammox reactors. Issue 26 (22nd November 2020)

• Record Type: Journal Article
• Authors: Gasa, Nomalanga P.; Nnadozie, Chika F.; Kosgey, Kiprotich; Bux, Faizal; Kumari, Sheena
• Is Part Of: Environmental technology. Volume 41:Issue 26(2020)
• Page Start: 3396
• Page End: 3411
• Publication Date: 2020-11-22
• Subjects: Wastewater -- nitrogen removal -- anammox -- ammonia oxidizing bacteria -- nitrite oxidizing bacteria; Environmental engineering -- Periodicals; Environmental protection -- Periodicals; 628.05
• DOI: 10.1080/09593330.2019.1610076
• Languages: English
• ISSNs: 0959-3330

Abstract

ABSTRACT: Anaerobic ammonium oxidation (anammox) presents an efficient alternative for conventional nitrogen removal process. In this study, the effect of varying Substrate (ammonium to nitrite) ratios on reactor performance and microbial community structures within three anaerobic sequencing batch reactors (ASBRs) was investigated. Three 1 L ASBRs (Reactors 1, 2 and 3) were operated under similar operational conditions. By varying the ammonium to nitrite ratios, a significant variation in nitrogen removal was observed after 170 days of operation: nitrogen removal efficiencies of 67.17 ± 7.29%, 57.13 ± 11.18% and 56.26 ± 17.05% in Reactors 3, 2 and 1 respectively were achieved. Similarly, using quantitative PCR, an overall variation in the population of anammox bacteria, ammonia oxidizing bacteria (AOB), Nitrospira and copy numbers of nirS, hzo and hzs genes were observed with varying degrees of expression. High throughput sequencing analysis further showed a shift in microbial community structure with an overall increase in population of Planctomycetia from 0.76% to (3%, 25% and 26%) and Betaproteobacteria from 5.38% to (19%, 21% and 43%) within Reactors 1, 2 and 3, respectively. In conclusion, different substrates ratio showed a significant influence on the overall nitrogen removal rate as well as the abundances of the different microbial groups. GRAPHICAL ABSTRACT: UF0001