Comparison of Different Carriers to Maintain a Stable Partial Nitrification Process for Low-Strength Wastewater Treatment

Practical application of the partial nitritation–anaerobic ammonium oxidation (anammox) process has attracted increasing attention because of its low operational costs. However, the nitritation process, as a promising way to supply nitrite for anammox, is sensitive to the variations in substrate con...

Full description

Bibliographic Details
Main Authors: Kuo Zhang, Xinjue Li, Shou-Qing Ni, Sitong Liu
Format: Article
Language:English
Published: Frontiers Media S.A. 2022-03-01
Series:Frontiers in Bioengineering and Biotechnology
Subjects:
Online Access:https://www.frontiersin.org/articles/10.3389/fbioe.2022.851565/full
_version_ 1818776505200672768
author Kuo Zhang
Xinjue Li
Shou-Qing Ni
Sitong Liu
author_facet Kuo Zhang
Xinjue Li
Shou-Qing Ni
Sitong Liu
author_sort Kuo Zhang
collection DOAJ
description Practical application of the partial nitritation–anaerobic ammonium oxidation (anammox) process has attracted increasing attention because of its low operational costs. However, the nitritation process, as a promising way to supply nitrite for anammox, is sensitive to the variations in substrate concentration and dissolved oxygen (DO) concentration. Therefore, a stable supply of nitrite becomes a real bottleneck in partial nitritation–anammox process, limiting their potential for application in mainstream wastewater treatment. In this study, five 18-L sequencing batch reactors were operated in parallel at room temperature (22°C ± 4°C) to explore the nitritation performance with different carrier materials, including sepiolite-nonwoven carrier (R1), zeolite-nonwoven carrier (R2), brucite-nonwoven carrier (R3), polyurethane carrier (R4), and nonwoven carrier (R5). The ammonia oxidation rate (AOR) in R1 reached the highest level of 0.174 g-N L−1 d−1 in phase II, which was 1.4-fold higher than the control reactor (R4). To guarantee a stable supply of nitrite for anammox process, the nitrite accumulation efficiency (NAE) was always higher than 77%, even though the free ammonia (FA) decreases to 0.08 mg-N/L, and the pH decreases to 6.8 ± 0.3. In phase V, the AOR in R1 reached 0.206 g-N L−1 d−1 after the DO content increase from 0.7 ± 0.3 mg/L to 1.7 ± 0.3 mg/L. The NAE in R1 was consistently higher than 68.6%, which was much higher than the other reactor systems (R2: 43.8%, R3: 46.6%, R4: 23.7%, R5: 22.7%). Analysis of 16S rRNA gene sequencing revealed that the relative abundance of Nitrobacter and Nitrospira in R1 was significantly lower than other reactors, indicating that the sepiolite carrier plays an important role in the inhibition of nitrite-oxidizing bacteria. These results indicate that the sepiolite nonwoven composite carrier can effectively improve the nitritation process, which is highly beneficial for the application of partial nitritation–anammox for mainstream wastewater treatment.
first_indexed 2024-12-18T11:14:00Z
format Article
id doaj.art-9e1fa38148c345fe91149b998053b0a9
institution Directory Open Access Journal
issn 2296-4185
language English
last_indexed 2024-12-18T11:14:00Z
publishDate 2022-03-01
publisher Frontiers Media S.A.
record_format Article
series Frontiers in Bioengineering and Biotechnology
spelling doaj.art-9e1fa38148c345fe91149b998053b0a92022-12-21T21:09:57ZengFrontiers Media S.A.Frontiers in Bioengineering and Biotechnology2296-41852022-03-011010.3389/fbioe.2022.851565851565Comparison of Different Carriers to Maintain a Stable Partial Nitrification Process for Low-Strength Wastewater TreatmentKuo Zhang0Xinjue Li1Shou-Qing Ni2Sitong Liu3Department of Environmental Sciences and Engineering, College of Environmental Sciences and Engineering, Peking University, Beijing, ChinaDepartment of Environmental Sciences and Engineering, College of Environmental Sciences and Engineering, Peking University, Beijing, ChinaShandong Provincial Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Shandong University, Jinan, ChinaDepartment of Environmental Sciences and Engineering, College of Environmental Sciences and Engineering, Peking University, Beijing, ChinaPractical application of the partial nitritation–anaerobic ammonium oxidation (anammox) process has attracted increasing attention because of its low operational costs. However, the nitritation process, as a promising way to supply nitrite for anammox, is sensitive to the variations in substrate concentration and dissolved oxygen (DO) concentration. Therefore, a stable supply of nitrite becomes a real bottleneck in partial nitritation–anammox process, limiting their potential for application in mainstream wastewater treatment. In this study, five 18-L sequencing batch reactors were operated in parallel at room temperature (22°C ± 4°C) to explore the nitritation performance with different carrier materials, including sepiolite-nonwoven carrier (R1), zeolite-nonwoven carrier (R2), brucite-nonwoven carrier (R3), polyurethane carrier (R4), and nonwoven carrier (R5). The ammonia oxidation rate (AOR) in R1 reached the highest level of 0.174 g-N L−1 d−1 in phase II, which was 1.4-fold higher than the control reactor (R4). To guarantee a stable supply of nitrite for anammox process, the nitrite accumulation efficiency (NAE) was always higher than 77%, even though the free ammonia (FA) decreases to 0.08 mg-N/L, and the pH decreases to 6.8 ± 0.3. In phase V, the AOR in R1 reached 0.206 g-N L−1 d−1 after the DO content increase from 0.7 ± 0.3 mg/L to 1.7 ± 0.3 mg/L. The NAE in R1 was consistently higher than 68.6%, which was much higher than the other reactor systems (R2: 43.8%, R3: 46.6%, R4: 23.7%, R5: 22.7%). Analysis of 16S rRNA gene sequencing revealed that the relative abundance of Nitrobacter and Nitrospira in R1 was significantly lower than other reactors, indicating that the sepiolite carrier plays an important role in the inhibition of nitrite-oxidizing bacteria. These results indicate that the sepiolite nonwoven composite carrier can effectively improve the nitritation process, which is highly beneficial for the application of partial nitritation–anammox for mainstream wastewater treatment.https://www.frontiersin.org/articles/10.3389/fbioe.2022.851565/fullnitritationanammoxcomposite carriersepiolitenitrogen removal
spellingShingle Kuo Zhang
Xinjue Li
Shou-Qing Ni
Sitong Liu
Comparison of Different Carriers to Maintain a Stable Partial Nitrification Process for Low-Strength Wastewater Treatment
Frontiers in Bioengineering and Biotechnology
nitritation
anammox
composite carrier
sepiolite
nitrogen removal
title Comparison of Different Carriers to Maintain a Stable Partial Nitrification Process for Low-Strength Wastewater Treatment
title_full Comparison of Different Carriers to Maintain a Stable Partial Nitrification Process for Low-Strength Wastewater Treatment
title_fullStr Comparison of Different Carriers to Maintain a Stable Partial Nitrification Process for Low-Strength Wastewater Treatment
title_full_unstemmed Comparison of Different Carriers to Maintain a Stable Partial Nitrification Process for Low-Strength Wastewater Treatment
title_short Comparison of Different Carriers to Maintain a Stable Partial Nitrification Process for Low-Strength Wastewater Treatment
title_sort comparison of different carriers to maintain a stable partial nitrification process for low strength wastewater treatment
topic nitritation
anammox
composite carrier
sepiolite
nitrogen removal
url https://www.frontiersin.org/articles/10.3389/fbioe.2022.851565/full
work_keys_str_mv AT kuozhang comparisonofdifferentcarrierstomaintainastablepartialnitrificationprocessforlowstrengthwastewatertreatment
AT xinjueli comparisonofdifferentcarrierstomaintainastablepartialnitrificationprocessforlowstrengthwastewatertreatment
AT shouqingni comparisonofdifferentcarrierstomaintainastablepartialnitrificationprocessforlowstrengthwastewatertreatment
AT sitongliu comparisonofdifferentcarrierstomaintainastablepartialnitrificationprocessforlowstrengthwastewatertreatment