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Wu J, Zhan M, Yuan L, Zhu Y, Lin W, Luo J. Sealing solid agar in serum bottles for rapid isolation and long-term preservation of chemoautotrophic ammonia-oxidizing bacteria. WATER RESEARCH 2024; 260:121916. [PMID: 38875857 DOI: 10.1016/j.watres.2024.121916] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/27/2024] [Revised: 06/06/2024] [Accepted: 06/08/2024] [Indexed: 06/16/2024]
Abstract
Ammonia-oxidizing bacteria (AOB) are ubiquitous on the earth and have broad applications in bioremediation. However, the number of their species with standing in nomenclature and deposited in Microbial Culture Collections still remains low. Moreover, only a few novel species have been reported over the last decades. In this study, we sealed agar in serum bottles to develop a kind of solid agar plate with the oxygen concentration in the headspace maintained at low levels. By using these plates, eight AOB isolates including two novel species were obtained. When AOB cells were grown on the sealed solid agar plates, the time to form visible colonies was largely reduced and the maximum diameter of colonies reached 2 mm, which makes the process of AOB isolation rapid and efficient. Based on five AOB isolates, the headspace oxygen concentration had a significant influence on AOB growth either on solid plate or in liquid culture. Especially, when grown under 21 % O2, the number of colonies formed on solid agar plates was very low and sometimes no visible colony formed. Besides the application on AOB isolation, the sealed solid agar plate was also effective for the enumeration and preservation of AOB cells. When preserved under room temperature for more than ten months, the AOB colonies on the plate could still be recovered. This method provides a feasible way to isolate more novel AOB species from the environment and deposit more species in Microbial Culture Collections.
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Affiliation(s)
- Jiajie Wu
- Guangdong Key Laboratory of Fermentation and Enzyme Engineering, School of Biology and Biological Engineering, South China University of Technology, Guangzhou 510006, PR China
| | - Manjun Zhan
- Guangdong Key Laboratory of Fermentation and Enzyme Engineering, School of Biology and Biological Engineering, South China University of Technology, Guangzhou 510006, PR China
| | - Lingling Yuan
- Guangdong Key Laboratory of Fermentation and Enzyme Engineering, School of Biology and Biological Engineering, South China University of Technology, Guangzhou 510006, PR China
| | - Yueyue Zhu
- Guangdong Key Laboratory of Fermentation and Enzyme Engineering, School of Biology and Biological Engineering, South China University of Technology, Guangzhou 510006, PR China
| | - Weitie Lin
- Guangdong Key Laboratory of Fermentation and Enzyme Engineering, School of Biology and Biological Engineering, South China University of Technology, Guangzhou 510006, PR China; MOE Joint International Research Laboratory of Synthetic Biology and Medicine, South China University of Technology, Guangzhou 510006, PR China.
| | - Jianfei Luo
- Guangdong Key Laboratory of Fermentation and Enzyme Engineering, School of Biology and Biological Engineering, South China University of Technology, Guangzhou 510006, PR China; MOE Joint International Research Laboratory of Synthetic Biology and Medicine, South China University of Technology, Guangzhou 510006, PR China.
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2
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Fu T, Fan Z, Li Y, Li Z, Zhao H, Feng Y, Xue G, Cui J, Yan C, Gan L, Feng J, Yuan J, You F. Roles of the Crp/Fnr Family Regulator ArcR in the Hemolysis and Biofilm of Staphylococcus aureus. Microorganisms 2023; 11:1656. [PMID: 37512829 PMCID: PMC10384999 DOI: 10.3390/microorganisms11071656] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2023] [Revised: 06/20/2023] [Accepted: 06/22/2023] [Indexed: 07/30/2023] Open
Abstract
Staphylococcus aureus is an opportunistic human pathogen that is often involved in severe infections such as pneumonia and sepsis in which bacterial virulence factors play a key role. Infections caused by S. aureus are often difficult to eradicate, particularly when they are associated with biofilm. The physiological roles of the Crp/Fnr family regulator ArcR are elusive in S. aureus. In this study, it was found that the deletion of arcR increased the hemolytic ability and biofilm formation in S. aureus. Differential gene expression analysis by RNA-seq and real-time quantitative reverse transcription PCR showed that genes associated with hemolytic ability (hla and hlb) and biofilm formation (icaA, icaB, icaC and icaD) were significantly upregulated compared with those in the wild-type strain. The results revealed that ArcR regulated the expression of the hla and ica operon by binding to their promoter regions, respectively. This study provided new insights into the functional importance of ArcR in regulating the virulence and biofilm of S. aureus.
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Affiliation(s)
- Tongtong Fu
- School of Basic Medical Sciences, Peking University, Beijing 100020, China
- Department of Bacteriology, Capital Institute of Pediatrics, Beijing 100020, China
| | - Zheng Fan
- Department of Bacteriology, Capital Institute of Pediatrics, Beijing 100020, China
| | - Yujie Li
- Department of Life Science and Medicine, University of Science and Technology of China, Hefei 230026, China
| | - Zhoufei Li
- Department of Bacteriology, Capital Institute of Pediatrics, Beijing 100020, China
| | - Hanqing Zhao
- Department of Bacteriology, Capital Institute of Pediatrics, Beijing 100020, China
| | - Yanling Feng
- Department of Bacteriology, Capital Institute of Pediatrics, Beijing 100020, China
| | - Guanhua Xue
- Department of Bacteriology, Capital Institute of Pediatrics, Beijing 100020, China
| | - Jinghua Cui
- Department of Bacteriology, Capital Institute of Pediatrics, Beijing 100020, China
| | - Chao Yan
- Department of Bacteriology, Capital Institute of Pediatrics, Beijing 100020, China
| | - Lin Gan
- Department of Bacteriology, Capital Institute of Pediatrics, Beijing 100020, China
| | - Junxia Feng
- Department of Bacteriology, Capital Institute of Pediatrics, Beijing 100020, China
| | - Jing Yuan
- Department of Bacteriology, Capital Institute of Pediatrics, Beijing 100020, China
| | - Fuping You
- School of Basic Medical Sciences, Peking University, Beijing 100020, China
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3
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Siriweera B, Ahmar Siddiqui M, Zou X, Chen G, Wu D. Integrated thiosulfate-driven denitrification, partial nitrification and anammox process in membrane-aerated biofilm reactor for low-carbon, energy-efficient biological nitrogen removal. BIORESOURCE TECHNOLOGY 2023; 382:129212. [PMID: 37230332 DOI: 10.1016/j.biortech.2023.129212] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/13/2023] [Revised: 05/13/2023] [Accepted: 05/18/2023] [Indexed: 05/27/2023]
Abstract
Combining multiple bioprocesses in a single membrane-aerated biofilm reactor (MABR) unit for wastewater treatment is an emerging research focus. This study investigated the feasibility of coupling thiosulfate-driven denitrification (TDD) with partial nitrification and anammox (PNA) in a MABR for the treatment of ammonium-containing wastewater. The integrated bioprocess was tested over a continuous operation period (>130 d) in two MABRs: one with a polyvinylidene fluoride membrane (MABR-1), and the other with micro-porous aeration tubes covered with non-wovenpolyester fabrics (MABR-2). After start-up, the MABR-1 and MABR-2 based on the TDD-PNA process achieved satisfactory total nitrogen removal efficiencies of 63% and 76%, with maximum oxygen utilisation efficiencies of up to 66% and 80% and nitrogen removal fluxes of 1.3 and 4.7 gN/(m2·d), respectively. Predictions from the AQUASIM-model verified the integrated bioprocess. These lab scale findings confirmed the applicability of MABR technology for simultaneous sulfur and nitrogen removal, promising for pilot-scale application.
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Affiliation(s)
- Buddhima Siriweera
- Department of Civil and Environmental Engineering, Water Technology Center, Hong Kong Branch of Chinese National Engineering Research Center for Control & Treatment of Heavy Metal Pollution, The Hong Kong University of Science and Technology, Hong Kong, China
| | - Muhammad Ahmar Siddiqui
- Department of Civil and Environmental Engineering, Water Technology Center, Hong Kong Branch of Chinese National Engineering Research Center for Control & Treatment of Heavy Metal Pollution, The Hong Kong University of Science and Technology, Hong Kong, China
| | - Xu Zou
- Department of Civil and Environmental Engineering, Water Technology Center, Hong Kong Branch of Chinese National Engineering Research Center for Control & Treatment of Heavy Metal Pollution, The Hong Kong University of Science and Technology, Hong Kong, China
| | - Guanghao Chen
- Department of Civil and Environmental Engineering, Water Technology Center, Hong Kong Branch of Chinese National Engineering Research Center for Control & Treatment of Heavy Metal Pollution, The Hong Kong University of Science and Technology, Hong Kong, China
| | - Di Wu
- Department of Civil and Environmental Engineering, Water Technology Center, Hong Kong Branch of Chinese National Engineering Research Center for Control & Treatment of Heavy Metal Pollution, The Hong Kong University of Science and Technology, Hong Kong, China; Centre for Environmental and Energy Research, Ghent University Global Campus, Incheon 21985, South Korea; Department of Green Chemistry and Technology, Ghent University, and Centre for Advanced Process Technology for Urban Resource Recovery (CAPTURE), Ghent 9000, Belgium.
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Zheng M, Mu G, Zhang A, Wang J, Chang F, Niu J, Wang X, Gao T, Zhao Z. Predominance of comammox bacteria among ammonia oxidizers under low dissolved oxygen condition. CHEMOSPHERE 2022; 308:136436. [PMID: 36115478 DOI: 10.1016/j.chemosphere.2022.136436] [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: 01/21/2022] [Revised: 08/19/2022] [Accepted: 09/10/2022] [Indexed: 06/15/2023]
Abstract
Although low-oxygen nitrification can significantly cut down the aeration demand in wastewater treatment plants, little is known about the community dynamics of relevant microorganisms under different oxygen concentrations. Here, by conducting a series of bioreactors with oxygen concentrations of 0%, 2%, 5%, 10%, 20%, 40%, and 70%, we provided a comprehensive investigation on the behaviors and performances of comammox bacteria (CMX), ammonia-oxidizing bacteria (AOB) and archaea (AOA) during the nitrification process. Quantitative PCR analysis demonstrated that CMX was the dominant ammonia-oxidizer under low oxygen condition (10%) after the four-month operation with the abundance increased by 8.65 times higher than the initial operation, whereas the growth of AOA and AOB was inhibited. Moreover, Nitrospira nitrosa dominated the CMX species (relative abundance >96%) in low dissolved oxygen concentrations, while Nitrospira nitrificans (3.39%) seemed to prefer high oxygen conditions. Our study indicates the long-term effects of oxygen concentrations on the niche differentiation of ammonia oxidizers, and highlights the significance of CMX in low-oxygen nitrification for reducing global carbon emission and energy consumption.
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Affiliation(s)
- Maosheng Zheng
- Key Laboratory of Resources and Environmental Systems Optimization, Ministry of Education, College of Environmental Science and Technology, North China Electric Power University, Beijing, 102206, China
| | - Guangli Mu
- Key Laboratory of Resources and Environmental Systems Optimization, Ministry of Education, College of Environmental Science and Technology, North China Electric Power University, Beijing, 102206, China
| | - Anqi Zhang
- Key Laboratory of Resources and Environmental Systems Optimization, Ministry of Education, College of Environmental Science and Technology, North China Electric Power University, Beijing, 102206, China
| | - Jiawen Wang
- College of Environmental Sciences and Engineering, Peking University, Key Laboratory of Water and Sediment Sciences, Ministry of Education, Beijing, 100871, China.
| | - Fang Chang
- Marine Resources Research Centre, Tianjin Research Institute for Water Transport Engineering, M.O.T., Tianjin, 300456, China
| | - Junfeng Niu
- Key Laboratory of Resources and Environmental Systems Optimization, Ministry of Education, College of Environmental Science and Technology, North China Electric Power University, Beijing, 102206, China
| | - Xinwei Wang
- Key Laboratory of Resources and Environmental Systems Optimization, Ministry of Education, College of Environmental Science and Technology, North China Electric Power University, Beijing, 102206, China
| | - Tian Gao
- Key Laboratory of Resources and Environmental Systems Optimization, Ministry of Education, College of Environmental Science and Technology, North China Electric Power University, Beijing, 102206, China
| | - Zhirong Zhao
- Key Laboratory of Resources and Environmental Systems Optimization, Ministry of Education, College of Environmental Science and Technology, North China Electric Power University, Beijing, 102206, China
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Joel Koffi N, Okabe S. Effect of poised cathodic potential on anodic ammonium nitrogen removal from domestic wastewater by air-cathode microbial fuel cells. BIORESOURCE TECHNOLOGY 2022; 348:126807. [PMID: 35124217 DOI: 10.1016/j.biortech.2022.126807] [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: 12/08/2021] [Revised: 01/27/2022] [Accepted: 01/28/2022] [Indexed: 06/14/2023]
Abstract
Performances of anodic ammonia oxidation have been investigated for various bioelectrochemical systems at a wide range of poised anodic potentials in the literature. The effect of poised cathodic potential on ammonium nitrogen (NH4+-N) and total nitrogen (TN, sum of NH4+-N, NO2--N, and NO3--N) removal from domestic wastewater by single chamber air-cathode microbial fuel cells (MFCs) was investigated. Poising the air-cathode potential at +0.7 V vs. SHE significantly increased current generation (from 11 ± 1 mA to 22.8 ± 5 mA) and oxygen permeation into the MFC through the air-cathode (from 75.4 ± 1.2 g-O2/m3/d to 151 ± 3.7 g-O2/m3/d), which consequently resulted in a high NH4+-N removal rate of 150 ± 13 g-NH4+-N/m3/d and TN removal rate of 63 ± 16 g-TN/m3/d. These high NH4+-N and TN removal rates could be attributed to the enhancement of dual respiratory pathways: the electrode-assisted anodic and aerobic NH4+ oxidation.
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Affiliation(s)
- N'dah Joel Koffi
- Division of Environmental Engineering, Faculty of Engineering, Hokkaido University, North-13, West-8, Kita-ku, Sapporo, Hokkaido 060-8628, Japan
| | - Satoshi Okabe
- Division of Environmental Engineering, Faculty of Engineering, Hokkaido University, North-13, West-8, Kita-ku, Sapporo, Hokkaido 060-8628, Japan.
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Farooq MS, Uzair M, Maqbool Z, Fiaz S, Yousuf M, Yang SH, Khan MR. Improving Nitrogen Use Efficiency in Aerobic Rice Based on Insights Into the Ecophysiology of Archaeal and Bacterial Ammonia Oxidizers. FRONTIERS IN PLANT SCIENCE 2022; 13:913204. [PMID: 35769304 PMCID: PMC9234532 DOI: 10.3389/fpls.2022.913204] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/05/2022] [Accepted: 05/16/2022] [Indexed: 05/22/2023]
Abstract
The abundance and structural composition of nitrogen (N) transformation-related microbial communities under certain environmental conditions provide sufficient information about N cycle under different soil conditions. This study aims to explore the major challenge of low N use efficiency (NUE) and N dynamics in aerobic rice systems and reveal the agronomic-adjustive measures to increase NUE through insights into the ecophysiology of ammonia oxidizers. Water-saving practices, like alternate wetting and drying (AWD), dry direct seeded rice (DDSR), wet direct seeding, and saturated soil culture (SSC), have been evaluated in lowland rice; however, only few studies have been conducted on N dynamics in aerobic rice systems. Biological ammonia oxidation is majorly conducted by two types of microorganisms, ammonia-oxidizing archaea (AOA) and ammonia-oxidizing bacteria (AOB). This review focuses on how diversified are ammonia oxidizers (AOA and AOB), whose factors affect their activities and abundance under different soil conditions. It summarizes findings on pathways of N cycle, rationalize recent research on ammonia oxidizers in N-cycle, and thereby suggests adjustive agronomic measures to reduce N losses. This review also suggests that variations in soil properties significantly impact the structural composition and abundance of ammonia oxidizers. Nitrification inhibitors (NIs) especially nitrapyrin, reduce the nitrification rate and inhibit the abundance of bacterial amoA without impacting archaeal amoA. In contrast, some NIs confine the hydrolysis of synthetic N and, therefore, keep low NH4 +-N concentrations that exhibit no or very slight impact on ammonia oxidizers. Variations in soil properties are more influential in the community structure and abundance of ammonia oxidizers than application of synthetic N fertilizers and NIs. Biological nitrification inhibitors (BNIs) are natural bioactive compounds released from roots of certain plant species, such as sorghum, and could be commercialized to suppress the capacity of nitrifying soil microbes. Mixed application of synthetic and organic N fertilizers enhances NUE and plant N-uptake by reducing ammonia N losses. High salt concentration promotes community abundance while limiting the diversity of AOB and vice versa for AOA, whereas AOA have lower rate for potential nitrification than AOB, and denitrification accounts for higher N2 production. Archaeal abundance, diversity, and structural composition change along an elevation gradient and mainly depend on various soil factors, such as soil saturation, availability of NH4 +, and organic matter contents. Microbial abundance and structural analyses revealed that the structural composition of AOA was not highly responsive to changes in soil conditions or N amendment. Further studies are suggested to cultivate AOA and AOB in controlled-environment experiments to understand the mechanisms of AOA and AOB under different conditions. Together, this evaluation will better facilitate the projections and interpretations of ammonia oxidizer community structural composition with provision of a strong basis to establish robust testable hypotheses on the competitiveness between AOB and AOA. Moreover, after this evaluation, managing soils agronomically for potential utilization of metabolic functions of ammonia oxidizers would be easier.
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Affiliation(s)
- Muhammad Shahbaz Farooq
- Institute of Environment and Sustainable Development in Agriculture, Chinese Academy of Agricultural Sciences, Beijing, China
- National Institute for Genomics and Advanced Biotechnology, Islamabad, Pakistan
| | - Muhammad Uzair
- National Institute for Genomics and Advanced Biotechnology, Islamabad, Pakistan
| | - Zubaira Maqbool
- Institute of Soil Science, Pir Mehr Ali Shah-Arid Agriculture University, Rawalpindi, Pakistan
| | - Sajid Fiaz
- Department of Plant Breeding and Genetics, The University of Haripur, Haripur, Pakistan
| | | | - Seung Hwan Yang
- Department of Biotechnology, Chonnam National University, Yeosu, South Korea
- *Correspondence: Seung Hwan Yang,
| | - Muhammad Ramzan Khan
- National Institute for Genomics and Advanced Biotechnology, Islamabad, Pakistan
- Muhammad Ramzan Khan,
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7
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Yuan D, Zheng L, Tan Q, Wang X, Xing Y, Wang H, Wang S, Zhu G. Comammox activity dominates nitrification process in the sediments of plateau wetland. WATER RESEARCH 2021; 206:117774. [PMID: 34757282 DOI: 10.1016/j.watres.2021.117774] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/05/2021] [Revised: 10/10/2021] [Accepted: 10/11/2021] [Indexed: 06/13/2023]
Abstract
The recent discovery of complete ammonia oxidation (comammox) has increased our understanding of nitrification. Although comammox has been shown to play an important role in plain wetland ecosystems, studies of comammox contribution are still limited in plateau wetland ecosystems. Here, we analyzed the abundance, activity, community and biogeochemical mechanisms of the comammox bacteria in Yunnan-kweichow and Qinghai-Tibet plateau wetlands from elevations of 1000-5000 m. Comammox bacteria were widely distributed in all 16 sediment samples with abundances higher than 0.96 ± 0.26 × 107 copies g-1 (n = 16). Comammox showed high activity (1.18 ± 0.17 to 1.98 ± 0.08 mg N kg-1 d-1) at high-elevation (3000-5000 m) and dominated the nitrification process (activity contribution: 37.20 - 60.62%). The activity contribution of ammonia-oxidizing bacteria (1.07 ± 0.08 to 2.79 ± 0.35 mg N kg-1 d-1) dominated the nitrification process (44.55 - 64.15%) in low-elevation (1000-3000 m) samples. All detected comammox Nitrospira belonged to clade A, while clade B was not detected. Elevation always had a strongest effect on key comammox species. Thus, we infer that elevation may drive the high relative abundance of the species Candidatus Nitrospira nitrificans (avg. 12.40%) and the low relative abundance of the species Nitrospira sp. SG-bin2 (avg. 4.75%) in high-elevation samples that showed a high comammox activity (avg. 1.62 mg N kg-1 d-1) and high contribution (avg. 46.08%) to the nitrification process. These results indicate that comammox may be an important and currently underestimated microbial nitrification process in plateau wetland ecosystems.
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Affiliation(s)
- Dongdan Yuan
- College of Water Sciences, Beijing Normal University, Beijing 100875, China
| | - Lei Zheng
- College of Water Sciences, Beijing Normal University, Beijing 100875, China.
| | - Qiuyang Tan
- College of Water Sciences, Beijing Normal University, Beijing 100875, China
| | - Xue Wang
- College of Water Sciences, Beijing Normal University, Beijing 100875, China
| | - Yuzi Xing
- College of Water Sciences, Beijing Normal University, Beijing 100875, China
| | - Huipeng Wang
- College of Water Sciences, Beijing Normal University, Beijing 100875, China
| | - Shanyun Wang
- Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
| | - Guibing Zhu
- Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
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Exploring the Meta-regulon of the CRP/FNR Family of Global Transcriptional Regulators in a Partial-Nitritation Anammox Microbiome. mSystems 2021; 6:e0090621. [PMID: 34636676 PMCID: PMC8510549 DOI: 10.1128/msystems.00906-21] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Microorganisms must respond to environmental changes to survive, often by controlling transcription initiation. Intermittent aeration during wastewater treatment presents a cyclically changing environment to which microorganisms must react. We used an intermittently aerated bioreactor performing partial nitritation and anammox (PNA) to investigate how the microbiome responds to recurring change. Meta-transcriptomic analysis revealed a dramatic disconnect between the relative DNA abundance and gene expression within the metagenome-assembled genomes (MAGs) of community members, suggesting the importance of transcriptional regulation in this microbiome. To explore how community members responded to cyclic aeration via transcriptional regulation, we searched for homologs of the catabolite repressor protein/fumarate and nitrate reductase regulatory protein (CRP/FNR) family of transcription factors (TFs) within the MAGs. Using phylogenetic analyses, evaluation of sequence conservation in important amino acid residues, and prediction of genes regulated by TFs in the MAGs, we identified homologs of the oxygen-sensing FNR in Nitrosomonas and Rhodocyclaceae, nitrogen-sensing dissimilative nitrate respiration regulator that responds to nitrogen species (DNR) in Rhodocyclaceae, and nitrogen-sensing nitrite and nitric oxide reductase regulator that responds to nitrogen species (NnrR) in Nitrospira MAGs. Our data also predict that CRP/FNR homologs in Ignavibacteria, Flavobacteriales, and Saprospiraceae MAGs sense carbon availability. In addition, a CRP/FNR homolog in a Brocadia MAG was most closely related to CRP TFs known to sense carbon sources in well-studied organisms. However, we predict that in autotrophic Brocadia, this TF most likely regulates a diverse set of functions, including a response to stress during the cyclic aerobic/anoxic conditions. Overall, this analysis allowed us to define a meta-regulon of the PNA microbiome that explains functions and interactions of the most active community members. IMPORTANCE Microbiomes are important contributors to many ecosystems, including ones where nutrient cycling is stimulated by aeration control. Optimizing cyclic aeration helps reduce energy needs and maximize microbiome performance during wastewater treatment; however, little is known about how most microbial community members respond to these alternating conditions. We defined the meta-regulon of a PNA microbiome by combining existing knowledge of how the CRP/FNR family of bacterial TFs respond to stimuli, with metatranscriptomic analyses to characterize gene expression changes during aeration cycles. Our results indicated that, for some members of the community, prior knowledge is sufficient for high-confidence assignments of TF function, whereas other community members have CRP/FNR TFs for which inferences of function are limited by lack of prior knowledge. This study provides a framework to begin elucidating meta-regulons in microbiomes, where pure cultures are not available for traditional transcriptional regulation studies. Defining the meta-regulon can help in optimizing microbiome performance.
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Nandy S, Arora U, Tarar P, Viggor S, Jõesaar M, Kivisaar M, Kapley A. Monitoring the growth, survival and phenol utilization of the fluorescent-tagged Pseudomonas oleovorans immobilized and free cells. BIORESOURCE TECHNOLOGY 2021; 338:125568. [PMID: 34274579 DOI: 10.1016/j.biortech.2021.125568] [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: 05/30/2021] [Revised: 07/09/2021] [Accepted: 07/10/2021] [Indexed: 06/13/2023]
Abstract
Bioaugmentation in wastewater treatment plants (WWTPs) is challenging due to low survival and persistence of applied microbes. This study aimed to track the capacity and survival of fluorescent-tagged Pseudomonas oleovoransICTN13 as a model organism applicable in bioaugmentation of phenol-containing wastewater. The isolate was immobilized in alginate biopolymer, and enhanced efficacy and survival for biodegradation of phenol against free cells were studied. Encapsulated cells resulted in enhanced phenol removal efficiency (~94%) compared to free cells (~72%). Encapsulation of cells facilitated an extended storage time of 30 days. Remarkably, phenol and COD removal efficacy of encapsulated cells was sustained up to ~ 92-93% in a reactor after 45 days, while free cells could produce ~ 80-84% removal efficiency. Fluorescence microscopy showed high survival of the encapsulated cells, whereas gradual deterioration of free cells was observed. Thus, the findings highlight the importance of bio augmented strain in WWTPs where encapsulation is a crucial factor.
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Affiliation(s)
- Sampurna Nandy
- Director's Research Cell, CSIR-National Environmental Engineering Research Institute, Nagpur 440020, India; Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India
| | - Upasana Arora
- Director's Research Cell, CSIR-National Environmental Engineering Research Institute, Nagpur 440020, India
| | - Pranay Tarar
- Director's Research Cell, CSIR-National Environmental Engineering Research Institute, Nagpur 440020, India
| | - Signe Viggor
- Institute of Molecular and Cell Biology, University of Tartu, Tartu 51010, Estonia
| | - Merike Jõesaar
- Institute of Molecular and Cell Biology, University of Tartu, Tartu 51010, Estonia
| | - Maia Kivisaar
- Institute of Molecular and Cell Biology, University of Tartu, Tartu 51010, Estonia
| | - Atya Kapley
- Director's Research Cell, CSIR-National Environmental Engineering Research Institute, Nagpur 440020, India; Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India.
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10
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Aguilar L, Gallegos Á, Martín Pérez L, Arias CA, Rubio R, Haulani L, García Raurich J, Pallarés M, de Pablo J, Morató J. Effect of intermittent induced aeration on nitrogen removal and denitrifying-bacterial community structure in Cork and gravel vertical flow pilot-scale treatment wetlands. JOURNAL OF ENVIRONMENTAL SCIENCE AND HEALTH. PART A, TOXIC/HAZARDOUS SUBSTANCES & ENVIRONMENTAL ENGINEERING 2021; 56:1121-1130. [PMID: 34415215 DOI: 10.1080/10934529.2021.1967652] [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: 12/01/2020] [Revised: 08/05/2021] [Accepted: 08/09/2021] [Indexed: 06/13/2023]
Abstract
In this work, we have evaluated the impact of intermittent induced aeration in total nitrogen (TN), ammonia (NH4-N) and nitrate-nitrogen (NO3-N) removal in four pilot-scale vertical flow constructed wetlands (VFCW) (two aerated two non-aerated) using cork by-product or gravel as the filter material and planted with Phragmites australis. Both aerated and non-aerated systems achieved high COD and BOD5 elimination rates (≥ 90%) at the end of the 5-month test period. However, the aerated systems presented maximal COD and BOD5 removal from the third month of operation onwards since air supply favored the oxidative bioprocesses occurring within the wetlands. Cork and gravel aerated VFCW also proved to be more efficient (p < 0.05) in NO3-N removal than the non-aerated systems and this upgraded performance was correlated with a significant higher relative abundance of the nirS gene. The aerated systems also showed a slightly improved NH4-N removal. Noticeably, cork VFCW showed higher TN removal mean values (∼35%) than gravel wetlands (27-28%) regardless aeration. Moreover, cork VFCW showed higher relative abundance of the nosZ gene. Our results demonstrated a better nitrogen elimination for the aerated cork pilot-scale VFCW, and this behavior was correlated with a higher abundance of both nirS and nosZ, two of the key functional genes involved in nitrogen metabolism.
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Affiliation(s)
- Lorena Aguilar
- UNESCO Chair on Sustainability, Universitat Politècnica de Catalunya, Terrassa, Spain
| | - Ángel Gallegos
- UNESCO Chair on Sustainability, Universitat Politècnica de Catalunya, Terrassa, Spain
| | - Leonardo Martín Pérez
- UNESCO Chair on Sustainability, Universitat Politècnica de Catalunya, Terrassa, Spain
- Instituto de Investigaciones en Ingeniería Ambiental, Química y Biotecnología Aplicada (INGEBIO-UCA, CONICET), Fac. de Química e Ingeniería del Rosario, Pontificia Universidad Católica Argentina (UCA-Rosario), Rosario (Santa Fe), Argentina
| | - Carlos A Arias
- Department of Biological Sciences, University of Aarhus, Arhus C, Denmark
- Aarhus University Centre for Water Technology WATEC, Aarhus University, Aarhus C, Denmark
| | - Raquel Rubio
- UNESCO Chair on Sustainability, Universitat Politècnica de Catalunya, Terrassa, Spain
| | - Leila Haulani
- UNESCO Chair on Sustainability, Universitat Politècnica de Catalunya, Terrassa, Spain
| | - Josep García Raurich
- Centro de Investigación en Seguridad y Control Alimentario (CRESCA), Depto. de Ingeniería Química, Universidad Politécnica de Cataluña-BarcelonaTech, Terrassa, Spain
| | - Marc Pallarés
- Grupo de Desarrollo Empresarial, I + D+i, S.L, C/Colom, Terrassa, Spain
| | - Joan de Pablo
- Resource Recovery and Environmental Management (R2EM), Depto. de Ingeniería Química, Universidad Politécnica de Cataluña-BarcelonaTech, Barcelona, Spain
| | - Jordi Morató
- UNESCO Chair on Sustainability, Universitat Politècnica de Catalunya, Terrassa, Spain
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Liu G, Wu X, Li D, Jiang L, Huang J, Zhuang L. Long-Term Low Dissolved Oxygen Operation Decreases N 2O Emissions in the Activated Sludge Process. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2021; 55:6975-6983. [PMID: 33904707 DOI: 10.1021/acs.est.0c07279] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Nitrous oxide (N2O) is an important greenhouse gas and a dominant ozone-depleting substance. Nitrification in the activated sludge process (ASP) is an important N2O emission source. This study demonstrated that a short-term low dissolved oxygen (DO) increased the N2O emissions by six times, while long-term low DO operation decreased the N2O emissions by 54% (P < 0.01). Under long-term low DO, the ammonia oxidizer abundance in the ASP increased significantly, and thus, complete nitrification was recovered and no NH3 or nitrite accumulated. Moreover, long-term low DO decreased the abundance of ammonia-oxidizing bacteria (AOB) by 28%, while increased the abundance of ammonia-oxidizing archaea (AOA) by 507%, mainly due to their higher oxygen affinity. As a result, AOA outnumbered AOB with the AOA/AOB amoA gene ratio increasing to 19.5 under long-term low DO. The efficient nitrification and decreased AOB abundance might not increase N2O production via AOB under long-term low DO conditions. The enriched AOA could decrease the N2O emissions because they were reported to lack canonical nitric oxide (NO) reductase genes that convert NO to N2O. Probably because of AOA enrichment, the positive and significant (P = 0.02) correlation of N2O emission and nitrite concentration became insignificant (P = 0.332) after 80 days of low DO operation. Therefore, ASPs can be operated with low DO and extended sludge age to synchronously reduce N2O production and carbon dioxide emissions owing to lower aeration energy without compromising the nitrification efficiency.
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Affiliation(s)
- Guoqiang Liu
- School of Environment, Guangdong Engineering Research Center of Water Treatment Processes and Materials and Guangdong Key Laboratory of Environmental Pollution and Health, Jinan University, Guangzhou 510632, China
| | - Xianwei Wu
- School of Environment, Guangdong Engineering Research Center of Water Treatment Processes and Materials and Guangdong Key Laboratory of Environmental Pollution and Health, Jinan University, Guangzhou 510632, China
| | - Deyong Li
- School of Environment, Guangdong Engineering Research Center of Water Treatment Processes and Materials and Guangdong Key Laboratory of Environmental Pollution and Health, Jinan University, Guangzhou 510632, China
| | - Lugao Jiang
- School of Environment, Guangdong Engineering Research Center of Water Treatment Processes and Materials and Guangdong Key Laboratory of Environmental Pollution and Health, Jinan University, Guangzhou 510632, China
| | - Ju Huang
- School of Environment, Guangdong Engineering Research Center of Water Treatment Processes and Materials and Guangdong Key Laboratory of Environmental Pollution and Health, Jinan University, Guangzhou 510632, China
| | - Li Zhuang
- School of Environment, Guangdong Engineering Research Center of Water Treatment Processes and Materials and Guangdong Key Laboratory of Environmental Pollution and Health, Jinan University, Guangzhou 510632, China
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12
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Li D, Fang F, Liu G. Efficient Nitrification and Low-Level N 2O Emission in a Weakly Acidic Bioreactor at Low Dissolved-Oxygen Levels Are Due to Comammox. Appl Environ Microbiol 2021; 87:e00154-21. [PMID: 33975896 PMCID: PMC8208134 DOI: 10.1128/aem.00154-21r] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2021] [Accepted: 03/13/2021] [Indexed: 01/31/2023] Open
Abstract
Nitrification is an essential process for nutrient removal from wastewater and an important emission source of nitrous oxide (N2O), which is a powerful greenhouse gas and a dominant ozone-depleting substance. In this study, nitrification and N2O emissions were tested in two weakly acidic (pH 6.3 to 6.8) reactors: one with dissolved oxygen (DO) at over 2.0 mg/liter and the other with DO at approximately 0.5 mg/liter. Efficient nitrification was achieved in both reactors. Compared to that in the high-DO reactor, N2O emission in the low-DO reactor decreased slightly, by 20%, and had insignificant correlation with the fluctuations of DO (P = 0.935) and nitrite (P = 0.713), indicating that N2O might not be produced mainly via nitrifier denitrification. Based on quantitative PCR (qPCR), quantitative fluorescent in situ hybridization (qFISH), and functional gene amplicon and metagenome sequencing, it was found that complete ammonia oxidizers (comammox), i.e., Nitrospira organisms, significantly outnumbered canonical ammonia-oxidizing bacteria (AOB) in both weakly acidic reactors, especially in the low-DO reactor with the comammox/AOB amoA gene ratio increasing from 6.6 to 17.1. Therefore, it was speculated that the enriched comammox was the primary cause for the slightly decreased N2O emission under long-term low DO in the weakly acidic reactor. This study demonstrated that the comammox Nitrospira can survive well under the weakly acidic and low-DO conditions, implying that achieving efficient nitrification with low N2O emission as well as low energy and alkalinity consumption is feasible for wastewater treatment.IMPORTANCE Nitrification in wastewater treatment is an important process for eutrophication control and an emission source for the greenhouse gas N2O. The nitrifying process is usually operated at a slightly alkaline pH and high DO (>2 mg/liter) to ensure efficient nitrification. However, it consumes a large amount of energy and chemicals, especially for wastewater without sufficient alkalinity. This paper demonstrates that comammox can adapt well to the weakly acidic and low-DO bioreactors, with a result of efficient nitrification and low N2O emission. These findings indicate that comammox organisms are significant for sustainable wastewater treatment, which provides an opportunity to achieve efficient nitrification with low N2O production as well as low energy and chemical consumption simultaneously.
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Affiliation(s)
- Deyong Li
- School of the Environment, Guangdong Engineering Research Center of Water Treatment Processes and Materials, Jinan University, Guangzhou, China
- School of the Environment, Guangdong Key Laboratory of Environmental Pollution and Health, Jinan University, Guangzhou, China
| | - Fang Fang
- College of the Environment and Ecology, Chongqing University, Chongqing, China
| | - Guoqiang Liu
- School of the Environment, Guangdong Engineering Research Center of Water Treatment Processes and Materials, Jinan University, Guangzhou, China
- School of the Environment, Guangdong Key Laboratory of Environmental Pollution and Health, Jinan University, Guangzhou, China
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13
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Gohain SB, Bordoloi S. Impact of municipal solid waste disposal on the surface water and sediment of adjoining wetland Deepor Beel in Guwahati, Assam, India. ENVIRONMENTAL MONITORING AND ASSESSMENT 2021; 193:278. [PMID: 33861382 DOI: 10.1007/s10661-021-09040-y] [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: 02/05/2020] [Accepted: 03/29/2021] [Indexed: 06/12/2023]
Abstract
The municipal solid waste (MSW) dump in Boragaon, Guwahati, lies on the fringe areas of the wetland, Deepor Beel, which is a Ramsar site. The study was undertaken to analyze the impact the solid waste dump has on the adjoining wetland. Five sampling locations (S1, S2, S3, S4 and S5) in the wetland were selected within a distance of 3000 m from the MSW dump for the continuous monitoring of the surface water and sediment of the wetland. Nineteen physicochemical parameters (pH, EC, air and water temperature, total hardness, alkalinity, turbidity, DO, free CO2, TDS, BOD, Na+, K+, Ca2+, Cl-, NO3-, HCO3-, PO43-, SO42-) were analysed in the surface water, and 7 physicochemical parameters (pH, EC, %OC, %N, PO43-, K+, Na+) were analysed in sediment. Heavy metals Cu, Ni, Cd, Cr, Mn, Zn and As were analysed in surface water and sediment samples. The results of the principal component analysis (PCA) and cluster analysis (CA) applied on the surface water data have aptly described the source of contamination in the study area to be from the adjoining MSW dump site. The surface spread of contamination from the MSW dump towards the wetland was evident from the regression equations drawn from the sediment data. The mean concentration of Mn, Cr, Ni, Cd and As in surface water exceeded the MPL (maximum permissible limit) of WHO 2011 (World Health Organization). The pollution load index (PLI) of sediment in the wetland shows that the study area is under the category of "progressive deterioration".
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Affiliation(s)
- Sonali Borpatra Gohain
- Resource Management and Environment Section, Institute of Advanced Study in Science and Technology (IASST), Paschim Boragaon, Guwahati, 781035, Assam, India.
| | - Sabitry Bordoloi
- Resource Management and Environment Section, Institute of Advanced Study in Science and Technology (IASST), Paschim Boragaon, Guwahati, 781035, Assam, India
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14
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Efficient nitrification and low N 2O emission in a weakly acidic bioreactor at low dissolved oxygen levels are due to comammox. Appl Environ Microbiol 2021; 87:AEM.00154-21. [PMID: 33741624 DOI: 10.1128/aem.00154-21] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
Nitrification is an essential process for nutrient removal from wastewater and an important emission source of nitrous-oxide (N2O), which is a powerful greenhouse gas and a dominant ozone-depleting substance. In this study, nitrification and N2O emissions were tested in two weakly acidic (pH = 6.3-6.8) reactors: one with dissolved oxygen (DO) over 2.0 mg/L and the other with DO approximately 0.5 mg/L. Efficient nitrification was achieved in both reactors. Compared to the high-DO reactor, N2O emission in the low-DO reactor decreased slightly by 20% and had insignificant correlation with the fluctuations of DO (P = 0.935) and nitrite (P = 0.713), indicating that N2O might not be mainly produced via nitrifier denitrification. Based on qPCR, qFISH, functional gene amplicon and metagenome sequencing, it was found that complete ammonia oxidizer (comammox) Nitrospira significantly outnumbered canonical ammonia-oxidizing bacteria (AOB) in both weakly acidic reactors, especially in the low DO reactor with the comammox/AOB amoA gene ratio increasing from 6.6 to 17.1. Therefore, it was speculated that the enriched comammox was the primary cause for the slightly decreased N2O emission under long-term low DO in weakly acidic reactor. This study demonstrated that comammox Nitrospira can survive well under the weakly acidic and low-DO conditions, implying that achieving efficient nitrification with low N2O emission as well as low energy and alkalinity consumption is feasible for wastewater treatment.ImportanceNitrification in wastewater treatment is an important process for eutrophication control and an emission source for greenhouse gas of N2O. The nitrifying process is usually operated at a slightly alkaline pH and high DO (>2 mg/L) to ensure efficient nitrification. However, it consumes a large amount of energy and chemicals especially for wastewater without sufficient alkalinity. This manuscript demonstrated that comammox can adapt well to the weakly acidic and low-DO bioreactors, with a result of efficient nitrification and low N2O emission. These findings indicate that comammox are significant for sustainable wastewater treatment, which provides an opportunity to achieve efficient nitrification with low N2O production as well as low energy and chemical consumption simultaneously.
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Comparison of the Performance and Microbial Community Structure of Two Outdoor Pilot-Scale Photobioreactors Treating Digestate. Microorganisms 2020; 8:microorganisms8111754. [PMID: 33171685 PMCID: PMC7695279 DOI: 10.3390/microorganisms8111754] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2020] [Revised: 11/04/2020] [Accepted: 11/06/2020] [Indexed: 12/24/2022] Open
Abstract
This study aimed at examining and comparing the nutrient removal efficiency, biomass productivity and microbial community structure of two outdoor pilot-scale photobioreactors, namely a bubble column and a raceway pond, treating the liquid fraction of an agricultural digestate. Bacterial and eukaryotic communities were characterized using a metabarcoding approach and quantitative PCR. The abundance, composition, diversity, and dynamics of the main microbes were then correlated to the environmental conditions and operational parameters of the reactors. Both photobioreactors were dominated either by Chlorella sp. or Scenedesmus sp. in function of temperature, irradiance and the nitrogen compounds derived by nitrification. Other species, such as Chlamydomonas and Planktochlorella, were sporadically present, demonstrating that they have more specific niche requirement. Pseudomonas sp. always dominated the bacterial community in both reactors, except in summertime, when a bloom of Calothrix occurred in the raceway pond. In autumn, the worsening of the climate conditions decreased the microalgal growth, promoting predation by Vorticella sp. The study highlights the factors influencing the structure and dynamics of the microbial consortia and which ecological mechanisms are driving the microbial shifts and the consequent reactor performance. On these bases, control strategies could be defined to optimize the management of the microalgal-based technologies.
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16
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Mutual Interaction between Temperature and DO Set Point on AOB and NOB Activity during Shortcut Nitrification in a Sequencing Batch Reactor in Terms of Energy Consumption Optimization. ENERGIES 2020. [DOI: 10.3390/en13215808] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Recently, many wastewater treatment plants (WWTPs) have had to deal with serious problems related to the restrictive requirements regarding the effluent quality, as well as significant energy consumption associated with it. In this situation, mainstream deammonification and/or shortened nitrification-denitrification via nitrite (so-called “nitrite shunt”) is a new promising strategy. This study shows the mechanisms and operating conditions (e.g., dissolved oxygen (DO) concentration, temp.), leading to the complete domination of ammonium oxidizing bacteria (AOB) over nitrite oxidizing bacteria (NOB) under aerobic conditions. Its successful application as shortcut nitrification in the sequencing batch reactor (SBR) technology will represent a paradigm shift for the wastewater industry, offering the opportunity for efficient wastewater treatment, energy-neutral or even energy-positive facilities, and substantial reductions in treatment costs. In this study, under low and moderate temperatures (10–16 °C), averaged DO concentrations (0.7 mg O2/L) were preferable to ensure beneficial AOB activity over NOB, by maintaining reasonable energy consumption. Elevated temperatures (~30 °C), as well as increased DO concentration, were recognized as beneficial for the NOB activity stimulation, thus under such conditions, the DO limitation seems to be a more prospective approach.
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17
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Abbas T, Zhang Q, Zou X, Tahir M, Wu D, Jin S, Di H. Soil anammox and denitrification processes connected with N cycling genes co-supporting or contrasting under different water conditions. ENVIRONMENT INTERNATIONAL 2020; 140:105757. [PMID: 32361577 DOI: 10.1016/j.envint.2020.105757] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/05/2020] [Revised: 04/12/2020] [Accepted: 04/21/2020] [Indexed: 06/11/2023]
Abstract
The anaerobic ammonium oxidizing bacteria (anammox) are the hidden culprit behind the excessive nitrogen loss under a favorable environment, since their detection and abundance get disturbed by several unknown factors. This study intends to find the gap between actual anammox working capacity under different water conditions and fertilizers in the laboratory. The 15N-isotopic tracer technique was used to measure anammox and denitrification rate, and anammox community structure was analyzed through high-throughput sequencing with cytochrome cd-1 nitrite reductase functional gene (an_nirS gene, initially found in Candidatus Scalindua). The experiment consisted of four treatments, i.e., (I) CK_ Control, (II) UR_Urea, (III) PM_Pig Manure, and (IV) SRF_ Slow release fertilizer, under two water conditions, i.e., (a) Continuous flooding_ CF, (b) Alternate wetting and drying_ AWD. Results showed that anammox under CF decreased over time by -40.24%, and denitrification increased up to 39.25%. However, anammox activity under AWD increased up to 10.62% with the availability of NO2-, and surprisingly accompanied by the reduction in denitrification loss (-31.97%), being the most critical factor. We found that soil nifH and AOB genes were strongly favorable for anammox activity, while we observed the presence of anammox and AOB genes co-existing at the same time in paddy soil. The high-throughput sequencing with an_nirS functional gene showed a much higher diversity of anammox genera ever reported, mostly uncultured and unidentified. We concluded that water management is more prominent than fertilizer for anammox, and the most critical factor is the duration of AWD cycle, because of short term air supply could boost anammox activity and gene abundance, and could reduce denitrifier activity as well as nirK gene abundance.
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Affiliation(s)
- Touqeer Abbas
- Zhejiang Provincial Key Laboratory of Agricultural Resources and Environment, Key Laboratory of Environment Remediation and Ecological Health, Ministry of Education, Zhejiang University, Hangzhou 310058, PR China
| | - Qichun Zhang
- Zhejiang Provincial Key Laboratory of Agricultural Resources and Environment, Key Laboratory of Environment Remediation and Ecological Health, Ministry of Education, Zhejiang University, Hangzhou 310058, PR China.
| | - Xiang Zou
- Zhejiang Provincial Key Laboratory of Agricultural Resources and Environment, Key Laboratory of Environment Remediation and Ecological Health, Ministry of Education, Zhejiang University, Hangzhou 310058, PR China
| | - Muhammad Tahir
- Department of Soil, Water, & Climate, Univ. of Minnesota, 1991 Upper Buford Cir, Falcon Heights, MN 55108, USA
| | - Dan Wu
- College of Biosystems Engineering and Food Science, Zhejiang University, Hangzhou 310058, PR China
| | - Shuquan Jin
- Ecology and Environment Institute, Ningbo Academy of Agricultural Science, Ningbo 315040, PR China
| | - Hongjie Di
- Zhejiang Provincial Key Laboratory of Agricultural Resources and Environment, Key Laboratory of Environment Remediation and Ecological Health, Ministry of Education, Zhejiang University, Hangzhou 310058, PR China
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18
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Navada S, Knutsen MF, Bakke I, Vadstein O. Nitrifying biofilms deprived of organic carbon show higher functional resilience to increases in carbon supply. Sci Rep 2020; 10:7121. [PMID: 32346018 PMCID: PMC7189377 DOI: 10.1038/s41598-020-64027-y] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2020] [Accepted: 04/08/2020] [Indexed: 11/09/2022] Open
Abstract
In nitrifying biofilms, the organic carbon to ammonia nitrogen (C/N) supply ratio can influence resource competition between heterotrophic and nitrifying bacteria for oxygen and space. We investigated the impact of acute and chronic changes in carbon supply on inter-guild competition in two moving bed biofilm reactors (MBBR), operated with (R1) and without (R0) external organic carbon supply. The microbial and nitrifying community composition of the reactors differed significantly. Interestingly, acute increases in the dissolved organic carbon inhibited nitrification in R1 ten times more than in R0. A sustained increase in the carbon supply decreased nitrification efficiency and increased denitrification activity to a greater extent in R1, and also increased the proportion of potential denitrifiers in both bioreactors. The findings suggest that autotrophic biofilms subjected to increases in carbon supply show higher nitrification and lower denitrification activity than carbon-fed biofilms. This has significant implications for the design of nitrifying bioreactors. Specifically, efficient removal of organic matter before the nitrification unit can improve the robustness of the bioreactor to varying influent quality. Thus, maintaining a low C/N ratio is important in nitrifying biofilters when acute carbon stress is expected or when anoxic activity (e.g. denitrification or H2S production) is undesirable, such as in recirculating aquaculture systems (RAS).
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Affiliation(s)
- Sharada Navada
- Department of Chemistry, NTNU - Norwegian University of Science and Technology, N-7491, Trondheim, Norway. .,Krüger Kaldnes AS (Veolia Water Technologies), N-3241, Sandefjord, Norway.
| | - Maja F Knutsen
- Department of Biotechnology and Food Science, NTNU - Norwegian University of Science and Technology, N-7491, Trondheim, Norway.,Oxy Solutions, Gaustadalleen 21, N-0349, Oslo, Norway
| | - Ingrid Bakke
- Department of Biotechnology and Food Science, NTNU - Norwegian University of Science and Technology, N-7491, Trondheim, Norway
| | - Olav Vadstein
- Department of Biotechnology and Food Science, NTNU - Norwegian University of Science and Technology, N-7491, Trondheim, Norway
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Mantovani M, Marazzi F, Fornaroli R, Bellucci M, Ficara E, Mezzanotte V. Outdoor pilot-scale raceway as a microalgae-bacteria sidestream treatment in a WWTP. THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 710:135583. [PMID: 31785903 DOI: 10.1016/j.scitotenv.2019.135583] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/26/2019] [Revised: 10/05/2019] [Accepted: 11/15/2019] [Indexed: 05/27/2023]
Abstract
This study aims at demonstrating the feasibility of using microalgae-bacteria consortia for the treatment of the sidestream flow of the supernatant from blackwater dewatering (centrate) in an urban wastewater treatment plant in Northern Italy. A 1200 L raceway reactor was used for the outdoor cultivation of a diverse community of Chlorella spp., Scenedesmus spp. and Chlamydomonas spp. in continuous operation mode with 10 days hydraulic retention time. During the trial, an average daily areal productivity of 5.5 ± 7.4 g TSS m-2 day-1 was achieved while average nutrient removal efficiencies were 86% ± 7% and 71% ± 10% for NH4-N and PO4-P, respectively. The microalgal nitrogen assimilation accounted for 10% of the nitrogen in the centrate while 34% was oxidized to nitrite and nitrate. The oxygen produced by microalgae fully covert the oxygen demand for nitrification. This suggests that the proposed process would reduce the aeration demand for nitrification in the water line of the plant, while producing algal biomass to be further valorized for energy or material recovery.
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Affiliation(s)
- Marco Mantovani
- Università degli Studi di Milano - Bicocca, Department of Earth and Environmental Sciences (DISAT), P.zza della Scienza 1, 20126 Milano, Italy.
| | - Francesca Marazzi
- Università degli Studi di Milano - Bicocca, Department of Earth and Environmental Sciences (DISAT), P.zza della Scienza 1, 20126 Milano, Italy
| | - Riccardo Fornaroli
- Università degli Studi di Milano - Bicocca, Department of Earth and Environmental Sciences (DISAT), P.zza della Scienza 1, 20126 Milano, Italy
| | - Micol Bellucci
- Politecnico di Milano, Department of Civil and Environmental Engineering (DICA), P.zza L. da Vinci 32, 20133 Milano, Italy
| | - Elena Ficara
- Politecnico di Milano, Department of Civil and Environmental Engineering (DICA), P.zza L. da Vinci 32, 20133 Milano, Italy
| | - Valeria Mezzanotte
- Università degli Studi di Milano - Bicocca, Department of Earth and Environmental Sciences (DISAT), P.zza della Scienza 1, 20126 Milano, Italy
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Banach-Wiśniewska A, Tomaszewski M, Cema G, Ziembińska-Buczyńska A. Medium shift influence on nitrogen removal bacteria: Ecophysiology and anammox process performance. CHEMOSPHERE 2020; 238:124597. [PMID: 31450106 DOI: 10.1016/j.chemosphere.2019.124597] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/06/2019] [Revised: 07/22/2019] [Accepted: 08/14/2019] [Indexed: 06/10/2023]
Abstract
In this study, we focused on the proportion of particular bacterial groups and changes in microbial community structure in relation to the anammox process parameters and the feeding medium strategy in the Sequencing Batch Reactor (SBR). In order to present an insight into the microbial dynamics while feeding medium shift from synthetic wastewater to landfill leachate, fluorescent in situ hybridization (FISH), Real Time PCR, PCR - DGGE (Polymerase Chain Reaction-Denaturing Gradient Gel Electrophoresis) and Reverse Transcription PCR-DGGE analysis were used. Feeding medium change has the strongest impact on relative abundance of denitrifiers and representatives of Planctomycetes. The relative abundancy of specific genes for all investigated nitrogen removal bacterial groups dropped after landfill leachate implementation. However, anammox consortium were able to adapt to the new reactor operating conditions and time for adaptation was estimated at the level of 90 days.
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Affiliation(s)
- Anna Banach-Wiśniewska
- Silesian University of Technology, Faculty of Power and Environmental Engineering, Environmental Biotechnology Department, Akademicka 2, 44-100, Gliwice, Poland.
| | - Mariusz Tomaszewski
- Silesian University of Technology, Faculty of Power and Environmental Engineering, Environmental Biotechnology Department, Akademicka 2, 44-100, Gliwice, Poland
| | - Grzegorz Cema
- Silesian University of Technology, Faculty of Power and Environmental Engineering, Environmental Biotechnology Department, Akademicka 2, 44-100, Gliwice, Poland
| | - Aleksandra Ziembińska-Buczyńska
- Silesian University of Technology, Faculty of Power and Environmental Engineering, Environmental Biotechnology Department, Akademicka 2, 44-100, Gliwice, Poland
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21
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Performance of Anammox Processes for Wastewater Treatment: A Critical Review on Effects of Operational Conditions and Environmental Stresses. WATER 2019. [DOI: 10.3390/w12010020] [Citation(s) in RCA: 44] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
The anaerobic ammonium oxidation (anammox) process is well-known as a low-energy consuming and eco-friendly technology for treating nitrogen-rich wastewater. Although the anammox reaction was widely investigated in terms of its application in many wastewater treatment processes, practical anammox application at the pilot and industrial scales is limited because nitrogen removal efficiency and anammox activity are dependent on many operational factors such as temperature, pH, dissolved oxygen concentration, nitrogen loading, and organic matter content. In practical application, anammox bacteria are possibly vulnerable to non-essential compounds such as sulfides, toxic metal elements, alcohols, phenols, and antibiotics that are potential inhibitors owing to the complexity of the wastewater stream. This review systematically summarizes up-to-date studies on the effect of various operational factors on nitrogen removal performance along with reactor type, mode of operation (batch or continuous), and cultured anammox bacterial species. The effect of potential anammox inhibition factors such as high nitrite concentration, high salinity, sulfides, toxic metal elements, and toxic organic compounds is listed with a thorough interpretation of the synergistic and antagonistic toxicity of these inhibitors. Finally, the strategy for optimization of anammox processes for wastewater treatment is suggested, and the importance of future studies on anammox applications is indicated.
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22
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Li X, Li Y, Li Y, Wu J. Enhanced nitrogen removal and quantitative analysis of removal mechanism in multistage surface flow constructed wetlands for the large-scale treatment of swine wastewater. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2019; 246:575-582. [PMID: 31202022 DOI: 10.1016/j.jenvman.2019.06.019] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/14/2019] [Revised: 05/31/2019] [Accepted: 06/05/2019] [Indexed: 06/09/2023]
Abstract
Constructed wetlands have recently been studied as a form of green infrastructure for the enhanced removal of nitrogen (N). This study aimed to demonstrate the use of multistage surface flow constructed wetland (SFCW) for treatment of swine wastewater. The results showed chemical oxygen demand (COD), total nitrogen (TN), NH4+, and NO3- removal rates of 16.3 g m-2 d-1, 9.14 g m-2 d-1, 7.75 g m-2 d-1, and 45.49 mg m-2 d-1, respectively. The sediment and plant absorption N rates were 2.44 g m-2 d-1, and 1.24 g m-2 d-1, respectively. Moreover, the microbial process which is the primary process, by which N is removed, accounted for 56.75-65.35%. Quantitative polymerase chain reaction (qPCR) revealed the highest microbial abundance in the segment of the SFCW with high N concentration. Ammonia-oxidizing bacteria (AOB) and nirK could be primarily responsible for the high removal rate of N. Factors like pH, DO, COD, N, and OM play an important role in influencing microbial abundance. It is suggested that the multistage SFCW has a promising future for the large scale treatment of swine wastewater.
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Affiliation(s)
- Xi Li
- Key Laboratory of Agro-ecological Processes in Subtropical Regions, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Hunan, 410125, PR China; Changsha Research Station for Agricultural & Environmental Monitoring, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Hunan, 410125, PR China
| | - Yuyuan Li
- Key Laboratory of Agro-ecological Processes in Subtropical Regions, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Hunan, 410125, PR China; Changsha Research Station for Agricultural & Environmental Monitoring, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Hunan, 410125, PR China.
| | - Yong Li
- Key Laboratory of Agro-ecological Processes in Subtropical Regions, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Hunan, 410125, PR China; Changsha Research Station for Agricultural & Environmental Monitoring, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Hunan, 410125, PR China
| | - Jinshui Wu
- Key Laboratory of Agro-ecological Processes in Subtropical Regions, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Hunan, 410125, PR China; Changsha Research Station for Agricultural & Environmental Monitoring, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Hunan, 410125, PR China
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23
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Jiang Y, Poh LS, Lim CP, Pan C, Ng WJ. Effect of free ammonia inhibition on process recovery of partial nitritation in a membrane bioreactor. ACTA ACUST UNITED AC 2019. [DOI: 10.1016/j.biteb.2019.02.014] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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24
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He W, Dong Y, Li C, Han X, Liu G, Liu J, Feng Y. Field tests of cubic-meter scale microbial electrochemical system in a municipal wastewater treatment plant. WATER RESEARCH 2019; 155:372-380. [PMID: 30856521 DOI: 10.1016/j.watres.2019.01.062] [Citation(s) in RCA: 47] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/14/2018] [Revised: 01/10/2019] [Accepted: 01/28/2019] [Indexed: 06/09/2023]
Abstract
A pilot microbial electrochemical system (MES) system with a total volume of 1.5 m3 was developed and operated outdoor in a municipal wastewater treatment plant (WWTP). Microbial separator based on the dynamic biofilm on low-cost porous matrix was applied to replace ion exchange membranes (IEMs), while the separate plug-in module architecture allowed the totally 336 pairs of MES units and 14 separator modules to be integrated into one wastewater tank. The separator layer equally divided the wastewater tank into 7 cathodic and 8 anodic compartments. Fed with primary sedimentation tank effluent of WWTP, the pilot MES achieved stable removal efficiency for chemical oxygen demand (91 ± 3%), total nitrogen (64 ± 2%) and ammonium nitrogen (91 ± 3%), which were complied with the first grade A standard of pollutants for municipal wastewater treatment plant (DSPMWTP) in China. The stable power output of pilot MES was 406 ± 30 mW m-3 based on effective liquid volume, or energy conversion performance of 2.03 × 10-3 kWh m-3 (one cubic meter of influent wastewater). The pilot MES achieved much lower effluent COD of 25 ± 7 mg L-1 with HRT of 5 h, while that of activated sludge process in WWTP was 43 ± 6 mg L-1 under HRT of 12 h. Even though the aeration of biocathode demanded a net electricity consumption of 3.44 × 10-3 kWh m-3, the low operation energy requirement for pilot MES was only 12% of that in a typical activated sludge process (0.3 kWh m-3). By avoiding the utilization of IEMs and redundant structural materials, the pilot MES achieved a low system cost of $1702.1 (or $1135 m-3) as well and promoted the further real-world application of MES.
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Affiliation(s)
- Weihua He
- State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, No 73 Huanghe Road, Nangang District, Harbin, 150090, China
| | - Yue Dong
- State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, No 73 Huanghe Road, Nangang District, Harbin, 150090, China
| | - Chao Li
- State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, No 73 Huanghe Road, Nangang District, Harbin, 150090, China
| | - Xiaoyu Han
- State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, No 73 Huanghe Road, Nangang District, Harbin, 150090, China
| | - Guohong Liu
- State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, No 73 Huanghe Road, Nangang District, Harbin, 150090, China
| | - Jia Liu
- State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, No 73 Huanghe Road, Nangang District, Harbin, 150090, China
| | - Yujie Feng
- State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, No 73 Huanghe Road, Nangang District, Harbin, 150090, China.
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25
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Nsenga Kumwimba M, Meng F. Roles of ammonia-oxidizing bacteria in improving metabolism and cometabolism of trace organic chemicals in biological wastewater treatment processes: A review. THE SCIENCE OF THE TOTAL ENVIRONMENT 2019; 659:419-441. [PMID: 31096373 DOI: 10.1016/j.scitotenv.2018.12.236] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/29/2018] [Revised: 11/20/2018] [Accepted: 12/15/2018] [Indexed: 05/27/2023]
Abstract
While there has been a significant recent improvement in the removal of pollutants in natural and engineered systems, trace organic chemicals (TrOCs) are posing a major threat to aquatic environments and human health. There is a critical need for developing potential strategies that aim at enhancing metabolism and/or cometabolism of these compounds. Recently, knowledge regarding biodegradation of TrOCs by ammonia-oxidizing bacteria (AOB) has been widely developed. This review aims to delineate an up-to-date version of the ecophysiology of AOB and outline current knowledge related to biodegradation efficiencies of the frequently reported TrOCs by AOB. The paper also provides an insight into biodegradation pathways by AOB and transformation products of these compounds and makes recommendations for future research of AOB. In brief, nitrifying WWTFs (wastewater treatment facilities) were superior in degrading most TrOCs than non-nitrifying WWTFs due to cometabolic biodegradation by the AOB. To fully understand and/or enhance the cometabolic biodegradation of TrOCs by AOB, recent molecular research has focused on numerous crucial factors including availability of the compounds to AOB, presence of growth substrate (NH4-N), redox potentials, microorganism diversity (AOB and heterotrophs), physicochemical properties and operational parameters of the WWTFs, molecular structure of target TrOCs and membrane-based technologies, may all significantly impact the cometabolic biodegradation of TrOCs. Still, further exploration is required to elucidate the mechanisms involved in biodegradation of TrOCs by AOB and the toxicity levels of formed products.
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Affiliation(s)
- Mathieu Nsenga Kumwimba
- School of Environmental Science and Engineering, Sun Yat-sen University, Guangzhou 510275, PR China; Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, Sun Yat-sen University, Guangzhou 510275, PR China; Faculty of Agronomy, Department of Natural Resources and Environmental Management, University of Lubumbashi, Democratic Republic of the Congo
| | - Fangang Meng
- School of Environmental Science and Engineering, Sun Yat-sen University, Guangzhou 510275, PR China; Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, Sun Yat-sen University, Guangzhou 510275, PR China.
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26
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Liu W, Chen W, Yang D, Shen Y. Functional and compositional characteristics of nitrifiers reveal the failure of achieving mainstream nitritation under limited oxygen or ammonia conditions. BIORESOURCE TECHNOLOGY 2019; 275:272-279. [PMID: 30594837 DOI: 10.1016/j.biortech.2018.12.065] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/27/2018] [Revised: 12/16/2018] [Accepted: 12/20/2018] [Indexed: 06/09/2023]
Abstract
For understanding the potential of achieving nitritation under different oxygen and ammonia levels, two activated sludge reactors with high (RH) and low (RL) dissolved oxygen (DO) were parallelly operated. During over two months continuous operation, rare nitrite accumulation was observed in both reactors. K-strategists Nitrosomonas oligotropha and r-strategists Nitrosomonas europaea were enriched in the RH and RL, respectively, yet their response to DO variations was almost identical. Although K-strategists Nitrospira defluvii dominated both reactors, species cultured with low-DO exhibited higher oxygen affinity. Instead of DO, ammonia and nitrite availability should be the key factor for the selective enrichment of these nitrifiers. Taken together, the limiting ammonia for ammonia oxidizing bacteria and the better oxygen-uptake capacity of nitrite oxidizing bacteria wasrespectively responsible for the failure of nitrite accumulation in the RH and RL. This study supported that high DO coupled with excess ammonia would favor the achievement of mainstream nitritation.
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Affiliation(s)
- Wenru Liu
- National & Local Joint Engineering Laboratory for Municipal Sewage Resource Utilization Technology, Suzhou University of Science and Technology, Suzhou 215009, China.
| | - Wenjing Chen
- School of Environmental Engineering and Science, Yangzhou University, Yangzhou, Jiangsu 225127, China
| | - Dianhai Yang
- School of Environmental Science and Engineering, Tongji University, Shanghai 200092, China
| | - Yaoliang Shen
- National & Local Joint Engineering Laboratory for Municipal Sewage Resource Utilization Technology, Suzhou University of Science and Technology, Suzhou 215009, China
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27
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Zhang X, Zheng S, Zhang H, Duan S. Autotrophic and heterotrophic nitrification-anoxic denitrification dominated the anoxic/oxic sewage treatment process during optimization for higher loading rate and energy savings. BIORESOURCE TECHNOLOGY 2018; 263:84-93. [PMID: 29730522 DOI: 10.1016/j.biortech.2018.04.113] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/29/2018] [Revised: 04/22/2018] [Accepted: 04/27/2018] [Indexed: 06/08/2023]
Abstract
This study clarified the dominant nitrogen (N)-transformation pathway and the key ammonia-oxidizing microbial species at three loading levels during optimization of the anoxic/oxic (A/O) process for sewage treatment. Comprehensive N-transformation activity analysis showed that ammonia oxidization was performed predominantly by aerobic chemolithotrophic and heterotrophic ammonia oxidization, whereas N2 production was performed primarily by anoxic denitrification in the anoxic unit. The abundances of ammonia-oxidizing bacteria (AOB), nitrite-oxidizing bacteria, and anaerobic AOB in activated sludge reflected their activities on the basis of high-throughput sequencing data. AOB amoA gene clone libraries revealed that the predominant AOB species in sludge samples shifted from Nitrosomonas europaea (61% at the normal loading level) to Nitrosomonas oligotropha (58% and 81% at the two higher loading levels). Following isolation and sequencing, the predominant culturable heterotrophic AOB in sludge shifted from Agrobacterium tumefaciens (42% at the normal loading level) to Acinetobacter johnsonii (52% at the highest loading level).
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Affiliation(s)
- Xueyu Zhang
- School of Environment, MOE Key Laboratory of Water and Sediment Sciences/State Key Lab of Water Environment Simulation, Beijing Normal University, Beijing 100875, China
| | - Shaokui Zheng
- School of Environment, MOE Key Laboratory of Water and Sediment Sciences/State Key Lab of Water Environment Simulation, Beijing Normal University, Beijing 100875, China.
| | - Hangyu Zhang
- School of Environment, MOE Key Laboratory of Water and Sediment Sciences/State Key Lab of Water Environment Simulation, Beijing Normal University, Beijing 100875, China
| | - Shoupeng Duan
- School of Environment, MOE Key Laboratory of Water and Sediment Sciences/State Key Lab of Water Environment Simulation, Beijing Normal University, Beijing 100875, China
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28
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How SW, Lim SY, Lim PB, Aris AM, Ngoh GC, Curtis TP, Chua ASM. Low-dissolved-oxygen nitrification in tropical sewage: an investigation on potential, performance and functional microbial community. WATER SCIENCE AND TECHNOLOGY : A JOURNAL OF THE INTERNATIONAL ASSOCIATION ON WATER POLLUTION RESEARCH 2018; 77:2274-2283. [PMID: 29757179 DOI: 10.2166/wst.2018.143] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Intensive aeration for nitrification is a major energy consumer in sewage treatment plants (STPs). Low-dissolved-oxygen (low-DO) nitrification has the potential to lower the aeration demand. However, the applicability of low-DO nitrification in the tropical climate is not well-understood. In this study, the potential of low-DO nitrification in tropical setting was first examined using batch kinetic experiments. Subsequently, the performance of low-DO nitrification was investigated in a laboratory-scale sequential batch reactor (SBR) for 42 days using real tropical sewage. The batch kinetic experiments showed that the seed sludge has a relatively high oxygen affinity. Thus, the rate of nitrification was not significantly reduced at low DO concentrations (0.5 mg/L). During the operation of the low-DO nitrification SBR, 90% of NH4-N was removed. The active low-DO nitrification was mainly attributed to the limited biodegradable organics in the sewage. Fluorescence in-situ hybridisation and 16S rRNA amplicon sequencing revealed the nitrifiers were related to Nitrospira genus and Nitrosomonadaceae family. Phylogenetic analysis suggests 47% of the operational taxonomic units in Nitrospira genus are closely related to a comammox bacteria. This study has demonstrated active low-DO nitrification in tropical setting, which is a more sustainable process that could significantly reduce the energy footprint of STPs.
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Affiliation(s)
- S W How
- Department of Chemical Engineering, Faculty of Engineering, University of Malaya, 50603 Kuala Lumpur, Malaysia E-mail:
| | - S Y Lim
- Department of Chemical Engineering, Faculty of Engineering, University of Malaya, 50603 Kuala Lumpur, Malaysia E-mail:
| | - P B Lim
- Indah Water Konsortium Sdn Bhd, No. 44, Jalan Dungun, Damansara Heights, 50490 Kuala Lumpur, Malaysia
| | - A M Aris
- Indah Water Konsortium Sdn Bhd, No. 44, Jalan Dungun, Damansara Heights, 50490 Kuala Lumpur, Malaysia
| | - G C Ngoh
- Department of Chemical Engineering, Faculty of Engineering, University of Malaya, 50603 Kuala Lumpur, Malaysia E-mail:
| | - T P Curtis
- School of Civil Engineering and Geosciences, Newcastle University, Newcastle upon Tyne NE1 7RU, United Kingdom
| | - A S M Chua
- Department of Chemical Engineering, Faculty of Engineering, University of Malaya, 50603 Kuala Lumpur, Malaysia E-mail:
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29
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Effect of Tidal Cycling Rate on the Distribution and Abundance of Nitrogen-Oxidizing Bacteria in a Bench-Scale Fill-and-Drain Bioreactor. WATER 2018. [DOI: 10.3390/w10040492] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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30
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Ribeiro RP, Bueno RF, Piveli RP, Kligerman DC, de Mello WZ, Oliveira JLM. The response of nitrous oxide emissions to different operating conditions in activated sludge wastewater treatment plants in Southeastern Brazil. WATER SCIENCE AND TECHNOLOGY : A JOURNAL OF THE INTERNATIONAL ASSOCIATION ON WATER POLLUTION RESEARCH 2017; 76:2337-2349. [PMID: 29144292 DOI: 10.2166/wst.2017.399] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
The continuous measurements of N2O emissions from the aeration tanks of three activated sludge wastewater treatment plants (WWTPs) operated with biological nitrogen removal (BNR) and non-BNR were performed during the different operating conditions of several parameters, such as aeration, dissolved oxygen (DO) profiling and organic shock loading (with landfill leachate). The nitrification process is the main driving force behind N2O emission peaks. There are indications that the variation of the air flow rate influenced N2O emissions; high N2O emissions denote over-aeration conditions or incomplete nitrification, with accumulation of NO2- concentrations. Thus, continuous measurements of N2O emissions can provide information on aeration adequacy and the efficiency of complete nitrification, with major focus on DO control, in order to reduce N2O emissions. An additional concern is the observed propensity of WWTPs in developing countries to receive landfill leachates in their wastewater systems. This practice could have adverse effects on climate change, since wastewater treatment during periods of organic shock loading emitted significantly higher amounts of N2O than without organic shock loading. In short, non-BNR WWTPs are subject to high N2O emissions, in contrast to BNR WWTP with controlled nitrification and denitrification processes.
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Affiliation(s)
- Renato P Ribeiro
- Departamento de Geoquímica, Instituto de Química, Universidade Federal Fluminense, Outeiro São João Batista, s/n, Niterói, RJ 24020-141, Brazil
| | - Rodrigo F Bueno
- Departamento de Engenharia Hidráulica e Ambiental, Escola Politécnica, Universidade de São Paulo, Avenida Professor Almeida Prado, 271, São Paulo, SP 05508-900, Brazil
| | - Roque P Piveli
- Departamento de Engenharia Hidráulica e Ambiental, Escola Politécnica, Universidade de São Paulo, Avenida Professor Almeida Prado, 271, São Paulo, SP 05508-900, Brazil
| | - Débora C Kligerman
- Departamento de Saneamento e Saúde Ambiental, Escola Nacional de Saúde Pública, Fundação Oswaldo Cruz, Rua Leopoldo Bulhões, 1480, Rio de Janeiro, RJ 21041-210, Brazil E-mail:
| | - William Z de Mello
- Departamento de Geoquímica, Instituto de Química, Universidade Federal Fluminense, Outeiro São João Batista, s/n, Niterói, RJ 24020-141, Brazil
| | - Jaime L M Oliveira
- Departamento de Saneamento e Saúde Ambiental, Escola Nacional de Saúde Pública, Fundação Oswaldo Cruz, Rua Leopoldo Bulhões, 1480, Rio de Janeiro, RJ 21041-210, Brazil E-mail:
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31
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Geed SR, Shrirame BS, Singh RS, Rai BN. Assessment of pesticides removal using two-stage Integrated Aerobic Treatment Plant (IATP) by Bacillus sp. isolated from agricultural field. BIORESOURCE TECHNOLOGY 2017; 242:45-54. [PMID: 28347623 DOI: 10.1016/j.biortech.2017.03.080] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/29/2017] [Revised: 03/10/2017] [Accepted: 03/11/2017] [Indexed: 06/06/2023]
Abstract
The biodegradation of synthetic wastewater containing Atrazine, Malathion and Parathion was studied in two stage Integrated Aerobic Treatment Plant using Bacillus sp. (consortia) isolated from agricultural field. The influent stream containing these pesticides with initial COD of 1232mg/L were fed to first reactor and treated effluent of first reactor was fed to second reactor. The maximum removal of pesticides in IATP was found to be greater than 90%. The various process parameters such as pH, DO, Redox potential and BOD5/COD were monitored during the treatment. The degradation of pesticides and its metabolites in the treated effluent were confirmed by GC-MS. Kinetic parameters such as first order rate constant (Kobs), cell yield (YX/C) and decay coefficients (Kdp) were evaluated and found to be 0.00425 per hr, 0.696mg of COD/mg MLSS and 0.0010 per hr respectively. This integrated process was found more effective than physico-chemical treatment of pesticides.
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Affiliation(s)
- S R Geed
- Department of Chemical Engineering and Technology, IIT (BHU), Varanasi 221 005, India
| | - B S Shrirame
- Department of Chemical Engineering and Technology, IIT (BHU), Varanasi 221 005, India
| | - R S Singh
- Department of Chemical Engineering and Technology, IIT (BHU), Varanasi 221 005, India
| | - B N Rai
- Department of Chemical Engineering and Technology, IIT (BHU), Varanasi 221 005, India.
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32
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Keene NA, Reusser SR, Scarborough MJ, Grooms AL, Seib M, Santo Domingo J, Noguera DR. Pilot plant demonstration of stable and efficient high rate biological nutrient removal with low dissolved oxygen conditions. WATER RESEARCH 2017; 121:72-85. [PMID: 28521237 PMCID: PMC7388030 DOI: 10.1016/j.watres.2017.05.029] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/07/2017] [Revised: 05/11/2017] [Accepted: 05/12/2017] [Indexed: 05/04/2023]
Abstract
Aeration in biological nutrient removal (BNR) processes accounts for nearly half of the total electricity costs at many wastewater treatment plants. Even though conventional BNR processes are usually operated to have aerated zones with high dissolved oxygen (DO) concentrations, recent research has shown that nitrification can be maintained using very low-DO concentrations (e.g., below 0.2 mg O2/L), and therefore, it may be possible to reduce energy use and costs in BNR facilities by decreasing aeration. However, the effect of reduced aeration on enhanced biological phosphorus removal (EBPR) is not understood. In this study, we investigated, at the pilot-scale level, the effect of using minimal aeration on the performance of an EBPR process. Over a 16-month operational period, we performed stepwise decreases in aeration, reaching an average DO concentration of 0.33 mg O2/L with stable operation and nearly 90% phosphorus removal. Under these low-DO conditions, nitrification efficiency was maintained, and nearly 70% of the nitrogen was denitrified, without the need for internal recycling of high nitrate aeration basin effluent to the anoxic zone. At the lowest DO conditions used, we estimate a 25% reduction in energy use for aeration compared to conventional BNR operation. Our improved understanding of the efficiency of low-DO BNR contributes to the global goal of reducing energy consumption during wastewater treatment operations.
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Affiliation(s)
- Natalie A Keene
- Department of Civil and Environmental Engineering, University of Wisconsin-Madison, USA.
| | | | - Matthew J Scarborough
- Department of Civil and Environmental Engineering, University of Wisconsin-Madison, USA.
| | | | - Matt Seib
- Madison Metropolitan Sewerage District, USA.
| | - Jorge Santo Domingo
- Water Supply and Water Resources Division, Environmental Protection Agency, Cincinnati, OH, USA.
| | - Daniel R Noguera
- Department of Civil and Environmental Engineering, University of Wisconsin-Madison, USA.
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33
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Hong X, Chen Z, Zhao C, Yang S. Nitrogen transformation under different dissolved oxygen levels by the anoxygenic phototrophic bacterium Marichromatium gracile. World J Microbiol Biotechnol 2017; 33:113. [PMID: 28470424 DOI: 10.1007/s11274-017-2280-z] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2017] [Accepted: 04/26/2017] [Indexed: 10/19/2022]
Abstract
Marichromatium gracile: YL28 (M. gracile YL28) is an anoxygenic phototrophic bacterial strain that utilizes ammonia, nitrate, or nitrite as its sole nitrogen source during growth. In this study, we investigated the removal and transformation of ammonium, nitrate, and nitrite by M. gracile YL28 grown in a combinatorial culture system of sodium acetate-ammonium, sodium acetate-nitrate and sodium acetate-nitrite in response to different initial dissolved oxygen (DO) levels. In the sodium acetate-ammonium system under aerobic conditions (initial DO = 7.20-7.25 mg/L), we detected a continuous accumulation of nitrate and nitrite. However, under semi-anaerobic conditions (initial DO = 4.08-4.26 mg/L), we observed a temporary accumulation of nitrate and nitrite. Interestingly, under anaerobic conditions (initial DO = 0.36-0.67 mg/L), there was little accumulation of nitrate and nitrite, but an increase in nitrous oxide production. In the sodium acetate-nitrite system, nitrite levels declined slightly under aerobic conditions, and nitrite was completely removed under semi-anaerobic and anaerobic conditions. In addition, M. gracile YL28 was able to grow using nitrite as the sole nitrogen source in situations when nitrogen gas produced by denitrification was eliminated. Taken together, the data indicate that M. gracile YL28 performs simultaneous heterotrophic nitrification and denitrification at low-DO levels and uses nitrite as the sole nitrogen source for growth. Our study is the first to demonstrate that anoxygenic phototrophic bacteria perform heterotrophic ammonia-oxidization and denitrification under anaerobic conditions.
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Affiliation(s)
- Xuan Hong
- Department of Bioengineering and Biotechnology, Huaqiao University, No. 668 Jimei Ave, Xiamen, 361021, People's Republic of China.,Xiamen Key Laboratory of Marine Medicinal Natural Products and Cell Engineering, Xiamen Medical College, Xiamen, 361008, People's Republic of China
| | - Zhongwei Chen
- Xiamen Key Laboratory of Marine Medicinal Natural Products and Cell Engineering, Xiamen Medical College, Xiamen, 361008, People's Republic of China
| | - Chungui Zhao
- Department of Bioengineering and Biotechnology, Huaqiao University, No. 668 Jimei Ave, Xiamen, 361021, People's Republic of China.
| | - Suping Yang
- Department of Bioengineering and Biotechnology, Huaqiao University, No. 668 Jimei Ave, Xiamen, 361021, People's Republic of China.
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34
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Fan H, Qi L, Liu G, Zhang Y, Fan Q, Wang H. Aeration optimization through operation at low dissolved oxygen concentrations: Evaluation of oxygen mass transfer dynamics in different activated sludge systems. J Environ Sci (China) 2017; 55:224-235. [PMID: 28477817 DOI: 10.1016/j.jes.2016.08.008] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2016] [Revised: 07/31/2016] [Accepted: 08/19/2016] [Indexed: 06/07/2023]
Abstract
In wastewater treatment plants (WWTPs) using the activated sludge process, two methods are widely used to improve aeration efficiency - use of high-efficiency aeration devices and optimizing the aeration control strategy. Aeration efficiency is closely linked to sludge characteristics (such as concentrations of mixed liquor suspended solids (MLSS) and microbial communities) and operating conditions (such as air flow rate and operational dissolved oxygen (DO) concentrations). Moreover, operational DO is closely linked to effluent quality. This study, which is in reference to WWTP discharge class A Chinese standard effluent criteria, determined the growth kinetics parameters of nitrifiers at different DO levels in small-scale tests. Results showed that the activated sludge system could meet effluent criteria when DO was as low as 0.3mg/L, and that nitrifier communities cultivated under low DO conditions had higher oxygen affinity than those cultivated under high DO conditions, as indicated by the oxygen half-saturation constant and nitrification ability. Based on nitrifier growth kinetics and on the oxygen mass transfer dynamic model (determined using different air flow rate (Q'air) and mixed liquor volatile suspended solids (MLVSS) values), theoretical analysis indicated limited potential for energy saving by improving aeration diffuser performance when the activated sludge system had low oxygen consumption; however, operating at low DO and low MLVSS could significantly reduce energy consumption. Finally, a control strategy coupling sludge retention time and MLVSS to minimize the DO level was discussed, which is critical to appropriate setting of the oxygen point and to the operation of low DO treatment technology.
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Affiliation(s)
- Haitao Fan
- Research Center for Low Carbon Technology of Water Environment, Renmin University of China, Beijing 100872, China
| | - Lu Qi
- Research Center for Low Carbon Technology of Water Environment, Renmin University of China, Beijing 100872, China.
| | - Guoqiang Liu
- School of Environment, Jinan University, Guangzhou 510632, China
| | - Yuankai Zhang
- Research Center for Low Carbon Technology of Water Environment, Renmin University of China, Beijing 100872, China
| | - Qiang Fan
- Research Center for Low Carbon Technology of Water Environment, Renmin University of China, Beijing 100872, China
| | - Hongchen Wang
- Research Center for Low Carbon Technology of Water Environment, Renmin University of China, Beijing 100872, China.
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Cao Y, van Loosdrecht MCM, Daigger GT. Mainstream partial nitritation-anammox in municipal wastewater treatment: status, bottlenecks, and further studies. Appl Microbiol Biotechnol 2017; 101:1365-1383. [PMID: 28084538 DOI: 10.1007/s00253-016-8058-7] [Citation(s) in RCA: 392] [Impact Index Per Article: 56.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2016] [Revised: 12/04/2016] [Accepted: 12/07/2016] [Indexed: 11/26/2022]
Abstract
Driven by energy neutral/positive of wastewater treatment plants, significant efforts have been made on the research and development of mainstream partial nitritation and anaerobic ammonium oxidation (anammox) (PN/A) (deammonification) process since the early 2010s. To date, feasibility of mainstream PN/A process has been demonstrated and proven by experimental results at various scales although with the low loading rates and elevated nitrogen concentration in the effluent at low temperatures (15-10 °C). This review paper provides an overview of the current state of research and development of mainstream PN/A process and critically analyzes the bottlenecks for its full-scale application. The paper discusses the following: (i) the current status of research and development of mainstream PN/A process; (ii) the interactions among aerobic ammonium-oxidizing bacteria, aerobic nitrite-oxidizing bacteria, anammox bacteria, and heterotrophic bacteria; (iii) the suppression of aerobic nitrite-oxidizing bacteria; (iv) process and bioreactors; and (v) suggested further studies including efficient and robust carbon concentrating pretreatment, deepening of understanding competition between autotrophic nitrogen-converting organisms, intensification of biofilm anammox activity, reactor design, and final polishing.
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Affiliation(s)
- Yeshi Cao
- , Blk 6, 41 Tiang Jia Xian, Suzhou, 215000, Jiangsu Province, China.
| | - Mark C M van Loosdrecht
- Department of Biotechnology, Delft University of Technology, Van der Maasweg 9, 2629 HZ, Delft, The Netherlands.
| | - Glen T Daigger
- Department of Civil and Environmental Engineering, University of Michigan, 2350 Hayward Street, Ann Arbor, MI, 48109, USA
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Liu W, Yang D. Evaluating the feasibility of ratio control strategy for achieving partial nitritation in a continuous floccular sludge reactor: Experimental demonstration. BIORESOURCE TECHNOLOGY 2017; 224:94-100. [PMID: 27914786 DOI: 10.1016/j.biortech.2016.11.100] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/07/2016] [Revised: 11/20/2016] [Accepted: 11/23/2016] [Indexed: 06/06/2023]
Abstract
To investigate the applicability of ratio control strategy to other systems, a continuous floccular sludge reactor was used in this study. It was found that nitrite accumulation was barely detected throughout 70days' investigation, being the average concentration in the effluent of 0.7±0.4mg/L. Batch experiments indicated that low dissolved oxygen (DO<0.3mg·L-1) greatly repressed the ammonium oxidizing bacteria (AOB) but only slightly inhibited the nitrite oxidizing bacteria (NOB). However, high-throughput sequencing revealed that the ratio of abundance between Nitrospira and Nitrosomonas, being the dominant NOB and AOB respectively, was considerably low (1.2%/18.7%). The weak oxygen gradients in floccular sludge and the selectively enriched K-strategist NOB Nitrospira under oxygen-limited conditions were both contributed to the failure of achieving partial nitritation; therefore, the rapid start-up of partial nitritation process based on proposed ratio control strategy is not feasible for continuous floccular sludge systems treating low-strength wastewater.
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Affiliation(s)
- Wenru Liu
- State Key Laboratory of Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Tongji University, Shanghai, China
| | - Dianhai Yang
- State Key Laboratory of Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Tongji University, Shanghai, China.
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Wang H, Liu J, He W, Qu Y, Li D, Feng Y. Energy-positive nitrogen removal from reject water using a tide-type biocathode microbial electrochemical system. BIORESOURCE TECHNOLOGY 2016; 222:317-325. [PMID: 27728834 DOI: 10.1016/j.biortech.2016.09.090] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/21/2016] [Revised: 09/20/2016] [Accepted: 09/21/2016] [Indexed: 05/24/2023]
Abstract
A tide-type biocathode microbial electrochemical system (TBMES) employing intermittent air accessible method was constructed for simultaneous carbon and nitrogen removal. The nitrification and denitrification processes occurred in cathode chamber were enhanced by raising frequency of catholyte feeding-draining process and lowering external resistance. At external resistance of 5Ω and frequency of 8cph, the TBMES removed 99.3±0.3% of COD and 57.7±1.1% of total nitrogen when treating synthetic medium with COD/N ratio of 3.0, concomitantly, a maximum power density of 10.6Wm-3 was achieved. Comparable performances were obtained for reject water treatment with a relatively lower COD/N ratio of 2.5, which were 88.6±1.3%, 53.2±3.8% and 8.9±0.2Wm-3 for COD removal, total nitrogen removal and maximum power density. The feeding-draining process consumed 14.3% of the total energy produced, and thus obviated energy-intensive aeration and achieved net energy output.
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Affiliation(s)
- Haiman Wang
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, No. 73 Huanghe Road, Nangang District, Harbin 150090, China
| | - Jia Liu
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, No. 73 Huanghe Road, Nangang District, Harbin 150090, China
| | - Weihua He
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, No. 73 Huanghe Road, Nangang District, Harbin 150090, China.
| | - Youpeng Qu
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, No. 73 Huanghe Road, Nangang District, Harbin 150090, China; School of Life Science and Technology, Harbin Institute of Technology, No. 2 Yikuang Street, Nangang District, Harbin 150080, China
| | - Da Li
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, No. 73 Huanghe Road, Nangang District, Harbin 150090, China
| | - Yujie Feng
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, No. 73 Huanghe Road, Nangang District, Harbin 150090, China
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38
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Stadler LB, Love NG. Impact of microbial physiology and microbial community structure on pharmaceutical fate driven by dissolved oxygen concentration in nitrifying bioreactors. WATER RESEARCH 2016; 104:189-199. [PMID: 27525582 DOI: 10.1016/j.watres.2016.08.001] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/30/2016] [Revised: 07/29/2016] [Accepted: 08/01/2016] [Indexed: 06/06/2023]
Abstract
Operation at low dissolved oxygen (DO) concentrations (<1 mg/L) in wastewater treatment could save utilities significantly by reducing aeration energy costs. However, few studies have evaluated the impact of low DO on pharmaceutical biotransformations during treatment. DO concentration can impact pharmaceutical biotransformation rates during wastewater treatment both directly and indirectly: directly by acting as a limiting substrate that slows the activity of the microorganisms involved in biotransformation; and indirectly by shaping the microbial community and selecting for a community that performs pharmaceutical biotransformation faster (or slower). In this study, nitrifying bioreactors were operated at low (∼0.3 mg/L) and high (>4 mg/L) DO concentrations to understand how DO growth conditions impacted microbial community structure. Short-term batch experiments using the biomass from the parent reactors were performed under low and high DO conditions to understand how DO concentration impacts microbial physiology. Although the low DO parent biomass had a lower specific activity with respect to ammonia oxidation than the high DO parent reactor biomass, it had faster biotransformation rates of ibuprofen, sulfamethoxazole, 17α-ethinylestradiol, acetaminophen, and atenolol in high DO batch conditions. This was likely because the low DO reactor had a 2x higher biomass concentration, was enriched for ammonia oxidizers (4x higher concentration), and harbored a more diverse microbial community (3x more unique taxa) as compared to the high DO parent reactor. Overall, the results show that there can be indirect benefits from low DO operation over high DO operation that support pharmaceutical biotransformation during wastewater treatment.
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Affiliation(s)
- Lauren B Stadler
- Department of Civil and Environmental Engineering, University of Michigan, 1351 Beal Avenue, EWRE, Ann Arbor, MI 48109, United States.
| | - Nancy G Love
- Department of Civil and Environmental Engineering, University of Michigan, 1351 Beal Avenue, EWRE, Ann Arbor, MI 48109, United States.
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Chen Y, Zhao Z, Peng Y, Li J, Xiao L, Yang L. Performance of a full-scale modified anaerobic/anoxic/oxic process: High-throughput sequence analysis of its microbial structures and their community functions. BIORESOURCE TECHNOLOGY 2016; 220:225-232. [PMID: 27573476 DOI: 10.1016/j.biortech.2016.07.095] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/10/2016] [Revised: 07/20/2016] [Accepted: 07/22/2016] [Indexed: 05/19/2023]
Abstract
The average COD, TN, TP, and NH4(+)-N elimination rates in a new wastewater treatment plant (WWTP) based on a modified A2/O process were 83%, 72.4%, 93.5%, and 98.6%, respectively, even under conditions of a low C/N ratio and low temperature. Among the four potential denitrifying units, the post-anoxic unit was the least efficient with respect to the removal efficiency. However, the structures of the bacterial community among samples obtained from the treatment units were similar, as demonstrated using Illumina Miseq high-throughput sequencing. Genera with nitrifying, denitrifying, hydrolyzing, and glycogen-accumulating activities were identified in all units, indicating that functional groups were highly enriched in the active sludges and thus enabled nitrogen removal. The key functional microorganisms responsible for nitrification-denitrification in the WWTP were species belonging to the genera Nitrospira, Hydrogenophilaceae, Comamonas, Dechloromonas, Thauera, Haliangium, and Halomonas.
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Affiliation(s)
- Yasong Chen
- School of the Environment, Nanjing University, State Key Laboratory for Pollution Control and Resource Reuse (SKL-PCRR), Nanjing University Xianlin Campus, Xianlin Avenue 163, Nanjing 210023, China
| | - Zheng Zhao
- Guilin University of Technology, Guangxi Key Laboratory of Environmental Pollution Control Theory and Technology, Guilin 541004, China
| | - Yuke Peng
- School of the Environment, Nanjing University, State Key Laboratory for Pollution Control and Resource Reuse (SKL-PCRR), Nanjing University Xianlin Campus, Xianlin Avenue 163, Nanjing 210023, China
| | - Jie Li
- School of the Environment, Nanjing University, State Key Laboratory for Pollution Control and Resource Reuse (SKL-PCRR), Nanjing University Xianlin Campus, Xianlin Avenue 163, Nanjing 210023, China
| | - Lin Xiao
- School of the Environment, Nanjing University, State Key Laboratory for Pollution Control and Resource Reuse (SKL-PCRR), Nanjing University Xianlin Campus, Xianlin Avenue 163, Nanjing 210023, China.
| | - Liuyan Yang
- School of the Environment, Nanjing University, State Key Laboratory for Pollution Control and Resource Reuse (SKL-PCRR), Nanjing University Xianlin Campus, Xianlin Avenue 163, Nanjing 210023, China
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40
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Forde P, Kennelly C, Gerrity S, Collins G, Clifford E. An evaluation of the performance and optimization of a new wastewater treatment technology: the air suction flow-biofilm reactor. ENVIRONMENTAL TECHNOLOGY 2015; 36:1188-1204. [PMID: 25413003 DOI: 10.1080/09593330.2014.982724] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
In this laboratory study, a novel wastewater treatment technology, the air suction flow-biofilm reactor (ASF-BR) - a sequencing batch biofilm reactor technology with a passive aeration mechanism - was investigated for its efficiency in removing organic carbon, nitrogen and phosphorus, from high-strength synthetic wastewaters. A laboratory-scale ASF-BR comprising 2 reactors, 350 mm in diameter and 450 mm in height, was investigated over 2 studies (Studies 1 and 2) for a total of 430 days. Study 1 lasted a total of 166 days and involved a 9-step sequence alternating between aeration, anoxic treatment and settlement. The cycle time was 12.1 h and the reactors were operated at a substrate loading rate of 3.60 g filtered chemical oxygen demand (CODf)/m2 media/d, 0.28 g filtered total nitrogen (TNf)/m2 media/d, 0.24 g ammonium-nitrogen (NH4-N)/m2 media/d and 0.07 g ortho-phosphate (PO4-P)/m2 media/d. The average removal rates achieved during Study 1 were 98% CODf, 88% TNf, 97% NH4-N and 35% PO4-P. During Study 2 (264 days), the unit was operated at a loading rate of 2.49 g CODf/m2 media/d, 0.24 g TNf/m2 media/d, 0.20 g NH4-N/m2 media/d and 0.06 PO4-P/m2 media/d. The energy requirement during this study was reduced by modifying the treatment cycle in include fewer pumping cycles. Removal rates in Study 2 averaged 97% CODf, 86% TNf, 99% NH4-N and 76% PO4-P. The excess sludge production of the system was evaluated and detailed analyses of the treatment cycles were carried out. Biomass yields were estimated at 0.09 g SS/g CODf, removed and 0.21 g SS/g CODf, removed for Studies 1 and 2, respectively. Gene analysis showed that the use of a partial vacuum did not affect the growth of ammonia-oxidizing bacteria. The results indicate that the ASF-BR and passive aeration technologies can offer efficient alternatives to existing technologies.
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Affiliation(s)
- P Forde
- a Civil Engineering, College of Engineering and Informatics , National University of Ireland, Galway , Galway , Ireland
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41
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Bellucci M, Ofiţeru ID, Beneduce L, Graham DW, Head IM, Curtis TP. A preliminary and qualitative study of resource ratio theory to nitrifying lab-scale bioreactors. Microb Biotechnol 2015; 8:590-603. [PMID: 25874592 PMCID: PMC4408191 DOI: 10.1111/1751-7915.12284] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2014] [Revised: 01/21/2015] [Accepted: 03/05/2015] [Indexed: 11/30/2022] Open
Abstract
The incorporation of microbial diversity in design would ideally require predictive theory that would relate operational parameters to the numbers and distribution of taxa. Resource ratio-theory (RRT) might be one such theory. Based on Monod kinetics, it explains diversity in function of resource-ratio and richness. However, to be usable in biological engineered system, the growth parameters of all the bacteria under consideration and the resource supply and diffusion parameters for all the relevant nutrients should be determined. This is challenging, but plausible, at least for low diversity groups with simple resource requirements like the ammonia oxidizing bacteria (AOB). One of the major successes of RRT was its ability to explain the ‘paradox of enrichment’ which states that diversity first increases and then decreases with resource richness. Here, we demonstrate that this pattern can be seen in lab-scale-activated sludge reactors and parallel simulations that incorporate the principles of RRT in a floc-based system. High and low ammonia and oxygen were supplied to continuous flow bioreactors with resource conditions correlating with the composition and diversity of resident AOB communities based on AOB 16S rDNA clone libraries. Neither the experimental work nor the simulations are definitive proof for the application of RRT in this context. However, it is sufficient evidence that such approach might work and justify a more rigorous investigation.
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Affiliation(s)
- Micol Bellucci
- School of Civil Engineering and Geosciences, Newcastle University, Newcastle upon Tyne, NE1 7RU, UK; Dipartimento di Scienze Agrarie, Alimentari ed Ambientali, Università di Foggia, via Napoli 25, Foggia, 71122, Italy
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42
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Fitzgerald CM, Camejo P, Oshlag JZ, Noguera DR. Ammonia-oxidizing microbial communities in reactors with efficient nitrification at low-dissolved oxygen. WATER RESEARCH 2015; 70:38-51. [PMID: 25506762 PMCID: PMC4564296 DOI: 10.1016/j.watres.2014.11.041] [Citation(s) in RCA: 138] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/15/2014] [Revised: 11/14/2014] [Accepted: 11/17/2014] [Indexed: 05/05/2023]
Abstract
Ammonia-oxidizing microbial communities involved in ammonia oxidation under low dissolved oxygen (DO) conditions (<0.3 mg/L) were investigated using chemostat reactors. One lab-scale reactor (NS_LowDO) was seeded with sludge from a full-scale wastewater treatment plant (WWTP) not adapted to low-DO nitrification, while a second reactor (JP_LowDO) was seeded with sludge from a full-scale WWTP already achieving low-DO nitrifiaction. The experimental evidence from quantitative PCR, rDNA tag pyrosequencing, and fluorescence in situ hybridization (FISH) suggested that ammonia-oxidizing bacteria (AOB) in the Nitrosomonas genus were responsible for low-DO nitrification in the NS_LowDO reactor, whereas in the JP_LowDO reactor nitrification was not associated with any known ammonia-oxidizing prokaryote. Neither reactor had a significant population of ammonia-oxidizing archaea (AOA) or anaerobic ammonium oxidation (anammox) organisms. Organisms isolated from JP_LowDO were capable of autotrophic and heterotrophic ammonia utilization, albeit without stoichiometric accumulation of nitrite or nitrate. Based on the experimental evidence we propose that Pseudomonas, Xanthomonadaceae, Rhodococcus, and Sphingomonas are involved in nitrification under low-DO conditions.
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Affiliation(s)
- Colin M Fitzgerald
- Department of Civil and Environmental Engineering, University of Wisconsin - Madison, 1415 Engineering Drive, Madison, WI 53706, USA.
| | - Pamela Camejo
- Department of Civil and Environmental Engineering, University of Wisconsin - Madison, 1415 Engineering Drive, Madison, WI 53706, USA.
| | - J Zachary Oshlag
- Department of Civil and Environmental Engineering, University of Wisconsin - Madison, 1415 Engineering Drive, Madison, WI 53706, USA.
| | - Daniel R Noguera
- Department of Civil and Environmental Engineering, University of Wisconsin - Madison, 1415 Engineering Drive, Madison, WI 53706, USA.
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43
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Yadav TC, Pal RR, Shastri S, Jadeja NB, Kapley A. Comparative metagenomics demonstrating different degradative capacity of activated biomass treating hydrocarbon contaminated wastewater. BIORESOURCE TECHNOLOGY 2015; 188:24-32. [PMID: 25727998 DOI: 10.1016/j.biortech.2015.01.141] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/28/2014] [Revised: 01/27/2015] [Accepted: 01/29/2015] [Indexed: 06/04/2023]
Abstract
This study demonstrates the diverse degradative capacity of activated biomass, when exposed to different levels of total dissolved solids (TDS) using a comparative metagenomics approach. The biomass was collected at two time points to examine seasonal variations. Four metagenomes were sequenced on Illumina Miseq platform and analysed using MG-RAST. STAMP tool was used to analyse statistically significant differences amongst different attributes of metagenomes. Metabolic pathways related to degradation of aromatics via the central and peripheral pathways were found to be dominant in low TDS metagenome, while pathways corresponding to central carbohydrate metabolism, nitrogen, organic acids were predominant in high TDS sample. Seasonal variation was seen to affect catabolic gene abundance as well as diversity of the microbial community. Degradation of model compounds using activated sludge demonstrated efficient utilisation of single aromatic ring compounds in both samples but cyclic compounds were not efficiently utilised by biomass exposed to high TDS.
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Affiliation(s)
- Trilok Chandra Yadav
- Environmental Genomics Division, National Environmental Engineering Research Institute, (CSIR-NEERI), Nehru Marg, Nagpur 440 020, India
| | - Rajesh Ramavadh Pal
- Environmental Genomics Division, National Environmental Engineering Research Institute, (CSIR-NEERI), Nehru Marg, Nagpur 440 020, India
| | - Sunita Shastri
- Environment Impact and Risk Assessment Division, CSIR-NEERI, India
| | - Niti B Jadeja
- Environmental Genomics Division, National Environmental Engineering Research Institute, (CSIR-NEERI), Nehru Marg, Nagpur 440 020, India
| | - Atya Kapley
- Environmental Genomics Division, National Environmental Engineering Research Institute, (CSIR-NEERI), Nehru Marg, Nagpur 440 020, India.
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44
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Eyice Ö, Ince O, Ince BK. Monitoring the abundance and the activity of ammonia-oxidizing bacteria in a full-scale nitrifying activated sludge reactor. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2015; 22:2328-2334. [PMID: 25185496 DOI: 10.1007/s11356-014-3519-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/02/2014] [Accepted: 08/24/2014] [Indexed: 06/03/2023]
Abstract
Cell-specific ammonia oxidation rate (AOR) has been suggested to be an indicator of the performance of nitrification reactors and to be used as an operational parameter previously. However, published AOR values change by orders of magnitude and studies investigating full-scale nitrification reactors are limited. Therefore, this study aimed at quantifying ammonia-oxidizing bacteria (AOB) and estimating their in situ cell-specific AOR in a full-scale activated sludge reactor treating combined domestic and industrial wastewaters. Results showed that cell-specific AOR changed between 5.30 and 9.89 fmol cell(-1) h(-1), although no significant variation in AOB cell numbers were obtained (1.54E + 08 ± 0.22 cell/ml). However, ammonia-removal efficiency varied largely (52-79 %) and was proportional to the cell-specific AOR in the reactor. This suggested that the cell-specific AOR might be the factor affecting the biological ammonia-removal efficiency of nitrification reactors independent of the AOB number. Further investigation is needed to establish an empirical relationship to use cell-specific AOR as a parameter to operate full-scale nitrification systems more effectively.
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Affiliation(s)
- Ö Eyice
- School of Life Sciences, University of Warwick, Coventry, UK, CV4 7AL,
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45
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Stadler LB, Su L, Moline CJ, Ernstoff AS, Aga DS, Love NG. Effect of redox conditions on pharmaceutical loss during biological wastewater treatment using sequencing batch reactors. JOURNAL OF HAZARDOUS MATERIALS 2015; 282:106-15. [PMID: 25200120 DOI: 10.1016/j.jhazmat.2014.08.002] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/31/2014] [Revised: 06/26/2014] [Accepted: 08/04/2014] [Indexed: 05/12/2023]
Abstract
We lack a clear understanding of how wastewater treatment plant (WWTP) process parameters, such as redox environment, impact pharmaceutical fate. WWTPs increasingly install more advanced aeration control systems to save energy and achieve better nutrient removal performance. The impact of redox condition, and specifically the use of microaerobic (low dissolved oxygen) treatment, is poorly understood. In this study, the fate of a mixture of pharmaceuticals and several of their transformation products present in the primary effluent of a local WWTP was assessed in sequencing batch reactors operated under different redox conditions: fully aerobic, anoxic/aerobic, and microaerobic (DO concentration ≈0.3mg/L). Among the pharmaceuticals that were tracked during this study (atenolol, trimethoprim, sulfamethoxazole, desvenlafaxine, venlafaxine, and phenytoin), overall loss varied between them and between redox environments. Losses of atenolol and trimethoprim were highest in the aerobic reactor; sulfamethoxazole loss was highest in the microaerobic reactors; and phenytoin was recalcitrant in all reactors. Transformation products of sulfamethoxazole and desvenlafaxine resulted in the reformation of their parent compounds during treatment. The results suggest that transformation products must be accounted for when assessing removal efficiencies and that redox environment influences the degree of pharmaceutical loss.
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Affiliation(s)
- Lauren B Stadler
- Department of Civil and Environmental Engineering, University of Michigan, 1351 Beal Avenue, EWRE, Ann Arbor, MI 48109, United States.
| | - Lijuan Su
- Department of Chemistry, University at Buffalo, State University of New York, Buffalo, NY 14260, United States.
| | - Christopher J Moline
- Department of Civil and Environmental Engineering, University of Michigan, 1351 Beal Avenue, EWRE, Ann Arbor, MI 48109, United States.
| | - Alexi S Ernstoff
- Department of Civil and Environmental Engineering, University of Michigan, 1351 Beal Avenue, EWRE, Ann Arbor, MI 48109, United States.
| | - Diana S Aga
- Department of Chemistry, University at Buffalo, State University of New York, Buffalo, NY 14260, United States.
| | - Nancy G Love
- Department of Civil and Environmental Engineering, University of Michigan, 1351 Beal Avenue, EWRE, Ann Arbor, MI 48109, United States.
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Arnaldos M, Pagilla KR. Occurrence and enrichment of 'bacterial sherpas': climb to sustainability in wastewater treatment. WATER SCIENCE AND TECHNOLOGY : A JOURNAL OF THE INTERNATIONAL ASSOCIATION ON WATER POLLUTION RESEARCH 2015; 72:1481-1487. [PMID: 26524438 DOI: 10.2166/wst.2015.364] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
The paper presents research on hemoglobin (Hb)-expressing bacteria in biological wastewater treatment systems. The outcome(s) will greatly reduce the aeration needs of wastewater treatment plants (WWTPs) and provide insight into emerging biological nitrogen removal processes using low dissolved oxygen (DO) conditions. In anthropogenic terms, the bacteria that express Hb could be considered as 'bacterial sherpas' that can function under low DO conditions. Hitherto, this functionality of bacteria has not been realized due to the initial response of the aerobic treatment stage: namely, morphology change by bacteria to filamentous forms to overcome oxygen mass transfer limitations causing bulking/foaming and nitrification inhibition. There is evidence, however, of the potential expression of Hb proteins by activated sludge (AS) bacteria. First, bacteria known to possess genes coding Hb proteins have been isolated from AS systems. Secondly, there is evidence that WWTPs are able to operate their biological processes at low DO without sludge bulking or incomplete nitrification. Our research has focused on nitrifying systems and has shown that this is due to prolonged operation at low DO conditions (0.1 mg O2/L), which allows sufficient time for bacterial acclimation. Additionally, it has been shown that enhanced Hb expression is linked to acclimation to low DO conditions.
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Affiliation(s)
- M Arnaldos
- R&D Department, Acciona Agua, Av. de les Garrigues 22, El Prat del Llobregat, Barcelona, Spain
| | - K R Pagilla
- Illinois Institute of Technology, Chicago, IL, USA E-mail:
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Rodriguez-Caballero A, Aymerich I, Poch M, Pijuan M. Evaluation of process conditions triggering emissions of green-house gases from a biological wastewater treatment system. THE SCIENCE OF THE TOTAL ENVIRONMENT 2014; 493:384-391. [PMID: 24954560 DOI: 10.1016/j.scitotenv.2014.06.015] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/05/2014] [Revised: 06/04/2014] [Accepted: 06/04/2014] [Indexed: 06/03/2023]
Abstract
In this study, methane (CH4) and nitrous oxide (N2O) emission dynamics of a plug-flow bioreactor located in a municipal full-scale wastewater treatment plant were monitored during a period of 10 weeks. In general, CH4 and N2O gas emissions from the bioreactor accounted for 0.016% of the influent chemical oxygen demand (COD) and 0.116% of the influent total Kjeldahl nitrogen (TKN) respectively. In order to identify the emission patterns in the different zones, the bioreactor was divided in six different sampling sites and the gas collection hood was placed for a period of 2-3 days in each of these sites. This sampling strategy also allowed the identification of different process perturbations leading to CH4 or N2O peak emissions. CH4 emissions mainly occurred in the first aerated site, and were mostly related with the influent and reject wastewater flows entering the bioreactor. On the other hand, N2O emissions were given along all the aerated parts of the bioreactor and were strongly dependant on the occurrence of process disturbances such as periods of no aeration or nitrification instability. Dissolved CH4 and N2O concentrations were monitored in the bioreactor and in other parts of the plant, as a contribution for the better understanding of the transport of these greenhouse gases across the different stages of the treatment system.
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Affiliation(s)
- A Rodriguez-Caballero
- Catalan Institute for Water Research (ICRA), Emili Grahit Street, 101, H(2)O Building, Scientific and Technological Park of the University of Girona, 17003 Girona, Spain
| | - I Aymerich
- Catalan Institute for Water Research (ICRA), Emili Grahit Street, 101, H(2)O Building, Scientific and Technological Park of the University of Girona, 17003 Girona, Spain
| | - M Poch
- Laboratory of Chemical and Environmental Engineering (LEQUIA-UdG), Institute of the Environment, University of Girona, Campus Montilivi s/n, E-17071 Girona, Spain
| | - M Pijuan
- Catalan Institute for Water Research (ICRA), Emili Grahit Street, 101, H(2)O Building, Scientific and Technological Park of the University of Girona, 17003 Girona, Spain.
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48
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Ofiţeru ID, Bellucci M, Picioreanu C, Lavric V, Curtis TP. Multi-scale modelling of bioreactor-separator system for wastewater treatment with two-dimensional activated sludge floc dynamics. WATER RESEARCH 2014; 50:382-95. [PMID: 24246170 DOI: 10.1016/j.watres.2013.10.053] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/26/2013] [Revised: 10/18/2013] [Accepted: 10/21/2013] [Indexed: 05/25/2023]
Abstract
A simple "first generation" multi-scale computational model of the formation of activated sludge flocs at micro-scale and reactor performance at macro-scale is proposed. The model couples mass balances for substrates and biomass at reactor scale with an individual-based approach for the floc morphology, shape and micro-colony development. Among the novel model processes included are the group attachment/detachment of micro-flocs to the core structure and the clustering of nitrifiers. Simulation results qualitatively describe the formation of micro-colonies of ammonia and nitrite oxidizers and the extracellular polymeric substance produced by heterotrophic microorganisms, as typically observed in fluorescence in situ hybridization images. These results are the first step towards realistic multi-scale multispecies models of the activated sludge wastewater treatment systems and a generic modelling strategy that could be extended to other engineered biological systems.
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Affiliation(s)
- Irina D Ofiţeru
- University Politehnica of Bucharest, Chemical Engineering Department, Polizu 1-7, Bucharest 011061, Romania; Newcastle University, School of Civil Engineering and Geosciences, Cassie Building, Newcastle upon Tyne NE1 7RU, United Kingdom.
| | - Micol Bellucci
- Newcastle University, School of Civil Engineering and Geosciences, Cassie Building, Newcastle upon Tyne NE1 7RU, United Kingdom
| | - Cristian Picioreanu
- Delft University of Technology, Department of Biotechnology, Julianalaan 67, 2628 BC Delft, The Netherlands
| | - Vasile Lavric
- University Politehnica of Bucharest, Chemical Engineering Department, Polizu 1-7, Bucharest 011061, Romania
| | - Thomas P Curtis
- Newcastle University, School of Civil Engineering and Geosciences, Cassie Building, Newcastle upon Tyne NE1 7RU, United Kingdom
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49
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Guadie A, Xia S, Zhang Z, Zeleke J, Guo W, Ngo HH, Hermanowicz SW. Effect of intermittent aeration cycle on nutrient removal and microbial community in a fluidized bed reactor-membrane bioreactor combo system. BIORESOURCE TECHNOLOGY 2014; 156:195-205. [PMID: 24508900 DOI: 10.1016/j.biortech.2014.01.008] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/21/2013] [Revised: 01/02/2014] [Accepted: 01/04/2014] [Indexed: 06/03/2023]
Abstract
Effect of intermittent aeration cycle (IAC=15/45-60/60min) on nutrient removal and microbial community structure was investigated using a novel fluidized bed reactor-membrane bioreactor (FBR-MBR) combo system. FBR alone was found more efficient for removing PO4-P (>85%) than NH4-N (<40%) and chemical oxygen demand (COD<35%). However, in the combo system, COD and NH4-N removals were almost complete (>98%). Efficient nitrification, stable mixed liquor suspended solid and reduced transmembrane pressure was also achieved. Quantitative real-time polymerase chain reaction results of total bacteria 16S rRNA gene copies per mL of mixed-liquor varied from (2.48±0.42)×10(9) initial to (2.74±0.10)×10(8), (6.27±0.16)×10(9) and (9.17±1.78)×10(9) for 15/45, 45/15 and 60/60min of IACs, respectively. The results of clone library analysis revealed that Proteobacteria (59%), Firmicutes (12%) and Bacteroidetes (11%) were the dominant bacterial group in all samples. Overall, the combo system performs optimum nutrient removal and host stable microbial communities at 45/15min of IAC.
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Affiliation(s)
- Awoke Guadie
- UNEP-Tongji Institute of Environment for Sustainable Development, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China
| | - Siqing Xia
- State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China.
| | - Zhiqiang Zhang
- State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China
| | - Jemaneh Zeleke
- Department of Microbiology and Microbial Engineering, School of Life Sciences, Fudan University, Shanghai 200433, China
| | - Wenshan Guo
- Center for Technology in Water and Wastewater, School of Civil and Environmental Engineering, University of Technology Sydney, Sydney, NSW 2007, Australia
| | - Huu Hao Ngo
- Center for Technology in Water and Wastewater, School of Civil and Environmental Engineering, University of Technology Sydney, Sydney, NSW 2007, Australia
| | - Slawomir W Hermanowicz
- Department of Civil and Environmental Engineering, University of California, Berkeley, CA 94720, United States
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50
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Correlation of seasonal nitrification failure and ammonia-oxidizing community dynamics in a wastewater treatment plant treating water from a saline thermal spa. ANN MICROBIOL 2014. [DOI: 10.1007/s13213-014-0811-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022] Open
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