Variations of N concentrations and microbial community in the start-up of anammox using anaerobic heterotrophic sludge: Influence of a long reaction-phase time and comparison of the efficiencies of attached-versus suspended-growth cultures

Tsung-Hsien Huang; Fang-Tsen Tung; Guan-Fu Chen; Wei-Hsiang Chen

doi:10.1016/j.chemosphere.2021.132151

Variations of N concentrations and microbial community in the start-up of anammox using anaerobic heterotrophic sludge: Influence of a long reaction-phase time and comparison of the efficiencies of attached-versus suspended-growth cultures

Chemosphere. 2022 Jan;287(Pt 2):132151. doi: 10.1016/j.chemosphere.2021.132151. Epub 2021 Sep 3.

Authors

Tsung-Hsien Huang¹, Fang-Tsen Tung¹, Guan-Fu Chen¹, Wei-Hsiang Chen²

Affiliations

¹ Institute of Environmental Engineering, National Sun Yat-sen University, Kaohsiung, 804, Taiwan.
² Institute of Environmental Engineering, National Sun Yat-sen University, Kaohsiung, 804, Taiwan; Aerosol Science and Research Center, National Sun Yat-sen University, Kaohsiung, 804, Taiwan; Department of Public Health, Kaohsiung Medical University, Kaohsiung, Taiwan. Electronic address: whchen@mail.nsysu.edu.tw.

PMID: 34517235
DOI: 10.1016/j.chemosphere.2021.132151

Abstract

Anaerobic sludge was capable of producing anaerobic ammonium oxidation (anammox) cultures. However, the low activity of anammox bacteria in the seed sludge often led to a long time for stable anammox to initiate. The objective of this study was to investigate the influence of an extended reaction-phase time in the sequencing batch reactor (SBR) on the rapid startup of anaerobic ammonium oxidation (anammox) using anaerobic heterotrophic bacteria as the seed sludge. After the startup, suspended and attached bacteria in anammox were separately analyzed for comparison. The variations of nitrogen concentrations and shifts of the microbial community structures were studied. The results showed that anammox occurred after a long reaction-phase time in the SBR with the efficient removals of NH₄⁺ (96.4%) and NO₂^- (99.8%). The effective NO₂^- treatment before anammox startup was attributable to inevitable denitrification or dissimilatory nitrate reduction (e.g., Denitratisoma). The occurrence of anammox was supported by the anammox stoichiometry, bacteria diversity variation, and principal component analysis. The overall nitrogen removal rate (NRR) and nitrogen removal efficiency (NRE) was 0.07 kg/m³-d and 92.8%, respectively. The relative molar quantities of NH₄⁺ and NO₂^- removed as well as N₂ and NO₃^- formed were 1(1):1.29(1.32):1.45(1.02):0.15(0.26), as the numbers in the parentheses represent the theoretical values. Denitratisoma and Desulfatiglans dominated in the seed sludge, whereas Candidatus_Jettenia abundances were significantly higher in anammox attached- (26.0%) and suspended-growth cultures (14.5%). Fifty-three genera were simultaneously identified in all samples, suggesting their importance in the startup of anammox from anaerobic sludge. Candidatus_Jettenia was observed to be more associated with the growth of anammox biofilm (the abundances were 26.0% and 14.5% in attached- and suspended-growth cultures, respectively) and supported the fine nitrogen removal performance in the attached-growth cultures.

Keywords: Anaerobic heterotrophic bacteria; Anammox; Microbial community; React phase; Sequencing batch reactor; Suspended- and attached-growth.

MeSH terms

Ammonium Compounds*
Anaerobiosis
Bioreactors
Denitrification
Microbiota*
Nitrogen
Oxidation-Reduction
Sewage

Substances

Ammonium Compounds
Sewage
Nitrogen