NOB suppression strategies in a mainstream membrane aerated biofilm reactor under exceptionally low lumen pressure
Integrating the aeration-efficient membrane aerated biofilm reactor (MABR) with anaerobic ammonium oxidation (anammox) could yield further reduction in energy in wastewater treatment facilities. However, nitrite oxidizing bacteria (NOB) suppression remained challenging due to the absence of intrinsi...
| Main Authors: | , , , |
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| Other Authors: | |
| Format: | Journal Article |
| Language: | English |
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2022
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| Subjects: | |
| Online Access: | https://hdl.handle.net/10356/161821 |
| _version_ | 1811691139089039360 |
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| author | Chen, Rongfen Cao, Shenbin Zhang, Liang Zhou, Yan |
| author2 | School of Civil and Environmental Engineering |
| author_facet | School of Civil and Environmental Engineering Chen, Rongfen Cao, Shenbin Zhang, Liang Zhou, Yan |
| author_sort | Chen, Rongfen |
| collection | NTU |
| description | Integrating the aeration-efficient membrane aerated biofilm reactor (MABR) with anaerobic ammonium oxidation (anammox) could yield further reduction in energy in wastewater treatment facilities. However, nitrite oxidizing bacteria (NOB) suppression remained challenging due to the absence of intrinsic inhibition factors in mainstream conditions. This study investigated selective NOB suppression strategies in MABR under <5 kPa lumen pressure. Three MABRs were seeded from different seeding sludge, and operated under various ammonium loading rates, aeration pressure, and temporary inhibitory shock conditions. The three reactors were operated for 170-456 days depending on studied parameters. The results showed that higher ammonium loading could create a substrate-oxygen imbalance and quickly contain emergent NOB activity when aeration pressure was not excessive. In addition, lowering of aeration pressure reversed nitrite oxidizing activities without affecting ammonium oxidizing bacteria (AOB). Cultivating partial nitritation biofilm under zero positive aeration pressure slowed down the growth of NOB yet resulted in self-induced anammox activities. With the aid of temporary free ammonia (FA)/free nitrous acid (FNA) treatment, full-nitrifying biofilm could be transformed to stable partial nitritation biofilm. More than 84% nitrite accumulation ratio (NAR) was sustained during stable operation in each reactor together with an ammonium removal rate of more than 100 mg-N/L/d. Microbial analysis revealed that Nitrosomonas was the main AOB taxon in the three reactors while K-strategist Nitrospira showed presence despite low nitrite oxidizing activities. Under zero positive pressure, proliferation of Nitrospira was much slower while Candidatus Brocadia was self-induced. Furthermore, Nitrospira showed downturn after temporary inhibition treatment. |
| first_indexed | 2024-10-01T06:15:08Z |
| format | Journal Article |
| id | ntu-10356/161821 |
| institution | Nanyang Technological University |
| language | English |
| last_indexed | 2024-10-01T06:15:08Z |
| publishDate | 2022 |
| record_format | dspace |
| spelling | ntu-10356/1618212022-09-21T01:27:33Z NOB suppression strategies in a mainstream membrane aerated biofilm reactor under exceptionally low lumen pressure Chen, Rongfen Cao, Shenbin Zhang, Liang Zhou, Yan School of Civil and Environmental Engineering Interdisciplinary Graduate School (IGS) Nanyang Environment and Water Research Institute Advanced Environmental Biotechnology Centre (AEBC) Engineering::Environmental engineering Ammonium Oxidizing Bacteria Biofilm Reactor Integrating the aeration-efficient membrane aerated biofilm reactor (MABR) with anaerobic ammonium oxidation (anammox) could yield further reduction in energy in wastewater treatment facilities. However, nitrite oxidizing bacteria (NOB) suppression remained challenging due to the absence of intrinsic inhibition factors in mainstream conditions. This study investigated selective NOB suppression strategies in MABR under <5 kPa lumen pressure. Three MABRs were seeded from different seeding sludge, and operated under various ammonium loading rates, aeration pressure, and temporary inhibitory shock conditions. The three reactors were operated for 170-456 days depending on studied parameters. The results showed that higher ammonium loading could create a substrate-oxygen imbalance and quickly contain emergent NOB activity when aeration pressure was not excessive. In addition, lowering of aeration pressure reversed nitrite oxidizing activities without affecting ammonium oxidizing bacteria (AOB). Cultivating partial nitritation biofilm under zero positive aeration pressure slowed down the growth of NOB yet resulted in self-induced anammox activities. With the aid of temporary free ammonia (FA)/free nitrous acid (FNA) treatment, full-nitrifying biofilm could be transformed to stable partial nitritation biofilm. More than 84% nitrite accumulation ratio (NAR) was sustained during stable operation in each reactor together with an ammonium removal rate of more than 100 mg-N/L/d. Microbial analysis revealed that Nitrosomonas was the main AOB taxon in the three reactors while K-strategist Nitrospira showed presence despite low nitrite oxidizing activities. Under zero positive pressure, proliferation of Nitrospira was much slower while Candidatus Brocadia was self-induced. Furthermore, Nitrospira showed downturn after temporary inhibition treatment. 2022-09-21T01:27:33Z 2022-09-21T01:27:33Z 2022 Journal Article Chen, R., Cao, S., Zhang, L. & Zhou, Y. (2022). NOB suppression strategies in a mainstream membrane aerated biofilm reactor under exceptionally low lumen pressure. Chemosphere, 290, 133386-. https://dx.doi.org/10.1016/j.chemosphere.2021.133386 0045-6535 https://hdl.handle.net/10356/161821 10.1016/j.chemosphere.2021.133386 34952024 2-s2.0-85121718242 290 133386 en Chemosphere © 2021 Elsevier Ltd. All rights reserved. |
| spellingShingle | Engineering::Environmental engineering Ammonium Oxidizing Bacteria Biofilm Reactor Chen, Rongfen Cao, Shenbin Zhang, Liang Zhou, Yan NOB suppression strategies in a mainstream membrane aerated biofilm reactor under exceptionally low lumen pressure |
| title | NOB suppression strategies in a mainstream membrane aerated biofilm reactor under exceptionally low lumen pressure |
| title_full | NOB suppression strategies in a mainstream membrane aerated biofilm reactor under exceptionally low lumen pressure |
| title_fullStr | NOB suppression strategies in a mainstream membrane aerated biofilm reactor under exceptionally low lumen pressure |
| title_full_unstemmed | NOB suppression strategies in a mainstream membrane aerated biofilm reactor under exceptionally low lumen pressure |
| title_short | NOB suppression strategies in a mainstream membrane aerated biofilm reactor under exceptionally low lumen pressure |
| title_sort | nob suppression strategies in a mainstream membrane aerated biofilm reactor under exceptionally low lumen pressure |
| topic | Engineering::Environmental engineering Ammonium Oxidizing Bacteria Biofilm Reactor |
| url | https://hdl.handle.net/10356/161821 |
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