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Xu R, Zhang W, Fu Y, Fan F, Zhou Z, Chen J, Liu W, Meng F. The positive roles of influent species immigration in mitigating membrane fouling in membrane bioreactors treating municipal wastewater. WATER RESEARCH 2023; 235:119907. [PMID: 37001232 DOI: 10.1016/j.watres.2023.119907] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/18/2022] [Revised: 03/18/2023] [Accepted: 03/21/2023] [Indexed: 06/19/2023]
Abstract
The influence of influent species immigration (ISI) on membrane fouling behaviors of membrane bioreactors (MBRs) treating municipal wastewater remains elusive, leading to an incomprehensive understanding of fouling ecology in MBRs. To address this issue, two anoxic/aerobic MBRs, which were fed with raw (named MBR-C) and sterilized (MBR-E) municipal wastewater, were operated. Compared with the MBR-E, the average fouling rate of the MBR-C was lowered by 30% over the long-term operation. In addition, the MBR-E sludge had significantly higher unified membrane fouling index and biofilm formation potential than the MBR-C sludge. Considerably larger flocs size and lower soluble microbial products (SMP) concentrations were observed in the MBR-C than in the MBR-E. Moreover, the 16S rRNA gene sequencing results showed that highly diverse and abundant populations responsible for floc-forming, hydrolysis/fermentation and SMP degradation readily inhabited the influent, shaping a unique microbial niche. Based on species mass balance-based assessment, most of these populations were nongrowing and their relative abundances were higher in the MBR-C than in the MBR-E. This suggested an important contribution of the ISI on the assemblage of these bacteria, thus supporting the increased flocs size and lowered SMP concentrations in the MBR-C. Moreover, the SMP-degrading related bacteria and functional pathways played a more crucial role in the MBR-C ecosystem as revealed by the bacterial co-occurrence network and Picrust2 analysis. Taken together, this study reveals the positive role of ISI in fouling mitigation and highlights the necessity for incorporating influent wastewater communities for fouling control in MBR plants.
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Affiliation(s)
- Ronghua Xu
- School of Environmental Science and Engineering, Sun Yat-sen University, Guangzhou, 510275, China; Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology (Sun Yat-sen University), Guangzhou, 510275, China
| | - Wentian Zhang
- School of Environmental Science and Engineering, Sun Yat-sen University, Guangzhou, 510275, China; Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology (Sun Yat-sen University), Guangzhou, 510275, China
| | - Yue Fu
- School of Environmental Science and Engineering, Sun Yat-sen University, Guangzhou, 510275, China; Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology (Sun Yat-sen University), Guangzhou, 510275, China
| | - Fuqiang Fan
- School of Environmental Science and Engineering, Sun Yat-sen University, Guangzhou, 510275, China; Advanced Institute of Natural Sciences, Beijing Normal University at Zhuhai, Zhuhai, 519087, China.
| | - Zanmin Zhou
- Zhuhai Urban Drainage Co., Ltd., Zhuhai, 519000, China
| | - Jincan Chen
- Zhuhai Urban Drainage Co., Ltd., Zhuhai, 519000, China
| | - Wanli Liu
- Zhuhai Water Environment Holdings Group Ltd., Zhuhai, 519000, China
| | - Fangang Meng
- School of Environmental Science and Engineering, Sun Yat-sen University, Guangzhou, 510275, China; Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology (Sun Yat-sen University), Guangzhou, 510275, China.
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Roman MD, Sava C, Iluțiu-Varvara DA, Mare R, Pruteanu LL, Pică EM, Jäntschi L. Biological Activated Sludge from Wastewater Treatment Plant before and during the COVID-19 Pandemic. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2022; 19:11323. [PMID: 36141596 PMCID: PMC9517470 DOI: 10.3390/ijerph191811323] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/28/2022] [Revised: 08/31/2022] [Accepted: 09/05/2022] [Indexed: 06/16/2023]
Abstract
The COVID-19 pandemic and the related measures brought a change in daily life that affected the characteristics of the municipal wastewater and further, of the biological activated sludge. The activated sludge process is the most widely used biological wastewater treatment process in developed areas. In this paper, we aim to show the situation of specific investigations concerning the variation of the physicochemical parameters and biological composition of the activated sludge from one conventional wastewater treatment plant from a metropolitan area. The investigations were carried out for three years: 2019, 2020 and 2021. The results showed the most representative taxa of microorganisms: Microtrix, Aspidisca cicada, Vorticella convallaria, Ciliata free of the unknown and Epistylis and Rotifers. Even if other microorganisms were found in the sludge flocs, their small presence did not influence in any way the quality of the activated sludge and of the wastewater treatment process. That is why we conclude that protozoa (especially Flagellates and Ciliates) and rotifers were the most important. Together with the values and variation of the physicochemical parameters, they indicated a good, healthy, and stable activated sludge, along with an efficient purifying treatment process, no matter the loading conditions.
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Affiliation(s)
- Marius-Daniel Roman
- Faculty of Building Services Engineering, Technical University of Cluj-Napoca, 28 Memorandumului Street, 400114 Cluj-Napoca, Romania
| | - Cornel Sava
- Faculty of Engineering Materials and the Environment, Technical University of Cluj-Napoca, 28 Memorandumului Street, 400114 Cluj-Napoca, Romania
| | - Dana-Adriana Iluțiu-Varvara
- Faculty of Building Services Engineering, Technical University of Cluj-Napoca, 28 Memorandumului Street, 400114 Cluj-Napoca, Romania
| | - Roxana Mare
- Faculty of Building Services Engineering, Technical University of Cluj-Napoca, 28 Memorandumului Street, 400114 Cluj-Napoca, Romania
| | - Lavinia-Lorena Pruteanu
- Department of Chemistry and Biology, North University Center at Baia Mare, Technical University of Cluj-Napoca, 76 Victoriei Street, 430122 Baia Mare, Romania
| | - Elena Maria Pică
- Faculty of Engineering Materials and the Environment, Technical University of Cluj-Napoca, 28 Memorandumului Street, 400114 Cluj-Napoca, Romania
| | - Lorentz Jäntschi
- Department of Physics and Chemistry, Technical University of Cluj-Napoca, 103-105 Bd. Muncii, 400641 Cluj-Napoca, Romania
- Institute for Doctoral Studies, Babes-Bolyai University, 1 M. Kogălniceanu Street, 400084 Cluj-Napoca, Romania
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3
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He S, Song N, Yao Z, Jiang H. An assessment of the purification performance and resilience of sponge-based aerobic biofilm reactors for treating polluted urban surface waters. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2022; 29:45919-45932. [PMID: 35150429 DOI: 10.1007/s11356-022-19083-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/26/2021] [Accepted: 02/02/2022] [Indexed: 06/14/2023]
Abstract
Pollutants are continuously released into surface waters, which decrease the dissolved oxygen (DO) concentration and leads to the formation of black-odorous water, especially in slow-flowing urban lakes and enclosed small ponds. In situ treatment by artificial aeration or water cycling, coupled with biofilm, can address this problem without occupying large amounts of land. In this study, we designed a novel sponge-based aerobic biofilm reactor (SABR) and evaluated its performance in purifying urban surface water under different conditions. In the urban lake water treatment, the continuous inflow results revealed that the NH4+-N and NO2--N concentrations in the effluent were stable and remained lower than 0.10 mg/L and 0.05 mg/L, respectively. Abrupt increases in the NH4+-N and NO2--N concentrations in the influent and sudden increases in the NH4+-N and NO2--N concentrations in the effluent were observed, and only 4 to 8 days were required for the concentrations to decline below 0.10 mg/L and 0.05 mg/L, respectively. Increases in the polyurethane sponge filling ratios in the SABRs can reduce the DO concentration but do not affect NH4+-N removal. When no biodegradable organic matter was present in the enclosed surface water, the degradation time of NH4+-N from 14.22 to 0.10 mg/L was only 9 days when SABRs were combined with water cycling, which was shorter than the time needed by water cycling alone (16 days), and most of the NH4+-N was converted to NO3--N. When massive amounts of biodegradable organic matter were present in the enclosed surface water, 22 days were required to remove the NH4+-N when SABRs were combined with water cycling. Our results indicated that organic matter could be used as a carbon source to eliminate the produced NO3--N in SABRs. Therefore, the newly developed bioreactor provides an effective approach for treating N-polluted urban surface waters.
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Affiliation(s)
- Shangwei He
- State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, 73 East Beijing Road, Nanjing, 210008, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Na Song
- State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, 73 East Beijing Road, Nanjing, 210008, China
| | - Zongbao Yao
- State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, 73 East Beijing Road, Nanjing, 210008, China
| | - Helong Jiang
- State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, 73 East Beijing Road, Nanjing, 210008, China.
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Sun H, Chang H, Tang W, Zhang X, Yang H, Zhang F, Zhang Y. Effects of influent immigration and environmental factors on bacterial assembly of activated sludge microbial communities. ENVIRONMENTAL RESEARCH 2022; 205:112426. [PMID: 34843723 DOI: 10.1016/j.envres.2021.112426] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/30/2021] [Revised: 11/17/2021] [Accepted: 11/19/2021] [Indexed: 05/13/2023]
Abstract
The functional mechanism of microbial assembly of activated sludge (AS) in urban wastewater treatment plants (UWTPs) remains unclear. A comprehensive quantitative evaluation of the contribution of influent immigration and environmental factors to AS community composition requires investigation. In this study, the microbial characteristics of six full-scale UWTPs with different influent compositions and environmental factors (altitude, temperature, dissolved oxygen (DO), pH, chemical oxygen demand (COD), total nitrogen (TN), ammonia nitrogen (NH4+-N), and total phosphorus (TP)) were analyzed to determine the main forces affecting the bacterial assembly of AS microbial communities. Abundant and core taxa were screened out based on the abundance and frequency of operational taxonomic units (OTUs) occurrence in all samples. Abundant OTUs (18.7% occurrence) accounted for 87.7% of the total 16S rRNA sequences, while rare OTUs (71.7% occurrence) accounted for only 7.8% of the total 16S rRNA sequences. A total of 135 OTUs were identified as core taxa, accounting for 14.6-26.2% of the total reads, of which 83 OTUs belonged to abundant taxa. The richness and uniformity of the influent community were significantly lower than those of the AS system. The community composition in influent varied from that in AS. Moreover, about 89.7% (86.5% of 16S rRNA sequences) OTUs in AS samples showed positive growth rates, indicating that immigration of influent communities had a limited effect on the microbial composition of AS. Redundancy analysis (RDA) combined with co-occurrence network showed that the bacterial assembly of microbial communities was significantly correlated with altitude, pH, and TN (P < 0.05), and these three parameters could explain 23.3%, 21.1%, and 17.7% of the bacterial assembly of AS microbial communities in UWTPs, respectively.
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Affiliation(s)
- Hongwei Sun
- School of Environmental and Material Engineering, Yantai University, Yantai, 264005, China.
| | - Huanhuan Chang
- School of Environmental and Municipal Engineering, Lanzhou Jiaotong University, Lanzhou, 730070, China
| | - Wei Tang
- Yantai City Drainage Service Center, Yantai, 264000, China
| | | | - Hao Yang
- School of Environmental and Municipal Engineering, Lanzhou Jiaotong University, Lanzhou, 730070, China
| | - Feng Zhang
- School of Environmental and Material Engineering, Yantai University, Yantai, 264005, China
| | - Yanxiang Zhang
- School of Environmental and Material Engineering, Yantai University, Yantai, 264005, China.
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5
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Chen X, Wei X, Yang Y, Wang S, Lu Q, Wang Y, Li Q, Wang S. Comparison of nitrogen removal efficiency and microbial characteristics of modified two-stage A/O, A 2/O and SBR processes. ENVIRONMENTAL GEOCHEMISTRY AND HEALTH 2021; 43:4687-4699. [PMID: 33963963 DOI: 10.1007/s10653-021-00855-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/28/2020] [Accepted: 02/05/2021] [Indexed: 06/12/2023]
Abstract
The low temperature of sewage in north China results in low performance of biological treatment at municipal wastewater treatment plants (MWTPs), especially in biological nitrogen removal. A modified two-stage A/O process with an embedded biofilm was proposed to enhance nitrogen removal. The operation performance of a pilot test was compared with an A2/O and SBR process at existing MWTPs to investigate the resistance to low temperature. The microbial communities for the three processes were compared based on the metagenomics results of 16sDNA high-throughput sequencing from activated sludge. The modified A/O resulted in a higher average removal of COD (90.12%) than A2/O (85.23%) and SBR (83.03%), especially of small-molecule organic compounds (< 500 Da) and macromolecular refractory organics (> 5 k Da); the TN removal rate of A2/O, SBR and the modified A/O was also increased from 74.47%, 70.63% and 78.46%, respectively. High-throughput sequencing revealed increased microbial diversity and an abundance of denitrifying functional bacteria was observed in the modified A/O process at low temperatures. The abundance of nitrite oxidation bacteria (NOB) including Nitrosomonas and Nitrospira, the amount was 1.76% and 2.34% in modified A/O, respectively, whereas NOB only accounted for 1.82% in A2/O and 1.35% in SBR.
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Affiliation(s)
- Xiurong Chen
- National Engineering Laboratory for High-Concentration Refractory Organic Wastewater Treatment Technologies (NELHROWTT), State Environmental Protection Key Laboratory of Environmental Risk Assessment and Control On Chemical Process, East China University of Science and Technology, Shanghai, 200237, People's Republic of China.
| | - Xiao Wei
- National Engineering Laboratory for High-Concentration Refractory Organic Wastewater Treatment Technologies (NELHROWTT), State Environmental Protection Key Laboratory of Environmental Risk Assessment and Control On Chemical Process, East China University of Science and Technology, Shanghai, 200237, People's Republic of China
| | - Yingying Yang
- National Engineering Laboratory for High-Concentration Refractory Organic Wastewater Treatment Technologies (NELHROWTT), State Environmental Protection Key Laboratory of Environmental Risk Assessment and Control On Chemical Process, East China University of Science and Technology, Shanghai, 200237, People's Republic of China
| | - Shanshan Wang
- National Engineering Laboratory for High-Concentration Refractory Organic Wastewater Treatment Technologies (NELHROWTT), State Environmental Protection Key Laboratory of Environmental Risk Assessment and Control On Chemical Process, East China University of Science and Technology, Shanghai, 200237, People's Republic of China
| | - Quanlin Lu
- National Engineering Laboratory for High-Concentration Refractory Organic Wastewater Treatment Technologies (NELHROWTT), State Environmental Protection Key Laboratory of Environmental Risk Assessment and Control On Chemical Process, East China University of Science and Technology, Shanghai, 200237, People's Republic of China
| | - Yuan Wang
- National Engineering Laboratory for High-Concentration Refractory Organic Wastewater Treatment Technologies (NELHROWTT), State Environmental Protection Key Laboratory of Environmental Risk Assessment and Control On Chemical Process, East China University of Science and Technology, Shanghai, 200237, People's Republic of China
| | - Qiuyue Li
- National Engineering Laboratory for High-Concentration Refractory Organic Wastewater Treatment Technologies (NELHROWTT), State Environmental Protection Key Laboratory of Environmental Risk Assessment and Control On Chemical Process, East China University of Science and Technology, Shanghai, 200237, People's Republic of China
| | - Shuoyuan Wang
- National Engineering Laboratory for High-Concentration Refractory Organic Wastewater Treatment Technologies (NELHROWTT), State Environmental Protection Key Laboratory of Environmental Risk Assessment and Control On Chemical Process, East China University of Science and Technology, Shanghai, 200237, People's Republic of China
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6
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Xu R, Fan F, Lin Q, Yuan S, Meng F. Overlooked Ecological Roles of Influent Wastewater Microflora in Improving Biological Phosphorus Removal in an Anoxic/Aerobic MBR Process. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2021; 55:6270-6280. [PMID: 33830745 DOI: 10.1021/acs.est.0c07891] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
The ecological roles of influent microflora in activated sludge communities have not been well investigated. Herein, parallel lab-scale anoxic/aerobic (A/O) membrane bioreactors (MBRs), which were fed with raw (MBR-C) and sterilized (MBR-T) municipal wastewater, were operated. The MBRs showed comparable nitrogen removal but superior phosphorus removal in MBR-C than MBR-T over the long-term operation. The MBR-C sludge community had higher diversity and deterministic assembly than the MBR-T sludge community as revealed by 16S rRNA gene sequencing and null model analysis. Moreover, the MBR-C sludge community had higher abundance of polyphosphate accumulating organisms (PAOs) and hydrolytic/fermentative bacteria (HFB) but lower abundance of glycogen-accumulating organisms (GAOs), in comparison with MBR-T sludge. Intriguingly, the results of both the net growth rate and Sloan's neutral model demonstrated that HFB in the sludge community were generally slow-growing or nongrowing and their consistent presence in activated sludge was primarily attributed to the HFB immigration from influent microflora. Positive correlations between PAOs and HFB and potential competitions between HFB and GAOs were observed, as revealed by the putative species-species associations in the ecological networks. Taken together, this work deciphers the positive ecological roles of influent microflora, particularly HFB, in system functioning and highlights the necessity of incorporating influent microbiota for the design and modeling of A/O MBR plants.
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Affiliation(s)
- Ronghua Xu
- School of Environmental Science and Engineering, Sun Yat-sen University, Guangzhou 510275, P. R. China
- Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, Sun Yat-sen University, Guangzhou 510275, P. R. China
- National Engineering Laboratory for Pollution Control and Waste Utilization in Livestock and Poultry Production, Changsha, Hunan 410125, P. R. China
| | - Fuqiang Fan
- School of Environmental Science and Engineering, Sun Yat-sen University, Guangzhou 510275, P. R. China
- Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, Sun Yat-sen University, Guangzhou 510275, P. R. China
- National Engineering Laboratory for Pollution Control and Waste Utilization in Livestock and Poultry Production, Changsha, Hunan 410125, P. R. China
| | - Qining Lin
- School of Environmental Science and Engineering, Sun Yat-sen University, Guangzhou 510275, P. R. China
- Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, Sun Yat-sen University, Guangzhou 510275, P. R. China
- National Engineering Laboratory for Pollution Control and Waste Utilization in Livestock and Poultry Production, Changsha, Hunan 410125, P. R. China
| | - Shasha Yuan
- School of Environmental Science and Engineering, Sun Yat-sen University, Guangzhou 510275, P. R. China
- Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, Sun Yat-sen University, Guangzhou 510275, P. R. China
- National Engineering Laboratory for Pollution Control and Waste Utilization in Livestock and Poultry Production, Changsha, Hunan 410125, P. R. China
| | - Fangang Meng
- School of Environmental Science and Engineering, Sun Yat-sen University, Guangzhou 510275, P. R. China
- Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, Sun Yat-sen University, Guangzhou 510275, P. R. China
- National Engineering Laboratory for Pollution Control and Waste Utilization in Livestock and Poultry Production, Changsha, Hunan 410125, P. R. China
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7
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Zhang S, Meng F. Core activated sludge communities are influenced little by immigration: Case study of a membrane bioreactor plant. J Environ Sci (China) 2021; 102:244-255. [PMID: 33637250 DOI: 10.1016/j.jes.2020.09.024] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2020] [Revised: 09/21/2020] [Accepted: 09/22/2020] [Indexed: 06/12/2023]
Abstract
Microbial immigrants arriving with influent wastewater may influence activated sludge (AS) ecosystems. However, the extent to which immigration impacts AS communities is still debated. To explore the intensity of immigration impact, we used sequencing technology to track the raw wastewater and AS communities from a membrane bioreactor plant over a 12-month period. We first distinguished core populations from peripheral ones in both raw wastewater and AS based on their occurrence frequency and abundance. The results showed that core OTUs (≥ 80% occurrence frequency) made up a large fraction (> 90%) of total sequences, while peripheral OTUs composed the majority of all detected OTUs but merely occupied a few sequences. A significant difference in core communities between the influent and AS was found, as well as between the compositions of core and peripheral populations. Additionally, the persistent functional bacteria of AS, although not numerically dominant, accounted for 96.24% of the total sequences related to nutrient turnover, suggesting the presence of a small number of longstanding and core functional bacteria in the AS ecosystem. Importantly, 64% of the 5188 OTUs in AS, which accounted for 91.51% of the sequences, exhibited positive growth rates, which suggested that their apparent abundances were due to growth within the plant, not from immigration. Taken together, these results demonstrated that the impact of influent populations on core AS communities was limited. Overall, this work provides quantitative insights into the impact of immigration, which is expected to advance our understanding of the AS community assembly.
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Affiliation(s)
- Shaoqing Zhang
- School of Civil Engineering, Guangzhou University, Guangzhou 510006, China; School of Environmental Science and Engineering, Sun Yat-sen University, Guangzhou 510275, China; Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, Sun Yat-sen University, Guangzhou 510275, China
| | - Fangang Meng
- School of Environmental Science and Engineering, Sun Yat-sen University, Guangzhou 510275, China; Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, Sun Yat-sen University, Guangzhou 510275, China.
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8
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Santillan E, Phua WX, Constancias F, Wuertz S. Sustained organic loading disturbance favors nitrite accumulation in bioreactors with variable resistance, recovery and resilience of nitrification and nitrifiers. Sci Rep 2020; 10:21388. [PMID: 33288775 PMCID: PMC7721871 DOI: 10.1038/s41598-020-78314-1] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2020] [Accepted: 11/13/2020] [Indexed: 01/04/2023] Open
Abstract
Sustained disturbances are relevant for environmental biotechnology as they can lead to alternative stable states in a system that may not be reversible. Here, we tested the effect of a sustained organic loading alteration (food-to-biomass ratio, F:M, and carbon-to-nitrogen ratio, C:N) on activated sludge bioreactors, focusing on the stability of nitrification and nitrifiers. Two sets of replicate 5-L sequencing batch reactors were operated at different, low and high, F:M (0.19–0.36 mg COD/mg TSS/d) and C:N (3.5–6.3 mg COD/mg TKN) conditions for a period of 74 days, following 53 days of sludge acclimation. Recovery and resilience were tested during the last 14 days by operating all reactors at low F:M and C:N (henceforth termed F:M–C:N). Stable nitrite accumulation (77%) was achieved through high F:M–C:N loading with a concurrent reduction in the abundance of Nitrospira. Subsequently, only two of the three reactors experiencing a switch back from high to low F:M–C:N recovered the nitrite oxidation function, with an increase in Nitrobacter as the predominant NOB, without a recovery of Nitrospira. The AOB community was more diverse, resistant and resilient than the NOB community. We showed that functional recovery and resilience can vary across replicate reactors, and that nitrification recovery need not coincide with a return to the initial nitrifying community structure.
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Affiliation(s)
- E Santillan
- Singapore Centre for Environmental Life Sciences Engineering, Nanyang Technological University, Singapore, 637551, Singapore.,Department of Civil and Environmental Engineering, University of California, Davis, CA, 95616, USA
| | - W X Phua
- School of Applied Science, Temasek Polytechnic, Singapore, 529765, Singapore
| | - F Constancias
- Singapore Centre for Environmental Life Sciences Engineering, Nanyang Technological University, Singapore, 637551, Singapore
| | - S Wuertz
- Singapore Centre for Environmental Life Sciences Engineering, Nanyang Technological University, Singapore, 637551, Singapore. .,Department of Civil and Environmental Engineering, University of California, Davis, CA, 95616, USA. .,School of Civil and Environmental Engineering, Nanyang Technological University, Singapore, 639798, Singapore.
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9
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Yu L, Wang Y, Li R, Zhang R, Zhang X, Hua S, Peng D. The differential proliferation of AOB and NOB during natural nitrifier cultivation and acclimation with raw sewage as seed sludge. RSC Adv 2020; 10:28277-28286. [PMID: 35519145 PMCID: PMC9055716 DOI: 10.1039/d0ra05252c] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2020] [Accepted: 07/16/2020] [Indexed: 11/21/2022] Open
Abstract
Nitrifier immigration from sewers to wastewater treatment systems is attracting increasing attention for understanding nitrifier community assembly mechanisms, and improving process modeling and operation. In this study, nitrifiers in raw sewage were cultivated and acclimated in a sequencing batch reactor (SBR) for 90 days to investigate the characteristics of the influent nitrifiers after immigration. During the experiment, specific nitrite utilization rate (SNUR) exceeded specific ammonia utilization rate (SAUR) when floc size reached 224 ± 46 μm, and nitrogen loss occurred at the same time. The ratio of nitrite oxidizing bacteria (NOB) to ammonia oxidizing bacteria (AOB) increased from 0.84 to 2.14 after cultivation. The Illumina MiSeq sequencing showed that the dominant AOB was Nitrosomonas sp. Nm84 and unidentified species, and the three most abundant Nitrospira were Nitrospira defluvii, Nitrospira calida, and unidentified Nitrospira spp. in both raw sewage and cultivated activated sludge. The shared reads of raw sewage and activated sludge were 48.76% for AOB and 89.35% for Nitrospira. These indicated that nitrifiers, especially NOB, immigrated from influent can survive and propagate in wastewater systems, which may be a significant hinder to suppress NOB in the application of advanced nitrogen remove process based on partial nitrification in the mainstream.
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Affiliation(s)
- Lifang Yu
- School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology #13, Yanta Road Xi'an 710055 China +86 029 82202729 +86 029 82202729.,Shaanxi Key Laboratory of Environmental Engineering, Xi'an University of Architecture and Technology Xi'an 710055 China
| | - Yu Wang
- School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology #13, Yanta Road Xi'an 710055 China +86 029 82202729 +86 029 82202729.,Key Laboratory of Northwest Water Resource, Environment and Ecology, MOE, Xi'an University of Architecture and Technology Xi'an 710055 China
| | - Ren Li
- School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology #13, Yanta Road Xi'an 710055 China +86 029 82202729 +86 029 82202729.,Key Laboratory of Northwest Water Resource, Environment and Ecology, MOE, Xi'an University of Architecture and Technology Xi'an 710055 China
| | - Ru Zhang
- School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology #13, Yanta Road Xi'an 710055 China +86 029 82202729 +86 029 82202729
| | - Xingxiu Zhang
- School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology #13, Yanta Road Xi'an 710055 China +86 029 82202729 +86 029 82202729
| | - Sisi Hua
- School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology #13, Yanta Road Xi'an 710055 China +86 029 82202729 +86 029 82202729
| | - Dangcong Peng
- School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology #13, Yanta Road Xi'an 710055 China +86 029 82202729 +86 029 82202729
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10
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Tang P, Yu D, Chen G, Zhang P, Wang X, Liu C, Huang S. Novel aerobic granular sludge culture strategy: Using granular sludge Anammox process effluent as a biocatalyst. BIORESOURCE TECHNOLOGY 2019; 294:122156. [PMID: 31561153 DOI: 10.1016/j.biortech.2019.122156] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/18/2019] [Revised: 09/12/2019] [Accepted: 09/14/2019] [Indexed: 06/10/2023]
Abstract
The effluent from granular sludge Anammox process was used as a biocatalyst to improve the culture rate of aerobic granular sludge, and the internal causes of this effect were studied. In this study, in sequencing batch reactor, the formation and changes of AGS was monitored with granular sludge Anammox process effluent added before and after. The community structure of AGS was analyzed by molecular biology methods. The results showed ammonia utilizing rate increased from 3.41 to 5.96 mgNH4+-N/(g VSS·h), NO2--N maintained a high accumulation rate, and the denitrification performance remained stable. On 40th day, the diameter of the AGS reached 3.5 mm, and the concentrations of PN and PS reached 330.5 and 62.9 mg/gVSS, respectively. The community structure has changed. Nitrosomonas (31.7%) became the new dominant bacteria. Signal molecules contained in the effluent as inter-species signal molecules could enhance the formation of AGS.
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Affiliation(s)
- Peng Tang
- School of Environmental Science and Engineering, Qingdao University, Qingdao 266071, PR China
| | - Deshuang Yu
- School of Environmental Science and Engineering, Qingdao University, Qingdao 266071, PR China
| | - Guanghui Chen
- School of Environmental Science and Engineering, Qingdao University, Qingdao 266071, PR China; National Engineering Laboratory for Advanced Municipal Wastewater Treatment and Reuse Technology, Beijing University of Technology, Beijing 100124, PR China.
| | - Peiyu Zhang
- School of Environmental Science and Engineering, Qingdao University, Qingdao 266071, PR China
| | - Xiaoxia Wang
- School of Environmental Science and Engineering, Qingdao University, Qingdao 266071, PR China
| | - Chengcheng Liu
- School of Environmental Science and Engineering, Qingdao University, Qingdao 266071, PR China
| | - Shuo Huang
- School of Environmental Science and Engineering, Qingdao University, Qingdao 266071, PR China
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Zheng W, Wen X. How exogenous influent communities and environmental conditions affect activated sludge communities in the membrane bioreactor of a wastewater treatment plant. THE SCIENCE OF THE TOTAL ENVIRONMENT 2019; 692:622-630. [PMID: 31539970 DOI: 10.1016/j.scitotenv.2019.07.310] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/09/2019] [Revised: 07/19/2019] [Accepted: 07/19/2019] [Indexed: 06/10/2023]
Abstract
In this study, the residual population of influent and activated sludge (AS) communities was defined based on their occurrence frequency and relative abundance through long-term and fine-scale sampling from the membrane bioreactor (MBR) of a wastewater treatment plant (WWTP). There were 481 OTUs defined as the residual OTUs, which taken up 67.90 ± 9.36% of relative abundance in the influent community. Besides, 6.76 ± 5.71% of the residual population migrated to and remained in the AS community. Additionally, the residual populations were more likely to be anaerobes and microaerobes. As the most predominant genus from residual community, the relative abundance of Arcobacter was reduced from 15.78 ± 3.58% in the influent to 1.15 ± 1.35% in the AS. The residues that migrated from the influent have increased the richness and evenness of AS community, as well as the dissimilarities among samples over long-term. The rank-abundance distribution showed identical pattern for the residual species between influent and AS. By adopting the analysis of neutral model, 2766 out of 7491 shared OTUs between influent and AS communities were identified as neutral OTUs, which respectively made up 53.9% and 41.8% of the total relative abundance of influent and AS communities. These indicated that the AS community was to some extent, but not entirely assembled by neutral process. For the residual community in the AS, dissolved oxygen (DO) was positively associated with several aerobic genera, meanwhile influent chemical oxygen demand (COD) had positive relationship with genus Pseudomonas. Last but most importantly, the influent community could not inoculate the nitrifiers in the AS, but instead, was able to inoculate the denitrifiers; as well as enhance the biodiversity and the ability of resisting external disturbance for the AS community in MBR.
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Affiliation(s)
- Wanlin Zheng
- State Key Joint Laboratory of Environmental Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, PR China
| | - Xianghua Wen
- State Key Joint Laboratory of Environmental Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, PR China.
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Microbial immigration in wastewater treatment systems: analytical considerations and process implications. Curr Opin Biotechnol 2019; 57:151-159. [PMID: 31030172 DOI: 10.1016/j.copbio.2019.02.021] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2018] [Revised: 02/12/2019] [Accepted: 02/24/2019] [Indexed: 11/21/2022]
Abstract
Microbial immigration from sewers to wastewater treatment systems is attracting increasing attention for understanding community assembly mechanisms, and improving process modeling and operation. While there is no consensus on approaches to analyze immigration, we suggest to classify them as relevant to either rare (non-observable) diffusive immigration or to time-continuous high-rate mass flow immigration (i.e. mass effects). When analyzed by a mass flow approach, heterotrophs appear to be strongly influenced by deterministic selection, suggesting that the heterotrophs should be subdivided into several functional guilds when assessing their assembly mechanisms. Conversely, nitrifiers appear to transfer neutrally from sewer to activated sludge, and this immigration can restore full nitrification in otherwise non-nitrifying reactors. With further refinement, these findings could be included in predictive process models with various objectives.
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