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Zheng Y, Wang Y, Yang X, Gao J, Xu G, Yuan J. Effective mechanisms of water purification for nitrogen-modified attapulgite, volcanic rock, and combined exogenous microorganisms. Front Microbiol 2022; 13:944366. [PMID: 36033894 PMCID: PMC9399813 DOI: 10.3389/fmicb.2022.944366] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2022] [Accepted: 07/15/2022] [Indexed: 12/07/2022] Open
Abstract
The study tested the water purification mechanism of the combination of microorganisms and purification materials via characteristic, enzymatic, and metagenomics methods. At 48 h, the removal rates of total nitrogen, total phosphorous, and Mn chemical oxygen demand in the combination group were 46.91, 50.93, and 65.08%, respectively. The alkaline phosphatase (AKP) activity increased during all times tested in the volcanic rock, Al@TCAP, and exogenous microorganism groups, while the organophosphorus hydrolase (OPH), dehydrogenase (DHO), and microbial nitrite reductase (NAR) activities increased at 36-48, 6-24, and 36-48 h, respectively. However, the tested activities only increased in the combination groups at 48 h. Al@TCAP exhibits a weak microbial loading capacity, and the Al@TCAP removal is primarily attributed to adsorption. The volcanic rock has a sufficient ability to load microorganisms, and the organisms primarily perform the removal for improved water quality. The predominant genera Pirellulaceae and Polynucleobacter served as the sensitive biomarkers for the treatment at 24, 36-48 h. Al@TCAP increased the expression of Planctomycetes and Actinobacteria, while volcanic rock increased and decreased the expression of Planctomycetes and Proteobacteria. The growth of Planctomycetes and the denitrification reaction were promoted by Al@TCAP and the exogenous microorganisms. The purification material addition group decreased the expression of Hyaloraphidium, Chytridiomycetes (especially Hyaloraphidium), and Monoblepharidomycetes and increased at 36-48 h, respectively. Ascomycota, Basidiomycota, and Kickxellomycota increased in group E, which enhanced the nitrogen cycle through microbial enzyme activities, and the growth of the genus Aspergillus enhanced the phosphorous purification effect.
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Affiliation(s)
- Yao Zheng
- Key Laboratory of Integrated Rice-Fish Farming Ecology, Ministry of Agriculture and Rural Affairs, Freshwater Fisheries Research Center (FFRC), Chinese Academy of Fishery Sciences (CAFS), Wuxi, China
- Wuxi Fishery College, Nanjing Agricultural University, Wuxi, China
| | - Yuqin Wang
- Wuxi Fishery College, Nanjing Agricultural University, Wuxi, China
| | - Xiaoxi Yang
- Key Laboratory of Integrated Rice-Fish Farming Ecology, Ministry of Agriculture and Rural Affairs, Freshwater Fisheries Research Center (FFRC), Chinese Academy of Fishery Sciences (CAFS), Wuxi, China
| | - Jiancao Gao
- Key Laboratory of Integrated Rice-Fish Farming Ecology, Ministry of Agriculture and Rural Affairs, Freshwater Fisheries Research Center (FFRC), Chinese Academy of Fishery Sciences (CAFS), Wuxi, China
| | - Gangchun Xu
- Key Laboratory of Integrated Rice-Fish Farming Ecology, Ministry of Agriculture and Rural Affairs, Freshwater Fisheries Research Center (FFRC), Chinese Academy of Fishery Sciences (CAFS), Wuxi, China
- Wuxi Fishery College, Nanjing Agricultural University, Wuxi, China
- *Correspondence: Gangchun Xu,
| | - Julin Yuan
- Key Laboratory of Healthy Freshwater Aquaculture, Ministry of Agriculture and Rural Affairs, Key Laboratory of Fish Health and Nutrition of Zhejiang Province, Zhejiang Institute of Freshwater Fisheries, Huzhou, China
- Julin Yuan,
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Wan X, Laureni M, Jia M, Volcke EIP. Impact of organics, aeration and flocs on N 2O emissions during granular-based partial nitritation-anammox. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 797:149092. [PMID: 34303231 PMCID: PMC7612980 DOI: 10.1016/j.scitotenv.2021.149092] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/14/2021] [Revised: 07/11/2021] [Accepted: 07/13/2021] [Indexed: 05/21/2023]
Abstract
Partial nitration-anammox is a resource-efficient technology for nitrogen removal from wastewater. However, the advantages of this nitrogen removal technology are challenged by the emission of N2O, a potent greenhouse gas. In this study, a granular sludge one-stage partial nitritation-anammox reactor comprising granules and flocs was run for 337 days in the presence of influent organics to investigate its effect on N removal and N2O emissions. Besides, the effect of aeration control strategies and flocs removal was investigated as well. The interpretation of the experimental results was complemented with modelling and simulation. The presence of influent organics (1 g COD g-1 N) helped to suppress NOB and significantly reduced the overall N2O emissions while having no significant effect on anammox activity. Besides, long-term monitoring of the reactor indicated that constant airflow rate control resulted in more stable effluent quality and less N2O emissions than DO control. Still, floc removal reduced N2O emissions at DO control but increased N2O emissions at constant airflow rate. Furthermore, anammox bacteria could significantly reduce N2O production during heterotrophic denitrification, likely via competition for NO with heterotrophs. Overall, this study demonstrated that the presence of influent organics together with proper aeration control strategies and floc management could significantly reduce the N2O emissions without compromising nitrogen removal efficiency during one-stage partial nitritation-anammox processes.
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Affiliation(s)
- Xinyu Wan
- BioCo Research Group, Department of Green Chemistry and Technology, Faculty of Bioscience Engineering, Ghent University, Coupure links 653, 9000, Ghent, Belgium
| | - Michele Laureni
- BioCo Research Group, Department of Green Chemistry and Technology, Faculty of Bioscience Engineering, Ghent University, Coupure links 653, 9000, Ghent, Belgium; Department of Biotechnology, Faculty of Applied Sciences, Delft University of Technology, Van der Maasweg 9, Delft 2629 HZ, the Netherlands
| | - Mingsheng Jia
- BioCo Research Group, Department of Green Chemistry and Technology, Faculty of Bioscience Engineering, Ghent University, Coupure links 653, 9000, Ghent, Belgium
| | - Eveline I P Volcke
- BioCo Research Group, Department of Green Chemistry and Technology, Faculty of Bioscience Engineering, Ghent University, Coupure links 653, 9000, Ghent, Belgium.
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Zhuang JL, Zhou YY, Liu YD, Li W. Flocs are the main source of nitrous oxide in a high-rate anammox granular sludge reactor: insights from metagenomics and fed-batch experiments. WATER RESEARCH 2020; 186:116321. [PMID: 32861184 DOI: 10.1016/j.watres.2020.116321] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/17/2020] [Revised: 07/10/2020] [Accepted: 08/19/2020] [Indexed: 06/11/2023]
Abstract
Nitrous oxide (N2O) emissions from anammox-based processes are well documented but insight into source of the N2O emission in high-rate anammox granular sludge reactors (AGSR) is limited. In this study, metagenomics and fed-batch experiments were applied to investigate the relative contributions of anammox granules and flocs to N2O production in a high-rate AGSR. Flocs, which constitute only ~10% of total biomass contributed about 60% of the total N2O production. Granules, the main contributor of nitrogen removal (~95%), were responsible for the remaining ~40% of N2O production. This result is inconsistent with reads-based analysis that found the gene encoding clade II type nitrous oxide reductase (nosZII) had similar abundances in both granules and flocs. Another notable trend observed was the relatively higher abundance of the gene for NO-producing nitrite reductase (nir) in comparison to the gene for the nitric oxide reductase gene (nor) in both granules and flocs, indicating nitric oxide (NO) may accumulate in the AGSR. This is significant since NO and N2O pulse assays demonstrated that NO could lead to N2O production from both granules and flocs. However, since anammox bacteria, which were shown to be in higher abundance in granules than in flocs, have the capacity to scavenge NO this provides a mechanism by which its inhibitory effects can be mitigated, limiting N2O release from the granules, consistent with experimental observation. These results demonstrate flocs are the main source of N2O emission in AGSR and provide lab-scale evidence that NO-dependent anammox can mitigate N2O emission.
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Affiliation(s)
- Jin-Long Zhuang
- National Engineering Laboratory for Industrial Wastewater Treatment, School of Resources and Environmental Engineering, East China University of Science and Technology, Shanghai, China; State Environmental Protection Key Laboratory of Environmental Risk Assessment and Control on Chemical Process, School of Resources and Environmental Engineering, East China University of Science and Technology, Shanghai, China
| | - Yuan-Yuan Zhou
- National Engineering Laboratory for Industrial Wastewater Treatment, School of Resources and Environmental Engineering, East China University of Science and Technology, Shanghai, China; State Environmental Protection Key Laboratory of Environmental Risk Assessment and Control on Chemical Process, School of Resources and Environmental Engineering, East China University of Science and Technology, Shanghai, China
| | - Yong-di Liu
- National Engineering Laboratory for Industrial Wastewater Treatment, School of Resources and Environmental Engineering, East China University of Science and Technology, Shanghai, China; State Environmental Protection Key Laboratory of Environmental Risk Assessment and Control on Chemical Process, School of Resources and Environmental Engineering, East China University of Science and Technology, Shanghai, China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai, China
| | - Wei Li
- National Engineering Laboratory for Industrial Wastewater Treatment, School of Resources and Environmental Engineering, East China University of Science and Technology, Shanghai, China; State Environmental Protection Key Laboratory of Environmental Risk Assessment and Control on Chemical Process, School of Resources and Environmental Engineering, East China University of Science and Technology, Shanghai, China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai, China.
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4
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Xiao P, Ai S, Zhou J, Luo X, Kang B, Feng L, Zhao T. N 2O profiles in the enhanced CANON process via long-term N 2H 4 addition: minimized N 2O production and the influence of exogenous N 2H 4 on N 2O sources. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2020; 27:37188-37198. [PMID: 31748991 DOI: 10.1007/s11356-019-06508-w] [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: 07/14/2019] [Accepted: 09/10/2019] [Indexed: 06/10/2023]
Abstract
Production of the greenhouse gas nitrous oxide (N2O) from the completely autotrophic nitrogen removal over nitrite (CANON) process is of growing concern. In this study, the effect of added hydrazine (N2H4) on N2O production during the CANON process was investigated. Long-term trace N2H4 addition minimized N2O production (0.018% ± 0.013% per unit total nitrogen removed) and maintaining high nitrogen removal capacity of CANON process (nitrogen removal rate and TN removal efficiency was 450 ± 60 mg N/L/day and 71 ± 8%, respectively). Ammonium oxidizing bacteria (AOB) was the main N2O producer. AOB activity inhibition by N2H4 decreased N2O production during aeration, and the N2H4 concentration was negatively correlated with N2O production rate in NH4+ oxidation via AOB, whereas N2O production was facilitated under anaerobic conditions because hydroxylamine (NH2OH) production was accelerated due to anammox bacteria (AnAOB) activity strengthen via N2H4. Added N2H4 completely degraded in the initial aeration phases of the CANON SBR, during which some N2H4 intensified anammox for total nitrogen removal to eliminate N2O production from nitrifier denitrification (ND) by anammox-associated, while the remaining N2H4 competed with NH2OH for hydroxylamine oxidoreductase (HAO) in AOB to inhibit intermediates formation that result in N2O production via NH2OH oxidation (HO) pathway, consequently decreasing total N2O production.
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Affiliation(s)
- Pengying Xiao
- College of Chemistry and Chemical Engineering, Chongqing University of Technology, No. 69 Hongguang Avenue, Chongqing, 400054, Banan District, People's Republic of China.
| | - Shuo Ai
- College of Chemistry and Chemical Engineering, Chongqing University of Technology, No. 69 Hongguang Avenue, Chongqing, 400054, Banan District, People's Republic of China
| | - Jing Zhou
- College of Chemistry and Chemical Engineering, Chongqing University of Technology, No. 69 Hongguang Avenue, Chongqing, 400054, Banan District, People's Republic of China
| | - Xiaojing Luo
- College of Chemistry and Chemical Engineering, Chongqing University of Technology, No. 69 Hongguang Avenue, Chongqing, 400054, Banan District, People's Republic of China
| | - Baowen Kang
- College of Chemistry and Chemical Engineering, Chongqing University of Technology, No. 69 Hongguang Avenue, Chongqing, 400054, Banan District, People's Republic of China
| | - Li Feng
- Chongqing Academy of Environmental Science, Chongqing, 400054, People's Republic of China
| | - Tiantao Zhao
- College of Chemistry and Chemical Engineering, Chongqing University of Technology, No. 69 Hongguang Avenue, Chongqing, 400054, Banan District, People's Republic of China.
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5
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Fang F, Li H, Jiang X, Deng X, Yan P, Guo J, Chen Y, Yang J. Significant N 2O emission from a high rate granular reactor for completely autotrophic nitrogen removal over nitrite. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2020; 266:110586. [PMID: 32392139 DOI: 10.1016/j.jenvman.2020.110586] [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: 01/20/2020] [Revised: 03/29/2020] [Accepted: 04/07/2020] [Indexed: 06/11/2023]
Abstract
Expanded granular sludge bed (EGSB) reactors were rarely applied for complete ammonium removal over nitrite. In this study, a high ammonium loading rate of 3677 mg N/L/d was achieved in an EGSB reactor. Approximately 5.5-8.5% of influent ammonium was converted to nitrous oxide (N2O) that is a potent greenhouse gas. Moreover, the percentage increased linearly with the increase in ammonium load. A model well matched the reactor dynamics. The model indicated that hydroxylamine (NH2OH) oxidation contributed to over 40% of produced N2O, and denitrification by ammonium oxidizing bacteria contributed to N2O emission significantly. Furthermore, the model suggests that a low oxygen concentration can result in a low N2O emission at the cost of a slightly low ammonium removal rate while influent organic matter play a minor role in reducing N2O emission. This study shows that EGSB reactors are effective in ammonium removal. In addition, the emission of N2O is significant.
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Affiliation(s)
- Fang Fang
- College of Environment and Ecology, Chongqing University, Chongqing, China.
| | - Hanxiang Li
- College of Environment and Ecology, Chongqing University, Chongqing, China
| | - Xin Jiang
- College of Environment and Ecology, Chongqing University, Chongqing, China
| | - Xiongwen Deng
- College of Environment and Ecology, Chongqing University, Chongqing, China
| | - Peng Yan
- College of Environment and Ecology, Chongqing University, Chongqing, China
| | - Jinsong Guo
- College of Environment and Ecology, Chongqing University, Chongqing, China
| | - Youpeng Chen
- College of Environment and Ecology, Chongqing University, Chongqing, China
| | - Jixiang Yang
- College of Environment and Ecology, Chongqing University, Chongqing, China; Chongqing Institute of Green and Intelligent Technology, Chinese Academy of Sciences, Chongqing, China.
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6
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Fang F, Li K, Guo JS, Wang H, Zhang P, Yan P. New insights into nitrous oxide emissions in a single-stage CANON process coupled with denitrification: thermodynamics and nitrogen transformation. WATER SCIENCE AND TECHNOLOGY : A JOURNAL OF THE INTERNATIONAL ASSOCIATION ON WATER POLLUTION RESEARCH 2020; 82:157-169. [PMID: 32910800 DOI: 10.2166/wst.2020.344] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
The dynamic characteristics of N2O emissions and nitrogen transformation in a sequencing batch biofilm reactor (SBBR) using the completely autotrophic nitrogen removal over nitrite (CANON) process coupled with denitrification were investigated via 15N isotope tracing and thermodynamic analysis. The results indicate that the Gibbs free energy (ΔG) values of N2O production by the nitrifier denitrification and heterotrophic denitrification reactions were greater than that of NH2OH oxidation, indicating that N2O was easier to produce via either nitrifier and heterotrophic denitrification than via NH2OH oxidation. Ammonia-oxidizing bacteria (AOB) denitrification exhibited a higher fs 0 (the fraction of electron-donor electrons utilized for cell synthesis) than NH2OH oxidation. Therefore, AOB preferred the denitrification pathway because of its growth advantage when N2O was produced by the AOB. The N2O emissions by hydroxylamine oxidation, AOB denitrification and heterotrophic denitrification in the SBBRs using different C/N ratios account for 5.4-7.6%, 45.2-60.8% and 33.8-47.2% of the N2O produced, respectively. The total N2O emission with C/N ratios of 0, 0.67 and 1 was 228.04, 205.57 and 190.4 μg N2O-N·g-1VSS, respectively. The certain carbon sources aid in the reduction of N2O emissions in the process.
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Affiliation(s)
- Fang Fang
- Key Laboratory of the Three Gorges Reservoir Region's Eco-Environment, Ministry of Education, Chongqing University, No.174, Shazhen Street, Chongqing 400045, China E-mail:
| | - Kai Li
- College of Eco-environment Engineering, Guizhou Minzu University, Huaxi District, Guiyang City, Guizhou 550025, China
| | - Jin-Song Guo
- Key Laboratory of the Three Gorges Reservoir Region's Eco-Environment, Ministry of Education, Chongqing University, No.174, Shazhen Street, Chongqing 400045, China E-mail:
| | - Han Wang
- College of Eco-environment Engineering, Guizhou Minzu University, Huaxi District, Guiyang City, Guizhou 550025, China
| | - Ping Zhang
- College of Eco-environment Engineering, Guizhou Minzu University, Huaxi District, Guiyang City, Guizhou 550025, China
| | - Peng Yan
- Key Laboratory of the Three Gorges Reservoir Region's Eco-Environment, Ministry of Education, Chongqing University, No.174, Shazhen Street, Chongqing 400045, China E-mail:
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7
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Chaiwong C, Koottatep T, Polprasert C. Comparative study on attached-growth photobioreactors under blue and red lights for treatment of septic tank effluent. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2020; 260:110134. [PMID: 32090830 DOI: 10.1016/j.jenvman.2020.110134] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/06/2019] [Revised: 01/08/2020] [Accepted: 01/11/2020] [Indexed: 06/10/2023]
Abstract
Attached-growth photobioreactors (AG-PBRs) employing low-cost attached-growth media were applied to treat septic tank effluent which contained abundant organic and nutrient matters as well as pathogenic microorganisms. This study investigated effects of blue and red LED lights on organic, nutrient and pathogenic removals, biomass productivity and compositions of microbial community in the AG-PBR system. The experimental results showed the blue AG-PBR to be more effective in removing chemical oxygen demand (COD), total nitrogen (TN) and ammonia nitrogen (NH3-N) and generating biomass productivity than those of the red AG-PBR (P < 0.05). Mass balance analysis indicated that the TN and total phosphorus (TP) were removed mainly by assimilation into the biomass. The TN removal rates via nitrification and denitrification processes in the blue AG-PBR were found to be higher than that of the red AG-PBR, corresponding to the observed results of bacterial biomass and abundances of nitrifying and denitrifying bacterial species in the treatment systems. The maximal areal algal biomass productivity of 47 gDW/(m2. d) in the blue AG-PBRs was found to be higher than those of other algal attached-growth systems. Although, the red and blue AG-PBR systems could effectively treat the septic tank effluent to meet the national and international discharge standards, based on treatment efficiencies and biomass productivity, the blue AG-PBR is recommended for treatment of septic tank effluent.
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Affiliation(s)
- Chawalit Chaiwong
- Environmental Engineering and Management, School of Environments Resources and Development, Asian Institute of Technology, P.O.Box 4, Klong Luang, Pathumthani, 12120, Thailand.
| | - Thammarat Koottatep
- Environmental Engineering and Management, School of Environments Resources and Development, Asian Institute of Technology, P.O.Box 4, Klong Luang, Pathumthani, 12120, Thailand.
| | - Chongrak Polprasert
- Department of Civil Engineering, Faculty of Engineering, Thammasat University, Pathumthani, 12120, Thailand.
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8
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Evaluating the effects of micro-zones of granular sludge on one-stage partial nitritation–anammox nitrogen removal. Bioprocess Biosyst Eng 2020; 43:1037-1049. [DOI: 10.1007/s00449-020-02302-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2019] [Accepted: 01/21/2020] [Indexed: 10/25/2022]
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9
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Yan P, Li K, Guo JS, Zhu SX, Wang ZK, Fang F. Toward N 2O emission reduction in a single-stage CANON coupled with denitrification: Investigation on nitrite simultaneous production and consumption and nitrogen transformation. CHEMOSPHERE 2019; 228:485-494. [PMID: 31051351 DOI: 10.1016/j.chemosphere.2019.04.148] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/04/2018] [Revised: 04/09/2019] [Accepted: 04/20/2019] [Indexed: 06/09/2023]
Abstract
A dynamic analysis approach for determining nitrite production and consumption rates was established to systematically investigate the characteristics of nitrogen transformation and N2O emission of the completely autotrophic nitrogen removal over nitrite (CANON) process coupled with denitrification using a sequencing batch biofilm reactor (SBBR). The results indicate that anaerobic ammonium-oxidizing bacteria was not inhibited significantly by low C/N ratios. There were no obvious differences in the nitrite production rate, nitrite consumption rate or nitrogen removal among reactors operated with C/N ratios of 0, 0.67 and 1.00, which suggested that the certain carbon source did not significantly affect the nitrite conversion and nitrogen removal in the process. More than 60% of total N2O emission is generated during the initial phase of each period in the SBBR. More than 94.5% of N2O was generated by NO2--N consumption via denitrification in the process. Interestingly, total N2O production drops by 16.7%, when the C/N ratio increases from 0 to 1. This phenomenon may be caused by the inhibition of N2O production via AOB denitrification. Therefore, an appropriate carbon source (C/N = 1.00) has the beneficial effect of reducing N2O emission by CANON coupled with denitrification. The results of this study provide an important empirical foundation for the mitigation of N2O emission in the CANON process coupled with denitrification.
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Affiliation(s)
- Peng Yan
- Key Laboratory of the Three Gorges Reservoir Region's Eco-Environment, Ministry of Education, Chongqing University, No. 174, Shazhen Street, Chongqing, 400045, China.
| | - Kai Li
- College of Eco-environment Engineering, Guizhou Minzu University, Huaxi District, Guiyang City, Guizhou, 550025, China
| | - Jin-Song Guo
- Key Laboratory of the Three Gorges Reservoir Region's Eco-Environment, Ministry of Education, Chongqing University, No. 174, Shazhen Street, Chongqing, 400045, China
| | - Si-Xi Zhu
- College of Eco-environment Engineering, Guizhou Minzu University, Huaxi District, Guiyang City, Guizhou, 550025, China
| | - Zhi-Kang Wang
- College of Eco-environment Engineering, Guizhou Minzu University, Huaxi District, Guiyang City, Guizhou, 550025, China
| | - Fang Fang
- Key Laboratory of the Three Gorges Reservoir Region's Eco-Environment, Ministry of Education, Chongqing University, No. 174, Shazhen Street, Chongqing, 400045, China.
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10
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Wan X, Baeten JE, Volcke EI. Effect of operating conditions on N2O emissions from one-stage partial nitritation-anammox reactors. Biochem Eng J 2019. [DOI: 10.1016/j.bej.2018.12.004] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
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11
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Wu N, Zeng M, Zhu B, Zhang W, Liu H, Yang L, Wang L. Impacts of different morphologies of anammox bacteria on nitrogen removal performance of a hybrid bioreactor: Suspended sludge, biofilm and gel beads. CHEMOSPHERE 2018; 208:460-468. [PMID: 29886334 DOI: 10.1016/j.chemosphere.2018.06.012] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/24/2017] [Revised: 05/29/2018] [Accepted: 06/02/2018] [Indexed: 06/08/2023]
Abstract
The difficulties in the anaerobic ammonium oxidation (anammox) process mainly consist of low microbial growth rates and long start-up times of bioreactors. The morphologies of anammox bacteria might affect nitrogen removal performance and microbial community. In this study, three morphologies of anammox bacteria, namely, suspended sludge, biofilm and suspended sludge embedded in gel beads, were compared in a hybrid bioreactor under anoxic conditions (DO concentration < 0.1 mg L-1). The results show that the average total inorganic nitrogen removal efficiency of a hybrid bioreactor reached 67 ± 15% with a maximum value of 80% for continuous synthetic wastewater feeding, and that the specific total inorganic nitrogen removal rate reached 15.75 mg·(gVSS·h)-1 regardless of the organic matter stress. Batch tests indicate that mainly suspended sludge (67%) and biofilm (26%) contributed to the anammox process, with the specific total inorganic nitrogen removal rate reaching 10.55 and 4.05 mg·(gVSS·h)-1, respectively. However, the embedding of sludge in gel resulted in nitrification instead of anammox with a nitrification rate of 0.20 ± 0.01 mg·(L·h)-1 due to the expansion of gel beads floating on the water surface. Therefore, a pore-forming technique was developed to produce more channels for gas dispersion inside the gel beads. In terms of microbial community, Candidatus Kuenenia involved in the anammox group was the most abundant genus in biofilm (43.4%) and suspended sludge (15.7%), while Nitrospira occupied the largest proportion in gel beads (25.6%). This study offers useful information for the selection of anammox bacteria morphology.
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Affiliation(s)
- Nan Wu
- College of Engineering and Technology, Tianjin Agricultural University, Tianjin 300384, China
| | - Ming Zeng
- College of Marine and Environmental Sciences, Tianjin University of Science & Technology, 300457 Tianjin, China.
| | - Baifeng Zhu
- College of Marine and Environmental Sciences, Tianjin University of Science & Technology, 300457 Tianjin, China
| | - Weiyu Zhang
- College of Engineering and Technology, Tianjin Agricultural University, Tianjin 300384, China
| | - Haixue Liu
- Laboratory of Agricultural Analysis, Tianjin Agricultural University, Tianjin 300384, China
| | - Lei Yang
- College of Engineering and Technology, Tianjin Agricultural University, Tianjin 300384, China
| | - Li Wang
- College of Engineering and Technology, Tianjin Agricultural University, Tianjin 300384, China
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12
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García-Ruiz MJ, Maza-Márquez P, González-López J, Osorio F. Nitrogen removal capacity and bacterial community dynamics of a Canon biofilter system at different organic matter concentrations. CHEMOSPHERE 2018; 193:591-601. [PMID: 29169135 DOI: 10.1016/j.chemosphere.2017.11.066] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/15/2017] [Revised: 10/31/2017] [Accepted: 11/14/2017] [Indexed: 06/07/2023]
Abstract
Three Canon bench-scale bioreactors with a volume of 2 L operating in parallel were configured as submerged biofilters. In the present study we investigated the effects of a high ammonium concentration (320 mgNH4+· L-1) and different concentrations of organic matter (0, 100 and 400 mgCOD·L-1) on the nitrogen removal capacity and the bacterial community structure. After 60 days, the Canon biofilters operated properly under concentrations of 0 and 100 mgCOD·L-1 of organic matter, with nitrogen removal efficiencies up to 85%. However, a higher concentration of organic matter (400 mgCOD·L-1) produced a partial inhibition of nitrogen removal (68.1% efficiency). The addition of higher concentrations of organic matter a modified the bacterial community structure in the Canon biofilter, increasing the proliferation of heterotrophic bacteria related to the genera of Thauera, Longilinea, Ornatilinea, Thermomarinilinea, unclassified Chlorobiales and Denitratisoma. However, heterotrophic bacteria co-exist with Nitrosomonas and Candidatus Scalindua. Thus, our study confirms the co-existence of different microbial activities (AOB, Anammox and denitrification) and the adaptation of a fixed-biofilm system to different concentrations of organic matter.
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Affiliation(s)
- María J García-Ruiz
- Institute of Water, University of Granada, Ramón y Cajal Street, 4, 18071, Granada, Spain.
| | - Paula Maza-Márquez
- Institute of Water, University of Granada, Ramón y Cajal Street, 4, 18071, Granada, Spain
| | - Jesús González-López
- Institute of Water, University of Granada, Ramón y Cajal Street, 4, 18071, Granada, Spain
| | - Francisco Osorio
- Institute of Water, University of Granada, Ramón y Cajal Street, 4, 18071, Granada, Spain
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