scholarly journals Metagenomics Response of Anaerobic Ammonium Oxidation (anammox) Bacteria to Bio-Refractory Humic Substances in Wastewater

Water ◽  
2019 ◽  
Vol 11 (2) ◽  
pp. 365 ◽  
Author(s):  
Yabing Meng ◽  
Li-Nan Huang ◽  
Fangang Meng
Keyword(s):  
Humic Substances ◽  
Anammox Bacteria ◽  
Ammonium Oxidation ◽  
Leachate Treatment ◽  
Term Operation ◽  
Comparative Metagenomics ◽  
Electron Shuttles ◽  
One Year ◽  
High Level

Anammox-based processes have been widely applied for the treatment of wastewater (e.g., wastewater irrigation systems and constructed wetland) which consists of bio-refractory humic substances. Nonetheless, the impacts of bio-refractory humic substances on anammox consortia are rarely reported. In the present study, three identical lab-scale anammox reactors (i.e., HS0, HS1 and HS10), two of which were dosed with humic substances at 1 and 10 mg·L−1, respectively, were operated for nearly one year. The long-term operation of the reactors showed that the presence of humic substances in influent had no significant influence on nitrogen removal rates. Despite this, comparative metagenomics showed changes in anammox microbiota structure during the exposure to humic substance; e.g., the relative abundance of Candidatus Kuenenia was lower in HS10 (18.5%) than that in HS0 (22.8%) and HS1 (21.7%). More specifically, a lower level of humic substances (1 mg·L−1) in influent led to an increase of genes responsible for signal transduction, likely due to the role of humic substances as electron shuttles. In contrast, a high level of humic substances (10 mg·L−1) resulted in a slight decrease of functional genes associated with anammox metabolism. This may partially be due to the biodegradation of the humic substances. In addition, the lower dosage of humic substances (1 mg·L−1) also stimulated the abundance of hzs and hdh, which encode two important enzymes in anammox reaction. Overall, this study indicated that the anammox system could work stably over a long period under humic substances, and that the process was feasible for leachate treatment.

scholarly journals Mapping of affordability levels for photovoltaic-based electricity generation in the solar belt of sub-Saharan Africa, East Asia and South Asia

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Sándor Szabó ◽  
Irene Pinedo Pascua ◽  
Daniel Puig ◽  
Magda Moner-Girona ◽  
Mario Negre ◽  
...  
Keyword(s):  
East Asia ◽  
South Asia ◽  
Electricity Generation ◽  
Sub Saharan Africa ◽  
Solar Photovoltaic ◽  
Term Operation ◽  
Sub Saharan ◽  
High Level ◽  
Do So

AbstractLack of access to modern forms of energy hampers efforts to reduce poverty. The provision of electricity to off-grid communities is therefore a long-standing developmental goal. Yet, many off-grid electrification projects neglect mid- and long-term operation and maintenance costs. When this is the case, electricity services are unlikely to be affordable to the communities that are the project’s primary target. Here we show that, compared with diesel-powered electricity generation systems, solar photovoltaic systems are more affordable to no less than 36% of the unelectrified populations in East Asia, South Asia, and sub-Saharan Africa. We do so by developing geo-referenced estimates of affordability at a high level of resolution (1 km2). The analysis illustrates the differences in affordability that may be found at the subnational level, which underscores that electrification investments should be informed by subnational data.

Steam Line Integrity Analyses for LTO: Enhancing Credibility With Comprehensive Measurement

2012 ◽  
Author(s):  
Horst Rothenhöfer ◽  
Andreas Manke
Keyword(s):  
Power Plant ◽  
Nuclear Power Plant ◽  
Nuclear Power ◽  
Simulation Models ◽  
Proper Function ◽  
Blow Down ◽  
Term Operation ◽  
High Level ◽  
Comprehensive Measurement

The safety relevant components of nuclear power plant Neckarwestheim 1 — in service since 1976 — have been reviewed and updated for long-term operation (LTO). The actions included hardware retrofits as well as updates of analysis according to the latest state of the scientific and technical knowledge. For large piping such as the steam lines, the established pipes have been retained while the supports have been optimized. All shock absorbers (snubbers) including corresponding inertia have been eliminated resulting in a defined guidance and statically defined displacements. The integrity analyses for the optimized steam lines, including break preclusion, have been validated successfully with comprehensive measurements. The verification has delivered an extra high level of credibility, exceeding the “standard” requirements to achieve fitness for service in long-term operation. Measurement and validation, which are the main focus of this paper, range from monitoring of service loads to the static and dynamic measurements of pressure, local temperatures and displacements during initial start-up after implementation of the design modifications. The proper function of supports has been proved and the quality of the simulation models has been confirmed. Some expected and some unexpected dynamic events have been detected during blow-down tests. It was demonstrated that the amplitudes of all dynamic loads stay within limits. The validation of analyses with comprehensive measurement has been an important proof of quality and delivered the redundancy required for the integrity of a nuclear power plant in service, enhancing the high level of safety even more.

scholarly journals A Live, AttenuatedBordetella pertussisVaccine Provides Long-Term Protection against Virulent Challenge in a Murine Model

2010 ◽  
Vol 18 (2) ◽  
pp. 187-193 ◽  
Author(s):  
Ciaran M. Skerry ◽  
Bernard P. Mahon
Keyword(s):  
Whooping Cough ◽  
Interleukin 17 ◽  
Vaccination Programs ◽  
Virulent Challenge ◽  
One Year ◽  
High Level ◽  
New Generation ◽  
Prior Infection ◽  
Persistent Response

ABSTRACTDespite successful mass vaccination programs, whooping cough remains a significant cause of neonatal mortality. Immunity induced by current vaccines wanes in adolescence, requiring additional immunizations to prevent resurgence. There is a need for a new generation of vaccines capable of conferring long-lasting immunity from birth. Recently, a live, attenuated whooping cough vaccine, BPZE1, has been developed. Here, an established murine immunization model was used to examine the induction and longevity of immunological memory. In this predictive model, BPZE1 conferred a level of protection against virulent bacterial challenge comparable to that conferred by recovery from prior infection, up to 1 year after immunization. One year after immunization with BPZE1, a pertussis-specific persistent response, with high levels of gamma interferon (IFN-γ), could be detected from spleen cells restimulated with inactivatedBordetella pertussis. BPZE1 induced low levels of interleukin-17 (IL-17) and no IL-10 or IL-5. BPZE1 immunization induced long-lasting, efficacious memory B-cell and specific antibody responses dominated by IgG2a, which were boosted by subsequent challenge. Finally, the antibody induced by BPZE1 was functionally relevant and could clear a virulentB. pertussisinfection in antibody-deficient mice following passive transfer. This study suggests that BPZE1 is capable of conferring a high level of long-lived effective protection against virulentB. pertussis.

Long-Term Release from High Level Waste Glass - Part IV: The Effect of Leaching Mechanism

1984 ◽  
Vol 44 ◽  
Author(s):  
Eberhard Freude ◽  
Bernd Grambow ◽  
Werner Lutze ◽  
Harald Rabe ◽  
Rodney C. Ewing
Keyword(s):  
Linear Time ◽  
High Surface ◽  
High Level Waste ◽  
Corrosion Mechanism ◽  
Surface Areas ◽  
One Year ◽  
The Stability ◽  
High Level ◽  
Long Term Behavior

During the past ten years extensive data have been determined for the corrosion of nuclear waste forms in short-term laboratory experiments (usually less than one year). The long-term behavior of glass has been inferred by: (1) the acceleration of corrosion rates at high temperatures [1]; (2) the use of high surface areas of the glass to small volumes of solution [1]; and the analysis of natural glasses altered over long periods of geologic time [2, 3]. The most recent efforts have concentrated on understanding the mechanisms of corrosion [1, 4, 5]. The corrosion mechanism may be used to make long-term extrapolations of the “stability” of the waste form. In this paper, we consider a linear time dependence for the corrosion under near saturation conditions and use a rate equation in the QTERM code [6, 7, 8] to model the long-term behavior of the German glass, C-31−3EC [9], JSS A [10, 11] and SRL TDS 131 [1]. The data base for C-31−3EC has been published elsewhere [9, 12, 13, 14], and we include experimental work completed by Rabe for boron and silica, at 200°C.

scholarly journals Model-based analysis of microbial consortia and microbial products in an anammox biofilm reactor

2018 ◽  
Vol 77 (7) ◽  
pp. 1951-1959 ◽  
Author(s):  
M. Azari ◽  
A. V. Le ◽  
M. Lübken ◽  
M. Denecke
Keyword(s):  
Relative Abundance ◽  
Inorganic Nitrogen ◽  
Biofilm Reactor ◽  
Microbial Consortia ◽  
Nitrifying Bacteria ◽  
Anammox Bacteria ◽  
Ammonium Oxidation ◽  
Leachate Treatment ◽  
Model Based ◽  
Microbial Products

Abstract A mathematical model for a granular biofilm reactor for leachate treatment was validated by long-term measured data to investigate the mechanisms and drivers influencing biological nitrogen removal and microbial consortia dynamics. The proposed model, based on Activated Sludge Model (ASM1), included anaerobic ammonium oxidation (anammox), nitrifying and heterotrophic denitrifying bacteria which can attach and grow on granular activated carbon (GAC) particles. Two kinetic descriptions for the model were proposed: with and without soluble microbial products (SMP) and extracellular polymeric substance (EPS). The model accuracy was checked using recorded total inorganic nitrogen concentrations in the effluent and estimated relative abundance of active bacteria using quantitative fluorescence in-situ hybridization (qFISH). Results suggested that the model with EPS kinetics fits better for the relative abundance of anammox bacteria and nitrifying bacteria compared to the model without EPS. The model with EPS and SMP confirms that the growth and existence of heterotrophs in anammox biofilm systems slightly increased due to including the kinetics of SMP production in the model. During the one-year simulation period, the fractions of autotrophs and EPS in the biomass were almost stable but the fraction of heterotrophs decreased which is correlated with the reduction in nitrogen surface loading on the biofilm.

scholarly journals Coupled anaerobic ammonium oxidation and hydrogenotrophic denitrification for simultaneous NH4-N and NO3-N removal

2018 ◽  
Vol 79 (5) ◽  
pp. 975-984 ◽  
Author(s):  
Tatsuru Kamei ◽  
Rawintra Eamrat ◽  
Kenta Shinoda ◽  
Yasuhiro Tanaka ◽  
Futaba Kazama
Keyword(s):  
Nitrogen Removal ◽  
Inorganic Nitrogen ◽  
Nitrate Removal ◽  
Fixed Bed ◽  
Anaerobic Ammonium Oxidation ◽  
Anammox Bacteria ◽  
Ammonium Oxidation ◽  
N Removal ◽  
Anammox Process

Abstract Nitrate removal during anaerobic ammonium oxidation (anammox) treatment is a concern for optimization of the anammox process. This study demonstrated the applicability and long-term stability of the coupled anammox and hydrogenotrophic denitrification (CAHD) process as an alternative method for nitrate removal. Laboratory-scale fixed bed anammox reactors (FBR) supplied with H2 to support denitrification were operated under two types of synthetic water. The FBRs showed simultaneous NH4-N and NO3-N removal, indicating that the CAHD process can support NO3-N removal during the anammox process. Intermittent H2 supply (e.g. 5 mL/min for a 1-L reactor, 14/6-min on/off cycle) helped maintain the CAHD process without deteriorating its performance under long-term operation and resulted in a nitrogen removal rate of 0.21 kg-N/m3/d and ammonium, nitrate, and dissolved inorganic nitrogen removal efficiencies of 73.4%, 80.4%, and 77%, respectively. The microbial community structure related to the CAHD process was not influenced by changes in influent water quality, and included the anammox bacteria ‘Candidatus Jettenia’ and a Sulfuritalea hydrogenivorans-like species as the dominant bacteria even after long-term reactor operation, suggesting that these bacteria are key to the CAHD process. These results indicate that the CAHD process is a promising method for enhancing the efficiency of anammox process.

Repairing Feedwater Heater Tubes Using Explosively Welded and Brazed Sleeves

2005 ◽  
Author(s):  
Thomas J. Muldoon
Keyword(s):  
High Pressure ◽  
High Load ◽  
Operating Period ◽  
Term Operation ◽  
Repair Strategy ◽  
Load Demand ◽  
Operating Margin ◽  
Leak Tightness ◽  
High Level

Failures in either the desuperheating zone or drainscooling zone may occur during the long term operation of high pressure feedwater heaters. When the number of failures gets high, the risk of the loss of generation or availability often requires replacement of a feedwater heater. Often, it is important to maintain a reasonably high level of heater availability while the replacement is planned and procured. It is prudent to minimize the potential for a catastrophic set of tube failures which could result in the potential for a turbine water induction incident or an extended repair outage. In such cases, a repair strategy that includes the use of tube sleeves, also referred to as liners, can provide a high level of leak tightness and can provide the operating margin and reliability to help get a heater through a critical operating period, such as a summer high load demand. Installing a sleeve, which is bonded to the tube on both ends, can provide this level of integrity.

Enrichment of Anaerobic Ammonium Oxidation (Anammox) Bacteria for Biological Nitrogen Removal of Wastewater

2013 ◽  
Vol 62 (2) ◽  
Author(s):  
Norjan Yusof ◽  
Hanisom Abdullah ◽  
Syakirah Samsudin ◽  
Mohd Ali Hassan
Keyword(s):  
Batch Reactor ◽  
Anaerobic Ammonium Oxidation ◽  
Anammox Bacteria ◽  
Ammonium Oxidation ◽  
Leachate Treatment ◽  
16S Rrna Sequence ◽  
Bottom Part ◽  
Enrichment Cultures ◽  
Anammox Activity ◽  
Biological Nitrogen

Anaerobic ammonium oxidation (anammox) bacteria enrichment was explored for the potential application of ammonium rich wastewater removal. Samples of sludge from mature and young landfill leachate treatment plants were screened and used as inocula for anammox enrichment cultures. Enrichments were monitored for N-NH3, N-NO2- and N-NO3- to detect anammox potential activity. Six of the twelve enrichment cultures showed anammox activity after more than five months of enrichment period. All enrichment cultures that gave positive results were obtained from bottom part of sequencing batch reactor (SBR) lagoon indicating localization of anammox bacteria in anaerobic condition.  Polymerase Chain Reaction (PCR) with specific primers targeting anammox and planctomycete were able to amplify the 16S rRNA sequence for anammox bacteria under PCR optimum condition. However, only three of six positive samples were successfully sequenced. DNA sequence analysis using NCBI (BLAST) and RDP showed that the anammox bacterial sequences of the investigated samples were identified as Candidatus Kuenenia stuttgartiensis with similarity of 100% (NCBI) and 99.3% (RDP).

scholarly journals Cometabolism of the Superphylum Patescibacteria with Anammox Bacteria in a Long-Term Freshwater Anammox Column Reactor

Water ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 208
Author(s):  
Suguru Hosokawa ◽  
Kyohei Kuroda ◽  
Takashi Narihiro ◽  
Yoshiteru Aoi ◽  
Noriatsu Ozaki ◽  
...  
Keyword(s):  
Heterotrophic Bacteria ◽  
Draft Genome ◽  
Marker Genes ◽  
Anammox Bacteria ◽  
Ammonium Oxidation ◽  
Column Reactor ◽  
Nitrite Nitrate ◽  
Anammox Process ◽  
Candidate Phyla Radiation

Although the anaerobic ammonium oxidation (anammox) process has attracted attention regarding its application in ammonia wastewater treatment based on its efficiency, the physiological characteristics of anammox bacteria remain unclear because of the lack of pure-culture representatives. The coexistence of heterotrophic bacteria has often been observed in anammox reactors, even in those fed with synthetic inorganic nutrient medium. In this study, we recovered 37 draft genome bins from a long-term-operated anammox column reactor and predicted the metabolic pathway of coexisting bacteria, especially Patescibacteria (also known as Candidate phyla radiation). Genes related to the nitrogen cycle were not detected in Patescibacterial bins, whereas nitrite, nitrate, and nitrous oxide-related genes were identified in most of the other bacteria. The pathway predicted for Patescibacteria suggests the lack of nitrogen marker genes and its ability to utilize poly-N-acetylglucosamine produced by dominant anammox bacteria. Coexisting Patescibacteria may play an ecological role in providing lactate and formate to other coexisting bacteria, supporting growth in the anammox reactor. Patescibacteria-centric coexisting bacteria, which produce anammox substrates and scavenge organic compounds produced within the anammox reactor, might be essential for the anammox ecosystem.

Selective Streptokinase Fibrinolysis in Femoro-Iliac Arterial Obstruction

1986 ◽  
Vol 27 (3) ◽  
pp. 279-283 ◽  
Author(s):  
K. Sørensen ◽  
V. Hegedüs
Keyword(s):  
Low Dose ◽  
Transluminal Angioplasty ◽  
Term Therapy ◽  
High Dose ◽  
Short Term ◽  
Short Term Therapy ◽  
One Year ◽  
High Level ◽  
Long Term Therapy

Percutaneous transluminal angioplasty of iliac and femoral arteries was in 17 patients combined with selective intra-arterial streptokinase treatment. The patients were divided into two groups, one given low dose long-term therapy and the other high dose short-term therapy. The experiences obtained during an observation period of over one year revealed greater benefit from high dose short-term therapy. It seems that the major cause of complications must be attributed to the development of a high level of streptokinase antibodies during low dose long-term therapy. References

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