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Hao Z, Zhao L, Liu J, Pu Q, Chen J, Meng B, Feng X. Relative importance of aceticlastic methanogens and hydrogenotrophic methanogens on mercury methylation and methylmercury demethylation in paddy soils. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 906:167601. [PMID: 37832685 DOI: 10.1016/j.scitotenv.2023.167601] [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: 08/22/2023] [Revised: 09/28/2023] [Accepted: 10/03/2023] [Indexed: 10/15/2023]
Abstract
The accumulation of methylmercury (MeHg) in paddy soil results from a subtle balance between inorganic mercury (e.g., HgII) methylation and MeHg demethylation. Methanogens not only act as Hg methylators but may also facilitate MeHg demethylation. However, the diverse methanogen flora (e.g., aceticlastic and hydrogenotrophic types) that exists under ambient conditions has not previously been considered. Accordingly, the roles of different types of methanogens in HgII methylation and MeHg degradation in paddy soils were studied using the Hg isotope tracing technique combined with the application of methanogen inhibitors/stimulants. It was found that the response of HgII methylation to methanogen inhibitors or stimulants was site-dependent. Specifically, aceticlastic methanogens were suggested as the potential HgII methylators at the low Hg level background site, whereas hydrogenotrophic methanogens were potentially involved in MeHg production as Hg levels increased. In contrast, both aceticlastic and hydrogenotrophic methanogens facilitated MeHg degradation across the sampling sites. Additionally, competition between hydrogenotrophic and aceticlastic methanogens was observed in Hg-polluted paddy soils, implying that net MeHg production could be alleviated by promoting aceticlastic methanogens or inhibiting hydrogenotrophic methanogens. The findings gained from this study improve the understanding of the role of methanogens in net MeHg formation and link carbon turnover to Hg biogeochemistry in rice paddy ecosystems.
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Affiliation(s)
- Zhengdong Hao
- State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550081, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Lei Zhao
- School of Management Science, Guizhou University of Finance and Economics, Guiyang 550025, China; Guizhou Key Laboratory of Big Data Statistical Analysis (No. [2019]5103), Guiyang 550025, China.
| | - Jiang Liu
- State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550081, China
| | - Qiang Pu
- State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550081, China
| | - Ji Chen
- State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550081, China
| | - Bo Meng
- State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550081, China.
| | - Xinbin Feng
- State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550081, China; University of Chinese Academy of Sciences, Beijing 100049, China
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2
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Zhang X, Zhao B, An Q, Zhang P. The influence of different nitrate concentrations on aerobic sludge granulation and the role of extracellular polymeric substances. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2023; 348:119226. [PMID: 37820429 DOI: 10.1016/j.jenvman.2023.119226] [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: 07/18/2023] [Revised: 09/13/2023] [Accepted: 10/02/2023] [Indexed: 10/13/2023]
Abstract
This study investigated the influence of nitrate on aerobic granular sludge (AGS) granulation. The introduction of nitrate at 5, 15 and 20 mg L-1 promoted AGS granulation, and the promoting effect was positively correlated with nitrate concentrations. Meanwhile, exogenous nitrate significantly increased denitrification rate in the AGS system. However, granular disintegration appeared at a long-term addition of nitrate. An in-deep analysis showed that nitrate stimulated the secretion of extracellular polymeric substances (EPS), especially the content of proteins, which might be the main reason for the AGS granulation. However, the rapid and excessive increase in EPS might cause granular disintegration, as excessive EPS blocked the transmission of substrates, leading to the increase of dead cells in the granules. Besides, nitrate also altered the hydrophobicity of EPS and the content of α-helix, 3-turned helix and polymeric chain that favored aggregation, which also affected AGS granulation. From the microbial community level, nitrate induced the enrichment of denitrifying bacteria, including those that also functioned as EPS producers, such as Micropruina and Flavobacterium, resulting in the rapid increase of functional enzymes associated with amino acid synthesis, thereby promoting the secretion of proteins in EPS. Conversely, disintegration caused by mass transfer blockage might lead to the loss of EPS producing bacteria and subsequent decrease in EPS content, further accelerating granular disintegration.
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Affiliation(s)
- Xinyi Zhang
- Key Laboratory of the Three Gorges Reservoir Region's Eco-Environment, Ministry of Education, Chongqing University, Chongqing, 400045, PR China; College of Environment and Ecology, Chongqing University, Chongqing, 400045, PR China
| | - Bin Zhao
- Key Laboratory of the Three Gorges Reservoir Region's Eco-Environment, Ministry of Education, Chongqing University, Chongqing, 400045, PR China; College of Environment and Ecology, Chongqing University, Chongqing, 400045, PR China.
| | - Qiang An
- Key Laboratory of the Three Gorges Reservoir Region's Eco-Environment, Ministry of Education, Chongqing University, Chongqing, 400045, PR China; College of Environment and Ecology, Chongqing University, Chongqing, 400045, PR China
| | - Peng Zhang
- Key Laboratory of the Three Gorges Reservoir Region's Eco-Environment, Ministry of Education, Chongqing University, Chongqing, 400045, PR China; College of Environment and Ecology, Chongqing University, Chongqing, 400045, PR China
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3
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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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4
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Xia Z, Cai W, Zhang J, Sun W, Jiang Z, Li Y, Ao Z, Chen H, Liu G, Qi L, Wang H. Optimization on structure and operation parameters of biofilter for decentralized sewage treatment. ENVIRONMENTAL RESEARCH 2023; 219:115004. [PMID: 36481369 DOI: 10.1016/j.envres.2022.115004] [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: 09/06/2022] [Revised: 11/16/2022] [Accepted: 12/04/2022] [Indexed: 06/17/2023]
Abstract
Aiming for treating decentralized domestic wastewater in rural China, this study evaluates the effects of ceramsite size and structure, and water recirculation parameters, upon the performance of recirculating biofilter (RBF). RBF shows stable capability of chemical oxygen demand (COD) remediation and ammonia nitrification. In addition, the microbial flora and structures of the various layers in the system are analyzed via high-throughput sequencing in order to study the microbial diversity. The results indicate that while the ceramic particle size has no significant influence on the COD remediation capacity, the ceramics with smaller particle sizes exhibit better ammonia nitrogen (NH4+-N) removal ability, with a first-order linear relationship between the influent ammonia nitrogen load and the effluent NH4+-N concentration in RBF (R2 > 0.64). An increased hydraulic load and intermittent operation are shown to deteriorate the water quality with respect to NH4+-N, while an increased recirculation ratio increases the removal rate of NH4+-N from the effluent. Further, the water distribution time has a stronger effect upon the NH4+-N concentration in the effluent than does the recirculation ratio. Moreover, the microbial structure of the multi-layer recirculating trickle biofilter varies significantly during the process. The results indicate that a high recirculation ratio, long water distribution time, and multi-layer structure will be beneficial for improving the pollutant treatment capacity of RBF.
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Affiliation(s)
- Zhiheng Xia
- Low-carbon Water Environment Technology Research Center, School of Environment & Natural Resources, Renmin University of China, Beijing, 100872, China.
| | - Wenqian Cai
- Technical Center for Soil, Agriculture and Rural Ecology and Environment, Ministry of Ecology and Environment, Beijing, 100012, China.
| | - Jinsen Zhang
- Low-carbon Water Environment Technology Research Center, School of Environment & Natural Resources, Renmin University of China, Beijing, 100872, China
| | - Wenzhuo Sun
- Low-carbon Water Environment Technology Research Center, School of Environment & Natural Resources, Renmin University of China, Beijing, 100872, China
| | - Zhao Jiang
- Low-carbon Water Environment Technology Research Center, School of Environment & Natural Resources, Renmin University of China, Beijing, 100872, China
| | - Yinghao Li
- Low-carbon Water Environment Technology Research Center, School of Environment & Natural Resources, Renmin University of China, Beijing, 100872, China
| | - Ziding Ao
- Low-carbon Water Environment Technology Research Center, School of Environment & Natural Resources, Renmin University of China, Beijing, 100872, China
| | - Huiling Chen
- Low-carbon Water Environment Technology Research Center, School of Environment & Natural Resources, Renmin University of China, Beijing, 100872, China
| | - Guohua Liu
- Low-carbon Water Environment Technology Research Center, School of Environment & Natural Resources, Renmin University of China, Beijing, 100872, China
| | - Lu Qi
- Low-carbon Water Environment Technology Research Center, School of Environment & Natural Resources, Renmin University of China, Beijing, 100872, China.
| | - Hongchen Wang
- Low-carbon Water Environment Technology Research Center, School of Environment & Natural Resources, Renmin University of China, Beijing, 100872, China
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Production efficiency and properties of poly(3hydroxybutyrate-co-3hydroxyvalerate) generated via a robust bacterial consortium dominated by Zoogloea sp. using acidified discarded fruit juices as carbon source. Int J Biol Macromol 2023; 226:1500-1514. [PMID: 36511266 DOI: 10.1016/j.ijbiomac.2022.11.262] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2022] [Revised: 11/23/2022] [Accepted: 11/24/2022] [Indexed: 11/27/2022]
Abstract
In the current study, a mixed microbial culture (MMC) of polyhydroxyalkanoates (PHAs) producers was developed under nutrient stress and was assessed as biocatalyst for the production of high-yielding PHAs from fermented (acidified) discarded fruit juices (DFJ). The structure of the MMC was analyzed periodically to determine its microbial dynamics, revealing that Zoogloae sp. dominated throughout the operation of the system. The efficiency of PHAs production from the MMC was further optimized in batch mode by altering the ratio of C to N, the ratio of carbon sources (propionate and butyrate), and the initial pH, and subsequently different fermentation mixtures of acidified DFJ were assessed as substrates at optimal conditions. Upon solvent extraction, the properties of recovered PHAs were analyzed, showing that in all cases P(3HB-co-3HV) was produced, with Tm ranging from 90.5 to 168.8 °C, and maximum obtained yields 54.61 ± 4.31 % and 43.27 ± 2.13 %, from synthetic substrates and DFJ, respectively. Overall, it was shown that the developed MMC can be efficiently applied as biocatalyst for the exploitation of sugary wastewaters, such as DFJ, towards bio-based and biodegradable plastics bearing the required properties to substitute fossil plastics, into the concept of a circular economy.
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Amancio Frutuoso FK, Ferreira Dos Santos A, da Silva França LL, Mendes Barros AR, Bezerra Dos Santos A. Influence of salt addition to stimulating biopolymers production in aerobic granular sludge systems. CHEMOSPHERE 2023; 311:137006. [PMID: 36330972 DOI: 10.1016/j.chemosphere.2022.137006] [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: 07/12/2022] [Revised: 09/27/2022] [Accepted: 10/23/2022] [Indexed: 06/16/2023]
Abstract
The influence of salt addition to stimulating biopolymers production in aerobic granular sludge (AGS) systems was evaluated. The control systems (R1: acetate and R2: propionate) initially obtained less accumulation of mixed liquor volatile suspended solids (MLVSS), indicating that the osmotic pressure in the salt-supplemented systems (R3: acetate and R4: propionate) contributed to biomass growth. However, the salt-supplemented systems collapsed between days 110 and 130 of operation. R3 and R4 showed better performance regarding nutrients removal due to the greater abundance of nitrifying and denitrifying bacteria and phosphate-accumulating organisms. Salt also contributed to the higher production of biopolymers such as alginate-like exopolymers (ALE) per gram of volatile suspended solids (VSS) (R1: 397 mgALE∙gVSS-1, R2: 140 mgALE∙gVSS-1, R3: 483 mgALE∙gVSS-1, R4: 311 mgALE∙gVSS-1). Amino acids like tyrosine and tryptophan were better identified in extracellular polymeric substances extract from salt-operated reactors. This study brings important results in the context of resource recovery by treating saline effluents.
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Affiliation(s)
| | - Amanda Ferreira Dos Santos
- Department of Hydraulic and Environmental Engineering, Federal University of Ceará, Fortaleza, Ceará, Brazil
| | | | | | - André Bezerra Dos Santos
- Department of Hydraulic and Environmental Engineering, Federal University of Ceará, Fortaleza, Ceará, Brazil.
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7
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Wan C, Fu L, Li Z, Liu X, Lin L, Wu C. Formation, application, and storage-reactivation of aerobic granular sludge: A review. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2022; 323:116302. [PMID: 36150350 DOI: 10.1016/j.jenvman.2022.116302] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/14/2022] [Revised: 08/31/2022] [Accepted: 09/14/2022] [Indexed: 06/16/2023]
Abstract
It was an important discovery in wastewater treatment that the microorganisms in the traditional activated sludge can form aerobic granular sludge (AGS) by self-aggregation under appropriate water quality and operation conditions. With a typical three-dimensional spherical structure, AGS has high sludge-water separation efficiency, great treatment capacity, and strong tolerance to toxic and harmful substances, so it has been considered to be one of the most promising wastewater treatment technologies. This paper comprehensively reviewed AGS from multiple perspectives over the past two decades, including the culture conditions, granulation mechanisms, metabolic and structural stability, storage, and its diverse applications. Some important issues, such as the reproducibility of culture conditions and the structural and functional stability during application and storage, were also summarized, and the research prospects were put forward. The aggregation behavior of microorganisms in AGS was explained from the perspectives of physiology and ecology of complex populations. The storage of AGS is considered to have large commercial potential value with the increase of large-scale applications. The purpose of this paper is to provide a reference for the systematic and in-depth study on the sludge aerobic granulation process.
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Affiliation(s)
- Chunli Wan
- Department of Environmental Science and Engineering, Fudan University, Shanghai, 200438, China
| | - Liya Fu
- Research Center of Environmental Pollution Control Engineering Technology, Chinese Research Academy of Environmental Sciences, Beijing, 100012, China
| | - Zhengwen Li
- Department of Environmental Science and Engineering, Fudan University, Shanghai, 200438, China
| | - Xiang Liu
- Department of Environmental Science and Engineering, Fudan University, Shanghai, 200438, China.
| | - Lin Lin
- Environmental Science and New Energy Technology Research Center, Tsinghua-Berkeley Shenzhen Institute, Tsinghua University, Shenzhen, 518055, China
| | - Changyong Wu
- Research Center of Environmental Pollution Control Engineering Technology, Chinese Research Academy of Environmental Sciences, Beijing, 100012, China.
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Song T, Zhang X, Li J. Aerobic granular sludge with filamentous bacteria immobilized by string carriers to treat simulated municipal wastewater in a continuous flow reactor. BIORESOURCE TECHNOLOGY 2022; 363:127917. [PMID: 36089129 DOI: 10.1016/j.biortech.2022.127917] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/12/2022] [Revised: 08/30/2022] [Accepted: 09/04/2022] [Indexed: 06/15/2023]
Abstract
Aerobic granular sludge with filamentous bacteria (FAGS) has displayed many desirable properties. However, the selective pressure based on settling speed cannot effectively separate FAGS from water in sequencing batch reactor (SBR), which limits FAGS development. In this study, a new selection pressure was created by adding string carriers. Strings were used as crystal nuclei to form immobilized FAGS to achieve rapid separation from water. The immobilization of FAGS was achieved in both SBR and continuous flow reactor (CFR). The immobilization and long-term operation of FAGS in CFR were explored. NH4+ and COD removal efficiency remained above 90 % and 85 %, respectively. Sphaerotilus, denitrifying microorganisms and EPS-secreting microorganisms were the main microorganisms in the immobilized FAGS. The selection pressure provided by the strings, the operating characteristics of the CFR, and the properties of Sphaerotilus may play key role in the immobilization of FAGS.
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Affiliation(s)
- Tao Song
- School of Civil and Environmental Engineering, Shenzhen Key Laboratory of Water Resource Application and Environmental Pollution Control, Harbin Institute of Technology, Shenzhen, Shenzhen, Guangdong 518055, PR China
| | - Xiaolei Zhang
- School of Civil and Environmental Engineering, Shenzhen Key Laboratory of Water Resource Application and Environmental Pollution Control, Harbin Institute of Technology, Shenzhen, Shenzhen, Guangdong 518055, PR China
| | - Ji Li
- School of Civil and Environmental Engineering, Shenzhen Key Laboratory of Water Resource Application and Environmental Pollution Control, Harbin Institute of Technology, Shenzhen, Shenzhen, Guangdong 518055, PR China; Shenzhen Key Laboratory of Water Resource Utilization and Environmental Pollution Control, Shenzhen 518055, PR China; State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin 150090, PR China.
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9
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Chen L, Wang XD, Chang JS, Lee DJ. Biofilm with highly heterogeneous interior structure for pollutant removal: Effects of individual extracellular polymeric substance. BIORESOURCE TECHNOLOGY 2022; 361:127669. [PMID: 35878769 DOI: 10.1016/j.biortech.2022.127669] [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: 06/14/2022] [Revised: 07/16/2022] [Accepted: 07/18/2022] [Indexed: 06/15/2023]
Abstract
For the first time, this study reveals the effects of an individual component of extracellular polymeric substances on the substrate consumption rates by the embedded cells based on the highly heterogeneous interior structures of a working biofilm. The flow-across mode in operation established a boundary-layer flow field with high transport resistance, making the uniformly structured model valid. Conversely, the flow field of the flow-through mode is determined by 46% jointly by proteins and β-d-glucopyranose polysaccharides. The substrate consumption rates hindered by β-d-glucopyranose polysaccharide is up to 60% over the 20%-40% biofilm height from the bottom, much lower than expected by the uniformly structured models. The strategies to maximize the biofilm performance have been suggested.
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Affiliation(s)
- Liuyi Chen
- Research Center of Engineering Thermophysics, North China Electric Power University, Beijing 102206, China; School of Energy Power and Mechanical Engineering, North China Electric Power University, Beijing 102206, China
| | - Xiao-Dong Wang
- Research Center of Engineering Thermophysics, North China Electric Power University, Beijing 102206, China; School of Energy Power and Mechanical Engineering, North China Electric Power University, Beijing 102206, China
| | - Jo-Shu Chang
- Research Center for Smart Sustainable Circular Economy, Tunghai University, Taichung 407, Taiwan
| | - Duu-Jong Lee
- Department of Mechanical Engineering, City University of Hong Kong, Kowloon Tong, Hong Kong; Department of Chemical Engineering & Materials Science, Yuan Ze University, Chung-Li 32003, Taiwan.
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Cydzik-Kwiatkowska A, de Jonge N, Poulsen JS, Nielsen JL. Unravelling gradient layers of microbial communities, proteins, and chemical structure in aerobic granules. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 829:154253. [PMID: 35276168 DOI: 10.1016/j.scitotenv.2022.154253] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/06/2021] [Revised: 02/26/2022] [Accepted: 02/26/2022] [Indexed: 06/14/2023]
Abstract
Most bacteria live in microbial assemblages like biofilms and granules, and each layer of these assemblages provides a niche for certain bacteria with specific metabolic functions. In this study, a gentle (non-destructive) extraction approach based on a cation exchange resin and defined shear was employed to gradually disintegrate biomass and collect single layers of aerobic granules from a full-scale municipal wastewater treatment plant. The microbial community composition of granule layers was characterized using next-generation sequencing (NGS) targeting the 16S rRNA gene, and protein composition was investigated using metaproteomics. The chemical composition of eroded layers was explored using Fourier Transformed Infrared Spectroscopy. On the surface of the granules, the microbial structure (flocculation-supporting Nannocystis sp.) as well as composition of extracellular polymers (extracellular DNA) and proteome (chaperonins and binding proteins) favored microbial aggregation. Extracellular polymeric substances in the granules were composed of mostly proteins and EPS-producers, such as Tetrasphaera sp. and Zoogloea sp., were evenly distributed throughout the granule structure. The interior of the granules harbored several denitrifiers (e.g., Thauera sp.), phosphate-accumulating denitrifiers (Candidatus Accumulibacter, Dechloromonas sp.) and nitrifiers (Candidatus Nitrotoga). Proteins associated with glycolytic activity were identified in the outer and middle granule layers, and proteins associated with phosphorus conversions, in the deeper layers. In conclusion, the use of an existing cation-exchange resin for gradual biomass disintegration, combined with NGS and metaproteomic analysis was demonstrated as a promising approach for simultaneously investigating the identity and functions of microbes in multilayered biofilm structures.
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Affiliation(s)
- Agnieszka Cydzik-Kwiatkowska
- University of Warmia and Mazury in Olsztyn, Faculty of Geoengineering, Department of Environmental Biotechnology, Sloneczna 45G, Olsztyn, Poland
| | - Nadieh de Jonge
- Aalborg University, Department of Chemistry and Bioscience, Fredrik Bajers Vej 7H, 9220 Aalborg, Denmark
| | - Jan Struckmann Poulsen
- Aalborg University, Department of Chemistry and Bioscience, Fredrik Bajers Vej 7H, 9220 Aalborg, Denmark
| | - Jeppe Lund Nielsen
- Aalborg University, Department of Chemistry and Bioscience, Fredrik Bajers Vej 7H, 9220 Aalborg, Denmark.
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11
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Sarvajith M, Nancharaiah YV. Enhancing biological nitrogen and phosphorus removal performance in aerobic granular sludge sequencing batch reactors by activated carbon particles. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2022; 303:114134. [PMID: 34839174 DOI: 10.1016/j.jenvman.2021.114134] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/08/2021] [Revised: 11/18/2021] [Accepted: 11/18/2021] [Indexed: 06/13/2023]
Abstract
Long start-up periods for aerobic granular sludge (AGS) formation and establishment of P removal pathways are challenges for widespread implementation of AGS process. External additives such as activated carbon (AC) attracted interest for accelerating AGS formation. However, the roles of AC in granulation and biological nutrient removal (BNR) are not understood. Here, the role of AC was investigated in decreasing start-up periods in AGS formation and BNR under different carbon substrate conditions (i.e., acetate (HAc), propionate (HPr) and HAc-HPr) in sequencing batch reactors (SBRs). AC addition increased aggregation index and settleability of activated sludge (AS) inoculum which minimized AS washout from SBRs. AC addition hastened AGS formation and establishment of BNR pathways by facilitating AS retention and biofilm formation. Feeding HAc or HAc-HPr supported better granulation (MLSS: 6-7 g l-1, SVI: 30-40 ml g-1) than HPr (MLSS: 4 g l-1, SVI: 70). The start-up periods for efficient total nitrogen (TN) removals were decreased to 22 and 16 d from 38 to 25 d, respectively, in AC augmented SBRs fed with either HAc or HAc-HPr. TN removals were higher at ≥95% in HAc or HAc-HPr fed SBRs. Total phosphorus (TP) removals were also higher in AC-augmented SBRs at 80% and ≥90% in HAc and HAc-HPr fed SBRs, respectively. In contrast, TN and TP removals were lower at 70% and 35%, respectively, in HPr fed SBR. Ammonium was primarily removed via nitritation-denitritation pathway. Phosphorus removal was at 1.7 to 2-fold higher in AC augmented SBRs and driven by enhanced biological phosphorus removal (EBPR) pathway. MiSeq sequencing and qPCR revealed higher enrichment of polyphosphate accumulating organisms (PAOs), denitrifying PAOs, and ammonia oxidizers in AC-augmented SBRs fed with HAc or HAc-HPr. This study demonstrates that AC addition can be considered for enrichment of PAOs and establishment of EBPR in aerobic granular SBRs.
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Affiliation(s)
- M Sarvajith
- Biofouling and Biofilm Processes Section, WSCD, Chemistry Group, Bhabha Atomic Research Centre, Kalpakkam, 603102, Tamil Nadu, India; Homi Bhabha National Institute, BARC Training School Complex, Anushakti Nagar, Trombay, Mumbai, 400 094, India
| | - Y V Nancharaiah
- Biofouling and Biofilm Processes Section, WSCD, Chemistry Group, Bhabha Atomic Research Centre, Kalpakkam, 603102, Tamil Nadu, India; Homi Bhabha National Institute, BARC Training School Complex, Anushakti Nagar, Trombay, Mumbai, 400 094, India.
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12
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Li Z, Li H, Zhao L, Liu X, Wan C. Understanding the role of cations and hydrogen bonds on the stability of aerobic granules from the perspective of the aggregation and adhesion behavior of extracellular polymeric substances. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 795:148659. [PMID: 34237538 DOI: 10.1016/j.scitotenv.2021.148659] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/11/2021] [Revised: 06/19/2021] [Accepted: 06/21/2021] [Indexed: 06/13/2023]
Abstract
Extracellular polymeric substances (EPS) were essential for the granulation and stability of aerobic granular sludge (AGS). In this study, the effects of electrostatic interactions, bridging effect of divalent cations, and hydrogen bonds on the EPS-EPS and EPS-surface interaction were verified by enhancing or reducing the specific interaction with the addition of cations or urea. The size and the surface properties of EPS aggregates were investigated, the adhesion behavior and viscoelasticity of EPS were analyzed by quartz crystal microbalance with dissipation monitoring. The changes of EPS in response to the various condition were analyzed by infrared spectroscopy and fluorescence spectrum. The electrostatic repulsion between EPS could be significantly reduced by Ca2+ addition. With the bridging effect, 10 μM of Ca2+ could reduce the negative charge of EPS more effectively than 200 μM of Na+. As Ca2+ could form the complex with the protein and Ca2+ was more inclined to bind with COO-, the Ca2+ took advantage of boosting the EPS-EPS and EPS-surface interaction than Mg2+ at the same ionic strength, which resulted in the denser structure of calcium-treated EPS. The destruction of hydrogen bonds by urea addition reduced the EPS-EPS and EPS-surface interaction, which confirmed the potential existence of hydrogen bonds in the interaction of EPS-EPS and EPS-surface. The removal of hydrogen bonds of EPS destroyed the protein's secondary structure and caused the unfolded state of the protein, which led to the looser structure of the EPS layer.
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Affiliation(s)
- Zhengwen Li
- Department of Environmental Science and Engineering, Fudan University, Shanghai 200438, China
| | - Huiqi Li
- Department of Environmental Science and Engineering, Fudan University, Shanghai 200438, China
| | - Lianfa Zhao
- Department of Environmental Science and Engineering, Fudan University, Shanghai 200438, China
| | - Xiang Liu
- Department of Environmental Science and Engineering, Fudan University, Shanghai 200438, China
| | - Chunli Wan
- Department of Environmental Science and Engineering, Fudan University, Shanghai 200438, China.
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13
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Wan C, Li Z, Shen Y, Liu X. Alternating nitrogen feeding strategy induced aerobic granulation: Influencing conditions and mechanism. J Environ Sci (China) 2021; 109:135-147. [PMID: 34607662 DOI: 10.1016/j.jes.2021.03.044] [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: 12/15/2020] [Revised: 03/30/2021] [Accepted: 03/30/2021] [Indexed: 06/13/2023]
Abstract
Effective cultivation of stable aerobic granular sludge (AGS) is a crucial step in the successful application of this technology, and the formation of AGS could be facilitated by some environmental stress conditions. Four identical sequencing batch reactors (SBRs) were established to investigate the aerobic granulation process under the same alternating ammonia nitrogen feeding strategy superimposed with different environmental conditions (inorganic carbon source, temperature, N/COD). Although various superimposed conditions induced a significant difference in the size, settling velocity, mechanic strength of AGS, mature aerobic granules could be successfully obtained in all four reactors after 70 days' operation, indicating the alternating ammonia nitrogen feeding strategy was the most critical factor for AGS formation. Based on the results of redundancy analysis, the presence of an inorganic carbon source could facilitate the cultivation of AGS with nitrification function, while the moderate temperature and fluctuant N/COD might benefit the cultivation of more stable AGS. In addition, superimposed stress conditions could result in the difference in the microbial population between four reactors, but the population diversity and abundance of microorganisms were not the determinants of AGS formation. This study provided an effective method for the cultivation of AGS by using alternating ammonia nitrogen feeding strategy.
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Affiliation(s)
- Chunli Wan
- Department of Environmental Science and Engineering, Fudan University, Shanghai 200438, China
| | - Zhengwen Li
- Department of Environmental Science and Engineering, Fudan University, Shanghai 200438, China
| | - Yanggui Shen
- College of Materials Science and Chemical Engineering, Harbin Engineering University, Harbin 150001, China
| | - Xiang Liu
- Department of Environmental Science and Engineering, Fudan University, Shanghai 200438, China.
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14
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Hamiruddin NA, Awang NA, Mohd Shahpudin SN, Zaidi NS, Said MAM, Chaplot B, Azamathulla HM. Effects of wastewater type on stability and operating conditions control strategy in relation to the formation of aerobic granular sludge - a review. WATER SCIENCE AND TECHNOLOGY : A JOURNAL OF THE INTERNATIONAL ASSOCIATION ON WATER POLLUTION RESEARCH 2021; 84:2113-2130. [PMID: 34810301 DOI: 10.2166/wst.2021.415] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Currently, research trends on aerobic granular sludge (AGS) have integrated the operating conditions of extracellular polymeric substances (EPS) towards the stability of AGS systems in various types of wastewater with different physical and biochemical characteristics. More attention is given to the stability of the AGS system for real site applications. Although recent studies have reported comprehensively the mechanism of AGS formation and stability in relation to other intermolecular interactions such as microbial distribution, shock loading and toxicity, standard operating condition control strategies for different types of wastewater have not yet been discussed. Thus, the dimensional multi-layer structural model of AGS is discussed comprehensively in the first part of this review paper, focusing on diameter size, thickness variability of each layer and diffusion factor. This can assist in facilitating the interrelation between disposition and stability of AGS structure to correspond to the changes in wastewater types, which is the main objective and novelty of this review.
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Affiliation(s)
- N A Hamiruddin
- School of Civil Engineering, Engineering Campus, Universiti Sains Malaysia, 14300 Nibong Tebal, Penang, Malaysia E-mail:
| | - N A Awang
- School of Civil Engineering, Engineering Campus, Universiti Sains Malaysia, 14300 Nibong Tebal, Penang, Malaysia E-mail:
| | - S N Mohd Shahpudin
- Advanced Medical and Dental Institute, Universiti Sains Malaysia, 13200 Kepala Batas, Penang, Malaysia
| | - N S Zaidi
- School of Civil Engineering, Faculty of Engineering, Universiti Teknologi Malaysia, 81310 UTM Johor Bahru, Malaysia
| | - M A M Said
- School of Civil Engineering, Engineering Campus, Universiti Sains Malaysia, 14300 Nibong Tebal, Penang, Malaysia E-mail:
| | - B Chaplot
- Department of Geography, M.J.K College, Bettiah, a constituent unit of B.R.A., Bihar University, Bettiah, Muzaffarpur, India
| | - H M Azamathulla
- Faculty of Engineering, The University of the West Indies, St. Augustine, Trinidad
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15
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Li Z, Li H, Tang R, Wan C, Zhang C, Tan X, Liu X. Understanding the dependence of start-up and stability of aerobic granule on pH from the perspective of adhesion behavior and properties of extracellular polymeric substances. ENVIRONMENTAL RESEARCH 2021; 198:111311. [PMID: 33989628 DOI: 10.1016/j.envres.2021.111311] [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: 01/02/2021] [Revised: 03/08/2021] [Accepted: 05/07/2021] [Indexed: 06/12/2023]
Abstract
The start-up and stability of aerobic granular sludge (AGS) could be greatly influenced by pH variation. The inner core in the aerobic granules provided adhesion sites for microbes by extracellular polymeric substances (EPS) adhesion, the adhesion behavior of EPS and the properties of adhesion layer formed by EPS with pH changes might directly affect the start-up efficiency and stability of AGS. In this study, the adhesion behavior of EPS at an inorganic surface and the viscoelasticity of the EPS adhesion layer with pH variation was investigated by quartz crystal microbalance with dissipation monitoring, and the response of functional groups and intermolecular interactions to pH changes was explored. Based on the interaction energy calculation, it was found that the charge repulsion between substances dominated the interactions between EPS components and between EPS and the surface by regulating protonation and deprotonation of the functional groups of EPS with pH variation. A lower energy barrier between EPS and the surface at a lower pH value could facilitate the adhesion of EPS at the surface, which favored the rapid start-up of AGS. Moreover, the high ratio of both α-helix and intermolecular hydrogen bond at an acid condition could enhance the gel-strength of EPS, which provide AGS the resistance ability against external disturbance. This study revealed the mechanism of the interactions in EPS adhesion process with the variation of pH and provided useful information for a better understanding of the stability of the AGS.
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Affiliation(s)
- Zhengwen Li
- Department of Environmental Science and Engineering, Fudan University, Shanghai, 200438, China
| | - Huiqi Li
- Department of Environmental Science and Engineering, Fudan University, Shanghai, 200438, China
| | - Rui Tang
- Department of Environmental Science and Engineering, Fudan University, Shanghai, 200438, China
| | - Chunli Wan
- Department of Environmental Science and Engineering, Fudan University, Shanghai, 200438, China.
| | - Chen Zhang
- Shanghai Municipal Engineering Design General Institute, Shanghai, 200092, China
| | - Xuejun Tan
- Shanghai Municipal Engineering Design General Institute, Shanghai, 200092, China
| | - Xiang Liu
- Department of Environmental Science and Engineering, Fudan University, Shanghai, 200438, China.
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16
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Wang W, Xue H, Wang H, Ma J, Wu M, Wang Y. High adhesion ability of anammox granular microbes directly revealed by QCM-D technique. ENVIRONMENTAL RESEARCH 2021; 194:110646. [PMID: 33359458 DOI: 10.1016/j.envres.2020.110646] [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: 09/03/2020] [Revised: 11/22/2020] [Accepted: 12/17/2020] [Indexed: 06/12/2023]
Abstract
Anammox bacteria are widely found to grow in bioaggregates form, but the reason for their high aggregation ability remains elusive. In this study, four kinds of sludge, i.e., anammox granules, anaerobic granules, aerobic granules, and partial nitrification flocs, were studied and compared to investigate their differences in adherence properties. We directly explored the adherence properties of sludge samples before and after extracellular polymeric substances (EPS) extraction, using quartz-crystal microbalance technique with dissipation monitoring technique. Results showed that EPS indeed stimulated the adherence properties of all sludge samples. The most striking feature here is that anammox consortia had the highest adhesion rate and mass, and formed the most compact layer on the gold-coated sensor surfaces both before and after EPS extraction among the four sludge samples, indicating their inherent high adhesion ability. The composition and spectral characteristics of EPS samples were also investigated, and it reveals that the relatively high extracellular proteins/polysaccharides ratio of anammox granules (3.2 ± 0.4) rather than total EPS concentration had contributed to their high adhesion ability. The findings are helpful for understanding the adherence properties of anammox bacteria, and will serve as a guide for further researches to exploring the aggregation process of anammox bacteria.
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Affiliation(s)
- Weigang Wang
- State Key Laboratory of Pollution Control and Resources Reuse, Shanghai Institute of Pollution Control and Ecological Security, College of Environmental Science and Engineering, Tongji University, Siping Road, Shanghai, 200092, PR China
| | - Hao Xue
- State Key Laboratory of Pollution Control and Resources Reuse, Shanghai Institute of Pollution Control and Ecological Security, College of Environmental Science and Engineering, Tongji University, Siping Road, Shanghai, 200092, PR China
| | - Han Wang
- State Key Laboratory of Pollution Control and Resources Reuse, Shanghai Institute of Pollution Control and Ecological Security, College of Environmental Science and Engineering, Tongji University, Siping Road, Shanghai, 200092, PR China
| | - Jie Ma
- State Key Laboratory of Pollution Control and Resources Reuse, Shanghai Institute of Pollution Control and Ecological Security, College of Environmental Science and Engineering, Tongji University, Siping Road, Shanghai, 200092, PR China
| | - Min Wu
- State Key Laboratory of Pollution Control and Resources Reuse, Shanghai Institute of Pollution Control and Ecological Security, College of Environmental Science and Engineering, Tongji University, Siping Road, Shanghai, 200092, PR China
| | - Yayi Wang
- State Key Laboratory of Pollution Control and Resources Reuse, Shanghai Institute of Pollution Control and Ecological Security, College of Environmental Science and Engineering, Tongji University, Siping Road, Shanghai, 200092, PR China.
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17
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Li Z, Wan C, Liu X, Wang L, Lee DJ. Understanding of the mechanism of extracellular polymeric substances of aerobic granular sludge against tetracycline from the perspective of fluorescence properties. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 756:144054. [PMID: 33277008 DOI: 10.1016/j.scitotenv.2020.144054] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/06/2020] [Revised: 11/19/2020] [Accepted: 11/19/2020] [Indexed: 06/12/2023]
Abstract
Aerobic granular sludge (AGS) exhibited an excellent removal efficiency and a high tolerance in the treatment of antibiotics wastewater. Extracellular polymeric substances (EPS) of AGS with abundant binding sites might serve as the first barrier to prevent the direct contact of antibiotics and cells, thereby keeping the stability of AGS. In this study, the investigations in the fluorescence properties and the molecular weight of AGS-EPS after interaction with tetracycline (TC) were combined to reveal the resistance mechanism of AGS-EPS against TC. The two-dimensional correlation spectroscopy (2D-COS) was utilized to analyze the interaction priority of the AGS-EPS components with TC. Results showed that TC interacted with proteins and humic acid in AGS-EPS by forming a complex through hydrogen bond and van der Waals force. Compared with humic acid, TC could preferentially interact with proteins and form more stable complexes. Moreover, the components with the larger molecular weight in AGS-EPS interact with TC prior to which with smaller molecular weight. Significantly, TC exhibited the potential of binding with the divalent cation of AGS-EPS and caused the conformation changes of the protein. Therefore, AGS-EPS could resist the TC at a certain concentration range by trapping antibiotics, while over-loaded TC would cause the instability of AGS due to the limited interaction site of AGS-EPS and the destructive effect of antibiotics on AGS-EPS. This study provided a theoretical basis for understanding the interaction mechanism between antibiotics and AGS-EPS and offered a reference for AGS to maintain the stability of granules under the threat of antibiotics.
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Affiliation(s)
- Zhengwen Li
- Department of Environmental Science and Engineering, Fudan University, Shanghai 200438, China
| | - Chunli Wan
- Department of Environmental Science and Engineering, Fudan University, Shanghai 200438, China.
| | - Xiang Liu
- Department of Environmental Science and Engineering, Fudan University, Shanghai 200438, China.
| | - Li Wang
- Center of Analysis and Measurement, Fudan University, Shanghai 200438, China
| | - Duu-Jong Lee
- Department of Chemical Engineering, National Taiwan University, Taipei 106, Taiwan
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18
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Wang BB, Luo Q, Li HJ, Yao Q, Zhang L, Zou JT, He F. Characterization of aerobic granules formed in an aspartic acid fed sequencing batch reactor under unfavorable hydrodynamic selection conditions. CHEMOSPHERE 2020; 260:127600. [PMID: 32758769 DOI: 10.1016/j.chemosphere.2020.127600] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/19/2020] [Revised: 05/27/2020] [Accepted: 06/30/2020] [Indexed: 06/11/2023]
Abstract
Granules initiation and development is the backbone of aerobic granular sludge technology. Feed composition can notably affect initiation and development of aerobic granules, and yield aerobic granules with distinct microbial community, morphology and structure. This paper reports an unexpected formation of aerobic granules in an aspartic acid fed SBR under unfavorable hydrodynamic selection conditions. Detailed characteristics of these aerobic granules were investigated in terms of morphology, structure, bioactivity and EPS. The results showed that due to the absence of favorable hydrodynamic selection pressure, the formed aerobic granules had an irregular shape with a rough outline and loose internal structure, which was quite different from mature aerobic granules. Bacteria in these aerobic granules were mainly presented in the form of microcolony with calcium and β-polysaccharides responsible for its mechanical stability. The high N/C ratio of aspartic acid enabled the enrichment of significant amount of nitrifiers within aerobic granules and thus resulted in high nitrification activity of these aerobic granules. The negatively charged and hydrophilic aspartic acid also induced the bacteria to secrete more exopolysaccharides for contributing to more neutral and hydrophilic surface of the aerobic granules, which was beneficial for aspartic acid capture. As a result, polysaccharides, rather than proteins, became the major components of EPS in these aerobic granules. This paper provides us a foundation to better understand the granulation potential of proteinaceous substrates that is frequently encountered in industrial wastewaters.
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Affiliation(s)
- Bin-Bin Wang
- College of Environment, Zhejiang University of Technology, Hangzhou, Zhejiang, 310014, China
| | - Qin Luo
- College of Environment, Zhejiang University of Technology, Hangzhou, Zhejiang, 310014, China
| | - Hui-Juan Li
- School of Environmental and Chemical Engineering, Xi'an Polytechnic University, Xi'an, Shaanxi, 710048, China
| | - Qian Yao
- School of Biological and Environmental Engineering, Xi'an University, Xi'an, Shaanxi, 710065, China
| | - Lin Zhang
- Center for Environmental Education and Communications, Ministry of Ecology and Environment, Beijing, 100029, China
| | - Jin-Te Zou
- College of Environment, Zhejiang University of Technology, Hangzhou, Zhejiang, 310014, China
| | - Feng He
- College of Environment, Zhejiang University of Technology, Hangzhou, Zhejiang, 310014, China.
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19
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Guo T, Ji Y, Zhao J, Horn H, Li J. Coupling of Fe-C and aerobic granular sludge to treat refractory wastewater from a membrane manufacturer in a pilot-scale system. WATER RESEARCH 2020; 186:116331. [PMID: 32877808 DOI: 10.1016/j.watres.2020.116331] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/19/2020] [Revised: 08/20/2020] [Accepted: 08/21/2020] [Indexed: 06/11/2023]
Abstract
A novel pilot-scale system based on aerobic granular sludge (AGS) as a biological treatment step was proposed to treat refractory wastewater from a membrane manufacturer. The components of the system included a microelectrolysis Fe-C filter, a hydrolysis acidification bioreactor (HA), sequence batch reactor 1 (AGS SBR1), sequence batch reactor 2 (AGS SBR2), and a membrane bioreactor (MBR). The Fe-C filter effectively improved the biodegradability of the wastewater components and introduced some byproducts (such as Fe2+, Fe3+, and Fe minerals) that are beneficial for the cultivation and stability of the AGS. Ideal conditions for aerobic granulation were maintained in the SBR, such as alternating feast and famine conditions. A selection pressure, including a hydraulic shear force and settling time, was also created therein. The results showed that the AGS was formed successfully in both SBR1 and SBR2, the sludge volume index after 30 min (SVI30) and mean particle size reached 34.2 mL/g and 720 µm, and 36.7 mL/g and 610 µm, respectively, and a satisfactory nutrient removal capacity was achieved in the system. During the entire experimental period, the microbial community changed significantly; enrichment of microbes with the secretion of extracellular polymeric substances (EPS), granule stabilization functions in the AGS, and the differentiation of microbes corresponding to the function of each unit were observed. The use of Fe-C, application of SBRs, and use of dewatered sludge as an inoculant played key roles in the cultivation and stability of the AGS.
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Affiliation(s)
- Tao Guo
- Key Laboratory of Microbial Technology for Industrial Pollution Control of Zhejiang Province, College of Environment, Zhejiang University of Technology, Hangzhou, China
| | - Yu Ji
- Hangzhou Tianchuang Environmental Technology Co., Ltd, Hangzhou, China
| | - Jingwei Zhao
- Hangzhou Tianchuang Environmental Technology Co., Ltd, Hangzhou, China
| | - Harald Horn
- Karlsruhe Institute of Technology, Engler-Bunte-Institut, Water Chemistry and Water Technology, Karlsruhe, Germany
| | - Jun Li
- Key Laboratory of Microbial Technology for Industrial Pollution Control of Zhejiang Province, College of Environment, Zhejiang University of Technology, Hangzhou, China.
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20
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Li Z, Lin L, Liu X, Wan C, Lee DJ. Understanding the role of extracellular polymeric substances in the rheological properties of aerobic granular sludge. THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 705:135948. [PMID: 31836231 DOI: 10.1016/j.scitotenv.2019.135948] [Citation(s) in RCA: 42] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/21/2019] [Revised: 11/29/2019] [Accepted: 12/03/2019] [Indexed: 06/10/2023]
Abstract
The gel-properties of aerobic granular sludge could sustain the mechanical strength and stability of granules during the operation of wastewater treatment. The contributing extracellular polymeric substances to the gel strength of aerobic granular sludge were verified from the perspective of rheological properties in this study. Moreover, the correlations between the molecular structure and gel properties of extracellular polymeric substances were established by analyzing rheological properties and spectrum results of extracellular polymeric substances extracted by various extraction methods. The results indicated that protein and polysaccharide were indispensable to maintain the cross-linking structure of extracellular polymeric substances. The gel strength of extracellular polymeric substances was positively correlated with the amount of α-helix of natural protein and intermolecular hydrogen bond between each component. The cation exchange resin method which retained the relatively higher ratio of α-helix of natural protein and intermolecular hydrogen bond could better preserve the gel properties of the original aerobic granular sludge. This study could provide a theoretical reference for the cultivation of aerobic granular sludge and the optimization of operating conditions of the reactor.
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Affiliation(s)
- Zhengwen Li
- Department of Environmental Science and Engineering, Fudan University, Shanghai 200433, China
| | - Lin Lin
- Tsinghua-Berkeley Shenzhen Institute, Tsinghua University, Shenzhen, China
| | - Xiang Liu
- Department of Environmental Science and Engineering, Fudan University, Shanghai 200433, China..
| | - Chunli Wan
- Department of Environmental Science and Engineering, Fudan University, Shanghai 200433, China..
| | - Duu-Jong Lee
- Department of Chemical Engineering, National Taiwan University, Taipei 106, Taiwan.; Department of Chemical Engineering, National Taiwan University of Science and Technology, Taipei 10607, Taiwan
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21
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Zou J, Pan J, Wu S, Qian M, He Z, Wang B, Li J. Rapid control of activated sludge bulking and simultaneous acceleration of aerobic granulation by adding intact aerobic granular sludge. THE SCIENCE OF THE TOTAL ENVIRONMENT 2019; 674:105-113. [PMID: 31004888 DOI: 10.1016/j.scitotenv.2019.04.006] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/12/2019] [Revised: 03/29/2019] [Accepted: 04/01/2019] [Indexed: 06/09/2023]
Abstract
The feasibility of rapidly controlling activated sludge bulking and accelerating aerobic sludge granulation was evaluated by adding intact aerobic granular sludge (AGS) to the bulking activated sludge (BAS) reactor. Two ratios of AGS to BAS (0.2 in the first reactor (R1), and 0.4 in the second reactor (R2)) were tested. The results indicate that the addition of AGS immediately improved the settling ability of BAS (sludge volume index at 30 min (SVI30) in R1 and R2 decreased from 173.1 mL/g to 130.8 and 91.3 mL/g, respectively) and gradually increased the biomass concentration (mixed liquor suspended solids (MLSS) in R1 and R2 increased to 4722 and 5190 mg/L, respectively), thus resolving the sludge bulking problem. Meanwhile, adding AGS not only promoted the BAS growth in aggregates, but also facilitated the selection of well-settling aggregates at an early stage. Consequently, the granulation process was significantly accelerated. The granulation time in R1 and R2 was 14 and 10 days, respectively, indicating that the higher ratio of AGS to BAS can result in the faster granulation. Partial nitrification could be maintained during the BAS granulation process when the initial inoculation of nitritation sludge was large enough. Additionally, the microbial community changed during the BAS granulation process. The genera Thauera and Zoogloea belonging to family Rhodobacteraceae were speculated to play an important role in the BAS granulation.
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Affiliation(s)
- Jinte Zou
- Key Laboratory of Microbial Technology for Industrial Pollution Control of Zhejiang Province, College of Environment, Zhejiang University of Technology, Hangzhou 310014, China
| | - Jiyang Pan
- College of Civil Engineering and Architecture, Zhejiang University of Technology, Hangzhou 310014, China
| | - Shuyun Wu
- Key Laboratory of Microbial Technology for Industrial Pollution Control of Zhejiang Province, College of Environment, Zhejiang University of Technology, Hangzhou 310014, China
| | - Mengjie Qian
- Key Laboratory of Microbial Technology for Industrial Pollution Control of Zhejiang Province, College of Environment, Zhejiang University of Technology, Hangzhou 310014, China
| | - Zhanfei He
- Key Laboratory of Microbial Technology for Industrial Pollution Control of Zhejiang Province, College of Environment, Zhejiang University of Technology, Hangzhou 310014, China
| | - Binbin Wang
- Key Laboratory of Microbial Technology for Industrial Pollution Control of Zhejiang Province, College of Environment, Zhejiang University of Technology, Hangzhou 310014, China
| | - Jun Li
- Key Laboratory of Microbial Technology for Industrial Pollution Control of Zhejiang Province, College of Environment, Zhejiang University of Technology, Hangzhou 310014, China.
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22
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Cai W, Huang W, Lei Z, Zhang Z, Lee DJ, Adachi Y. Granulation of activated sludge using butyrate and valerate as additional carbon source and granular phosphorus removal capacity during wastewater treatment. BIORESOURCE TECHNOLOGY 2019; 282:269-274. [PMID: 30875594 DOI: 10.1016/j.biortech.2019.03.017] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/25/2018] [Revised: 03/03/2019] [Accepted: 03/04/2019] [Indexed: 06/09/2023]
Abstract
As an efficient and low-cost phosphorus (P) removal method from wastewater, enhanced biological phosphorus removal process always faces the insufficient carbon source issue. In this study, two identical sequencing batch reactors were used to cultivate aerobic granular sludge, in which butyrate (Rb) and valerate (Rv), two major volatile fatty acids that can be produced from anaerobic fermentation of waste biomass, were respectively applied as additional carbon source. Both reactors exhibited almost same excellent organics and total nitrogen removals during 120 days' operation, about 95.2-95.7% and 67.9-68.0% respectively with noticeable difference in P removal. Compared to the granules in Rv (24.3 mg P/g-total solids), bigger and more stable ones with higher P removal capacity (11.5 mg P/g-volatile solids∙d) were finally achieved in Rb, containing higher P content (36.0 mg P/g-total solids) with more orthophosphate and polyphosphate accumulated. Microbial community analysis reflected more polyphosphate-accumulating organisms (Rhodocyclus-related bacteria and Actinobacteria) in the granules from Rb.
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Affiliation(s)
- Wei Cai
- College of Biological and Agricultural Engineering, Jilin University, Changchun 130022, China; Graduate School of Life and Environmental Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8572, Japan
| | - Wenli Huang
- MOE Key Laboratory of Pollution Process and Environmental Criteria, College of Environmental Science and Engineering, Nankai University, No. 94 Weijin Road, Nankai District, Tianjin 300071, China
| | - Zhongfang Lei
- Graduate School of Life and Environmental Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8572, Japan.
| | - Zhenya Zhang
- Graduate School of Life and Environmental Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8572, Japan
| | - Duu-Jong Lee
- Department of Chemical Engineering, National Taiwan University, Taipei 106, Taiwan
| | - Yasuhisa Adachi
- Graduate School of Life and Environmental Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8572, Japan
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23
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Wang S, Ma X, Wang Y, Du G, Tay JH, Li J. Piggery wastewater treatment by aerobic granular sludge: Granulation process and antibiotics and antibiotic-resistant bacteria removal and transport. BIORESOURCE TECHNOLOGY 2019; 273:350-357. [PMID: 30448688 DOI: 10.1016/j.biortech.2018.11.023] [Citation(s) in RCA: 44] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/01/2018] [Revised: 11/03/2018] [Accepted: 11/05/2018] [Indexed: 06/09/2023]
Abstract
The aim of this work was to study the responses of aerobic granulation process to antibiotics and investigate the antibiotics and antibiotic-resistant bacteria (ARB) removal and transport. Results showed that aerobic granular sludge (AGS) was dominant in the bioreactor at day 45, and the relatively high protein content from tightly bound extracellular polymeric substances (TB-EPS) facilitated aerobic granulation and maintained biomass stabilization. The protein contents in EPS and TB-EPS were positively correlated with relative hydrophobicity, thereby improving the adsorption capacity among hydrophobic particles. The chemical oxygen demand (COD), NH3-N, and total N removal efficiencies were 98.0%, 97.0%, and 92.4%, respectively. Five antibiotics, including kanamycin, tetracycline, ciprofloxacin, ampicillin, and erythromycin, were examined in piggery wastewater, with concentrations up to the concentration range of 29.4-44.1 µg/l, and the total antibiotics removal rate reached up to 88.4% ± 4.5%. A total of 5.2% of the total antibiotics were discharged from bioreactor, and 62.5% of the total antibiotics were degraded, and 32.3% of total antibiotics were adsorbed by aerobic granules. The presence of antibiotics rarely exhibited an influence on AGS formation, and the relatively high microbial activity of aerobic granules was beneficial to antibiotics removal. The ARB removal rate increased up to 89.4% ± 3.3%, but a large amount of ARB was enriched in aerobic granules.
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Affiliation(s)
- Shuo Wang
- Jiangsu Key Laboratory of Anaerobic Biotechnology, School of Environment and Civil Engineering, Jiangnan University, Wuxi 214122, China; Jiangsu College of Water Treatment Technology and Material Collaborative Innovation Center, Suzhou 215009, China; Department of Civil Engineering, Schulich School of Engineering, University of Calgary, Calgary T2N 1N4, Canada
| | - Xinxin Ma
- Jiangsu Key Laboratory of Anaerobic Biotechnology, School of Environment and Civil Engineering, Jiangnan University, Wuxi 214122, China
| | - Yuying Wang
- Jiangsu Key Laboratory of Anaerobic Biotechnology, School of Environment and Civil Engineering, Jiangnan University, Wuxi 214122, China
| | - Guocheng Du
- Ministry Key Laboratory of Industrial Biotechnology, School of Biotechnology, Jiangnan University, Wuxi 214122, China
| | - Joo-Hwa Tay
- Department of Civil Engineering, Schulich School of Engineering, University of Calgary, Calgary T2N 1N4, Canada
| | - Ji Li
- Jiangsu Key Laboratory of Anaerobic Biotechnology, School of Environment and Civil Engineering, Jiangnan University, Wuxi 214122, China; Jiangsu College of Water Treatment Technology and Material Collaborative Innovation Center, Suzhou 215009, China.
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Wang S, Qian K, Zhu Y, Yi X, Zhang G, Du G, Tay JH, Li J. Reactivation and pilot-scale application of long-term storage denitrification biofilm based on flow cytometry. WATER RESEARCH 2019; 148:368-377. [PMID: 30396102 DOI: 10.1016/j.watres.2018.10.072] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/06/2018] [Revised: 10/16/2018] [Accepted: 10/25/2018] [Indexed: 06/08/2023]
Abstract
The work provides a method on the basis of flow cytometry to evaluate the performance of denitrification biofilm during the preservation, reactivation and pilot-scale operation process. The viable cell ratio of denitrification biofilm significantly reduced and further led to the decrease of denitrification capacity after long-term preservation for 5 months. Protein component in tightly bound extracellular polymeric substances (TB-EPS) could serve to enhance microbial adhesion and promote denitrification biofilm formation. With the significant correlation of viable cell ratio and microbial characteristics, 4 °C was more appropriate for preserving denitrification biofilm and conducive to maintain the relatively high denitrification capacity. A maximum denitrification rate of 5.80 gNO3--N/m2·d was obtained in pilot-scale anoxic-oxic (AO) process and Dechloromonas became greater prevalence in denitrification suspended carriers. Furthermore, the enrichment of Pseudomonas, Parcubacteria, Acidovorax, Aquabacterium and Unclassified_Flavobacteriaceae enhanced biofilm formation and nutrient conservation. The significantly positive correlation between viable cell ratio and the ratio of nitrate reduction to COD consumption was discovered, and the indices of Chao, ACE, Shannon and Simpson of denitrification biofilm were positively correlated with viable cell ratio, meaning that flow cytometry analysis was reasonable and suitable to evaluate the performances of denitrification biofilm.
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Affiliation(s)
- Shuo Wang
- Jiangsu Key Laboratory of Anaerobic Biotechnology, School of Environment and Civil Engineering, Jiangnan University, Wuxi, 214122, China; Jiangsu College of Water Treatment Technology and Material Collaborative Innovation Center, Suzhou, 215009, China; Department of Civil Engineering, Schulich School of Engineering, University of Calgary, Calgary, T2N 1N4, Canada
| | - Kai Qian
- Jiangsu Key Laboratory of Anaerobic Biotechnology, School of Environment and Civil Engineering, Jiangnan University, Wuxi, 214122, China
| | - Yin Zhu
- Jiangsu Key Laboratory of Anaerobic Biotechnology, School of Environment and Civil Engineering, Jiangnan University, Wuxi, 214122, China
| | - Xuesong Yi
- School of Environmental Science and Engineering, Hainan University, Haikou, 570028, China
| | - Guangsheng Zhang
- Jiangsu Key Laboratory of Anaerobic Biotechnology, School of Environment and Civil Engineering, Jiangnan University, Wuxi, 214122, China; Jiangsu College of Water Treatment Technology and Material Collaborative Innovation Center, Suzhou, 215009, China
| | - Guocheng Du
- Ministry Key Laboratory of Industrial Biotechnology, School of Biotechnology, Jiangnan University, Wuxi, 214122, China
| | - Joo-Hwa Tay
- Department of Civil Engineering, Schulich School of Engineering, University of Calgary, Calgary, T2N 1N4, Canada
| | - Ji Li
- Jiangsu Key Laboratory of Anaerobic Biotechnology, School of Environment and Civil Engineering, Jiangnan University, Wuxi, 214122, China; Jiangsu College of Water Treatment Technology and Material Collaborative Innovation Center, Suzhou, 215009, China.
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de Sousa Rollemberg SL, Mendes Barros AR, Milen Firmino PI, Bezerra Dos Santos A. Aerobic granular sludge: Cultivation parameters and removal mechanisms. BIORESOURCE TECHNOLOGY 2018; 270:678-688. [PMID: 30201322 DOI: 10.1016/j.biortech.2018.08.130] [Citation(s) in RCA: 87] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/16/2018] [Revised: 08/29/2018] [Accepted: 08/30/2018] [Indexed: 06/08/2023]
Abstract
Aerobic granular sludge (AGS) has been the focus of many investigations, and the main parameters responsible for AGS formation are hydrodynamic shear force, short periods and feast-famine cycles. However, some other parameters are associated with AGS maintenance after long periods of operation. This review evaluates the parameters responsible for AGS formation and maintenance and some reference values are proposed. In addition, some discussions are addressed about the main metabolic pathways that AGS uses for the removal of some compounds, such as nutrients, organic matter, dyes, recalcitrant compounds, among others. Finally, the main microbial groups present in the AGS and their respective functions are discussed. It is also highlighted that many parameters that are taken as reference currently for AGS cultivation and maintenance can be optimized for energy savings, implementation costs, among others, as well as a greater recovery of resources during wastewater treatment, within the scope of the biorefinery concept.
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Affiliation(s)
| | | | - Paulo Igor Milen Firmino
- Department of Hydraulic and Environmental Engineering, Federal University of Ceará, Fortaleza, Ceará, Brazil
| | - André Bezerra Dos Santos
- Department of Hydraulic and Environmental Engineering, Federal University of Ceará, Fortaleza, Ceará, Brazil.
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Xia J, Ye L, Ren H, Zhang XX. Microbial community structure and function in aerobic granular sludge. Appl Microbiol Biotechnol 2018; 102:3967-3979. [PMID: 29550989 DOI: 10.1007/s00253-018-8905-9] [Citation(s) in RCA: 77] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2017] [Revised: 02/22/2018] [Accepted: 02/26/2018] [Indexed: 12/28/2022]
Abstract
Aerobic granular sludge (AGS), a self-immobilized microbial consortium containing different functional microorganisms, is receiving growing attention, since it has shown great technological and economical potentials in the field of wastewater treatment. Microbial community is crucial for the formation, stability, and pollutant removal efficiency of aerobic granules. This mini-review systematically summarizes the recent findings of the microbial community structure and function of AGS and discusses the new research progress in the microbial community dynamics during the granulation process and spatial distribution patterns of the microbiota in AGS. The presented information may be helpful for the in-depth theoretical study and practical application of AGS technology in the future.
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Affiliation(s)
- Juntao Xia
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, 163 Xianlin Avenue, Nanjing, 210023, China
| | - Lin Ye
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, 163 Xianlin Avenue, Nanjing, 210023, China.
| | - Hongqiang Ren
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, 163 Xianlin Avenue, Nanjing, 210023, China
| | - Xu-Xiang Zhang
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, 163 Xianlin Avenue, Nanjing, 210023, China.
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Gonzalez-Martinez A, Muñoz-Palazon B, Rodriguez-Sanchez A, Maza-Márquez P, Mikola A, Gonzalez-Lopez J, Vahala R. Start-up and operation of an aerobic granular sludge system under low working temperature inoculated with cold-adapted activated sludge from Finland. BIORESOURCE TECHNOLOGY 2017; 239:180-189. [PMID: 28521227 DOI: 10.1016/j.biortech.2017.05.037] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/17/2017] [Revised: 05/04/2017] [Accepted: 05/07/2017] [Indexed: 06/07/2023]
Abstract
An aerobic granular sludge system has been started-up and operated at 7°C temperature using cold-adapted activated sludge as inoculum. The system could form granular biomass due to batch operation allowing for just 5-3min of biomass sedimentation. Scanning electron microscopy showed that fungi helped in the granular biomass formation in the early stages of the granule formation. The removal performance of the system was of 92-95% in BOD5, 75-80% in COD, 70-76% in total nitrogen and 50-60% in total phosphorous. The bacterial community structure from cold-adapted activated sludge changed during the operational time, leading to a final configuration dominated by Microbacteriaceae members Microbacterium and Leucobacter, which were strongly correlated to biomass settling velocity and bioreactor performance, as suggested by multivariate redundancy analyses. This experiment showed that aerobic granular sludge systems could be successfully started-up and operated, with high performance, under low operational temperatures when using cold-adapted biomass as inoculum.
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Affiliation(s)
| | - Barbara Muñoz-Palazon
- Institute of Water Research, University of Granada, C/Ramon y Cajal, 4, 18071 Granada, Spain
| | | | - Paula Maza-Márquez
- Institute of Water Research, University of Granada, C/Ramon y Cajal, 4, 18071 Granada, Spain
| | - Anna Mikola
- Department of Built Environment, University of Aalto, P.O. Box 15200, Aalto, FI-00076 Espoo, Finland
| | - Jesus Gonzalez-Lopez
- Institute of Water Research, University of Granada, C/Ramon y Cajal, 4, 18071 Granada, Spain
| | - Riku Vahala
- Department of Built Environment, University of Aalto, P.O. Box 15200, Aalto, FI-00076 Espoo, Finland
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Volatile Fatty Acids Production from Codigestion of Food Waste and Sewage Sludge Based on β-Cyclodextrins and Alkaline Treatments. ARCHAEA-AN INTERNATIONAL MICROBIOLOGICAL JOURNAL 2016; 2016:1698163. [PMID: 28096735 PMCID: PMC5206858 DOI: 10.1155/2016/1698163] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/18/2016] [Accepted: 06/19/2016] [Indexed: 11/17/2022]
Abstract
Volatile fatty acids (VFAs) are preferred valuable resources, which can be produced from anaerobic digestion process. This study presents a novel technology using β-cyclodextrins (β-CD) pretreatment integrated alkaline method to enhance VFAs production from codigestion of food waste and sewage sludge. Experiment results showed that optimized ratio of food waste to sewage sludge was 3 : 2 because it provided adequate organic substance and seed microorganisms. Based on this optimized ratio, the integrated treatment of alkaline pH 10 and β-CD addition (0.2 g/g TS) performed the best enhancement on VFAs production, and the maximum VFAs production was 8631.7 mg/L which was 6.13, 1.38, and 1.57 times higher than that of control, initial pH 10, and 0.2 g β-CD/g TS treatment, respectively. Furthermore, the hydrolysis rate of protein and polysaccharides was greatly improved in integration treatment, which was 1.18–3.45 times higher than that of other tests. Though the VFAs production and hydrolysis of polymeric organics were highly enhanced, the primary bacterial communities with different treatments did not show substantial differences.
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Wan C, Shen Y, Chen S, Liu X, Liu G, Lai JY, Lee DJ. Microstructural strength deterioration of aerobic granule sludge under organic loading swap. BIORESOURCE TECHNOLOGY 2016; 221:671-676. [PMID: 27660187 DOI: 10.1016/j.biortech.2016.09.056] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/25/2016] [Revised: 09/09/2016] [Accepted: 09/12/2016] [Indexed: 06/06/2023]
Abstract
This study revealed that the gross indicators commonly adopted for monitoring the performance of aerobic granular sludge processes are not capable of probing the microstructural deterioration of granule interior upon organic loading swaps. These granules subjected to loading swaps retained their global characteristics: appearances, sizes and settling velocities, chemical oxygen demand (COD) and ammonia-nitrogen removal capacities. However, the granule interior strength, as determined by ultrasound method, was largely weakened upon COD switch-off and was not recovered in the subsequent COD re-supply stage. In response to COD switch-off, the 5.6kDa polysaccharides component of granule extracellular polymeric substances (EPS) was diminished. Correspondingly, two bacterial species, Thauera and Sphingomonas sp., were faded away together with the significant decline in contents of intracellular cyclic dimeric GMP (c-di-GMP). The microstructural integrity of granules was seriously deteriorated upon COD switch-off, which was not detectable by the commonly adopted gross indicators.
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Affiliation(s)
- Chunli Wan
- Department of Environmental Science and Engineering, Fudan University, Shanghai 200433, China
| | - Yanggui Shen
- College of Materials Science and Chemical Engineering, Harbin Engineering University, Harbin 150001, China
| | - Si Chen
- Department of Environmental Science and Engineering, Fudan University, Shanghai 200433, China
| | - Xiang Liu
- Department of Environmental Science and Engineering, Fudan University, Shanghai 200433, China
| | - Guangmin Liu
- College of Materials Science and Chemical Engineering, Harbin Engineering University, Harbin 150001, China
| | - Juin-Yih Lai
- R&D Center for Membrane Technology, Department of Chemical Engineering, Chung Yuan Christian University, Chungli, Taiwan
| | - Duu-Jong Lee
- R&D Center for Membrane Technology, Department of Chemical Engineering, Chung Yuan Christian University, Chungli, Taiwan; Department of Chemical Engineering, National Taiwan University of Science and Technology, Taipei 10607, Taiwan; Department of Chemical Engineering, National Taiwan University, Taipei 10617, Taiwan.
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Hu J, Zhang Q, Chen YY, Lee DJ. Drying and recovery of aerobic granules. BIORESOURCE TECHNOLOGY 2016; 218:397-401. [PMID: 27392096 DOI: 10.1016/j.biortech.2016.06.121] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/29/2016] [Revised: 06/25/2016] [Accepted: 06/28/2016] [Indexed: 06/06/2023]
Abstract
To dehydrate aerobic granules to bone-dry form was proposed as a promising option for long-term storage of aerobic granules. This study cultivated aerobic granules with high proteins/polysaccharide ratio and then dried these granules using seven protocols: drying at 37°C, 60°C, 4°C, under sunlight, in dark, in a flowing air stream or in concentrated acetone solutions. All dried granules experienced volume shrinkage of over 80% without major structural breakdown. After three recovery batches, although with loss of part of the volatile suspended solids, all dried granules were restored most of their original size and organic matter degradation capabilities. The strains that can survive over the drying and storage periods were also identified. Once the granules were dried, they can be stored over long period of time, with minimal impact yielded by the applied drying protocols.
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Affiliation(s)
- Jianjun Hu
- Collaborative Innovation Center of Biomass Energy, Henan Agricultural University, Henan Province, Zhengzhou, China
| | - Quanguo Zhang
- Collaborative Innovation Center of Biomass Energy, Henan Agricultural University, Henan Province, Zhengzhou, China
| | - Yu-You Chen
- Department of Chemical Engineering, National Taiwan University, Taipei 106, Taiwan
| | - Duu-Jong Lee
- Collaborative Innovation Center of Biomass Energy, Henan Agricultural University, Henan Province, Zhengzhou, China; Department of Chemical Engineering, National Taiwan University, Taipei 106, Taiwan; Department of Chemical Engineering, National Taiwan University of Science and Technology, Taipei 106, Taiwan.
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Zhang Q, Hu J, Lee DJ. Aerobic granular processes: Current research trends. BIORESOURCE TECHNOLOGY 2016; 210:74-80. [PMID: 26873285 DOI: 10.1016/j.biortech.2016.01.098] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/13/2015] [Revised: 01/23/2016] [Accepted: 01/25/2016] [Indexed: 06/05/2023]
Abstract
Aerobic granules are large biological aggregates with compact interiors that can be used in efficient wastewater treatment. This mini-review presents new researches on the development of aerobic granular processes, extended treatments for complicated pollutants, granulation mechanisms and enhancements of granule stability in long-term operation or storage, and the reuse of waste biomass as renewable resources. A discussion on the challenges of, and prospects for, the commercialization of aerobic granular process is provided.
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Affiliation(s)
- Quanguo Zhang
- Collaborative Innovation Center of Biomass Energy, Henan Agricultural University, Henan Province, Zhengzhou, China
| | - Jianjun Hu
- Collaborative Innovation Center of Biomass Energy, Henan Agricultural University, Henan Province, Zhengzhou, China
| | - Duu-Jong Lee
- Collaborative Innovation Center of Biomass Energy, Henan Agricultural University, Henan Province, Zhengzhou, China; Department of Chemical Engineering, National Taiwan University of Science and Technology, Taipei 10607, Taiwan; Department of Chemical Engineering, National Taiwan University, Taipei 10617, Taiwan.
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