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Zheng H, Yin Z, Chen L, He H, Li Z, Lv X, Chen J, Du W, Lin X. Effects of salinity on nitrogen reduction pathways in estuarine wetland sediments. MARINE POLLUTION BULLETIN 2024; 207:116834. [PMID: 39142052 DOI: 10.1016/j.marpolbul.2024.116834] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/08/2024] [Revised: 07/24/2024] [Accepted: 08/08/2024] [Indexed: 08/16/2024]
Abstract
Denitrification, anammox, and DNRA are three important nitrogen (N) reduction pathways in estuarine sediments. Although salinity is an important variables controlling microbial growth and activities, knowledge about the effects of changing salinity on those three processes in estuarine and coastal wetland sediments are not well understood. Herein, we performed a 60-d microcosms experiment with different salinities (0, 5, 15, 25 and 35 ‰) to explore the vital role of salinity in controlling N-loss and N retention in estuarine wetland sediments. The results showed that sediment organic matter, sulfide, and nitrate (NO3-) were profoundly decreased with increasing salinity, while sediment ammonium (NH4+) and ferrous (Fe2+) varied in reverse patterns. Meanwhile, N-loss and N retention rates and associated gene abundances were differentially inhibited with increasing salinity, while the contributions of denitrification, anammox, and DNRA to total nitrate reduction were apparently unaffected. Moreover, denitrification rate was the most sensitive to salinity, and then followed by DNRA, while anammox was the weakest among these three processes. In other words, anammox bacteria showed a wide range of salinity tolerance, while both denitrification and DNRA reflected a relatively limited dynamic range of it. Our findings could provide insights into temporal interactive effects of salinity on sediment physico-chemical properties, N reduction rates and associated gene abundances. Our findings can improve understanding of the effects of saltwater incursion on the N fate and N balance in estuarine and coastal sediments.
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Affiliation(s)
- Hao Zheng
- Key Laboratory of Marine Environmental Survey Technology and Application, South China Sea Marine Survey Center, Ministry of Natural Resources, Guangzhou 510300, China
| | - Zhengxin Yin
- Key Laboratory of Marine Environmental Survey Technology and Application, South China Sea Marine Survey Center, Ministry of Natural Resources, Guangzhou 510300, China.
| | - Liang Chen
- Key Laboratory of Marine Environmental Survey Technology and Application, South China Sea Marine Survey Center, Ministry of Natural Resources, Guangzhou 510300, China
| | - Huizhong He
- Key Laboratory of Marine Environmental Survey Technology and Application, South China Sea Marine Survey Center, Ministry of Natural Resources, Guangzhou 510300, China
| | - Zhengyuan Li
- Key Laboratory of Marine Environmental Survey Technology and Application, South China Sea Marine Survey Center, Ministry of Natural Resources, Guangzhou 510300, China
| | - Xiuya Lv
- Key Laboratory of Marine Environmental Survey Technology and Application, South China Sea Marine Survey Center, Ministry of Natural Resources, Guangzhou 510300, China
| | - Jiyu Chen
- Key Laboratory of Marine Environmental Survey Technology and Application, South China Sea Marine Survey Center, Ministry of Natural Resources, Guangzhou 510300, China
| | - Wei Du
- Yunnan Provincial Key Laboratory of Soil Carbon Sequestration and Pollution Control, Faculty of Environmental Science & Engineering, Kunming University of Science & Technology, Kunming 650500, China
| | - Xianbiao Lin
- Frontiers Science Center for Deep Ocean Multispheres and Earth System, and Key Laboratory of Marine Chemistry Theory and Technology, Ministry of Education, Ocean University of China, Qingdao 266100, China.
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Wang Y, Zhang Z, Lin L, Xing G, Jiang Y, Cao W, Zhang Y. Interspecies electron transfer and microbial interactions in a novel Fe(II)-mediated anammox coupled mixotrophic denitrification system. BIORESOURCE TECHNOLOGY 2024; 403:130852. [PMID: 38761867 DOI: 10.1016/j.biortech.2024.130852] [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: 03/27/2024] [Revised: 05/14/2024] [Accepted: 05/14/2024] [Indexed: 05/20/2024]
Abstract
This study effectively coupled anammox and mixotrophic denitrification at a high nitrogen load rate of 6.84 g N/L/d with 40 mg/L Fe(II). Fe(II) enhanced the activity of nitrate reductase, nitrite reductase, and hydrazine dehydrogenase enzymes, facilitating accelerated ATP synthesis. Through electrochemical experiments, interspecies electron transfer processes in coupled system were explored. Fe(II) promoted flavin mononucleotide secretion, enhancing electron-donating and electron-accepting capacity by 2.8 and 1.3 times, respectively. Fe(II) triggered the enrichment of autotrophic denitrifying bacteria (Azospira and Hydrogenophaga), transitioning from single organic nutrient to mixotrophic denitrification. Meanwhile, Fe(II) increased Candidatus_Kuenenia abundance from 35.2 % to 49.0 %, establishing the competitive advantage of anammox bacteria over completed denitrifying bacteria (Comamonas). The synergistic interactions between anammox and various denitrification pathways achieved a nitrogen removal rate of 5.88 g N/L/d, with anammox contribution rate of 88.3 %. This study provides insights into broadening the application of partial denitrification /anammox and electron transfer in multi-bacterial coupling systems.
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Affiliation(s)
- Ying Wang
- Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystem, College of the Environment & Ecology, Xiamen University, Xiamen, Fujian 361102, China
| | - Zikun Zhang
- Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystem, College of the Environment & Ecology, Xiamen University, Xiamen, Fujian 361102, China
| | - Lan Lin
- Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystem, College of the Environment & Ecology, Xiamen University, Xiamen, Fujian 361102, China
| | - Guowei Xing
- Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystem, College of the Environment & Ecology, Xiamen University, Xiamen, Fujian 361102, China
| | - Yushi Jiang
- Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystem, College of the Environment & Ecology, Xiamen University, Xiamen, Fujian 361102, China
| | - Wenzhi Cao
- Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystem, College of the Environment & Ecology, Xiamen University, Xiamen, Fujian 361102, China
| | - Yanlong Zhang
- Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystem, College of the Environment & Ecology, Xiamen University, Xiamen, Fujian 361102, China; Fujian Key Laboratory of Coastal Pollution Prevention and Control (CPPC), College of Environment & Ecology, Xiamen University, Xiamen, Fujian 361102, China; Fujian Institute for Sustainable Oceans, Xiamen University, Xiamen, Fujian 361102, China.
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Wang Y, Zhang Z, Jiang Y, Cao W, Lin JG, Zhang Y. Spatial difference in nitrogen removal pathways and microbial functional diversity in an EGSB reactor during the start-up of PD/Anammox. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 907:168004. [PMID: 37875193 DOI: 10.1016/j.scitotenv.2023.168004] [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: 07/24/2023] [Revised: 10/09/2023] [Accepted: 10/19/2023] [Indexed: 10/26/2023]
Abstract
The start-up of a relatively high nitrogen load PD/Anammox in an EGSB reactor was achieved through strategies of bioaugmentation, mass transfer enhancement, and COD/NO3--N control, with NRR of 5.2 g N/L/d. Longitudinal heterogeneity in EGSB reactor induced divergent nitrogen conversion pathways and enriched different functional microorganisms between stratified sludge. Along the elevation of the reactor, the proportion of removed nitrogen through anammox increased continuously from bottom, middle and up, which were 65.0 %, 79.8 %, and 84.1 %, respectively, consistent with the trend of ex-situ activities calculated with Gompertz model. The bottom zone played a role in mixed nitrogen conversion to provide NO2--N accumulation and nitrogen removal, with higher abundance of Thauera, Denitratisoma and Ignavibacterium. The middle part was enriched Candidatus_Kuenenia (12.51 %), and up inhibited completed denitrification, together forming the anammox dominant zone. The proposed functional zones in the EGSB reactor provided approaches for the optimisation of high-load PD/Anammox systems.
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Affiliation(s)
- Ying Wang
- Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystem, College of the Environment & Ecology, Xiamen University, Xiamen, Fujian 361102, China
| | - Zikun Zhang
- Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystem, College of the Environment & Ecology, Xiamen University, Xiamen, Fujian 361102, China
| | - Yushi Jiang
- Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystem, College of the Environment & Ecology, Xiamen University, Xiamen, Fujian 361102, China
| | - Wenzhi Cao
- Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystem, College of the Environment & Ecology, Xiamen University, Xiamen, Fujian 361102, China
| | - Jih-Gaw Lin
- Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystem, College of the Environment & Ecology, Xiamen University, Xiamen, Fujian 361102, China; National Yang Ming Chiao Tung University, Taiwan
| | - Yanlong Zhang
- Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystem, College of the Environment & Ecology, Xiamen University, Xiamen, Fujian 361102, China; Fujian Key Laboratory of Coastal Pollution Prevention and Control (CPPC), College of Environment & Ecology, Xiamen University, Xiamen, Fujian 361102, China; Fujian Institute for Sustainable Oceans, Xiamen University, Xiamen, Fujian 361102, China.
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Zhang Q, Lin L, Chen Y, Wang Y, Li X, Li L, Cao W, Zhang Y. Dual-edged effects and mechanisms of hydroxylamine in partial denitrification-anaerobic ammonium oxidation system. ENVIRONMENTAL RESEARCH 2023; 235:116664. [PMID: 37451572 DOI: 10.1016/j.envres.2023.116664] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/07/2023] [Revised: 07/10/2023] [Accepted: 07/11/2023] [Indexed: 07/18/2023]
Abstract
The combination of partial denitrification (PD) and anaerobic ammonium oxidation (anammox) is a novel and promising nitrogen removal process. Regulating the synergistic reaction between denitrifiers and anammox bacteria (AnAOB) is the key to achieving stable and efficient PD-anammox performance. In this study, 10 mg/L of hydroxylamine (NH2OH) was considered to efficiently promote the bacterial activity, microbial energy flow, and the synergy of functional microflora. As a result, the nitrogen removal rate (NRR) significantly increased from 0.05 to 0.30 g N/L/d in parallel with an increase in the nitrogen loading rate (NLR) from 0.10 to 0.40 g N/L/d. However, the dual-edged effect of NH2OH was also confirmed. The long-term presence of NH2OH caused overgrowth of complete-denitrifying bacteria and decreased the NRR to 0.11 g N/L/d. Additionally, NH2OH enhanced nitrous oxide (N2O) emissions via chemical pathways as well as enhanced denitrification Fortunately, the inhibition caused by NH2OH was reversible by stopping the dosing, the reactor restored to stable operation with an NRR of 0.27 g N/L/d. Analysis of metabolic intensity and pathways revealed the effecting process and mechanism of NH2OH on the PD-anammox system. This study verified the dual-edged effects and mechanisms of NH2OH, therefore proving a theoretical basis and technical reference for the application of PD-anammox.
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Affiliation(s)
- Qi Zhang
- Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystem, Xiamen University, Xiamen, Fujian, 361102, China
| | - Lan Lin
- Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystem, Xiamen University, Xiamen, Fujian, 361102, China
| | - Yuqi Chen
- Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystem, Xiamen University, Xiamen, Fujian, 361102, China
| | - Yuzheng Wang
- Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystem, Xiamen University, Xiamen, Fujian, 361102, China
| | - Xiao Li
- Xiamen Junhong Environmental Solid Waste Disposal Co., Ltd., Xiamen, Fujian, 361102, China
| | - Linxi Li
- Xiamen Junhong Environmental Solid Waste Disposal Co., Ltd., Xiamen, Fujian, 361102, China
| | - Wenzhi Cao
- Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystem, Xiamen University, Xiamen, Fujian, 361102, China
| | - Yanlong Zhang
- Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystem, Xiamen University, Xiamen, Fujian, 361102, China; Fujian Key Laboratory of Coastal Pollution Prevention and Control (CPPC), College of Environment and Ecology, Xiamen University, Xiamen, Fujian, 361102, China.
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Dsane VF, An S, Choi Y. Distinctive differences in the granulation of saline and non-saline enriched anaerobic ammonia oxidizing (AMX) bacteria. J Environ Sci (China) 2022; 122:162-173. [PMID: 35717082 DOI: 10.1016/j.jes.2021.08.057] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2021] [Revised: 08/11/2021] [Accepted: 08/11/2021] [Indexed: 06/15/2023]
Abstract
The growing interest in the anaerobic ammonium oxidizing (AMX) process in treating high nitrogen containing wastewaters and a comprehensive study into the granulation mechanism of these bacteria under diverse environmental conditions over the years have been unequal. To this effect, the distinctive differences in saline adapted AMX (S_AMX) and non-saline adapted AMX (NS_AMX) granules are presented in this study. It was observed that substrate utilisation profiles, granule formation mechanism, and pace towards granulation differed marginally for the two adaptation conditions. The different microbial dominant aggregation types aided in splitting the 471 days operated lab-scale SBRs into three distinct phases. In both reactors, phase III (granules dominant phase) showed the highest average nitrogen removal efficiency of 87.9% ± 4.8% and 85.6% ± 3.6% for the S_AMX and NS_AMX processes, respectively. The extracellular polymeric substances (EPS) quantity and major composition determined its role either as a binding agent in granulation or a survival mechanism in saline adaptation. It was also observed that granules of the S_AMX reactor were mostly loosely and less condensed aggregates of smaller sub-units and flocs while those of the NS_AMX reactor were compact agglomerates. The ionic gradient in saline enrichment led to an increased activity of the Na+/K+ - ATPase, hence enriched granules produced higher cellular adenosine triphosphate molecules which finally improved the granules active biomass ratio by 32.96%. Microbial community showed that about three to four major known AMX species made up the granules consortia in both reactors. Proteins and expression of functional genes differed for these different species.
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Affiliation(s)
- Victory Fiifi Dsane
- Department of Environmental Engineering, Chungnam National University, Daejeon 305-764, Korea; Department of Food Process Engineering, University of Ghana, Legon, Ghana
| | - Sumin An
- Department of Environmental & IT Convergence Engineering, Chungnam National University, Daejeon 305-764, Korea
| | - Younggyun Choi
- Department of Environmental & IT Convergence Engineering, Chungnam National University, Daejeon 305-764, Korea.
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Zhang Q, Lin L, Chen Y, Cao W, Zhang Y. Effects of hydroxylamine on treatment of anaerobic digestate of pig manure in partial nitrification-anaerobic ammonium oxidation. BIORESOURCE TECHNOLOGY 2022; 363:128015. [PMID: 36155814 DOI: 10.1016/j.biortech.2022.128015] [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: 07/28/2022] [Revised: 09/18/2022] [Accepted: 09/19/2022] [Indexed: 06/16/2023]
Abstract
Partial nitrification-anaerobic ammonium oxidation (PN-anammox) was started up within 40 days by bioaugmentation and aeration control, and its performance in the treatment of anaerobic digestate of pig manure (ADPM) was evaluated. Inhibitors in ADPM decreased the nitrogen removal rate (NRR) by 0.24 g N/L/d. The effect and mechanism of hydroxylamine (NH2OH) alleviation of PN-anammox inhibition during ADPM treatment were investigated. As an intermediate product of anammox and ammonia-oxidizing bacteria, NH2OH strengthened energy metabolism, improved the activity and abundance of functional bacteria, and eliminated miscellaneous bacteria, increasing the average NRR by 31%. However, the average nitrous oxide emission was increased by 10.1% via hydroxylamine oxidation. The results showed that synergy and competition among nitrogen-transforming microorganisms were crucial for NRR and that NH2OH played an essential role in maintaining efficient operation. This study lays a foundation for restoring PN-anammox for treating livestock wastewater.
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Affiliation(s)
- Qi Zhang
- College of the Environment & Ecology, Xiamen University, South Xiang'an Road, Xiang'an District, Xiamen, Fujian 361102, China
| | - Lan Lin
- Department of Civil and Environmental Engineering, Graduate School of Engineering, Tohoku University, 6-6-06 Aramaki Aza Aoba, Aoba-ku, Sendai, Miyagi 980-8579, Japan
| | - Yuqi Chen
- College of the Environment & Ecology, Xiamen University, South Xiang'an Road, Xiang'an District, Xiamen, Fujian 361102, China
| | - Wenzhi Cao
- College of the Environment & Ecology, Xiamen University, South Xiang'an Road, Xiang'an District, Xiamen, Fujian 361102, China; Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystem, Xiamen University, Xiamen 361102, China
| | - Yanlong Zhang
- College of the Environment & Ecology, Xiamen University, South Xiang'an Road, Xiang'an District, Xiamen, Fujian 361102, China; Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystem, Xiamen University, Xiamen 361102, China; Fujian Key Laboratory of Coastal Pollution Prevention and Control (CPPC), College of Environment and Ecology, Xiamen University, Xiamen, Fujian 361102, China.
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Choi Y, Dsane VF, Jeon H, Jeong S, Oh T, Choi Y. The role of magnetite (Fe 3O 4) particles for enhancing the performance and granulation of anammox. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 845:157218. [PMID: 35810899 DOI: 10.1016/j.scitotenv.2022.157218] [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: 05/12/2022] [Revised: 06/06/2022] [Accepted: 07/04/2022] [Indexed: 06/15/2023]
Abstract
In this study, two lab-scale sequencing batch reactors each with an effective volume of 2.3 L were operated as C-AMX (no carrier addition) and M-AMX (magnetite carrier added) for 147 days with synthetic wastewater at an NLR range of 0.19-0.47 kgN/m3/d. The long-term effect of magnetite on the granulation and performance of anammox bacteria in terms of nitrogen removal and other essential parameters were confirmed. In phase I (1-24 days), M-AMX took approximately 12 days to obtain a nitrogen removal rate (NRR) above 80 % of the initial input nitrogen. Although free nitrous acid inhibited the reactor at a high concentration at the onset of phase III, the NRR of M-AMX recovered about 3.7 times faster than that of C-AMX. In addition, it was confirmed that the M-AMX granules had a dense and compact structure compared to C-AMX, and the presence of the carrier promoted the development of these resilient granules. While the measured microbial stress gradually increased in C-AMX reactor, a vice versa was observed in the M-AMX reactor as granulation proceeded. Compared to other alternative iron-based carrier particles, the stable crystal structure of magnetite as a carrier created a mechanism where filamentous bacteria groups were repelled from the granulation hence the microbial stress in the M-AMX in the final phase was 61.54 % lower than that in the C-AMX. The iron rich environment created by the magnetite addition led to Ignavibacteria, (a Feammox bacteria) increasing significantly in the M-AMX bioreactor.
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Affiliation(s)
- Yuri Choi
- Department of Environmental & IT Convergence Engineering, Chungnam National University, Daejeon, Republic of Korea
| | - Victory Fiifi Dsane
- Department of Environmental & IT Convergence Engineering, Chungnam National University, Daejeon, Republic of Korea; Department of Food Process Engineering, University of Ghana, Legon, Ghana
| | - Haejun Jeon
- Department of Environmental & IT Convergence Engineering, Chungnam National University, Daejeon, Republic of Korea
| | - Sohee Jeong
- Department of Environmental & IT Convergence Engineering, Chungnam National University, Daejeon, Republic of Korea
| | - Taeseok Oh
- BKT Company Ltd., Korea Sinseong-dong, Daejeon, South Korea
| | - Younggyun Choi
- Department of Environmental & IT Convergence Engineering, Chungnam National University, Daejeon, Republic of Korea.
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Fiifi Dsane V, Jeon H, Choi Y, Choi Y. A comprehensive root cause analysis of anammox bioreactor performance decline. BIORESOURCE TECHNOLOGY 2022; 349:126895. [PMID: 35217160 DOI: 10.1016/j.biortech.2022.126895] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/21/2021] [Revised: 02/17/2022] [Accepted: 02/18/2022] [Indexed: 06/14/2023]
Abstract
The cultivation of anaerobic ammonia oxidizing bacteria (anammox) has gained enormous awareness over the last few decades. Although numerous studies focus massively on successfully growing these anammox to different enrichment environments, in reality, the failure rates are somewhat comparable to the reported success rates. This study combines a variety of measurement techniques to observe and monitor the sequence of a bioreactor performance decline following elevated influent substrate concentration. After attaining stable substrate removal throughout a nitrogen loading rate (NLR) range of 0.691 to 1.669 kg-N·m-3·d-1, the performance of the lab-scale anammox-sequencing batch reactor (SBR) abruptly broke down as the NLR reached 2.01 kg-N·m-3·d-1. The gathered information showed that the increased NLR firstly caused a significant and unfavorable change in the free ammonia (FA) and free nitrous acid (FNA) concentration in the bioreactor. A subsequent drop in N2 production and a decline from a peak high of 0.381 to a low of 0.012 kg-N·kg-VSS-3·d-1 of the specific nitrogen removal rate (SNRR) led to an 82% absurd decline in microbial cellular energy production. Prior to these anammox switching to survival mode and secreting larger quantities (32% higher) of extracellular polymeric substances (EPS), the activity of syntrophic decomposers increased substantially leading to the internal production of excess CO2 in the bioreactor and thereby diverging the bioreactor pH to lower levels. The purposes of this study are to understand the reason an anammox process shows different signals during a decline phase and to enable immediate response to performance deterioration.
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Affiliation(s)
- Victory Fiifi Dsane
- Department of Environmental Engineering, Chungnam National University, Daejeon, Republic of Korea; Department of Food Process Engineering, University of Ghana, Legon, Ghana
| | - Haejun Jeon
- Department of Environmental & IT Convergence Engineering, Chungnam National University, Daejeon, Republic of Korea
| | - Yuri Choi
- Department of Environmental & IT Convergence Engineering, Chungnam National University, Daejeon, Republic of Korea
| | - Younggyun Choi
- Department of Environmental & IT Convergence Engineering, Chungnam National University, Daejeon, Republic of Korea.
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A Simple Analysis Method of Specific Anammox Activity Using a Respirometer. APPLIED SCIENCES-BASEL 2022. [DOI: 10.3390/app12031121] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Anaerobic ammonium oxidation (anammox) is a biological nitrogen removal process with attractive prospects, such as no carbon addition, less aeration, lower greenhouse gas generation, and lower sludge production. However, it is difficult to maintain a stable anammox process since the anammox bacteria have a slow growth rate and high sensitivity to many factors. Therefore, it is very important to analyze and maintain the anammox activity as a process indicator for its successful operation. The conventional method for measuring the concentration of nitrogen compounds, such as ammonium, nitrite, or nitrogen gas is inconvenient during the reaction time for specific anammox activity (SAA) analysis, which can result in an inaccurately determined SAA due to the substrate loss and temperature change. In this study, a respirometer was utilized to analyze the SAA. The SAA values from a respirometer (rSAA) showed a similar pattern to the SAA values (mSAA) from the conventional method. All of the SAA analyses showed the highest value at 35 °C with a granule size of <1 mm. Statistical analysis showed no significant differences regardless of the analysis method, since the p-values for the t-test and Wilcoxon rank-sum test were >0.05. Therefore, the respirometer can be used as a simple and efficient tool for SAA analysis. Moreover, the operating maintenance and management of the anammox process can be improved due to the simple SAA analysis in the field.
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Huang TH, Tung FT, Chen GF, Chen WH. Variations of N concentrations and microbial community in the start-up of anammox using anaerobic heterotrophic sludge: Influence of a long reaction-phase time and comparison of the efficiencies of attached-versus suspended-growth cultures. CHEMOSPHERE 2022; 287:132151. [PMID: 34517235 DOI: 10.1016/j.chemosphere.2021.132151] [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: 05/04/2021] [Revised: 08/29/2021] [Accepted: 09/01/2021] [Indexed: 06/13/2023]
Abstract
Anaerobic sludge was capable of producing anaerobic ammonium oxidation (anammox) cultures. However, the low activity of anammox bacteria in the seed sludge often led to a long time for stable anammox to initiate. The objective of this study was to investigate the influence of an extended reaction-phase time in the sequencing batch reactor (SBR) on the rapid startup of anaerobic ammonium oxidation (anammox) using anaerobic heterotrophic bacteria as the seed sludge. After the startup, suspended and attached bacteria in anammox were separately analyzed for comparison. The variations of nitrogen concentrations and shifts of the microbial community structures were studied. The results showed that anammox occurred after a long reaction-phase time in the SBR with the efficient removals of NH4+ (96.4%) and NO2- (99.8%). The effective NO2- treatment before anammox startup was attributable to inevitable denitrification or dissimilatory nitrate reduction (e.g., Denitratisoma). The occurrence of anammox was supported by the anammox stoichiometry, bacteria diversity variation, and principal component analysis. The overall nitrogen removal rate (NRR) and nitrogen removal efficiency (NRE) was 0.07 kg/m3-d and 92.8%, respectively. The relative molar quantities of NH4+ and NO2- removed as well as N2 and NO3- formed were 1(1):1.29(1.32):1.45(1.02):0.15(0.26), as the numbers in the parentheses represent the theoretical values. Denitratisoma and Desulfatiglans dominated in the seed sludge, whereas Candidatus_Jettenia abundances were significantly higher in anammox attached- (26.0%) and suspended-growth cultures (14.5%). Fifty-three genera were simultaneously identified in all samples, suggesting their importance in the startup of anammox from anaerobic sludge. Candidatus_Jettenia was observed to be more associated with the growth of anammox biofilm (the abundances were 26.0% and 14.5% in attached- and suspended-growth cultures, respectively) and supported the fine nitrogen removal performance in the attached-growth cultures.
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Affiliation(s)
- Tsung-Hsien Huang
- Institute of Environmental Engineering, National Sun Yat-sen University, Kaohsiung, 804, Taiwan
| | - Fang-Tsen Tung
- Institute of Environmental Engineering, National Sun Yat-sen University, Kaohsiung, 804, Taiwan
| | - Guan-Fu Chen
- Institute of Environmental Engineering, National Sun Yat-sen University, Kaohsiung, 804, Taiwan
| | - Wei-Hsiang Chen
- Institute of Environmental Engineering, National Sun Yat-sen University, Kaohsiung, 804, Taiwan; Aerosol Science and Research Center, National Sun Yat-sen University, Kaohsiung, 804, Taiwan; Department of Public Health, Kaohsiung Medical University, Kaohsiung, Taiwan.
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