In-situ characterization of microbial community in an A/O submerged membrane bioreactor with nitrogen removal

2004 ◽  
Vol 50 (8) ◽  
pp. 41-48 ◽  
Author(s):  
A. Sofia ◽  
W.-T. Liu ◽  
S.L. Ong ◽  
W.J. Ng
Keyword(s):  
Bacterial Community ◽  
Nitrogen Removal ◽  
Membrane Bioreactor ◽  
Ammonia Oxidation ◽  
Paracoccus Denitrificans ◽  
Pseudomonas Stutzeri ◽  
Laboratory Scale ◽  
Negative Results

The bacterial community involved in removing nitrogen from sewage and their preferred DO environment within an anoxic/oxic membrane bioreactor (A/O MBR) was investigated. A continuously operated laboratory-scale A/O MBR was maintained for 360 d. At a sludge age of 150 d and a C/N ratio of 3.5, the system was capable of removing 88% of the influent nitrogen from raw wastewater through typical nitrogen removal transformations (i.e. aerobic ammonia oxidation and anoxic nitrate reduction). Characterization of the A/O MBR bacterial community was carried out using fluorescence in situ hybridization (FISH) techniques. FISH results further showed that Nitrosospira spp. and Nitrospira spp. were the predominant groups of ammonia and nitrite oxidizing group, respectively. They constituted up to 11% and 6% of eubacteria at DO below 0.05 mg/l (low DO), respectively, and about 14% and 9% of eubacteria at DO between 2–5 mg/l (sufficient DO), respectively, indicating preference of nitrifiers for a higher DO environment. Generally low counts of the genus Paracoccus were detected while negative results were observed for Paracoccus denitrificans, Alcaligenes spp, and Pseudomonas stutzeri under the low and sufficient DO environments. The overall results indicate that Nitrosospira spp., Nitrospira spp. and members of Paracoccus spp. can be metabolically functional in nitrogen removal in the laboratory-scale A/O MBR system.

Enhanced nitrogen removal and in situ microbial community in a two-step feed oxic/anoxic/oxic-membrane bioreactor (O/A/O-MBR) process

2019 ◽  
Vol 94 (4) ◽  
pp. 1315-1322 ◽  
Author(s):  
Ning Li ◽  
Wei Zeng ◽  
Zhijia Miao ◽  
Baogui Wang ◽  
Zaixing Li ◽  
...  
Keyword(s):  
Microbial Community ◽  
Nitrogen Removal ◽  
Membrane Bioreactor

scholarly journals Performance and microbial community of the CANON process in a sequencing batch membrane bioreactor with elevated COD/N ratios

2020 ◽  
Vol 81 (1) ◽  
pp. 138-147
Author(s):  
Xiaoling Zhang ◽  
Xincong Liu ◽  
Meng Zhang
Keyword(s):  
Organic Matter ◽  
Microbial Community ◽  
Nitrogen Removal ◽  
Membrane Bioreactor ◽  
Ammonia Oxidation ◽  
Heterotrophic Bacteria ◽  
Removal Rate ◽  
Ammonia Oxidizing Bacteria ◽  
Anaerobic Ammonia Oxidation ◽  
Canon Process

Abstract In this study, the effects of elevated chemical oxygen demand/nitrogen (COD/N) ratios on nitrogen removal, production and composition of the extracellular polymer substances (EPS) and microbial community of a completely autotrophic nitrogen removal via nitrite (CANON) process were studied in a sequencing batch membrane bioreactor (SBMBR). The whole experiment was divided into two stages: the CANON stage (without organic matter in influent) and the simultaneous partial nitrification, anaerobic ammonia oxidation and denitrification (SNAD) stage (with organic matter in influent). When the inflow ammonia nitrogen was 420 mg/L and the COD/N ratio was no higher than 0.8, the addition of COD was helpful to the CANON process; the total nitrogen removal efficiency (TNE) was improved from approximately 65% to more than 75%, and the nitrogen removal rate (NRR) was improved from approximately 0.255 kgN/(m3·d) to approximately 0.278 kgN/(m3•d), while the TNE decreased to 60%, and the NRR decreased to 0.236 kgN/(m3•d) when the COD/N ratio was elevated to 1.0. For the EPS, the amounts of soluble EPS (SEPS) and loosely bound EPS (LB-EPS) were both higher in the CANON stage than in the SNAD stage, while the amount of tightly bound EPS (TB-EPS) in the SNAD stage was significantly higher due to the proliferation of heterotrophic bacteria. The metagenome sequencing technique was used to analyse the microbial community in the SBMBR. The results showed that the addition of COD altered the structure of the bacterial community in the SBMBR. The amounts of Candidatus ‘Anammoxoglobus’ of anaerobic ammonia oxidation bacteria (AAOB) and Nitrosomonas of ammonia oxidizing bacteria (AOB) both decreased significantly, and Nitrospira of nitrite oxidizing bacteria (NOB) was always in the reactor, although the amount changed slightly. A proliferation of denitrifiers related to the genera of Thauera, Dokdonella and Azospira was found in the SBMBR.

Characterization of amoA and hao Genes Responsible for Ammonia Oxidation Reaction in CANON System

2011 ◽  
Vol 183-185 ◽  
pp. 1014-1019
Author(s):  
Hai Yan Zou ◽  
Jun Li Huang ◽  
Fang Fang ◽  
Jin Song Guo
Keyword(s):  
Nitrogen Removal ◽  
Oxidation Reaction ◽  
High Efficiency ◽  
Ammonia Oxidation ◽  
Residual Activity ◽  
Maximum Activity ◽  
Ammonia Oxidizing Bacteria ◽  
Hydroxylamine Oxidoreductase ◽  
Optimum Ph

In this research the genes (amoA and hao) for ammonia monooxygenase (AMO) and hydroxylamine oxidoreductase (HAO) responsible for ammonia oxidation reaction in completely autotrophic nitrogen removal over nitrite process were cloned and sequenced, and the recombinant protein of AMO and HAO was expressed and characterized. The optimum temperature for AMO activity was 55 °C and more than 40% of the maximum activity was retained from 15-50 °C. The optimum pH for the enzyme was found to be pH 11.0. The highest activity for HAO was observed at 45 °C. More than 50% of the maximum activity was retained even at 55 °C. The dependence of HAO on pH was strong and only average 15% of residual activity left at pH ranging from 3.0-9.0. Study on the molecular and biochemistry properties of recombinant AMO and HAO will benefit for the manipulation of ammonia-oxidizing bacteria to achieve the goal of high efficiency of nitrogen removal.

The Research of Fluorescence In Situ Hybridization Approach Applied in Denitrification Bacteria in Metal Membrane Bioreactor

2013 ◽  
Vol 864-867 ◽  
pp. 1490-1493
Author(s):  
Pan Zhang ◽  
Yuan Hua Xie
Keyword(s):  
Population Structure ◽  
In Situ Hybridization ◽  
Nitrogen Removal ◽  
Membrane Bioreactor ◽  
Metal Membrane ◽  
Quality Of Water ◽  
Preliminary Study ◽  
Optimized Conditions

To research the composition and proportion of the denitrying bacterium in denitrification tank and increase the nitrogen removals rate. With the purpose of explore the curve between the amount of different denitrying bacterium and the quality of water treating, then find out the optimum of the species of nitrogen removal bacteria and the amount of the specific type of microorganism in the denitrification tank of metal membrane bioreactor at the optimized conditions of the water treating effects. The fluorescence in situ hybridization (FISH) approach is applied in this research, to set a preliminary study on the space-time character of denitrification bacteria population structure in denitrifical tank.

Model experiments on improving nitrogen removal in laboratory scale subsurface constructed wetlands by enhancing the anaerobic ammonia oxidation

2007 ◽  
Vol 56 (3) ◽  
pp. 145-150 ◽  
Author(s):  
D. Paredes ◽  
P. Kuschk ◽  
F. Stange ◽  
R.A. Müller ◽  
H. Köser
Keyword(s):  
Nitrogen Removal ◽  
Ammonia Oxidation ◽  
Operating Conditions ◽  
Laboratory Scale ◽  
Synthetic Wastewater ◽  
Scale Model ◽  
Model Experiments ◽  
Anaerobic Ammonia Oxidation ◽  
High Ammonia ◽  
Process Strategy

Anaerobic ammonia oxidation (Anammox) has been identified as a new general process-strategy for nitrogen removal in wastewater treatment. In order to evaluate the role and effects of the Anammox process in wetlands, laboratory-scale model experiments were performed with planted fixed bed reactors. A reactor (planted with Juncus effusus) was fed with synthetic wastewater containing 150–200 mg L−1 NH+4 and 75–480 mg L−1 NO−2. Under these operating conditions, the plants were affected by the high ammonia and nitrite concentrations and the nitrogen removal rate fell within the same range of 45–49 mg N d−1 (equivalent to 0.64–0.70 g Nm−2d−1) as already reported by other authors. In order to stimulate the rate of nitrogen conversion, the planted reactor was inoculated with Anammox biomass. As a result, the rate of nitrogen removal was increased 4–5-fold and the toxic effects on the plants also disappeared. The results show that, in principle, subsurface flow wetlands can also function as an “Anammox bioreactor”. However, the design of a complete process for the treatment of waters with a high ammonia load and, in particular, the realisation of simple technical solutions for partial nitrification have still to be developed.

scholarly journals Aerobic Denitrifying Bacteria That Produce Low Levels of Nitrous Oxide

2003 ◽  
Vol 69 (6) ◽  
pp. 3152-3157 ◽  
Author(s):  
Naoki Takaya ◽  
Maria Antonina B. Catalan-Sakairi ◽  
Yasushi Sakaguchi ◽  
Isao Kato ◽  
Zhemin Zhou ◽  
...  
Keyword(s):  
Nitrous Oxide ◽  
Nitrogen Removal ◽  
Paracoccus Denitrificans ◽  
Pseudomonas Stutzeri ◽  
Denitrifying Bacteria ◽  
Continuous Cultures ◽  
Aerobic Conditions ◽  
Stage Process ◽  
Low Levels ◽  
Microbial N

ABSTRACT Most denitrifiers produce nitrous oxide (N2O) instead of dinitrogen (N2) under aerobic conditions. We isolated and characterized novel aerobic denitrifiers that produce low levels of N2O under aerobic conditions. We monitored the denitrification activities of two of the isolates, strains TR2 and K50, in batch and continuous cultures. Both strains reduced nitrate (NO3 −) to N2 at rates of 0.9 and 0.03 μmol min−1 unit of optical density at 540 nm−1 at dissolved oxygen (O2) (DO) concentrations of 39 and 38 μmol liter−1, respectively. At the same DO level, the typical denitrifier Pseudomonas stutzeri and the previously described aerobic denitrifier Paracoccus denitrificans did not produce N2 but evolved more than 10-fold more N2O than strains TR2 and K50 evolved. The isolates denitrified NO3 − with concomitant consumption of O2. These results indicated that strains TR2 and K50 are aerobic denitrifiers. These two isolates were taxonomically placed in the β subclass of the class Proteobacteria and were identified as P. stutzeri TR2 and Pseudomonas sp. strain K50. These strains should be useful for future investigations of the mechanisms of denitrifying bacteria that regulate N2O emission, the single-stage process for nitrogen removal, and microbial N2O emission into the ecosystem.

scholarly journals Direct Detection by In Situ PCR of theamoA Gene in Biofilm Resulting from a Nitrogen Removal Process

2001 ◽  
Vol 67 (11) ◽  
pp. 5261-5266 ◽  
Author(s):  
Tatsuhiko Hoshino ◽  
Naohiro Noda ◽  
Satoshi Tsuneda ◽  
Akira Hirata ◽  
Yuhei Inamori
Keyword(s):  
Nitrogen Removal ◽  
Ammonia Oxidation ◽  
Direct Detection ◽  
Small Subunit ◽  
Gene Encoding ◽  
In Situ Pcr ◽  
Alexa Fluor ◽  
Biological Removal ◽  
Naphthoic Acid

ABSTRACT Ammonia oxidation is a rate-limiting step in the biological removal of nitrogen from wastewater. Analysis of microbial communities possessing the amoA gene, which is a small subunit of the gene encoding ammonia monooxygenase, is important for controlling nitrogen removal. In this study, the amoA gene present in Nitrosomonas europaea cells in a pure culture and biofilms in a nitrifying reactor was amplified by in situ PCR. In this procedure, fixed cells were permeabilized with lysozyme and subjected to seminested PCR with a digoxigenin-labeled primer. Then, the amplicon was detected with an alkaline phosphatase-labeled antidigoxigenin antibody and HNPP (2-hydroxy-3-naphthoic acid-2′-phenylanilide phosphate), which was combined with Fast Red TR, and with an Alexa Fluor 488-labeled antidigoxigenin antibody. The amoAgene in the biofilms was detected with an unavoidable nonspecific signal when the former method was used for detection. On the other hand, the amoA gene in the biofilms was detected without a nonspecific signal, and the cells possessing the amoAgene were clearly observed near the surface of the biofilm when Alexa Fluor 488-labeled antidigoxigenin antibody was used for detection. Although functional gene expression was not detected in this study, detection of cells in a biofilm based on their function was demonstrated.

scholarly journals Nitrogen removal using an anammox membrane bioreactor at low temperature

2015 ◽  
Vol 72 (12) ◽  
pp. 2148-2153 ◽  
Author(s):  
Takanori Awata ◽  
Yumiko Goto ◽  
Tomonori Kindaichi ◽  
Noriatsu Ozaki ◽  
Akiyoshi Ohashi
Keyword(s):  
Low Temperature ◽  
Nitrogen Removal ◽  
Membrane Bioreactor ◽  
Membrane Bioreactors ◽  
Distinct Advantage ◽  
Anammox Bacteria ◽  
Short Term ◽  
Term Operation ◽  
Anammox Activity

Membrane bioreactors (MBRs) have the ability to completely retain biomass and are thus suitable for slowly growing anammox bacteria. In the present study, an anammox MBR was operated to investigate whether the anammox activity would remain stable at low temperature, without anammox biomass washout. The maximum nitrogen removal rates were 6.7 and 1.1 g-N L−1 day−1 at 35 °C and 15 °C, respectively. Fluorescence in situ hybridization and 16S rRNA-based phylogenetic analysis revealed no change in the predominant anammox species with temperature because of the complete retention of anammox biomass in the MBR. These results indicate that the predominant anammox bacteria in the MBR cannot adapt to a low temperature during short-term operation. Conversely, anammox activity recovered rapidly after restoring the temperature from the lower value to the optimal temperature (35 °C). The rapid recovery of anammox activity is a distinct advantage of using an MBR anammox reactor.

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