Effects of Stepwise Adjustment of C/N during the Start-Up of Submerged Membrane Bioreactors (SMBRs) on the Aerobic Denitrification of Wastewater

Based on the improved high-efficiency sewage treatment performance of submerged membrane bioreactors (SMBRs), we focused on how to adjust the C/N ratio of the influent water during reactor start-up to prevent an excessive C/N ratio from causing membrane fouling. In this study, an experimental method...

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Main Authors: Yinan Zhang, Yuxin Fang, Banglong Wang, Hangjun Zhang, Jiafeng Ding
Format: Article
Language:English
Published: MDPI AG 2021-11-01
Series:Water
Subjects:
Online Access:https://www.mdpi.com/2073-4441/13/22/3251
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author Yinan Zhang
Yuxin Fang
Banglong Wang
Hangjun Zhang
Jiafeng Ding
author_facet Yinan Zhang
Yuxin Fang
Banglong Wang
Hangjun Zhang
Jiafeng Ding
author_sort Yinan Zhang
collection DOAJ
description Based on the improved high-efficiency sewage treatment performance of submerged membrane bioreactors (SMBRs), we focused on how to adjust the C/N ratio of the influent water during reactor start-up to prevent an excessive C/N ratio from causing membrane fouling. In this study, an experimental method of gradually adjusting the influent C/N ratio to quickly start the reactor was proposed, and the results showed that biofilm formation in R1 (SMBR, three influent C/N ratios of 5, 10, and 20) was approximately completed in 32 days, shorter than that (40 days) required in R2 (SMBR, influent C/N ratio of 20). Higher removal efficiencies of 76.4% for TN, 70.1% for COD, and 79.2% for NH<sub>3</sub>-N were obtained in R1 than in R2. The high-throughput sequencing results indicated that after 150 days of operation, the Shannon index of bacteria in R1 increased from 2.97 to 4.41 and the growth of <i>Nakamurella</i>, <i>Ferruginibacter</i>, and <i>Rhodanobacter</i> was promoted in the reactor, which indicated substantial microbial diversity in the biofilm. Therefore, gradually adjusting the influent C/N ratio could effectively enhance the nitrogen removal performance of denitrification microbial communities in SMBRs. This study offers a reliable approach for starting the SMBR-enhanced biological nutrient removal process in wastewater treatment plants by gradually adjusting the influent C/N ratio.
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spelling doaj.art-a3c902042d55457f918cf26475d0098c2023-11-23T02:00:55ZengMDPI AGWater2073-44412021-11-011322325110.3390/w13223251Effects of Stepwise Adjustment of C/N during the Start-Up of Submerged Membrane Bioreactors (SMBRs) on the Aerobic Denitrification of WastewaterYinan Zhang0Yuxin Fang1Banglong Wang2Hangjun Zhang3Jiafeng Ding4School of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou 311121, ChinaSchool of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou 311121, ChinaSchool of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou 311121, ChinaSchool of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou 311121, ChinaSchool of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou 311121, ChinaBased on the improved high-efficiency sewage treatment performance of submerged membrane bioreactors (SMBRs), we focused on how to adjust the C/N ratio of the influent water during reactor start-up to prevent an excessive C/N ratio from causing membrane fouling. In this study, an experimental method of gradually adjusting the influent C/N ratio to quickly start the reactor was proposed, and the results showed that biofilm formation in R1 (SMBR, three influent C/N ratios of 5, 10, and 20) was approximately completed in 32 days, shorter than that (40 days) required in R2 (SMBR, influent C/N ratio of 20). Higher removal efficiencies of 76.4% for TN, 70.1% for COD, and 79.2% for NH<sub>3</sub>-N were obtained in R1 than in R2. The high-throughput sequencing results indicated that after 150 days of operation, the Shannon index of bacteria in R1 increased from 2.97 to 4.41 and the growth of <i>Nakamurella</i>, <i>Ferruginibacter</i>, and <i>Rhodanobacter</i> was promoted in the reactor, which indicated substantial microbial diversity in the biofilm. Therefore, gradually adjusting the influent C/N ratio could effectively enhance the nitrogen removal performance of denitrification microbial communities in SMBRs. This study offers a reliable approach for starting the SMBR-enhanced biological nutrient removal process in wastewater treatment plants by gradually adjusting the influent C/N ratio.https://www.mdpi.com/2073-4441/13/22/3251microbial communitiesC/N ratiosubmerged membrane bioreactors (SMBRs)biofilm formation
spellingShingle Yinan Zhang
Yuxin Fang
Banglong Wang
Hangjun Zhang
Jiafeng Ding
Effects of Stepwise Adjustment of C/N during the Start-Up of Submerged Membrane Bioreactors (SMBRs) on the Aerobic Denitrification of Wastewater
Water
microbial communities
C/N ratio
submerged membrane bioreactors (SMBRs)
biofilm formation
title Effects of Stepwise Adjustment of C/N during the Start-Up of Submerged Membrane Bioreactors (SMBRs) on the Aerobic Denitrification of Wastewater
title_full Effects of Stepwise Adjustment of C/N during the Start-Up of Submerged Membrane Bioreactors (SMBRs) on the Aerobic Denitrification of Wastewater
title_fullStr Effects of Stepwise Adjustment of C/N during the Start-Up of Submerged Membrane Bioreactors (SMBRs) on the Aerobic Denitrification of Wastewater
title_full_unstemmed Effects of Stepwise Adjustment of C/N during the Start-Up of Submerged Membrane Bioreactors (SMBRs) on the Aerobic Denitrification of Wastewater
title_short Effects of Stepwise Adjustment of C/N during the Start-Up of Submerged Membrane Bioreactors (SMBRs) on the Aerobic Denitrification of Wastewater
title_sort effects of stepwise adjustment of c n during the start up of submerged membrane bioreactors smbrs on the aerobic denitrification of wastewater
topic microbial communities
C/N ratio
submerged membrane bioreactors (SMBRs)
biofilm formation
url https://www.mdpi.com/2073-4441/13/22/3251
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