Comparing nitrite-limited and ammonium-limited anammox processes treating low-strength wastewater: Functional and population heterogeneity

Wenru Liu; Jiajun Song; Jianfang Wang; Peng Wu; Yaoliang Shen; Dianhai Yang

doi:10.1016/j.chemosphere.2020.127290

Comparing nitrite-limited and ammonium-limited anammox processes treating low-strength wastewater: Functional and population heterogeneity

Chemosphere. 2020 Nov:258:127290. doi: 10.1016/j.chemosphere.2020.127290. Epub 2020 Jun 5.

Authors

Wenru Liu¹, Jiajun Song², Jianfang Wang³, Peng Wu⁴, Yaoliang Shen³, Dianhai Yang⁵

Affiliations

¹ National & Local Joint Engineering Laboratory for Municipal Sewage Resource Utilization Technology, Suzhou University of Science and Technology, Suzhou, 215009, China; School of Environmental Science and Engineering, Suzhou University of Science and Technology, Suzhou, 215009, China. Electronic address: liuwenru1987@126.com.
² School of Environmental Science and Engineering, Suzhou University of Science and Technology, Suzhou, 215009, China.
³ National & Local Joint Engineering Laboratory for Municipal Sewage Resource Utilization Technology, Suzhou University of Science and Technology, Suzhou, 215009, China; School of Environmental Science and Engineering, Suzhou University of Science and Technology, Suzhou, 215009, China.
⁴ National & Local Joint Engineering Laboratory for Municipal Sewage Resource Utilization Technology, Suzhou University of Science and Technology, Suzhou, 215009, China; School of Environmental Science and Engineering, Suzhou University of Science and Technology, Suzhou, 215009, China. Electronic address: wupengniu@126.com.
⁵ State Key Laboratory of Pollution Control and Resources Reuse, Tongji University, Shanghai, 200092, China.

PMID: 32535448
DOI: 10.1016/j.chemosphere.2020.127290

Abstract

Biomass segregation between granules/biofilm and flocs is widespread in anammox-based processes. The segregation of biomass allows for easy control of processes stability. The goal of this study is to understand the biomass segregation in two anoxic anammox reactors respectively operated in nitrite-limited (R_NO2) and ammonium-limited (R_NH4) modes treating low-strength wastewater at 20 °C. Results showed that size-based biomass segregation was developed in both reactors. But the functional and population heterogeneity was more significant in the ammonium-limited anammox reactor. The activity and abundance of anammox bacteria in large granules were significantly higher than that in flocs under the ammonium-limited conditions. The large granules played a major role in nitrogen removal in R_NH4. By contrast, both large granules and small flocs contributed significantly to the nitrogen loss in the nitrite-limited anammox reactor, since a large number of anammox bacteria existed in both granules and flocs. Besides, a number of Nitrospira-like NOB were also detected in both anoxic anammox reactors, which primarily inhabited in flocs seemingly droved by the availability of oxygen. But the abundance of Nitrospira in R_NH4 was much higher than that in R_NO2. All these results suggested that selective flocs removal would be necessary for R_NH4 to improve its anammox performance but non-essential for R_NO2. The two anammox reactors shared the predominant anammox species with the closest relative to Ca. Brocadia sp. 40 (98%). Unexpectedly, the anammox species grew faster in R_NH4. But the microbial diversity and evenness was much greater in R_NO2, suggesting its higher functional stability.

Keywords: Anammox; Biomass segregation; Flocs; Granular sludge; Mainstream.

Publication types

Comparative Study

MeSH terms

Ammonium Compounds / metabolism*
Bacteria / metabolism
Biofilms
Biomass
Bioreactors / microbiology*
Nitrites / metabolism*
Nitrogen / metabolism
Oxidation-Reduction
Waste Disposal, Fluid / instrumentation
Waste Disposal, Fluid / methods*
Wastewater / chemistry*

Substances

Ammonium Compounds
Nitrites
Waste Water
Nitrogen