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Wei ZY, Feng M, Zhang DX, Jiang CY, Deng Y, Wang ZJ, Feng K, Song Y, Zhou N, Wang YL, Liu SJ. Deep insights into the assembly mechanisms, co-occurrence patterns, and functional roles of microbial community in wastewater treatment plants. ENVIRONMENTAL RESEARCH 2024; 263:120029. [PMID: 39299446 DOI: 10.1016/j.envres.2024.120029] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/01/2024] [Revised: 09/11/2024] [Accepted: 09/17/2024] [Indexed: 09/22/2024]
Abstract
The understanding of activated sludge microbial status and roles is imperative for improving and enhancing the performance of wastewater treatment plants (WWTPs). In this study, we conducted a deep analysis of activated sludge microbial communities across five compartments (inflow, effluent, and aerobic, anoxic, anaerobic tanks) over temporal scales, employing high-throughput sequencing of 16S rRNA amplicons and metagenome data. Clearly discernible seasonal patterns, exhibiting cyclic variations, were observed in microbial diversity, assembly, co-occurrence network, and metabolic functions. Notably, summer samples exhibited higher α-diversity and were distinctly separated from winter samples. Our analysis revealed that microbial community assembly is influenced by both stochastic processes (66%) and deterministic processes (34%), with winter samples demonstrating more random assembly compared to summer. Co-occurrence patterns were predominantly mutualistic, with over 96% positive correlations, and summer networks were more organized than those in winter. These variations were significantly correlated with temperature, total phosphorus and sludge volume index. However, no significant differences were found among microbial community across five compartments in terms of β diversity. A core community of keystone taxa was identified, playing key roles in eight nitrogen and eleven phosphorus cycling pathways. Understanding the assembly mechanisms, co-occurrence patterns, and functional roles of microbial communities is essential for the design and optimization of biotechnological treatment processes in WWTPs.
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Affiliation(s)
- Zi-Yan Wei
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
| | - Min Feng
- School of Water Resources and Environment, China University of Geosciences, Beijing, China
| | - Ding-Xi Zhang
- Department of Marine Sciences, University of Georgia, Athens, GA, USA
| | - Cheng-Ying Jiang
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
| | - Ye Deng
- Key Laboratory of Environmental Biotechnology of CAS, Research Center for Eco- Environmental Sciences, Chinese Academy of Sciences, Beijing, China
| | - Zhu-Jun Wang
- School of Tropical Agriculture and Forestry (School of Agriculture and Rural Affairs & School of Rural Revitalization), Hainan University, Haikou, China
| | - Kai Feng
- Key Laboratory of Environmental Biotechnology of CAS, Research Center for Eco- Environmental Sciences, Chinese Academy of Sciences, Beijing, China
| | - Yang Song
- PetroChina Planning and Engineering Institute, Beijing, China
| | - Nan Zhou
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
| | - Yu-Lin Wang
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao, China
| | - Shuang-Jiang Liu
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China; State Key Laboratory of Microbial Technology, Shandong University, Qingdao, China.
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2
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Guo L, Li L, Zhou S, Xiao P, Zhang L. Metabolomic insight into regulatory mechanism of heterotrophic bacteria nitrification-aerobic denitrification bacteria to high-strength ammonium wastewater treatment. BIORESOURCE TECHNOLOGY 2024; 394:130278. [PMID: 38168563 DOI: 10.1016/j.biortech.2023.130278] [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: 10/17/2023] [Revised: 12/28/2023] [Accepted: 12/28/2023] [Indexed: 01/05/2024]
Abstract
This work aimed to elucidate the metabolic mechanism of heterotrophic nitrification-aerobic denitrification (HN-AD) bacteria influenced by varying concentrations of ammonium nitrogen (NH4+-N) in high-strength synthetic wastewater treatment. The results showed that the removal rates of NH4+-N and total nitrogen, along with enzymatic activities related to nitrification and denitrification, increased with rising NH4+-N concentrations (N500:500 mg/L, N1000:1000 mg/L and N2000:2000 mg/L). The relative abundances of HN-AD bacteria were 50 %, 62 % and 82 % in the three groups. In the N2000 group, the cAMP signaling pathway, glycerophospholipid metabolites, purines and pyrimidines related to DNA/RNA synthesis, electron donor NAD+-related energy, the tricarboxylic acid (TCA) cycle and glutamate metabolism were upregulated. Therefore, influent NH4+-N at 2000 mg/L promoted glutamate metabolism to accelerate the TCA cycle, and enhanced cellular energy and advanced denitrification activity of bacteria for HN-AD. This mechanism, in turn, enhanced microbial growth and the carbon and nitrogen metabolism of bacteria for HN-AD.
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Affiliation(s)
- Lei Guo
- School of Chemistry and Chemical Engineering, Chongqing University of Technology, Chongqing 400054, China; School of Chemical Engineering, Chongqing Chemical Industry Vocational College, Chongqing 401228, China
| | - Longshan Li
- School of Chemistry and Chemical Engineering, Chongqing University of Technology, Chongqing 400054, China
| | - Shibo Zhou
- School of Chemistry and Chemical Engineering, Chongqing University of Technology, Chongqing 400054, China
| | - PengYing Xiao
- School of Chemistry and Chemical Engineering, Chongqing University of Technology, Chongqing 400054, China.
| | - Lei Zhang
- School of Chemistry and Chemical Engineering, Chongqing University of Technology, Chongqing 400054, China
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3
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Zhang Y, Zhang J, Yu D, Li J, Zhao X, Ma G, Zhi J, Dong G, Miao Y. Migration of microorganisms between nitrification-denitrification flocs, anammox biofilms and blank carriers during mainstream anammox start-up. BIORESOURCE TECHNOLOGY 2024; 393:130129. [PMID: 38040314 DOI: 10.1016/j.biortech.2023.130129] [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: 10/07/2023] [Revised: 11/17/2023] [Accepted: 11/28/2023] [Indexed: 12/03/2023]
Abstract
To solve the shortage of inoculum, the feasibility of establishing simultaneous partial nitrification, anammox, and denitrification (SNAD) reactor through inoculating nitrification-denitrification sludge, anammox biofilm and blank carriers was investigated. Advanced nitrogen removal efficiency of 91.2 ± 3.6 % was achieved. Bacteria related to nitrogen removal and fermentation were enriched in anammox biofilm, blank carriers and flocs, and the abundance of dominant anaerobic ammonia oxidizing bacteria (AnAOB), Candidatus Brocadia, reached 3.4 %, 0.5 % and 0.3 %, respectively. Candidatus Competibacter and Calorithrix became the dominant denitrifying bacteria (DNB) and fermentative bacteria (FB), respectively. The SNAD system was successfully established, and new mature biofilms formed in blank carriers, which could provide inoculum for other anammox processes. Partial nitrification, partial denitrification and aerobic_chemoheterotrophy were existed and facilitated AnAOB enrichment. Microbial correlation networks revealed the cooperation between DNB, FB and AnAOB that promoted nitrogen removal. Overall, the SNAD process was started up through inoculating more accessible inoculum.
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Affiliation(s)
- Yu Zhang
- School of Environmental Science and Engineering, Qingdao University, Qingdao 266071, PR China
| | - Jianhua Zhang
- School of Environmental and Municipal Engineering, Qingdao University of Technology, Qingdao 266520, PR China
| | - Deshuang Yu
- School of Environmental Science and Engineering, Qingdao University, Qingdao 266071, PR China
| | - Jiawen Li
- School of Environmental Science and Engineering, Qingdao University, Qingdao 266071, PR China
| | - Xinchao Zhao
- School of Environmental Science and Engineering, Qingdao University, Qingdao 266071, PR China
| | - Guocheng Ma
- School of Environmental Science and Engineering, Qingdao University, Qingdao 266071, PR China
| | - Jiaru Zhi
- School of Environmental Science and Engineering, Qingdao University, Qingdao 266071, PR China
| | - Guoqing Dong
- School of Environmental Science and Engineering, Qingdao University, Qingdao 266071, PR China
| | - Yuanyuan Miao
- School of Environmental and Municipal Engineering, Qingdao University of Technology, Qingdao 266520, PR China; School of Environmental Science and Engineering, Qingdao University, Qingdao 266071, PR China.
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4
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Ni M, Zhao Y, Pan Y, Li D, Huang Y, Chen Z, Li L, Song Z. A new insight in enhancing phosphate enrichment in biofilm process: Comparison of the key metabolic pathways in highly-efficient and dominant PAOs based on metagenomics. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2023; 341:118114. [PMID: 37163833 DOI: 10.1016/j.jenvman.2023.118114] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/30/2023] [Revised: 04/28/2023] [Accepted: 05/05/2023] [Indexed: 05/12/2023]
Abstract
The formation of dominant phosphate-accumulating organisms (PAOs) is essential for the high enrichment of phosphate in biofilm sequencing batch reactors (BSBR) for phosphorus recovery. The dominant PAOs in the biofilm process have not been isolated and purified, and the key metabolic pathways that promote the formation of dominant PAOs are still unclear. In this study, four strains of highly-efficient PAOs were obtained by an innovative isolation procedure. The relationship between the abundance of highly-efficient and dominant PAOs and the phosphate removal ability was compared. We found that the abundance of PAOs was positively correlated with the phosphate removal efficiency in vitro pure culture and complex biofilm process. Metagenomics analysis revealed that compared with highly-efficient PAOs cultured in vitro, dominant PAOs in biofilms had unique key metabolic pathways, F-ATPases and N-Acyl homoserine lactones (AHLs). F-ATPases are important for maintaining the proton motive force (PMF) required for the uptake of carbon sources by PAOs, and AHLs are participating in phosphate metabolism through quorum sensing (QS) mediated secretion of extracellular polymeric substance (EPS). The formation of dominant PAOs was promoted by optimizing carbon source uptake and phosphate metabolism. This study revealed that the difficult isolation of dominant PAOs was due to the AHLs-mediated QS, and we identified the key pathways regulating the formation of dominant PAOs in biofilms through genomics analysis. Our findings provide insights in enhancing phosphate enrichment in BSBR by modulating the components of microbial community under the low concentration of carbon source consumption.
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Affiliation(s)
- Min Ni
- School of Environmental Science and Engineering, Suzhou University of Science and Technology, Suzhou, 215009, China; Jiangsu Key Laboratory of Environmental Science and Engineering, Suzhou University of Science and Technology, Suzhou, 215009, China
| | - Yimeng Zhao
- School of Environmental Science and Engineering, Suzhou University of Science and Technology, Suzhou, 215009, China
| | - Yang Pan
- School of Environmental Science and Engineering, Suzhou University of Science and Technology, Suzhou, 215009, China; National and Local Joint Engineering Laboratory of Municipal Sewage Resource Utilization Technology, Suzhou University of Science and Technology, Suzhou, 215009, China.
| | - Dapeng Li
- School of Environmental Science and Engineering, Suzhou University of Science and Technology, Suzhou, 215009, China; National and Local Joint Engineering Laboratory of Municipal Sewage Resource Utilization Technology, Suzhou University of Science and Technology, Suzhou, 215009, China
| | - Yong Huang
- School of Environmental Science and Engineering, Suzhou University of Science and Technology, Suzhou, 215009, China; National and Local Joint Engineering Laboratory of Municipal Sewage Resource Utilization Technology, Suzhou University of Science and Technology, Suzhou, 215009, China
| | - Zhiqiang Chen
- Harbin Institute of Technology, Harbin, 150006, China
| | - Lu Li
- School of Environmental Science and Engineering, Suzhou University of Science and Technology, Suzhou, 215009, China; National and Local Joint Engineering Laboratory of Municipal Sewage Resource Utilization Technology, Suzhou University of Science and Technology, Suzhou, 215009, China
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5
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Cao S, Koch K, Duan H, Wells GF, Ye L, Zhao Y, Du R. In a quest for high-efficiency mainstream partial nitritation-anammox (PN/A) implementation: One-stage or two-stage? THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 883:163540. [PMID: 37086997 DOI: 10.1016/j.scitotenv.2023.163540] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/20/2023] [Revised: 04/07/2023] [Accepted: 04/12/2023] [Indexed: 05/03/2023]
Abstract
Partial nitritation-anammox (PN/A) process is known as an energy-efficient technology for wastewater nitrogen removal, which possesses a great potential to bring wastewater treatment plants close to energy neutrality with reduced carbon footprint. To achieve this goal, various PN/A processes implemented in a single reactor configuration (one-stage system) or two separately dedicated reactors configurations (two-stage system) were explored over the past decades. Nevertheless, large-scale implementation of these PN/A processes for low-strength municipal wastewater treatment has a long way to go owing to the low efficiency and effectiveness in nitrogen removal. In this work, we provided a comprehensive analysis of one-stage and two-stage PN/A processes with a focus on evaluating their engineering application potential towards mainstream implementation. The difficulty for nitrite-oxidizing bacteria (NOB) out-selection was revealed as the critical operational challenge to achieve the desired effluent quality. Additionally, the operational strategies of low oxygen commonly adopted in one-stage systems for NOB suppression and facilitating anammox bacteria growth results in a low nitrogen removal rate (NRR). Introducing denitrification into anammox system was found to be necessary to improve the nitrogen removal efficiency (NRE) by reducing the produced nitrate with in-situ utilizing the organics from wastewater itself. However, this may lead to part of organics oxidized with additional oxygen consumed in one-stage system, further compromising the NRR. By applying a relatively high dissolved oxygen in PN reactor with residual ammonium control, and followed by a granules-based anammox reactor feeding with a small portion of raw municipal wastewater, it appeared that two-stage system could achieve a good effluent quality as well as a high NRR. In contrast to the widely studied one-stage system, this work provided a unique perspective that more effort should be devoted to developing a two-stage PN/A process to evaluate its application potential of high efficiency and economic benefits towards mainstream implementation.
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Affiliation(s)
- Shenbin Cao
- National Engineering Laboratory for Advanced Municipal Wastewater Treatment and Reuse Technology, Beijing University of Technology, Beijing 100124, China; Chair of Urban Water Systems Engineering, Technical University of Munich, Am Coulombwall 3, 85748 Garching, Germany; College of Architecture and Civil Engineering, Faculty of Architecture, Civil and Transportation Engineering (FACTE), Beijing University of Technology, Beijing, 100124, China
| | - Konrad Koch
- Chair of Urban Water Systems Engineering, Technical University of Munich, Am Coulombwall 3, 85748 Garching, Germany
| | - Haoran Duan
- School of Chemical Engineering, the University of Queensland, St. Lucia, Queensland 4072, Australia
| | - George F Wells
- Department of Civil and Environmental Engineering, Northwestern University, Evanston, IL 60208, United States
| | - Liu Ye
- School of Chemical Engineering, the University of Queensland, St. Lucia, Queensland 4072, Australia
| | - Yingfen Zhao
- School of Chemical Engineering, the University of Queensland, St. Lucia, Queensland 4072, Australia
| | - Rui Du
- National Engineering Laboratory for Advanced Municipal Wastewater Treatment and Reuse Technology, Beijing University of Technology, Beijing 100124, China; Water Chemistry and Water Technology, Engler-Bunte-Institut, Karlsruhe Institute of Technology, Karlsruhe 76131, Germany.
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6
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De Carluccio M, Sabatino R, Eckert EM, Di Cesare A, Corno G, Rizzo L. Co-treatment of landfill leachate with urban wastewater by chemical, physical and biological processes: Fenton oxidation preserves autochthonous bacterial community in the activated sludge process. CHEMOSPHERE 2023; 313:137578. [PMID: 36529163 DOI: 10.1016/j.chemosphere.2022.137578] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/21/2022] [Revised: 12/02/2022] [Accepted: 12/14/2022] [Indexed: 06/17/2023]
Abstract
The impact of Fenton oxidation (FO) and Air stripping (AS) pre-treatments on the bacterial community of a biological activated sludge (B-AS) process for the co-treatment of mature landfill leachate (MLL) and urban wastewater (UWW) was assessed. In this work high-throughput sequencing was used to identify changes in the composition of the bacterial communities when exposed to different landfill leachate's pre-treatments. The combination of FO and AS to increase biodegradability (BOD5/COD) and reduce ammonia concentration (NH3) respectively, allowed to successfully operate the B-AS and effectively treat MLL. In particular, BOD5/COD resulted to be the key factor for bacterial community shifting. The microbiological community of the B-AS, mainly composed by the phylum Bacteroidota (Saprospiraceae, PHOS-HE51, Chitinophagaceae) after FO pre-treatment, shifted to Pseudomonadota (Caulobacteraceae and Hyphomicrobiaceae) when FO was not used. At the same time a drastic reduction in BOD5 removal was observed (90%-58%). On the other hand, high NH3 concentration affected the abundance of the family Saprospiraceae, known to play a key role in the degradation of complex organic compounds in B-AS. The results obtained suggest that a suitable combination of pre-treatments can reduce the negative effect of MLL on the B-AS process, reducing the pressure on autochthonous bacteria and therefore the acclimatization time of the biological process.
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Affiliation(s)
- Marco De Carluccio
- Water Science and Technology Group (WaSTe), Department of Civil Engineering, University of Salerno, Via Giovanni Paolo II 132, 84084, Fisciano SA, Italy
| | - Raffaella Sabatino
- Water Research Institute (IRSA) - MEG Molecular Ecology Group, CNR - National Research Council of Italy, Largo Tonolli 50, 28922, Verbania, Italy
| | - Ester M Eckert
- Water Research Institute (IRSA) - MEG Molecular Ecology Group, CNR - National Research Council of Italy, Largo Tonolli 50, 28922, Verbania, Italy
| | - Andrea Di Cesare
- Water Research Institute (IRSA) - MEG Molecular Ecology Group, CNR - National Research Council of Italy, Largo Tonolli 50, 28922, Verbania, Italy
| | - Gianluca Corno
- Water Research Institute (IRSA) - MEG Molecular Ecology Group, CNR - National Research Council of Italy, Largo Tonolli 50, 28922, Verbania, Italy
| | - Luigi Rizzo
- Water Science and Technology Group (WaSTe), Department of Civil Engineering, University of Salerno, Via Giovanni Paolo II 132, 84084, Fisciano SA, Italy.
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7
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Cheenakula D, Griebel K, Montag D, Grömping M. Concept development of a mainstream deammonification and comparison with conventional process in terms of energy, performance and economical construction perspectives. Front Microbiol 2023; 14:1155235. [PMID: 37113237 PMCID: PMC10126410 DOI: 10.3389/fmicb.2023.1155235] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2023] [Accepted: 03/13/2023] [Indexed: 04/29/2023] Open
Abstract
Deammonification for nitrogen removal in municipal wastewater in temperate and cold climate zones is currently limited to the side stream of municipal wastewater treatment plants (MWWTP). This study developed a conceptual model of a mainstream deammonification plant, designed for 30,000 P.E., considering possible solutions corresponding to the challenging mainstream conditions in Germany. In addition, the energy-saving potential, nitrogen elimination performance and construction-related costs of mainstream deammonification were compared to a conventional plant model, having a single-stage activated sludge process with upstream denitrification. The results revealed that an additional treatment step by combining chemical precipitation and ultra-fine screening is advantageous prior the mainstream deammonification. Hereby chemical oxygen demand (COD) can be reduced by 80% so that the COD:N ratio can be reduced from 12 to 2.5. Laboratory experiments testing mainstream conditions of temperature (8-20°C), pH (6-9) and COD:N ratio (1-6) showed an achievable volumetric nitrogen removal rate (VNRR) of at least 50 gN/(m3∙d) for various deammonifying sludges from side stream deammonification systems in the state of North Rhine-Westphalia, Germany, where m3 denotes reactor volume. Assuming a retained Norganic content of 0.0035 kgNorg./(P.E.∙d) from the daily loads of N at carbon removal stage and a VNRR of 50 gN/(m3∙d) under mainstream conditions, a resident-specific reactor volume of 0.115 m3/(P.E.) is required for mainstream deammonification. This is in the same order of magnitude as the conventional activated sludge process, i.e., 0.173 m3/(P.E.) for an MWWTP of size class of 4. The conventional plant model yielded a total specific electricity demand of 35 kWh/(P.E.∙a) for the operation of the whole MWWTP and an energy recovery potential of 15.8 kWh/(P.E.∙a) through anaerobic digestion. In contrast, the developed mainstream deammonification model plant would require only a 21.5 kWh/(P.E.∙a) energy demand and result in 24 kWh/(P.E.∙a) energy recovery potential, enabling the mainstream deammonification model plant to be self-sufficient. The retrofitting costs for the implementation of mainstream deammonification in existing conventional MWWTPs are nearly negligible as the existing units like activated sludge reactors, aerators and monitoring technology are reusable. However, the mainstream deammonification must meet the performance requirement of VNRR of about 50 gN/(m3∙d) in this case.
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Affiliation(s)
- Dheeraja Cheenakula
- Institute NOWUM-Energy, FH Aachen, University of Applied Sciences, Jülich, Germany
- *Correspondence: Dheeraja Cheenakula,
| | - Kai Griebel
- Institute of Environmental Engineering, RWTH Aachen, Aachen, Germany
| | - David Montag
- Institute of Environmental Engineering, RWTH Aachen, Aachen, Germany
| | - Markus Grömping
- Institute NOWUM-Energy, FH Aachen, University of Applied Sciences, Jülich, Germany
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Wang Y, Fu M, Wu B, Huang M, Ma T, Zang H, Jiang H, Zhang Y, Li C. Insight into biofilm-forming patterns: biofilm-forming conditions and dynamic changes in extracellular polymer substances. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2022; 29:89542-89556. [PMID: 35852740 DOI: 10.1007/s11356-022-21645-5] [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: 03/16/2022] [Accepted: 06/20/2022] [Indexed: 06/15/2023]
Abstract
The microbial biofilm adheres to the surface of the carrier, which protects the pollutant-degrading bacteria and resists harsh environments; thus, research on biofilm-forming patterns will help promote the application of biofilms in wastewater treatment. Herein, univariate analysis and response surface methodology (RSM) confirmed that glucose and mannose at 3-5 g/L promoted biofilm formation. Notably, the microplate method demonstrated that compared to trivalent cations, divalent cations could more greatly enhance the activity (especially magnesium) of the biofilm matrix, and the period of biofilm formation in the three strains was divided into the following stages: initial attachment (0-10 h), microcolony (10-24 h), maturation (24-48 h), and dispersion (36-72 h). During maturation, large amounts of extracellular polysaccharides (EPs) and extracellular DNA (eDNA) were distributed in the extracellular and intracellular spaces, respectively, as observed by super-resolution structured illumination microscopy (SR-SIM). This study enhances the understanding of the characteristics and patterns of biofilm formation and can facilitate the application of biofilms in wastewater treatment.
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Affiliation(s)
- Yue Wang
- College of Resource and Environment, Northeast Agricultural University, Harbin, 150030, China
| | - Meng Fu
- College of Resource and Environment, Northeast Agricultural University, Harbin, 150030, China
| | - Bowen Wu
- College of Resource and Environment, Northeast Agricultural University, Harbin, 150030, China
| | - Mingyan Huang
- College of Resource and Environment, Northeast Agricultural University, Harbin, 150030, China
| | - Tian Ma
- College of Resource and Environment, Northeast Agricultural University, Harbin, 150030, China
| | - Hailian Zang
- College of Resource and Environment, Northeast Agricultural University, Harbin, 150030, China
| | - Hanyi Jiang
- College of Resource and Environment, Northeast Agricultural University, Harbin, 150030, China
| | - Yuting Zhang
- College of Resource and Environment, Northeast Agricultural University, Harbin, 150030, China
| | - Chunyan Li
- College of Resource and Environment, Northeast Agricultural University, Harbin, 150030, China.
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9
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Chen D, Zhao L, Wang Z, Li Y, Li Y, Yin M, Wang X, Yang Y. Successional dynamics of low C/N activated sludge system under salinity shock: Performance, nitrogen removal pathways, microbial community, and assembly. CHEMOSPHERE 2022; 307:135703. [PMID: 35842038 DOI: 10.1016/j.chemosphere.2022.135703] [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: 04/08/2022] [Revised: 06/29/2022] [Accepted: 07/11/2022] [Indexed: 06/15/2023]
Abstract
Limited carbon (low C/N) and salinity stress affect the stability of wastewater treatment plants. However, the effect of salinity shock on activated sludge systems with low C/N ratio wastewater remains unclear. An anaerobic/aerobic/anoxic sequencing batch reactor treating low C/N wastewater was established to investigate the effects of salinity shock on system performance, nitrogen removal pathways, microbial community, interactions, and assembly. The results showed that the effluent COD concentration could maintain a stable level, and the average COD removal efficiency was 94.9%. However, total nitrogen removal was significantly inhibited. With the addition of salinity, efficiencies of total nitrogen removal and simultaneous nitrification and denitrification decreased from 91.4 to 73.8% to 86.7 and 39.7%, respectively; however, nitrite reduction capacity increased by 25.4%. After removing salinity, ammonia oxidation capacity further deteriorated, evidenced by the increase in effluent NH4+-N from 8.0 to 11.8 mg/L. During the salinity shock, partial nitrification became the main nitrogen removal pathway because of the inhibition of Nitrospira and high nitrite accumulation ratio (>99.0%). Molecular ecological network analysis indicated that increased competition, decreased total modules, and disappearance of keystone taxa were related to the deterioration of ammonia oxidation capacity and simultaneous nitrification and denitrification. Moreover, the abundant denitrification module and increased denitrifiers contributed to the increase in nitrite reduction capacity. Salinity shock under low C/N conditions resulted in a stronger stochastic community assembly. This study provided information that can help enable stable operations for treating low C/N wastewater.
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Affiliation(s)
- Daying Chen
- School of Environmental Science and Engineering, Tianjin University, Tianjin, 300072, China; Beijing Engineering Research Center of Environmental Material for Water Purification, College of Chemical Engineering, Beijing University of Chemical Technology, Beijing, 100029, China
| | - Lin Zhao
- School of Environmental Science and Engineering, Tianjin University, Tianjin, 300072, China
| | - Zhimin Wang
- Beijing Engineering Research Center of Environmental Material for Water Purification, College of Chemical Engineering, Beijing University of Chemical Technology, Beijing, 100029, China; Beijing Drainage Group Co., LTD, Beijing, 100061, China
| | - Yihan Li
- School of Environmental Science and Engineering, Tianjin University, Tianjin, 300072, China
| | - Yang Li
- School of Environmental Science and Engineering, Tianjin University, Tianjin, 300072, China
| | - Meilin Yin
- School of Chemical Engineering, Tianjin University, Tianjin, 300072, China
| | - Xiaohui Wang
- Beijing Engineering Research Center of Environmental Material for Water Purification, College of Chemical Engineering, Beijing University of Chemical Technology, Beijing, 100029, China
| | - Yongkui Yang
- School of Environmental Science and Engineering, Tianjin University, Tianjin, 300072, China.
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10
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Awad H, El-Mewafi M, Negm MS, Gar Alalm M. A divided flow aerobic-anoxic baffled reactor for simultaneous nitrification-denitrification of domestic wastewater. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 833:155247. [PMID: 35429571 DOI: 10.1016/j.scitotenv.2022.155247] [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: 03/19/2022] [Revised: 04/07/2022] [Accepted: 04/08/2022] [Indexed: 06/14/2023]
Abstract
A novel aerobic-anoxic baffled reactor is designed for the effective denitrification of real domestic wastewater without an external carbon source. The flow is divided between two inlets at the beginning of each zone to provide a carbon source for the denitrifying bacteria. The effects of operating parameters such as the ratio of chemical oxygen demand to nitrogen (COD/N), flow division ratio, and hydraulic retention time (HRT) on the nitrogen removal were investigated. The optimum values of COD/N and HRT were estimated using response surface methodology (RSM) coupled with a central composite experimental design. The addition of porous biomass support media considerably improved the denitrification and removal of COD. Furthermore, the aerobic-anoxic system showed high stability against sudden HRT and COD/N ratio changes. The microbial analysis showed that Alcaligenes, Achromobacter, and Bordetella were the dominant denitrifying bacteria in the anoxic zone, whereas other species coexisted in the aerobic zone.
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Affiliation(s)
- Hossam Awad
- Public Works Engineering Department, Faculty of Engineering, Mansoura University, Mansoura 35516, Egypt; Civil Engineering Department, Faculty of Engineering, Delta University for Science and Technology, Gamasa, Egypt
| | - Mahmoud El-Mewafi
- Public Works Engineering Department, Faculty of Engineering, Mansoura University, Mansoura 35516, Egypt
| | - Mohamed Shaaban Negm
- Department of Public Works Engineering, Faculty of Engineering, Ain Shams University, Cairo, Egypt
| | - Mohamed Gar Alalm
- Public Works Engineering Department, Faculty of Engineering, Mansoura University, Mansoura 35516, Egypt.
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11
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Qian Y, Guo Y, Shen J, Qin Y, Li YY. Biofilm growth characterization and treatment performance in a single stage partial nitritation/anammox process with a biofilm carrier. WATER RESEARCH 2022; 217:118437. [PMID: 35447572 DOI: 10.1016/j.watres.2022.118437] [Citation(s) in RCA: 28] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/30/2021] [Revised: 04/02/2022] [Accepted: 04/07/2022] [Indexed: 06/14/2023]
Abstract
Biofilm carriers can avoid microorganism washout while maintaining a high amount of biomass, but are also associated with a long biofilm formation period and biofilm aging. A single stage partial nitritation/anammox process (single stage PN/A) reactor was setup to study the biofilm growth characterization and treatment performance under an NLR of 0.53 to 0.90 gN/L/d over one year. Biofilm growth was divided into three stages: the formation stage, maturation stage and aging stage. The initial biofilm was observed at day 84. A nitrogen removal efficiency of 83.4% was achieved at an NLR of 0.90 gN/L/d during the mature biofilm stage. Starvation, nitrogen gas accumulation and hydroxyapatite formation resulted in biofilm aging. After mechanical stirring treatment, biofilm reactivation was achieved by biofilm re-formation within one month. There is clear potential for phosphorus recovery, as indicated by the 5.24% - 6.29% phosphorus content in the biofilm (similar to the 5%-7% phosphorus content in enhanced biological phosphate removal sludge). The AnAOB genera abundance in the biofilm maintained at a high level of 18.25%-32.31%, while the abundance of AnAOB increased from the initial 4.10% to 13.78% after mechanical stirring treatment in the suspended sludge ensured biofilm reactivation. The results of this study clearly show that mechanical stirring treatment can be used to achieve the biofilm reactivation as the biofilm fills with the hollow cylindrical carrier. This study has potential as a useful reference for the realization of the wide application of the biofilm single stage PN/A process in the future.
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Affiliation(s)
- Yunzhi Qian
- Graduate School of Environmental Studies, Tohoku University, 6-6-06 Aza-Aoba, Aramaki, Aoba-ku, Sendai, Miyagi 980-8579, Japan
| | - Yan Guo
- Department of Environmental Engineering, School of Energy and Environmental Engineering, University of Science and Technology Beijing, Beijing 100083, China; Department of Civil and Environmental Engineering, Graduate School of Engineering, Tohoku University, 6-6-06 Aza-Aoba, Aramaki, Aoba-ku, Sendai, Miyagi 980-8579, Japan
| | - Junhao Shen
- Graduate School of Environmental Studies, Tohoku University, 6-6-06 Aza-Aoba, Aramaki, Aoba-ku, Sendai, Miyagi 980-8579, Japan
| | - Yu Qin
- Department of Civil and Environmental Engineering, Graduate School of Engineering, Tohoku University, 6-6-06 Aza-Aoba, Aramaki, Aoba-ku, Sendai, Miyagi 980-8579, Japan
| | - Yu-You Li
- Graduate School of Environmental Studies, Tohoku University, 6-6-06 Aza-Aoba, Aramaki, Aoba-ku, Sendai, Miyagi 980-8579, Japan; Department of Civil and Environmental Engineering, Graduate School of Engineering, Tohoku University, 6-6-06 Aza-Aoba, Aramaki, Aoba-ku, Sendai, Miyagi 980-8579, Japan.
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12
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Su B, Liu Q, Liang H, Zhou X, Zhang Y, Liu G, Qiao Z. Simultaneous partial nitrification, anammox, and denitrification in an upflow microaerobic membrane bioreactor treating middle concentration of ammonia nitrogen wastewater with low COD/TN ratio. CHEMOSPHERE 2022; 295:133832. [PMID: 35124081 DOI: 10.1016/j.chemosphere.2022.133832] [Citation(s) in RCA: 38] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/20/2021] [Revised: 01/03/2022] [Accepted: 01/31/2022] [Indexed: 06/14/2023]
Abstract
The rapid start-up and operating characteristics of simultaneous partial nitrification, anammox, and denitrification (SNAD) process was investigated using synthetic wastewater with a low C/N ratio (COD: NH4+-N = 200 mg/L: 200 mg/L) in a novel upflow microaerobic membrane bioreactor (UMMBR). The average removal efficiencies of COD, NH4+-N, and TN in the stable phase were 89%, 96%, and 86%, respectively. Carmine granule, which coexisted with sludge floc, appeared on day 83. The high sludge concentration (12.9-17.2 g/L) and the upflow mode of the UMMBR could establish some anaerobicregions for anammox process. The anammox bacteria and short-cut denitrification (NO2-→N2) bacteria with activities of 4.46 mg NH4+-N/gVSS·h and 2.57 mg NO2--N/gVSS·h contributed TN removal of 39% and 61% on day 129, respectively. High-throughput sequencing analysis revealed that the ammonia-oxidizing archaea (AOA, 49.45% in granule and 17.05% in sludge floc) and ammonia-oxidizing bacterial (AOB, 1.30% in sludge floc) dominated the nitrifying microbial community. Candidatus Jettenia (47.14%) and Denitratisoma (10.92%) mainly existed in granule with positive correlations. Some heterotrophic bacteria (OLB13, SJA-15, 1-20, SBR1031, and SJA-28) in sludge floc benefited system stability and sludge activity and protected Candidatus Jettenia from adverse environments.
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Affiliation(s)
- Bensheng Su
- College of Chemical Engineering, Beijing University of Chemical Technology, Beijing, 100029, China.
| | - Qi Liu
- College of Chemical Engineering, Beijing University of Chemical Technology, Beijing, 100029, China
| | - Huili Liang
- College of Chemical Engineering, Beijing University of Chemical Technology, Beijing, 100029, China
| | - Xiaohua Zhou
- College of Chemical Engineering, Beijing University of Chemical Technology, Beijing, 100029, China
| | - Yuanjie Zhang
- College of Chemical Engineering, Beijing University of Chemical Technology, Beijing, 100029, China
| | - Guangqing Liu
- College of Chemical Engineering, Beijing University of Chemical Technology, Beijing, 100029, China
| | - Zhuangming Qiao
- Shandong Meiquan Environmental Protection Technology CO., Ltd, Shandong, 250002, China
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13
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Mehrani MJ, Azari M, Teichgräber B, Jagemann P, Schoth J, Denecke M, Mąkinia J. Performance evaluation and model-based optimization of the mainstream deammonification in an integrated fixed-film activated sludge reactor. BIORESOURCE TECHNOLOGY 2022; 351:126942. [PMID: 35257883 DOI: 10.1016/j.biortech.2022.126942] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/10/2022] [Revised: 02/25/2022] [Accepted: 03/01/2022] [Indexed: 06/14/2023]
Abstract
This study aimed to model and optimize mainstream deammonification in an integrated fixed-film activated sludge (IFAS) pilot plant under natural seasonal temperature variations. The effect of gradually decreasing temperature on the performance was evaluated during a winter season and a transition period to summer conditions, and the correlation of the performance parameters was investigated using principal component analysis (PCA). The optimization of intermittent aeration in the long-term (30 days) dynamic conditions with on/off ratio and dissolved oxygen (DO) set-point control was used to maximize the N-removal rate (NRR) and N-removal efficiency (NRE). Optimization results (DO set-point of 0.2-0.25 mgO2/L, and on/off ratio of 0.05) increased the NRE and NRR of total inorganic N (daily average) from 30% to > 50% and 15 gN/m3d to 25 gN/m3d, respectively. This novel long-term optimization strategy is a powerful tool for enhancing the efficiency in mainstream deammonification.
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Affiliation(s)
- Mohamad-Javad Mehrani
- Department of Urban Water- and Waste Management, University of Duisburg-Essen, Universitätsstraße 15, 45141, Essen, Germany; Faculty of Civil and Environmental Engineering, Gdansk University of Technology, Ul. Narutowicza 11/12, 80-233, Gdansk, Poland
| | - Mohammad Azari
- Department of Aquatic Environmental Engineering, Institute for Water and River Basin Management, Karlsruhe Institute of Technology (KIT), Gotthard-Franz-Str. 3, Karlsruhe 76131, Germany.
| | - Burkhard Teichgräber
- EMSCHERGENOSSENSCHAFT and LIPPEVERBAND, Kronprinzenstrasse 24, 45128, Essen, Germany
| | - Peter Jagemann
- EMSCHERGENOSSENSCHAFT and LIPPEVERBAND, Kronprinzenstrasse 24, 45128, Essen, Germany
| | - Jens Schoth
- EMSCHERGENOSSENSCHAFT and LIPPEVERBAND, Kronprinzenstrasse 24, 45128, Essen, Germany
| | - Martin Denecke
- Department of Urban Water- and Waste Management, University of Duisburg-Essen, Universitätsstraße 15, 45141, Essen, Germany
| | - Jacek Mąkinia
- Faculty of Civil and Environmental Engineering, Gdansk University of Technology, Ul. Narutowicza 11/12, 80-233, Gdansk, Poland
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14
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Zhang W, Yu D, Zhang J, Miao Y, Zhao X, Ma G, Li J, Zhang Y. Start-up of mainstream anammox process through inoculating nitrification sludge and anammox biofilm: Shift in nitrogen transformation and microorganisms. BIORESOURCE TECHNOLOGY 2022; 347:126728. [PMID: 35063624 DOI: 10.1016/j.biortech.2022.126728] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/25/2021] [Revised: 01/11/2022] [Accepted: 01/13/2022] [Indexed: 06/14/2023]
Abstract
The feasibility of starting up mainstream single-stage partial nitrification-anammox (SPNA) system by inoculating nitrification sludge and anammox biofilm was investigated. The SPNA system treating low-strength synthetic wastewater was rapidly started up with TN removal efficiency of 88.5 ± 1.8% and effluent nitrate concentration of 7.2 ± 1.2 mg/L. Both the abundance and maximum activity of nitrite oxidizing bacteria (NOB) in flocs decreased obviously. Interestingly, the abundance of anaerobic ammonium oxidizing bacteria (AnAOB) in flocs increased from 0.213% to 0.346% despite the sludge retention time (SRT) of flocs decreased to 60 days, the AnAOB in biofilm was 0.434%. That meant AnAOB gradually enriched in flocs and accounted for a fairly high proportion. The inhibition of NOB, partial denitrification and increased aerobic_chemoheterotrophy function in flocs might be the main reasons for AnAOB enrichment. The possibility of simultaneous fermentation, partial denitrification and anammox reaction was predicted in biofilm, further improving the stability of the system.
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Affiliation(s)
- Wenke Zhang
- School of Environmental Science and Engineering, Qingdao University, Qingdao 266071, PR China
| | - Deshuang Yu
- School of Environmental Science and Engineering, Qingdao University, Qingdao 266071, PR China
| | - Jianhua Zhang
- School of Environmental and Municipal Engineering, Qingdao University of Technology, Qingdao 266033, PR China
| | - Yuanyuan Miao
- School of Environmental Science and Engineering, Qingdao University, Qingdao 266071, PR China.
| | - Xinchao Zhao
- School of Environmental Science and Engineering, Qingdao University, Qingdao 266071, PR China
| | - Guocheng Ma
- School of Environmental Science and Engineering, Qingdao University, Qingdao 266071, PR China
| | - Jiawen Li
- School of Environmental Science and Engineering, Qingdao University, Qingdao 266071, PR China
| | - Yu Zhang
- School of Environmental Science and Engineering, Qingdao University, Qingdao 266071, PR China
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15
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Hausherr D, Niederdorfer R, Morgenroth E, Joss A. Robustness of mainstream anammox activity at bench and pilot scale. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 796:148920. [PMID: 34328880 DOI: 10.1016/j.scitotenv.2021.148920] [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: 03/12/2021] [Revised: 06/28/2021] [Accepted: 07/05/2021] [Indexed: 05/21/2023]
Abstract
New technologies and processes, such as mainstream anammox, aim to reduce energy requirements of wastewater treatment and improve effluent quality. However, in municipal wastewater (MWW) anammox system are often unstable due to process control disturbance, influent variability, or unwanted nitrite oxidizing bacteria (NOB). This study examines the anammox system by focusing on anammox activity and its robustness in a mainstream environment. An 8 m3 pilot-scale sequencing batch reactor (SBR) receiving pretreated MWW (with external nitrite addition) was seeded with pre-colonized carriers. Within six months at 12-20 °C an anammox activity of 200 gN·m-3·d-1 was achieved. After the startup an anammox activity of 260 ± 83 gN·m-3·d-1 was maintained over 450 days. The robustness of the anammox activity was analyzed through three disturbance experiments. Anammox biofilm on carriers were exposed to dissolved oxygen (DO = 1.6 mg·L-1, intermittent aeration), organic loading rate (OLR, C/N increased from 2:1 to 5:1) and temperature disturbances (20 °C to 12 °C) in triplicate 12 L bench scale reactors. The anammox activity and microbial community was monitored during these disturbances. The DO and OLR disturbance experiments were replicated at pilot scale to investigate upscaling effects. Bench and pilot scale anammox activity were unaffected by the DO disturbance. Similarly, an increase in OLR did not deteriorate the bench and pilot scale anammox activity, if nitrate was available. When, at bench scale, the reactor temperature was reduced from 20 °C to 12 °C overnight, anammox activity decreased significantly, this was not the case for the slow seasonal temperature changes (12-25 °C) at pilot scale where no strong temperature dependency was detected in winter. Metagenomic analysis revealed a broad range of Brocadiaceae species with no single dominant anammox species. Anammox thrive under mainstream conditions and can withstand typical process disruptions.
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Affiliation(s)
- Damian Hausherr
- Eawag: Swiss Federal Institute of Aquatic Science and Technology, 8600 Dübendorf, Switzerland.
| | - Robert Niederdorfer
- Eawag: Swiss Federal Institute of Aquatic Science and Technology, 6047 Kastanienbaum, Switzerland
| | - Eberhard Morgenroth
- Eawag: Swiss Federal Institute of Aquatic Science and Technology, 8600 Dübendorf, Switzerland; ETH Zürich, Institute of Environmental Engineering, 8093 Zürich, Switzerland
| | - Adriano Joss
- Eawag: Swiss Federal Institute of Aquatic Science and Technology, 8600 Dübendorf, Switzerland
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16
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Xu X, Ma S, Jiang H, Yang F. Start-up of the anaerobic hydrolysis acidification (ANHA)- simultaneous partial nitrification, anammox and denitrification (SNAD)/enhanced biological phosphorus removal (EBPR) process for simultaneous nitrogen and phosphorus removal for domestic sewage treatment. CHEMOSPHERE 2021; 275:130094. [PMID: 33676280 DOI: 10.1016/j.chemosphere.2021.130094] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/09/2020] [Revised: 02/13/2021] [Accepted: 02/21/2021] [Indexed: 06/12/2023]
Abstract
The simultaneous partial nitrification, anammox and denitrification (SNAD) process has been widely used in domestic sewage biological denitrification technology because of its high efficiency and low consumption. However, the simultaneous removal of another important pollution element, phosphorus, has been difficult, and its C/N ratio limitation of the influent is strict. The start-up of the anaerobic hydrolysis acidification (ANHA)- simultaneous partial nitrification, anammox and denitrification (SNAD)/enhanced biological phosphorus removal (EBPR) coupling process achieves the treatment of urban sewage for carbon, nitrogen and phosphorus removal. Under optimal conditions, the final total nitrogen and total phosphorus removal rates reached 91.59% and 89.10%, respectively. High-throughput sequencing technology showed that the ANHA reactor was mainly Lactococcus. At the same time, the main bacteria in the SNAD/EBPR process were anammox bacteria (AnAOB, Candidatus_Kuenenia, Candidatus_Brocadia) primarily existing in biofilms, while the ammonium oxidizing bacteria (AOB, Nitrosomonas), denitrifying polyphosphate-accumulating organisms (DPAOs, Pseudomonas, Flavobacterium, Bdellovibrio) and Denitrifying bacteria (DNB, Thauera, Denitratisoma, Rhodobacteraceae).were mainly found in the suspended sludge. These conclusions provide valuable information for the full-scale treatment of domestic sewage.
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Affiliation(s)
- Xiaochen Xu
- Key Laboratory of Industrial Ecology and Environmental Engineering (MOE), School of Environmental Science and Technology, Dalian University of Technology, Linggong Road 2, Dalian, 116024, China.
| | - Shiqi Ma
- Key Laboratory of Industrial Ecology and Environmental Engineering (MOE), School of Environmental Science and Technology, Dalian University of Technology, Linggong Road 2, Dalian, 116024, China
| | - Hongbin Jiang
- Key Laboratory of Industrial Ecology and Environmental Engineering (MOE), School of Environmental Science and Technology, Dalian University of Technology, Linggong Road 2, Dalian, 116024, China
| | - Fenglin Yang
- Key Laboratory of Industrial Ecology and Environmental Engineering (MOE), School of Environmental Science and Technology, Dalian University of Technology, Linggong Road 2, Dalian, 116024, China
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17
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Xiao W, Xu G, Li G. Effect of nanobubble application on performance and structural characteristics of microbial aggregates. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 765:142725. [PMID: 33069472 DOI: 10.1016/j.scitotenv.2020.142725] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/07/2020] [Revised: 09/11/2020] [Accepted: 09/26/2020] [Indexed: 06/11/2023]
Abstract
Herein an investigation on the performance and structural properties with aspects of stability, composition, functional group, and three-dimensional distribution were approached to evaluate the influence of nanobubble aeration to the two most common microbial aggregates, activated sludge and biofilm. This study found that applying nanobubble effectively provided extra oxygen for microbial aggregates and achieved a 10.58% improvement in total nitrogen removal. The structure of microbial aggregates was enhanced, where extracellular protein and polysaccharides respectively increased as maximum as 3.40 and 1.70 times in biofilm and activated sludge, accompanied by the development of activated sludge floc size and the thickness of biofilm. Further investigation on extracellular polymeric substance and surface of microbial aggregates showed the composition of functional substances of microbial aggregates were shifted by the application of nanobubble, especially the oxygen-sensitive ones. Confocal laser scanning microscopy imaging visualized that the nanobubble changed the morphology of biofilm to a more evenly one. However, an adaptive process was more needed for activated sludge rather than biofilm, it suggested application of NB optimized the distribution of functional microorganisms in-depth and the metabolism pathway of them by accelerating the structure development of microbial aggregates, especially for biofilm.
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Affiliation(s)
- Wanting Xiao
- School of Environment, Harbin Institute of Technology, Harbin 150090, PR China
| | - Guoren Xu
- School of Environment, Harbin Institute of Technology, Harbin 150090, PR China; College of Resources and Environment, University of Chinese Academy of Sciences (UCAS), Beijing 100049, PR China.
| | - Guibai Li
- School of Environment, Harbin Institute of Technology, Harbin 150090, PR China.
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