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Wan C, Li Z, Deng L, Yuan Y, Wu C. Microbial population properties in the hierarchically structured aerobic granular sludge: Phenotype and genotype. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 867:161164. [PMID: 36632901 DOI: 10.1016/j.scitotenv.2022.161164] [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: 09/30/2022] [Revised: 12/02/2022] [Accepted: 12/20/2022] [Indexed: 06/17/2023]
Abstract
Aerobic granular sludge (AGS) is a layered microbial aggregate formed by the ordered self-assembly of different microbial populations. In this study, the outer layer (OL), middle layer (ML), and the inner layer (IL) of matured AGS were obtained by circular cutting. The adhesion of microorganisms in IL was significantly higher than that in OL and ML during the famine period, while the adhesion of microorganisms in ML and OL was significantly higher than that in IL during the feast period, confirming that the formation of AGS started in the famine period, and the feast period promoted the increase of particle size. Microorganisms in the three-layer structure were highly diverse and rich in genes for cytochrome c oxidase synthesis with oxygen as the electron acceptor. G_Pseudoxanthomonas was the dominant bacterium in OL. Its spatial distribution increased gradually from the inside to the outside. G_Rhodanobacter was the dominant bacterium in IL. Its spatial distribution gradually decreased from the inside to the outside. The microorganisms in IL contained abundant pili genes. During the self-assembly process of particle formation, G_ Rhodanobaker adhered stronger than G_ Pseudoxanthomonas. The interface between aerobic and anoxic was about 0.6 mm away from the granule surface. Combined with the electron mediator properties of the extracellular polymeric substance (EPS) in granules, it was speculated that the degradation of organic substrates located in the anoxic layer relied on EPS as a mediator for long-range electron transfer, and finally transferred electrons to O2. This study provides a new viewpoint on the formation mechanism of AGS from the perspective of the ordered self-assembly of microorganisms, offering a theoretical basis for the optimal selection of culture conditions and the application of AGS technology.
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Affiliation(s)
- Chunli Wan
- Department of Environmental Science and Engineering, Fudan University, Shanghai 200433, China
| | - Zhengwen Li
- Department of Environmental Science and Engineering, Fudan University, Shanghai 200433, China
| | - Liyan Deng
- Research Center of Environmental Pollution Control Technology, Chinese Research Academy of Environmental Sciences, Beijing 100012, China
| | - Yue Yuan
- Research Center of Environmental Pollution Control Technology, Chinese Research Academy of Environmental Sciences, Beijing 100012, China
| | - Changyong Wu
- Research Center of Environmental Pollution Control Technology, Chinese Research Academy of Environmental Sciences, Beijing 100012, China.
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2
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Removal of Total Dissolved Solids from Reverse Osmosis Concentrates from a Municipal Wastewater Reclamation Plant by Aerobic Granular Sludge. WATER 2018. [DOI: 10.3390/w10070882] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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Li W, Zheng P, Ji J, Zhang M, Guo J, Zhang J, Abbas G. Floatation of granular sludge and its mechanism: a key approach for high-rate denitrifying reactor. BIORESOURCE TECHNOLOGY 2013; 152:414-419. [PMID: 24316483 DOI: 10.1016/j.biortech.2013.11.056] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/06/2013] [Revised: 11/14/2013] [Accepted: 11/20/2013] [Indexed: 06/02/2023]
Abstract
A high-rate denitrifying automatic circulate (DAC) reactor has been developed recently, and it is promising to become an alternative in nitrogen removal from wastewaters. However, the performance of DAC reactor was disturbed by the floatation of granular sludge at high-loads. The results showed that: the floatation of granular sludge led to a serious biomass washout and a sharp decrease of biomass concentration. The floatation of granular sludge was ascribed to a low sludge density originated from the holdup of gaseous products. The average density and average gas holdup ratio of floated granular sludge were 913 kg m(-3) and 11.8% (by volume), respectively. The floatation of granular sludge could disappear by releasing gas when sludge was in the state of elastic expansion, but it would become worse by holding gas when it entered the plastic expansion state. The plastic expansion of granules was significantly correlated with the less content of extracellular polymeric substances.
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Affiliation(s)
- Wei Li
- Department of Environmental Engineering, Zhejiang University, Hangzhou 310058, China
| | - Ping Zheng
- Department of Environmental Engineering, Zhejiang University, Hangzhou 310058, China.
| | - Junyuan Ji
- College of Environmental Science and Engineering, Ocean University of China, Qingdao 266100, China
| | - Meng Zhang
- Department of Environmental Engineering, Zhejiang University, Hangzhou 310058, China
| | - Jun Guo
- College of Environmental Science and Engineering, Tongji University, Shanghai 200000, China
| | - Jiqiang Zhang
- Department of Environmental Engineering, Zhejiang University, Hangzhou 310058, China
| | - Ghulam Abbas
- Department of Environmental Engineering, Zhejiang University, Hangzhou 310058, China; Department of Chemical Engineering, University of Gujrat, Gujrat, Pakistan
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Zhou M, Gong J, Yang C, Pu W. Simulation of the performance of aerobic granular sludge SBR using modified ASM3 model. BIORESOURCE TECHNOLOGY 2013; 127:473-481. [PMID: 23147123 DOI: 10.1016/j.biortech.2012.09.076] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/13/2012] [Revised: 09/17/2012] [Accepted: 09/22/2012] [Indexed: 06/01/2023]
Abstract
The activated sludge model No. 3 (ASM3) was modified to describe the biological reactions in aerobic granular sludge SBR. The simultaneous storage and growth, nitrification and denitrification were all accounted for in modified model. The sensitivities of effluent COD, NH(4)(+) -N, and TN toward the stoichiometric and kinetic coefficients were analyzed. A standard set of parameters obtained from a combination of literature data was chosen for the model. The experimental results for the time profile of COD, NH(4)(+) -N, and TN in a typical cycle were used to verify the ASM3 model. The verification results show the model established is applicable for simulating the perfo rmance of an aerobic granule-based SBR. A comparison of the measured and predicted values of substrate removal for both the modified ASM3 and the original ASM3 was also performed. The verification and comparison results show the modified ASM3 model describes the aerobic granule-based SBR better and more mechanistically.
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Affiliation(s)
- Man Zhou
- College of Environmental Science and Engineering, Huazhong University of Science and Technology, Luoyu Road 1037, Wuhan 430074, PR China
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Seviour T, Lambert LK, Pijuan M, Yuan Z. Structural determination of a key exopolysaccharide in mixed culture aerobic sludge granules using NMR spectroscopy. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2010; 44:8964-8970. [PMID: 21033741 DOI: 10.1021/es102658s] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Nuclear magnetic resonance (NMR) techniques were used to elucidate the structure of an exopolysaccharide material previously revealed to be important in formation of aerobic granules. The 1D NMR spectral data acquired showed that this gel-forming polysaccharide was a major component of granular EPS, while 1D and 2D NMR spectra showed it consisted of eight sugar residues. These were assigned as α-galactose, α-rhamnose, 2-acetoamido-2-deoxy-α-galactopyranuronic acid, β-mannose, β-galactose, β-glucuronate, β-glucosamine, and N-acetyl β-galactosamine. With the exception of 2-acetoamido-2-deoxy-α-galactopyranuronic acid, a highly unusual sugar, their presence was confirmed with high-performance anion-exchange chromatography with pulsed amperometric detection (HPAEC-PAD). Carbon and proton shifts were assigned for each sugar. Heteronuclear multiple bond correlation (HMBC) and nuclear Overhauser enhancement spectroscopy (NOESY) were used to identify linkage sites between individual sugar residues. This gel-forming exopolysaccharide appeared to be a highly complex single heteropolysaccharide with a repeat sequence of α-galactose, β-mannose, β-glucosamine, N-acetyl-β-galactosamine, and 2-acetoamido-2-deoxy-α-galactopyranuronic acid. It has a disaccharide branch of β-galactose and β-glucuronic acid attached to 2-acetoamido-2-deoxy-α-galactopyranuronic acid and an α-rhamnose branch attached to α-galactose.
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Affiliation(s)
- Thomas Seviour
- The University of Queensland, Advanced Water Management Centre, St. Lucia, QLD 4072, Australia
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Liu L, Sheng GP, Li WW, Zeng RJ, Yu HQ. Experimental and numerical analysis of the hydrodynamic behaviors of aerobic granules. AIChE J 2010. [DOI: 10.1002/aic.12476] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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7
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Ni BJ, Yu HQ. Mathematical modeling of aerobic granular sludge: A review. Biotechnol Adv 2010; 28:895-909. [DOI: 10.1016/j.biotechadv.2010.08.004] [Citation(s) in RCA: 65] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2010] [Revised: 08/02/2010] [Accepted: 08/12/2010] [Indexed: 11/25/2022]
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Liu L, Li WW, Sheng GP, Liu ZF, Zeng RJ, Liu JX, Yu HQ, Lee DJ. Microscale hydrodynamic analysis of aerobic granules in the mass transfer process. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2010; 44:7555-7560. [PMID: 20839859 DOI: 10.1021/es1021608] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
The internal structure of aerobic granules has a significant impact on the hydrodynamic performance and mass transfer process, and severely affects the efficiency and stability of granules-based reactors for wastewater treatment. In this study, for the first time the granule complex structure was correlated with the hydrodynamic performance and substrates reactions process. First, a series of multiple fluorescence stained confocal laser scanning microscopy images of aerobic granules were obtained. Then, the form and structure of the entire granule was reconstructed. A three-dimensional computational fluid dynamics study was carried out for the hydrodynamic analysis. Two different models were developed on the basis of different fluorescence stained confocal laser scanning microscopy images to elucidate the roles of the granule structure in the hydrodynamic and mass transfer processes of aerobic granules. The fluid flow behavior, such as the velocity profiles, the pathlines and hence the hydrodynamic drag force, exerted on the granule in a Newtonian fluid, was studied by varying the Reynolds number. Furthermore, the spatial distribution of dissolved nutrients (e.g., oxygen) was acquired by solving the convection-diffusion equations on the basis of the reconstructed granule structure. This study demonstrates that the reconstructed granule model could offer a better understanding to the mass transfer process of aerobic granules than simply considering the granule structure to be homogeneous.
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Affiliation(s)
- Li Liu
- Department of Chemistry, University of Science & Technology of China, Hefei 230026, China
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Adav SS, Lin JCT, Yang Z, Whiteley CG, Lee DJ, Peng XF, Zhang ZP. Stereological assessment of extracellular polymeric substances, exo-enzymes, and specific bacterial strains in bioaggregates using fluorescence experiments. Biotechnol Adv 2010; 28:255-80. [DOI: 10.1016/j.biotechadv.2009.08.006] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2009] [Revised: 08/07/2009] [Accepted: 08/08/2009] [Indexed: 10/20/2022]
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Treating chemical industries influent using aerobic granular sludge: Recent development. J Taiwan Inst Chem Eng 2009. [DOI: 10.1016/j.jtice.2009.02.002] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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Physical and hydrodynamic properties of aerobic granules produced in sequencing batch reactors. Sep Purif Technol 2008. [DOI: 10.1016/j.seppur.2008.07.002] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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Adav SS, Lee DJ, Show KY, Tay JH. Aerobic granular sludge: Recent advances. Biotechnol Adv 2008; 26:411-23. [PMID: 18573633 DOI: 10.1016/j.biotechadv.2008.05.002] [Citation(s) in RCA: 472] [Impact Index Per Article: 29.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2008] [Revised: 04/10/2008] [Accepted: 05/06/2008] [Indexed: 10/22/2022]
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