Application of experimental research methodology to the study of nitrification in mixed culture

1996 ◽  
Vol 34 (1-2) ◽  
pp. 245-252 ◽  
Author(s):  
M. Mauret ◽  
E. Paul ◽  
E. Puech-Costes ◽  
M. T. Maurette ◽  
P. Baptiste
Keyword(s):  
Experimental Research ◽  
Research Methodology ◽  
Ammonia Concentration ◽  
Ammonia Removal ◽  
Nitrite Accumulation ◽  
Experimental Conditions ◽  
Specific Effects ◽  
Consecutive Reactions ◽  
Two Parameters ◽  
Positive Effect

Nitrification is an aerobic process formed by two consecutive reactions: nitritation and nitratation. Using an experimental research methodology, we have studied the specific effects and the possible interactions between initial ammonia concentration, pH and temperature on these two reactions as well as on the experimental conditions leading to a nitrite build-up. In the experimental field studied (35 < [N-NH4+]O mg.l−1 < 90, 15 < T°C < 25 and 7 < pH < 8.5), the statistic interpretation of the results shows that only temperature and pH have a significant positive effect on ammonia removal. Moreover, the effect of these two parameters is linear. As for nitrite accumulation, the temperature effect is negligible and a strong interaction between [N-NH4]O and pH is revealed. When the values of these two variables are high, nitratation is inhibited and 50% of the nitrogen introduced at the beginning accumulates temporarily in the form of nitrites. The results clearly show that a high NH3 concentration inhibits Nitrobacter, starting from between 6.6 and 8.9 mg N-NH3.l−1. This research enables a better understanding of the nitrite build-up phenomena which can be thus minimized or maximized in the case of new process of nitrogen treatment.

Nitrogen removal characteristics of nitrification and denitrification filters

1994 ◽  
Vol 29 (10-11) ◽  
pp. 409-416 ◽  
Author(s):  
F. Çeçen ◽  
I. E. Gönenç
Keyword(s):  
Nitrogen Removal ◽  
Rate Constants ◽  
Order Rate Constant ◽  
Zero Order ◽  
Ammonia Removal ◽  
Nitrite Accumulation ◽  
Order Kinetic ◽  
Order Rate ◽  
In Series ◽  
Nitrification And Denitrification

The kinetics of nitrogen removal was studied in upflow submerged nitrification and denitrification filters in series. Nitrification followed first-, half-, and zero-order kinetics. For the half-order range the half-order rate constant was about 0.9gNH4-N1/2m−1/2d−1. The zero-order rate constants for the DO ranges of 2-3 mg/L and 4-5 mg/L were found as 0.47 gNH4-Nm−2d−1 and 1.82 gNH4-Nm−2d−1, respectively. In the zero-order region ammonia removal proceeded as a half-order reaction in oxygen concentration and the half-order rate constants were about 1.4-2.7 gO21/2m−1/2d−1. Nitrite accumulation reached a considerable degree at bulk oxygen to bulk ammonia ratios lower than 5 since the formation of nitrate was inhibited. Similar to nitrification half- and zero-order kinetic regions were also observed in denitrification. The half- and zero-order rate constants for carbon unlimited cases (influent COD/NOx-N>5) were about 0.23 gNOx-N1/2m−1/2d−1 and 1.9 gNOx-Nm−2d−1, respectively. The nitrite produced in the nitrification stage could be reduced in denitrification. The removal kinetics in the presence of nitrite was found to be similar to the kinetics when the influent consisted of nitrate only.

scholarly journals Reaction of Ion Exchange Resins with Fenton’s Reagent

Environments ◽  
2018 ◽  
Vol 5 (11) ◽  
pp. 123 ◽  
Author(s):  
Leandro de Araujo ◽  
Júlio Marumo
Keyword(s):  
Ion Exchange ◽  
Catalyst Concentration ◽  
Setting Time ◽  
Ion Exchange Resins ◽  
Experimental Conditions ◽  
Final Volume ◽  
Different Temperatures ◽  
Axial Compressive Strength ◽  
Exchange Resins ◽  
Two Parameters

One of the most common treatment methods for spent ion exchange resins is their immobilization in cement, which reduces the release of radionuclides into the environment. Although this method is efficient, it considerably increases the final volume of the waste due to its low incorporation capacity. This work aims to evaluate the degradation of ion exchange resins by the Fenton process (H2O2/Fe2+). The resin evaluated was a mixture of cationic and anionic resins, both non-radioactive. The reactions were conducted by varying the catalyst concentration (25, 50, 100, and 150 mmol L−1) and the volume of hydrogen peroxide. Three different temperatures were evaluated by varying the flow of reactants, which were 50, 60, and 70 °C. Cement specimens were prepared from the treated solutions and two parameters were assessed—namely, final setting time and axial compressive strength. The results showed that the experimental conditions were suitable to dissolve the resins, and the Fe3+ produced as precipitate during the experiments increased the resistance of the final product. The immobilized product complied with the limits established by regulation.

scholarly journals THE EFFECTIVENESS OF OBSTACLE RACE GAME TOWARD STUDENTS’ MOTIVATION IN LEARNING GRAMMAR

2018 ◽  
Vol 5 (1) ◽  
pp. 12
Author(s):  
Baiq Deni Kurniati
Keyword(s):  
Research Design ◽  
Experimental Research ◽  
Test Score ◽  
Sampling Technique ◽  
Research Data ◽  
T Test ◽  
Second Grade ◽  
Second Grade Students ◽  
Sample Technique ◽  
Positive Effect

This research was aimed to find out the effectiveness of Obstacle Race Game toward students’ motivation in learning grammar and to find out the correlation between students’ motivation and grammar at MA Darul Husaini Sanggeng. The kind of this research is experimental research (quantitative approach). This research design was applied pretest-posttest design. The population of this research was all of the second grade students of MA Darul Husaini Sanggeng. The sample of this research was consist of two classes namely XI-A as experimental class consist of 17 students and XI-B as control class consist of 17 students. The sample technique used in this research was saturated sampling technique. The technique which was used to analysis the data was t-test and r-test formula. From the research data found that the t-test score is higher than t-table (2,635>2, 021). Based on the result of this research, it can be conclude that the Obstacle Race Game has positive effect towards students’ motivation in learning grammar. From the research data found that r-test is higher than r-table (0,990>0,482). It can be conclude that there is correlation between students’ motivation and grammar.

Methodology for the Research Conducted

2021 ◽  
pp. 190-226
Keyword(s):  
Experimental Research ◽  
Research Methodology ◽  
Systems Design ◽  
Controlled Environment ◽  
Research Methodologies ◽  
In The Wild ◽  
The Individual

This chapter describes and discusses a combination of research methodologies (e.g., experimental, theoretical, and systems design) used in this research, allowing us to eliminate as much as possible every limitation that can be encountered with the individual methods themselves. For example, experimental research methodology has a limitation because the experiments are performed mainly in a controlled environment and might not reflect properly some practices performed ‘in the wild'. But combining this with some survey and prototype (system's) design reduced such limitations. The knowledge gained from carrying out preliminary experimentation is used in the next chapter to design and model the Hybrid-AutoML system.

scholarly journals Does Addition of Perch Larvae as Prey Affect the Growth, Development and Cannibalism Rate of Pikeperch Larvae?

Fishes ◽  
2019 ◽  
Vol 4 (1) ◽  
pp. 21 ◽  
Author(s):  
Aurore Cortay ◽  
Tatiana Colchen ◽  
Pascal Fontaine ◽  
Alain Pasquet
Keyword(s):  
Group Structure ◽  
Stocking Density ◽  
Perca Fluviatilis ◽  
Experimental Conditions ◽  
Live Prey ◽  
Cultured Fish ◽  
Cannibalism Rate ◽  
Two Parameters ◽  
Size Heterogeneity ◽  
Group Structures

Cannibalism occurs in many cultured fish species, especially at the larval and juvenile stages of piscivorous taxa. In farmed percid species, such as pikeperch (Sander lucioperca), intra-cohort cannibalism is a major issue inducing significant losses of the initial stocking density during the first weeks of rearing. Therefore, the present study was designed to investigate the effects of perch larvae (Perca fluviatilis) as live prey on growth, survival and cannibalism in pikeperch larvae under experimental conditions. Additionally, zootechnical and behavioural variables linked to aggressiveness (S postures, attacks, bites and ingestion), and group structures were considered. The survival rate was not different between the two groups (72% with prey vs. 69% without prey), but the cannibalism rate was higher in the group with the prey (28% vs. 10%). The means of final weight and length of pikeperch larvae were higher in the group fed with perch larvae, but size heterogeneity measured by the coefficients of variation for these two parameters did not differ. The specific growth rate was higher in the group fed with perch larvae, but there was no difference between the two groups concerning Fulton’s condition factor. Among all the behavioural variables (aggressiveness, group structure), none differed between the two groups.

scholarly journals The study of the ferroconcrete beams with thrust on the foil bearings during short-term dynamic loading

2020 ◽  
Vol 315 ◽  
pp. 07003
Author(s):  
Oleg Kumpyak ◽  
Daud Galyautdinov
Keyword(s):  
Dynamic Loading ◽  
Experimental Research ◽  
Fracture Strength ◽  
Considerable Increase ◽  
Intensity Increase ◽  
Short Term ◽  
Foil Bearings ◽  
Horizontal Shift ◽  
Power Intensity ◽  
Positive Effect

While designing and maintaining ferroconcrete beam constructions subjected to a short-term dynamic loading, it is necessary to consider the emergence of the thrust reaction; this leads to a considerable increase of durability and fracture strength. It is also necessary to consider the use of foil bearings as the power-intensity increase of the researched constructions. The aim of the experimental research is to expose the reasonability of using foil bearings in thrust constructions. The paper presents the results of the experimental research of ferroconcrete beam constructions with thrust on foil bearings during short-term dynamic loading. The influence of the thrust on the durability, deformability and fracture strength of ferroconcrete constructions during short-term dynamic loading, as well as joint use of foil bearings and limitation of support contour horizontal shift are studied. The results of the research indicate the positive effect of using foil bearings in the constructions with thrust.

Rapid start-up of a nitrifying reactor using aerobic granular sludge as seed sludge

2012 ◽  
Vol 65 (3) ◽  
pp. 581-588 ◽  
Author(s):  
Naohiro Kishida ◽  
Goro Saeki ◽  
Satoshi Tsuneda ◽  
Ryuichi Sudo
Keyword(s):  
Removal Rate ◽  
Granular Sludge ◽  
Ammonia Removal ◽  
High Rate ◽  
Aerobic Granular Sludge ◽  
Nitrite Accumulation ◽  
Ammonia Oxidizing Bacteria ◽  
Continuous Stirred Tank Reactor ◽  
Start Up ◽  
Seed Sludge

In this study, the effectiveness of aerobic granular sludge as seed sludge for rapid start-up of nitrifying processes was investigated using a laboratory-scale continuous stirred-tank reactor (CSTR) fed with completely inorganic wastewater which contained a high concentration of ammonia. Even when a large amount of granular biomass was inoculated in the reactor, and the characteristics of influent wastewater were abruptly changed, excess biomass washout was not observed, and biomass concentration was kept high at the start-up period due to high settling ability of the aerobic granular sludge. As a result, an ammonia removal rate immediately increased and reached more than 1.0 kg N/m3/d within 20 days and up to 1.8 kg N/m3/d on day 39. Subsequently, high rate nitritation was stably attained during 100 days. However, nitrite accumulation had been observed for 140 days before attaining complete nitrification to nitrate. Fluorescence in situ hybridization analysis revealed the increase in amount of ammonia-oxidizing bacteria which existed in the outer edge of the granular sludge during the start-up period. This microbial ecological change would make it possible to attain high rate ammonia removal.

Effect of Adding Cognitively Demanding Tasks on Soccer Skill Performance

1992 ◽  
Vol 75 (3) ◽  
pp. 955-961 ◽  
Author(s):  
Matthew D. Smith ◽  
Craig J. Chamberlin
Keyword(s):  
Motor Task ◽  
Experimental Conditions ◽  
Secondary Tasks ◽  
Soccer Ball ◽  
Geometric Shapes ◽  
Functional Interference ◽  
Skill Performance ◽  
Dual Task Performance ◽  
Main Effects ◽  
Positive Effect

The effect of adding cognitively demanding elements to the performance of a real-world motor task in which functional interference among the elements in performance existed was investigated across level of expertise. The primary task involved running as quickly as possible through a 15.25-m slalom course. Two secondary tasks were used, dribbling of a soccer ball and identification of geometric shapes projected on a screen located at the end of the slalom course. 4 novice, 5 intermediate, and 5 expert female soccer players served as subjects and performed three trials each of three experimental conditions: running through the slalom course, running through the slalom course while dribbling a soccer ball, and running through the slalom course while dribbling a soccer ball and identifying geometric shapes. Analysis of variance using a 3 (experimental condition) × 3 (level of expertise) design gave significant main effects and a significant interaction. The latter indicated that, although the addition of cognitively demanding elements caused a decrement in performance, the amount of decrement decreased as level of expertise increased. It was concluded that structural interference between elements of performance decreased the positive effect of automation of one element on dual task performance.

Exploration of rapid start-up of the CANON process from activated sludge inoculum in a sequencing biofilm batch reactor (SBBR)

2015 ◽  
Vol 73 (3) ◽  
pp. 535-542 ◽  
Author(s):  
Yangfan Deng ◽  
Xiaoling Zhang ◽  
Ying Miao ◽  
Bo Hu
Keyword(s):  
Nitrogen Removal ◽  
Dna Analysis ◽  
Removal Rate ◽  
Batch Reactor ◽  
Ammonia Concentration ◽  
Nitrite Accumulation ◽  
Start Up ◽  
Fast Start ◽  
Total Nitrogen Removal ◽  
Canon Process

In this study, a laboratory-scale sequencing biofilm batch reactor (SBBR) was employed to explore a fast start-up of completely autotrophic nitrogen removal over nitrite (CANON) process. Partial nitrification was achieved by controlling free ammonia concentration and operating at above 30 °C; then the reactor was immediately operated with alternating periods of aerobiosis and anaerobiosis to start the anammox process. The CANON process was successfully achieved in less than 50 d, and the total-nitrogen removal efficiency and the nitrogen removal rate were 81% and 0.14 kg-N m−3 d−1 respectively. Afterwards, with the increasing of ammonium loading rate a maximum nitrogen removal rate of 0.39 kg-N m−3 d−1 was achieved on day 94. DNA analysis showed that ‘Candidatus Brocadia’ was the dominant anammox species and Nitrosomonas was the dominant aerobic ammonium-oxidizing bacteria in the CANON reactor. This study revealed that due to shortening the persistent and stable nitrite accumulation period the long start-up time of the CANON process can be significantly reduced.

Long-Term Traces of Tachistoscopic Word Perception

1967 ◽  
Vol 25 (1) ◽  
pp. 25-35
Author(s):  
Lee E. Doerries ◽  
E. Rae Harcum
Keyword(s):  
Critical Word ◽  
Word Perception ◽  
Experimental Task ◽  
Control Groups ◽  
Experimental Conditions ◽  
Consolidation Effect ◽  
First Time ◽  
Positive Effect ◽  
Special Control

Threshold durations were determined by the Method of Limits for a series of 8-letter nonsense words. For experimental Os the threshold for a critical word was obtained a second time after threshold determinations for 0, 1, 2, 4, or 8 different filler-words had intervened. For control Os no word was repeated in the series. Instructions introduced a set against seeing any word again after its threshold had been obtained the first time. The second threshold for a critical word was lower than the first for all experimental conditions; this effect could not be attributed to practice. The greatest effect occurred when 2 filler-words intervened. The positive effect after 8 words had intervened indicates that the trace was still present after 7 min. Greater threshold decrements for special control groups, for whom the interpolated activity was unrelated to the experimental task, indicate a consolidation effect on the trace under those conditions.

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