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1
Gormican, Stephen Joseph. "Water circulation, dissolved oxygen, and ammonia concentrations in fish-net cages." Thesis, University of British Columbia, 1989. http://hdl.handle.net/2429/27458.
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Fish farming in the protected waters of British Columbia is relatively new, but has undergone a phenomenal growth in the last ten years. Little investigation has been reported with respect to conditions within the net-cages employed in growing salmon at fish farms. In particular, the role of water quality and water exchange has not been examined in relation to local mariculture husbandry practices and hydrography.
The first part of this study compared water quality and water flow in two locations, one in Jervis Inlet with a deep entrance sill and the- other in Sechelt Inlet which has a shallow entrance sill. Marked variations in hydrography occurred between the two sites as a result of the differences in sill depth. An internal wave generated at the Sechelt Inlet sill caused daily fluctuations in stratification and hence water properties within the net-cages. No such variations were observed at the Jervis Inlet site.
In the second part of this study, water quality and water flow was_ measured in various locations in and near a raft of 24 net-cages. Generally, it was found that within the raft, water flow was diminished in those cages located downstream of the predominate flow direction. However, local topography was thought to have caused marked variation in water quality and water exchange patterns in two of the cages.
Ammonia concentrations were not observed to exceed reported sublethal concentrations at any time, over a 25 h period, at any of the depths sampled, within the net-cages. Dissolved oxygen concentrations did, at some depths and times, approach values at which some stress may be felt due to low oxygen.
Linear regressions between water quality and water speed were not found to be significant in most cases. The coefficient of determinations were low, indicating that current speed accounted for less than 27% of the variation in water quality.<br>Science, Faculty of<br>Zoology, Department of<br>Graduate
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Rumburg, Brian Paul. "Differential optical absorption spectroscopy (DOAS) measurements of atmospheric ammonia in the mid-ultraviolet from a dairy concentrations, emissions, and modeling /." Online access for everyone, 2006. http://www.dissertations.wsu.edu/Dissertations/Spring2006/b%5Frumburg%5F031006.pdf.
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Paz, Manzano Henry Alexander. "Use of ash and nitrogen concentrations in manure to estimate loss of ammonia over time." The Ohio State University, 2009. http://rave.ohiolink.edu/etdc/view?acc_num=osu1252691981.
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Yang, Fan. "Mesophilic anaerobic digestion conducted in single unit reactor at increasing ammonia concentrations." Thesis, Högskolan i Halmstad, Bio- och miljösystemforskning (BLESS), 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:hh:diva-16920.
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The use of mesophilic anaerobic digestion for treatment of organic wastes is a growing biotechnology for sustainable energy supply. Ammonia inhibition is a major problem in anaerobic digestion mainly when digestion of nitrogen-rich substrates such as livestock wastes and manure occurs. This paper provides a summary of research conducted on ammonia inhibition of the anaerobic process. An experiment with mesophilic digestions of swine manure was conducted in single unit reactors, which were controlled under different ammonia concentrations by addition of NH4Cl in different amounts. From the experimental results, it was shown that NH4Cl could be an effective chemical agent for removing foam and scum in the digester. Methane production was decreased with the increasing NH4Cl addition until a collapse was observed between 11.2 g NH4+-N/l and 13.2 g NH4+-N/l. Contrary to the findings in thermophilic digestion, a dysfunction of acidogenesis was also observed since both gas and methane production was delayed with increasing NH4Cl addition. These findings suggest different ammonia inhibition principles in mesophilic and thermophilic digestion. It was further indicated that methanogenesis could produce a high percentage of methane although gas production was inhibited.
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Tate, Paul. "Ammonia Sampling using Ogawa® Passive Samplers." Scholar Commons, 2002. http://purl.fcla.edu/fcla/etd/SFE0000021.
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Bembry, Earl Dan. "Comparison of Ammonia and Particulate Matter Air Sample Concentrations at Task-Locations within Swine Confinement Buildings." Digital Commons @ East Tennessee State University, 2009. https://dc.etsu.edu/etd/1880.
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Introduction: A task-associated analysis of ammonia and particulate matter concentrations was conducted on swine farms in breeding and gestation barns. The purpose of this study was to determine if specific tasks performed by workers increase concentrations of ammonia and particulate matter exposure.
Methods: An exploratory, descriptive design was used to determine if swine confinement workers have increased ammonia and particulate matter exposure when performing assigned tasks in breeding and gestation barns. A convenience sample of 8 workers volunteered from among all breeding and gestation workers (n=24). Data collection occurred in the morning at each of the 8 farms and continued until tasks were completed (~4 hrs). Analysis of covariance (ANCOVA) was computed to determine if the type of task or type of barn was related to workers' exposure to ammonia or particulate matter.
Results: Ammonia levels were below the sensitivity of the instrument (<0.1) except on 1 morning when the ammonia concentration was recorded at 8 ppm. However, concentrations above 0.1 ppm lasted for less than 5 minutes. Consequently, this variable was not included in the analysis. Correlation analysis was used to answer the 1st research question. The results suggested a statistically significant decrease in particulate matter as the number of operating fans increased. Analysis of covariance (ANCOVA) was used to answer the last 2 research questions. The results suggested a significant interactive effect between the type of confinement barn and the type of tasks workers were performing. The barn types differed by the number of exhaust fans and the type of animal waste disposal system.
Conclusions: Occupational health nurses can use study results to implement interventions to minimize worker exposures. These results indicate that understanding the relationship between building design and type of work tasks along with the importance of proper ventilation may minimize worker exposure to harmful particulate matter in SCBs during the summer months.
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Williams, Ischer Sarah Ashlee. "Evaluation of a sprinkler cooling system on inhalable dust and ammonia concentrations in broiler chicken production." Thesis, University of Iowa, 2016. https://ir.uiowa.edu/etd/3216.
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Indoor air contaminants such as dust and gases are present in concentrations that may be hazardous to worker health in poultry production. Poultry dust may contain inflammatory agents (e.g., endotoxin) and inhalation exposure has been associated with pulmonary symptoms. The current control practice to reduce worker exposure to poultry dust is the use of respiratory protection (e.g., filtering face-piece respirators). Limited research has been conducted to evaluate engineering controls to reduce dust concentrations in broiler chicken production. Therefore, the purpose of this research was to evaluate the effectiveness of a water sprinkling system to reduce inhalable dust and ammonia concentrations in a broiler chicken house.
Inhalable dust and ammonia concentrations were measured daily for the production cycle of a flock of broiler chickens (63 days). Inhalable dust was measured gravimetrically using an inhalable sampler and ammonia was measured by a direct reading sensor. Sampling was performed on a stationary mannequin inside two broiler chicken houses. One house used a sprinkler cooling system to deliver a water mist throughout the house and the second house was an untreated control. The sprinkler system activated 5 days after chicken placement and continued through day 63 of the broiler chicken production cycle. The following sprinkler activation program was used each hour from 6am to 10pm: days 5 – 9 five seconds, days 10 – 14 ten seconds, and days 15-63 for fifteen seconds.
Geometric mean (GM) inhalable dust concentrations collected in the treatment house (5.2 mg/m3) were lower than those found in the control house (6.0 mg/m3). The GM ammonia concentration within the treatment house was higher at 10.6 ppm (GSD: 1.80), compared to the control house (GM 9.51 ppm; GSD: 1.77). However, the observed differences were not statistically significant (p = 0.33 and p = 0.34, respectively).
Concentrations of inhalable dust were reduced by 11β when using the water sprinkling system, however the reduction was not statistically significant. The observed reduction in dust concentration was not sufficient to eliminate the need for respiratory protection.
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Iyathurai, Gunaretnam. "Effects of high protein diet intake, ammonia and urea concentrations on mid-luteal phase endometrial gene expression levels in post-partum dairy cows." Thesis, University of British Columbia, 2012. http://hdl.handle.net/2429/41979.
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Fertility in high producing dairy cows has been decreasing over decades. Elevated ammonia and urea levels in circulation and reproductive fluids due to high protein intake is one of the major contributory factors for decreasing fertility observed in dairy cows. The objectives of this study were to examine the effects of a) ammonia and urea, and b) high protein diet intake on the mRNA expression levels of mid-luteal phase endometrial candidate fertility genes in lactating dairy cows.
In experiment I, the mRNA levels of endometrial candidate genes were measured using qRT-PCR after treating the endometrial tissues (100mg/well) with different concentrations of ammonium chloride (0, 75, 150, 300, 600 μM) or urea (0, 4, 8, 12, 16 mM), in-vitro. A high concentration of ammonium chloride (600 μM) or urea (16 mM) decreased (P<0.05) the expression levels of FGF2 and IGFBP1 genes when compared to the control. However, a mild concentration of ammonium chloride (150 μM) or urea (4 mM) increased (P<0.05) the expression levels of HSPA1A, IGFBP3, SERPINA14 and BCL2 genes. The expression levels of IGF1 and BAX genes were not affected (P>0.05) by any of the ammonium chloride or urea concentrations tested.
In experiment II, the mRNA levels of the candidate genes were measured using qRT-PCR in the mid-luteal phase endometrium of post partum dairy cows fed with a high (17.3% DM) or a low (14.8% DM) protein diet. The mRNA levels of all genes tested except IL1A were not different (P>0.05) between the two groups. The mean number of small and large follicles, mean size of large follicles, mean size of CL, and the number of days to first ovulation were negatively affected by high protein diet intake. Milk analysis showed higher (P<0.05) MUN levels in the high protein group relative to that of low protein. Milk yield was not different (P>0.05) between the two groups.
I conclude from this study that the deleterious effect of excess dietary protein on dairy cow fertility may be due to alterations in follicular and CL dynamics and therefore embryo quality rather than any changes in the uterine environment.
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Abbott, William. "The Development of a Fluorescence-based Reverse Flow Injection Analysis (rFIA) Method for Quantifying Ammonium at Nanomolar Concentrations in Oligotrophic Seawater." Scholar Commons, 2015. http://scholarcommons.usf.edu/etd/5892.
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The goal of this thesis was to adopt a reverse flow injection analysis (rFIA) technique to the fluorometric analysis of the reaction o-phthaldialdehyde (OPA) with ammonium, allowing accurate measurements of ammonium concentrations lower than the detection limit of the widely used indophenol blue (IPB) colorimetric method while accounting for the background fluorescence of seawater. Ammonium is considered an essential nutrient for primary productivity, especially in the nutrient depleted surface ocean where as the most reduced form of dissolved inorganic nitrogen, it is readily assimilated via metabolic pathways. Challenges in the quantification of ammonium require more sensitive analytical techniques for a greater understanding of the biogeochemical cycling of ammonium in the oligotrophic ocean. On-line and automated flow analysis techniques are capable of mitigating some of the challenges. Fluorescent-based methods out-perform colorimetric methods in terms of detection limits and sensitivity. Presented here is the development of an rFIA technique paired with an OPA-sulfite chemistry. For this method, a sulfite-formaldehyde reagent is mixed with the sample stream and then injected with the OPA reagent before being heated. Fluorescence is measured before and at the peak of the OPA injection, differentiating the background fluorescence from the analyte signal. Experiments to optimize reaction parameters and characterize the effects of salinity and potentially interfering species were conducted. The newly developed method offers a reasonable throughput (18 samples per hour), low limit of detection (1.1 nM) ammonium analysis technique with automatic background fluorescence correction suitable for oligotrophic seawater as a preferable alternative to the low sensitivity and high limit of detection IPB colorimetric method.
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Alsouleman, Khulud [Verfasser], Michaela [Akademischer Betreuer] Dippold, Frank [Gutachter] Beneke, Michaela [Gutachter] Dippold, and Michael [Gutachter] Klocke. "Potential Impact of Increasing Ammonia Concentrations upon Microbial Population Dynamics in Anaerobic Meso- and Thermophilic driven Fermenters / Khulud Alsouleman ; Gutachter: Frank Beneke, Michaela Dippold, Michael Klocke ; Betreuer: Michaela Dippold." Göttingen : Niedersächsische Staats- und Universitätsbibliothek Göttingen, 2020. http://d-nb.info/1204255954/34.
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Reese, Emyrei. "Comparison of Agricultural Area Source Ammonia Gas Concentration and Flux Measurements." DigitalCommons@USU, 2010. https://digitalcommons.usu.edu/etd/543.
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This study was conducted in order to compare and evaluate a variety of ammonia (NH3) measurement techniques for determination of ambient gas phase concentration and evaluation of system fluxes. This was accomplished by measuring NH3 emitted from area sources within two dairies, one located in south-central Idaho and another in central California. The measurement techniques utilized included: an array of passive diffusion samplers, a single annular denuder system, a single or paired Fourier transform infrared spectrometer(s) (FTIR), a paired (upwind and downwind) set of differential optical absorption spectrometers (DOAS), and a portable wind tunnel in conjunction with a chemiluminescence monitor. The concentrations measured were manipulated by methods of inverse modeling using the ISCST3, AERMOD, and WindTrax models to yield estimated emission rates for individual sources, as well as an overall dairy emission rate. Furthermore, a comparison of the different techniques took place, and it was concluded that in the context of measuring agricultural area sources, the spectroscopy techniques, FTIR and DOAS, were likely the most desirable systems. This conclusion was based on the systems' ability to yield high precision, path integrated concentration measurements that do not require actual collection of sample. However, as long as a proper deployment scheme is utilized, the passive diffusion samplers also offered a viable option, especially when funding is limited.
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Wright, Patricia Anne. "Ammonia stores and excretion in fish : relationship to pH." Thesis, University of British Columbia, 1987. http://hdl.handle.net/2429/27654.
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The distribution and transfer of ammonia between intracellular and extracellular compartments of fish and the external water environment was investigated. In vivo and in vitro experiments were performed on the freshwater rainbow trout (Salmo gairdneri) and the intact, seawater lemon sole (Parophrys vetulus).
The distribution of ammonia and H⁺ ions were compared between red cells and plasma (in vivo and in vitro) taken from rainbow trout at rest and during hypercapnia. At rest (in vivo and in vitro) measured intracellular ammonia levels were equal to those predicted by the plasma to red cell pH gradient. The same was not true during hypercapnia, where measured red cell ammonia levels were greater than predicted levels. The addition of the Na⁺/K⁺ ATPase inhibitor, ouabain, had no effect on ammonia accumulation during hypercapnia. It was concluded that ammonia is passively distributed according to plasma-to-red cell H⁺ ion distribution in blood at resting pH values, but under hypercapnic conditions, ammonia accumulation must be due to some other active uptake mechanism.
The distribution of ammonia and ¹⁴C-DMO were compared in white muscle, heart, brain, red cells, and plasma of lemon sole (in vivo) at rest, during hypercapnia, and following exercise. The red cell ammonia distribution at rest and during an extracellular acidosis (hypercapnia and exercise) was similar to that found in rainbow trout. Red cells are unusual in that H⁺ ions are passively distributed according to membrane potential (Em), whereas in other tissues, this is not the case. In white muscle, heart, and brain under all experimental conditions, intracellular ammonia levels far exceeded those predicted by transmembrane pH gradients. Calculated ENH₄₊ values in these tissues were very close to published resting values of Em. It was concluded that NH₄₊ is permeable across cell membranes and that intracellular ammonia stores are not determined by transmembrane pH gradients in lemon sole.
The pH of interlamellar water was investigated in rainbow trout by following changes in the downstream pH of expired water using a stopped-flow method. As water flowed over the gills of control fish, there was a significant decrease in water pH. Acetazolamide (carbonic anhydrase (CA) inhibitor) added to the water increased the CO₂ disequilibrium, while CA eliminated the CO₂ disequilibrium relative to control water. Mucus excreted by the fish was found to contain CA activity by the pH-stat technique. It was concluded that water acidification is due to the conversion of excreted CO₂ to HCO₃₋ and H+ at the gill surface.
A possible function of CA at the external gill surface is to facilitate carbon dioxide and ammonia excretion. Acetazolamide or CA added to the water did not alter carbon dioxide (MCO₂) or ammonia (MAmm) excretion in intact rainbow trout. Methazolamide (CA inhibitor) or methazolamide + amiloride (Na⁺ uptake inhibitor) added to the water had no effect on plasma NH₃ tensions (PNH₃), but increased MAmm slightly compared to control fish. In general, methazolamide resulted in an increase in the diffusing capacity of ammonia. The interpretation of these results was complicated by the fact that rapid serial blood sampling resulted in a universal blood alkalosis. The intact resting fish is unsuitable for studying the interaction between water boundary layer chemistry and excretion across the gill.
With the blood-perfused trout head preparation it was demonstrated that MC0₂ and MAmm are linked through chemical reactions in the external water boundary layer adjacent to the gill. Pre-incubation of blood with acetazolamide reduced MC0₂ and MAMM in the blood-perfused head. Increasing the buffering capacity of inspired water, significantly reduced MAMM, but MC0₂ was unaffected. Each of these experimental treatments significantly reduced the acidification of ventilatory water flowing over the gills. It is proposed that the catalysed conversion of excreted C0₂ to form HCO₃₋ and H⁺ ions in the gill boundary layer provides a continual supply of H⁺ ions needed for the removal of NH₃ to NH₄₊, which reduces water NH₃ levels and facilitates ammonia excretion.
Gas transfer variables in the blood-perfused head preparation were compared to intact cannulated fish with and without oral masks. Oxygen uptake (MO₂) and MCO₂ were lower, and MAMM, higher in the blood-perfused head compared to in, vivo values. these discrepancies were due to differences in venous O₂,
CO₂, and ammonia levels, which determine mean gradients across
the gills. It was concluded that the blood-perfused head is a
suitable preparation for studying the interaction between MCO₂ and MAMM because the overall efficiency of transfer of NH₃ CO₂ was very similar between in. vitro and in vivo preparations,<br>Science, Faculty of<br>Zoology, Department of<br>Graduate
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Jantakananuruk, Nattikarn. "Performance, Temperature and Concentration Profiles in a Non-Isothermal Ammonia-Fueled Tubular SOFC." Digital WPI, 2019. https://digitalcommons.wpi.edu/etd-theses/1295.
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Ammonia has emerged as an attractive potential hydrogen carrier due to its extremely high energy density (hydrogen density), ease of storage and transportation as a liquid, and carbon-free nature. Direct utilization of ammonia in high-temperature solid oxide fuel cells (SOFCs) has been demonstrated over the past decade. Concurrence of in situ endothermic ammonia decomposition and exothermic electrochemical hydrogen oxidation permit efficient heat integration. In this study, the experimental analyses of axial temperature and concentration profiles along the tubular SOFC (t-SOFC) fed directly with ammonia are performed to investigate the coupled ammonia decomposition and hydrogen oxidation reactions as well as the effect of polarization. Fast ammonia decomposition over the Ni catalyst is evident at the inlet of t-SOFC and complete ammonia conversion is confirmed above 600ºC. It is found that direct ammonia-fueled t-SOFC and an equivalent hydrogen-nitrogen fueled t-SOFC provide identical performances. With 100 SCCM of ammonia fuel feed, a maximum power of 12.2 W and fuel utilization of 81% are obtained at 800ºC in a t-SOFC with active area of 32 cm2. The temperature and concentration profiles validate that the efficient heat integration inside ammonia-fueled t-SOFC is feasible if t-SOFC is operated at the temperature of 700ºC and below. The 23-hour performance test and SEM-EDS images of the fresh and used Ni-YSZ cermet surfaces confirm uniform performance and good durability of ammonia t-SOFC.
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Ilchenko, A. O. "Technology development of obtaining high concentration ammonia water and liquid multiple-nutrient fertilizers on its basis." Thesis, Sumy State University, 2017. http://essuir.sumdu.edu.ua/handle/123456789/63230.
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Decreasing of the crop productivity and falling-off in agricultural production make farmers in Ukraine look for a solution from the critical situation. The main factor of increasing productivity and effective land use is applying organic and mineral manure. The use of organic fertilizers is complicated by a sharp reduction in the number of livestock, and thus the number of organics as well. Farmers don’t have enough money to stock up with mineral fertilizers. According to the world experience, using liquid fertilizers is the most technologically and economically advantageous. They provide drastic fertilizer loss reduction, full mechanization of handling operations, high uniform soil fertilization and labor costs reduction.
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Levilly, Ronan. "Contribution au développement d'un analyseur continu d'ammoniac atmosphérique. Mesures de concentrations en région Bretagne." Rennes 1, 2003. http://www.theses.fr/2003REN10083.
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L'analyse de l'ammoniac atmosphérique peut être réalisée par de nombreuses techniques. Cependant, peu autorisent la mesure automatique et continue de concentrations de l'ordre du æg. M-3. C'est dans ce but que s'inscrit ce travail. Pour cela, la technique du "diffusion scrubber" a été retenue. Il s'agit d'une membrane tube alimentée d'un coté par un flux d'air et de l'autre par un flux de solution absorbante adéquate. En utilisant une solution acide, il est possible de collecter l'ammoniac puis de l'analyser par chromatographie ionique. Le seuil de détection de cette technique se situe au environ de 0,3 æg. M-3. Des mesures de concentrations en ammoniac atmosphérique ont été menées sur divers sites d'Ille et Vilaine et des Côtes d'Armor. Elles ont permis de montrer l'influence importante de la météorologie sur les concentrations, ainsi que les différences existantes entre des sites de fortes et de faibles émissions d'ammoniac. Ces travaux ont contribué à doter les instances de contrôle de la qualité de l'air breton d'un outil de mesure efficace et fiable pour la détermination de l'ammoniac atmosphérique et ont servi à relever les premières valeurs en ammoniac sur la région Bretagne.
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Meng, Yiyu. "Nitrite oxidising bacteria in soil : examination of the interactions with ammonia oxidisers and the influence of pH on their diversity and distribution." Thesis, University of Aberdeen, 2016. http://digitool.abdn.ac.uk:80/webclient/DeliveryManager?pid=231853.
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Nitrification is a central part of the nitrogen cycle, whereby the most reduced form, ammonia, is converted to the most oxidised form, nitrate via nitrite. The first step is performed by ammonia oxidising bacteria (AOB) and archaea (AOA), with the second step performed by nitrite oxidising bacteria (NOB). Although both groups are closely associated in nature, ammonia oxidisers have received more attention compared to NOB as ammonia oxidation is considered the rate-limiting step. Nitrobacter and Nitrospira are two important groups of soil NOB. To determine whether there are specific associations of AOA or AOB with certain NOB, the effect of organic and inorganic ammonia sources was tested by adding glutamate or ammonium sulphate to soil together with either 5% 12CO2 or 13CO2 to determined autotrophic growth by DNA-SIP. The results demonstrated that while the various ammonia and nitrite oxidisers responded differently, there was no direct evidence of specific coupled interactions. The effects of soil pH on Nitrobacter and Nitrospira was then investigated in a long-term pH gradient in an agricultural field. The results demonstrated that Nitrospira abundance was lower in acidic soils, whereas Nitrobacter abundance remained equally or more abundant. pH also influenced the relative distribution of Nitrobacter and Nitrospira populations, with distinct community structures at both high and low pH. The interaction of AOA and NOB was further investigated in a co-culture experiment, and demonstrated that the removal of nitrite and free nitrous acid NOB enhanced both rates and amounts of ammonia oxidised, indicating that in acidic environments these relationships may be particularly critical. Finally, the use of the compound PTIO was investigated for potential use in elucidating specific relationships between AOA and NOB. Results demonstrated a lack of specificity for the target group, and was unstable in soil, and therefore its use in soil should proceed with caution.
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Curfman, Christopher L. "Micellar properties of spermicidal and microbicidal quaternary ammonium surfactants." Thesis, This resource online, 1996. http://scholar.lib.vt.edu/theses/available/etd-03042009-041158/.
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Owusu-Agyeman, Isaac. "Systems for ammonium concentration for further removal in the partial nitritation/anammox technology." Thesis, KTH, VA-teknik, Vatten, Avlopp och Avfall, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-99356.
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Anammox is one of the main processes discovered quite recently for removal of ammonium from wastewater. Anammox process is cost effective, in that low energy and carbon source is needed. Partial nitritation is a perquisite for anammox in wastewater treatment for removal nitrogen and therefore partial nitritation/Anammox technology is studied substantially and applied in full-scale. However, the technology at present can only be used to treat high rich ammonium streams. Application of Anammox for treatment of low ammonium wastewater is not possible because of low yield of Anammox bacteria. The study aimed at devising strategies for using the Anammox technology to treat wastewater streams with low concentration of ammonium nitrogen. The objective was to get systems that could concentrate ammonium from low ammonium waste streams, so as to be able to treat it with partial nitritation/Anammox process. Two methods were used to concentrate ammonium: ion exchange and reverse osmosis. Ion exchange method was used to concentrate UASB effluents of about 24 - 40 mg NH4-N/l to 188 - 367 mg NH4-N/l respectively which is about 9 times the initial concentrations. At VRF 5, 163 mg NH4-N/l concentrate was attained from 41.8 mg NH4-N/l RO feed. Results also showed that concentrates from both methods are able to be treated with partial nitritation/Anammox technology. However it took more than 32 hours to complete treatment of ion exchange concentrates while it took less than 24 hours to finish the partial nitritation/Anammox process of RO concentrates. The longer time taken can be attributed to high salinity of the concentrates which is as a result of NaCl which was used for regeneration in ion exchange process. Both ion exchange and reverse osmosis are viable methods for concentrating ammonium from UASB effluents. Dissolved oxygen was very important factor that influenced the biological process.
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Awobusuyi, Tolulope David. "Concentration of Ammonium from Dilute Aqueous Solutions using Commercially Available Reverse Osmosis Membranes." Thesis, Université d'Ottawa / University of Ottawa, 2016. http://hdl.handle.net/10393/34642.
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Several commercially available reverse osmosis (RO) membranes were characterized with aqueous solutions of ammonium sulfate, potassium triphosphate, and mixtures of these two salts at different feed concentrations, compositions and pressures. The objective of this study was to investigate the rejection of these solutes, in particular the ammonium ion (NH4+), by different RO membranes. The aqueous solutions were assumed to come from an anaerobic digester via a process, currently under investigation by CHFour Biogas Inc., to maintain low concentrations of ammonia in the digester in order to maximize the biogas production. The ammonium ions present in the liquid produced from the process are then concentrated using membrane separation. The concentrated ammonium solution would be a valuable fertilizer that could be used by agriculture.
The membranes were characterized with three models: the solution-diffusion model, the Kedem-Katchalsky model, also known as the irreversible thermodynamics model, and the Donnan Steric Pore Model (DSPM). The solution-diffusion and irreversible thermodynamics models were found to be inadequate for proper membrane characterization and the use of the DSPM model yielded membrane properties in good agreement with those found in already existing literature. The pore radius of investigated membranes ranged from 0.39 to 0.51 nm. The effect of pH on membrane surface charge was also studied, with the conclusion that increases in pH led to increasingly negative surface charges. This affected the transport of individual ions through the membrane due to preferential passage of the counter-ions. The effects of applied pressure on the stoichiometric nature of salt rejections were also studied.
The minimal observed rejection from the range of experiments carried out using ammonium sulfate was 93%Non-stoichiometric rejections of ions were also observed in the experiments with single and multiple solutes. Furthermore, the rejection of ammonium ions in the presence of other ions (K+, SO42-, PO43-) increased as feed concentration increased, which was a result of the synergistic effects of feed pH and ionic interactions. The minimum NH4+ rejection in the presence of other ions was 95.4%, which suitability using RO membranes for concentration of ammonium from dilute aqueous solutions.
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Bischoff, Timothy William. "Ammonium production by Bipolaris maydis race T on L-asparagine and its relationship to pH /." The Ohio State University, 1986. http://rave.ohiolink.edu/etdc/view?acc_num=osu1487265555440415.
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Quaresma, FabrÃzia da Silva. "Lethal concentration (LC50-96h) and sublethal effects of un-ionized ammonia on haematological para parameters of fingerlings tambacu (Colossoma macropomum x Piaractus mesopotamicus)." Universidade Federal do CearÃ, 2016. http://www.teses.ufc.br/tde_busca/arquivo.php?codArquivo=16666.
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CoordenaÃÃo de AperfeiÃoamento de Pessoal de NÃvel Superior<br>A amÃnia à um composto tÃxico para os organismos aquÃticos e em elevadas concentraÃÃes na Ãgua pode causar diversas alteraÃÃes no animal. Dessa forma, torna-se importante determinar o limite de tolerÃncia dos animais aquÃticos cultivados à essa substÃncia. Sendo assim, o objetivo do trabalho foi determinar a concentraÃÃo letal mÃdia (CL50-96h) da amÃnia nÃo ionizada (NH3) em alevinos de tambacu (Colossoma macropomum x Piaractus mesopotamicus), em teste de toxicidade aguda e avaliar os efeitos de concentraÃÃes subletais atravÃs da anÃlise de parÃmetros hematÃlogicos. No teste de toxicidade aguda, os alevinos foram expostos à amÃnia, nas concentraÃÃes de: 0,09 (controle); 0,54; 1,23; 2,52; 3,44 e 3,66 mg L-1 NH3, que foram obtidas a partir da aplicaÃÃo de NH4Cl. O teste teve duraÃÃo de 96h e as mortalidades foram registradas ao longo desse perÃodo. A CL50 foi determinada pelo mÃtodo estatÃstico Trimmed Spearman Karber. No teste de exposiÃÃo subletal à amÃnia, utilizou-se as concentraÃÃes: 0,04 (controle), 0,19 e 0,35 mg L-1 NH3. Para anÃlise dos parÃmetros hematolÃgicos, foram realizadas coletas de sangue antes da adiÃÃo de NH4Cl (tempo zero) e apÃs 96h de exposiÃÃo. Os parÃmetros hematolÃgicos analisados foram: hematÃcrito (Ht), taxa de hemoglobina (Hb), nÃmero de eritrÃcitos (RBC), volume corpuscular mÃdio (VCM), hemoglobina corpuscular mÃdia (HCM) e concentraÃÃo de hemoglobina corpuscular mÃdia (CHCM). Os dados dos parÃmetros hematolÃgicos foram submetidos à anÃlise de variÃncia (ANOVA) e quando houve diferenÃa significativa entre os tratamentos, as mÃdias foram comparadas duas a duas atravÃs do teste de Tukey (α=0,05). A CL50-96h da amÃnia nÃo ionizada (NH3) para alevinos do hÃbrido tambacu foi 1,63 mg L-1. ApÃs exposiÃÃo de 96h a 0,35 mg L-1 NH3, os peixes apresentaram reduÃÃes significativas no Ht e VCM e aumento significativo na CHCM. Jà Hb, RBC e HCM nÃo diferiram significativamente entre os tratamentos e o tempo 0. A exposiÃÃo de alevinos de tambacu por curto perÃodo de tempo a 0,19 mg L-1 de amÃnia nÃo ionizada (NH3) nÃo causa alteraÃÃes significativas nos parÃmetros hematolÃgicos desses peixes.<br>Ammonia is a toxic compound to aquatic organisms and at high concentrations in the water can cause various changes in the animal. Therefore, it becomes important to determine the tolerance of farmed aquatic animals for that substance. Thus, the aim of this study was to determine the median lethal concentration (LC50-96h) of un-ionized ammonia (NH3) in fingerlings tambacu (Colossoma macropomum x Piaractus mesopotamicus) in acute toxicity test and evaluate the effects of concentrations sublethal through the analysis of hematological parameters. In the acute toxicity test,
the fingerl ings were exposed to ammonia at concentrations of: 0,09 (control); 0,54; 1,23; 2,52; 3
,44 and 3,66 mg L-1NH3, which were obtained from the application of NH4Cl. The test lasted 96 hours and mortalities were recorded over that period. The LC50 was determin ed by statistical method Trimmed Spearman Karber . In sublethal exposure to ammonia test concentrations used were : 0,04 (control), 0,19
and 0,35mg L-1NH3.For analysis of hematological parameters,
blood samples were collected before the addition of
NH4Cl(timezero) and after 96 hours of exposure.The
hematological parameters analyzed were: hematocrit (
Ht), hemoglobin(Hb), red blood cell count(RBC)
mean corpuscular volume (MCV), mean corpuscular
hemoglobin (MCH) and mean corpuscular hemoglobin
concentration(MCHC). Data hematological parameters
were subjected to analysis of variance (ANOVA)
and when there was a significant difference between treatments , the averages were compared in pairs
through the Tukey's HSD test (α=0,05).LC50-96h of theun
- ionized ammonia (NH3) to fingerlings the hybrid tambacu
was 1,63m g L-1. After 96h exposure to 0,35 mg L-1NH3, fish showed significant reductions in hematocrit and the
MCV and significant increase in MCHC. Already Hb,RBC and
MCH did not differ significantly between treatments and time 0. The exposure to fingerlins tambacu for short period
to 0,19 mg L -1 of un-ionized ammonia (NH3) does not cause significant changes in hematological parameters
of these fish.
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Grigorová, Eva. "Spectroscopic methods for concentration measurements and calibration of reactive gases." Thesis, Lille 1, 2010. http://www.theses.fr/2010LIL10152/document.
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Le sujet de ma thèse concerne l´application des méthodes spectroscopiques utilisées pour la détection et la mesure de concentration de différentes espèces intéressantes du point de vue de leur réactivité et pour leur rôle dans des domaines très variés comme en chimie atmosphérique, en astrochimie ou encore dans le corps humain. Pour la première fois l´analyse de la bande de vibration asymétrique v4 du radical FCO2 a été effectuée ainsi que celle de la bande v2 . FCO2 est un des produits intermédiaires importants dans les processus de dégradation des carbures d´halogène. Ce travail à conduit à la détermination précise des constantes moléculaires (y compris celles de structure fine) des deux bandes de vibration.Nous avons également effectué l´identification de l´ion radicalaire CS+ par spectroscopie millimétrique, dans la gamme de fréquence 414 - 622 GHz. L´analyse globale avec les données infrarouges disponibles a permis de déterminer précisément les valeurs de la constante de rotation et de la constante de structure fine. J’ai ensuite effectué la mesure des spectres des cyanures BrCN et CH3CN par spectroscopie infrarouge à transformée de Fourier. J´ai aussi étudié la réactivité de ces molécules ainsi que leurs produits de décomposition dans un plasma à basse température. Finalement, j´ai étudié l´impact écologique de l´ammoniaque sur l´environnement ainsi que le rôle des arbres sur la concentration en ammoniaque atmosphérique. Une cuve opto-acoustique a ainsi été conçue pour mesurer les concentrations de l´ammoniaque et d´autres gaz présents en très faible quantité<br>Description of the work is divided into four thematic parts describing four independently performed experiments. The analyses of the asymmetrical vibration ν4 band and the symmetrical ν2 band of the FCO2 radical, that belong to significant intermediate products of degradation processes of halogen hydrocarbons, were performed for the first time within this work. The detailed analysis led to the determination of the rotational constants, centrifugal distortion constants and fine structure constants for both bands. For the first time we performed the unambiguous identification of the radical ion CS+ by high resolution millimetrewave spectroscopy in the frequency range 414 - 622 GHz. The complex analysis allowed us to accurately determine the values of the rotational constant as well as the fine structure constant. Experiments were also perform to measure spectra of cyan BrCN and CH3CN using time resolved Fourier transform infrared spectroscopy. These molecules as well as their disintegration products in the low temperature plasma environment were carefully studied. Finally, I have studied the ecological impact of ammonia (NH3) on the environment and the influence of trees on the amount of ammonia in the air. For this purpose, an optoacoustic cell was designed and assembled to measure trace amounts of ammonia and other gaseous substances
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Wedeinge, Josef. "The effect of quick freezing and fast thawing on stored seawater nutrient concentrations of dissolved inorganic phosphate, nitrate and ammonium." Master's thesis, University of Cape Town, 2004. http://hdl.handle.net/11427/6446.
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Includes bibliographical references (leaves 43-44).<br>In an attempt to improve the quality of preserving seawater nutrients for delayed analyses, a sample of unfiltered and aged nutrient-depleted seawater was obtained from Marine and Coastal Management (M&CM) and spiked with small different volumes of standard nutrient solutions. These were prepared into 100 mL glass bottles to constitute the lowest, intermediate and highest levels of dissolved inorganic phosphate (0.5, 1.5, 3.0 μM), nitrate (5, 15 and 30 μM) and ammonium (0.5, 1.5, 2.5 μM) that are found in the southern Benguela region. After spiking, the samples were analysed to determine their "true" initial concentrations and immediately quick frozen using liquid nitrogen. A time series analysis (up to seven weeks) was performed by first fast-thawing the samples using a microwave oven and fixing up the nutrients within 20 minutes. Variations in nutrient concentrations did not exceed 7% for phosphate, 4.0% for nitrate at all levels and 8% for ammonium at the intermediate and highest levels, but varied by 19.2% at the lowest level. Statistical tests for significance of the means were made at a = 0.05 level and no difference was found at any level for the nitrate, and the lowest level phosphate. The higher levels of phosphate, and all ammonium were found to be significantly different. Hence, the experimental conditions employed in this paper would not be recommended for the all ammonium and the higher levels of phosphate concentrations. These variations were however not large or regular in pattern but erratic, which suggested that they were not due to microorganisms and optimizing those conditions may well to yield improved results.
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Morris, Raymond Anthony. "Investigation of the Optimal Dissolved CO2 Concentration and pH Combination for the Growth of Nitrifying Bacteria." Scholar Commons, 2011. http://scholarcommons.usf.edu/etd/3256.
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Ammonium (NH4+) is a biological nutrient that is transformed in a wastewater treatment plant (WWTP) in a process called activated sludge. This is accomplished in an aerobic environment using microorganisms and inorganic carbon that convert the ammonium to nitrate (NO3-). This process is termed nitrification. Removal of ammonium is necessary due to its oxygen demand and toxicity to the environment.
Nitrification is considered a slow process due to the slow growth rate of the nitrifying bacteria. Ammonia oxidizing bacteria (AOB) first covert the ammonium (NH4+) to nitrite (NO2-) followed by conversion to nitrate (NO3-) by nitrite oxidizing bacteria (NOB). These slow rates limit the treatment capacity of the WWTP.
The initial hypothesis suggested that these slow rates were due to limited carbon in the aeration basin of a WWTP. A series of designed experiments and observational studies revealed substantial dissolved CO2 exists throughout a WWTP. Based on these findings, the central research focused on determining if an optimum dissolved CO2 concentration/ pH combination exists that maximizes nitrification.
Experimentation conducted at a pH of 7.0 and varying concentrations of dissolved CO2 concentration revealed inhibition at low (<5 mg/l) and high (>30 mg/l) dissolved CO2 concentration levels. Further research found that optimum nitrification can be attained in a dissolved CO2 concentration range of 10 - 15 mg/l and a pH range of 7.5 - 8.0. A maximum specific growth rate of 1.05 - 1.15 days-1 was achieved. A partitioning of the sums of squares from these designed experiments found that pH accounts for approximately 83 percent of the sums of squares due to treatment with the dissolved CO2 concentration accounting for 17 percent. This suggests that pH is the dominant factor affecting nitrification when dissolved CO2 concentration is optimized.
Analysis of the growth kinetics for two of the designed experiments was conducted. However, a set of parameters could not be found that described growth conditions for all operating conditions. Evaluating the results from these two experiments may suggest that a microbial population shift occurred between 16 and 19 mg/l of dissolved CO2 concentration. These dissolved CO2 concentrations represent pH values of 7.1 and 7.0, respectively, and were compared to experimentation conducted at a pH of 7.0. Though the pH difference is minor, in combination with the elevated dissolved CO2 concentration, a microbial shift was hypothesized.
Microbial samples were collected from the designed experiment that optimized dissolved CO2 concentration (5, 10 and 15 mg/l) and pH (6.5, 7.0, 7.5 and 8.0). These samples were evaluated using Fluorescence in situ hybridizations (FISH) to determine the population density of common ammonium oxidizing bacteria (AOB) (Nitrosomonas and Nitrosospira) and nitrite oxidizing bacteria (NOB) Nitrobacter and Nitrospirae). The dominant AOB and NOB microbes were found to be Nitrosomonas and Nitrospirae.
These results suggest that increased nitrification rates can be achieved by incorporating appropriate controls in a wastewater treatment plant (WWTP). With higher nitrification rates, lower nitrogen values can be obtained which will reduce the WWTP effluent nitrogen concentration. Conversely, these increased nitrification rates can also reduce the volume of an aeration basin given similar effluent nitrogen concentrations.
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Fuska, Jana. "The effect of ammonium chloride and leupeptin on the concentration of prosaposin in endosomes and lysosomes of Marshall cells." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1998. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape10/PQDD_0025/MQ50770.pdf.
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Armstrong, Christen Taylor. "Nitrogen Isotope Fractionation and Toxin Production during The Uptake of Micromolar Concentrations of Nitrate, Ammonium, and Urea By A Marine Dinoflagellate." W&M ScholarWorks, 2017. https://scholarworks.wm.edu/etd/1499449867.
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Despite an increased global interest in harmful algal bloom (HAB) species and eutrophication, the relationship between nutrient sources and changes in species composition or toxicity remains unclear. Stable isotopes are routinely used to identify and track nitrogen (N) sources to water bodies, as sources can be differentiated based on stable isotope values. While literature is available describing N fractionation by diatoms and coccolithophores, data are greatly lacking regarding isotope fractionation by dinoflagellates. Here we investigate the fractionation of nitrogen isotopes by saxitoxin-producing Alexandrium fundyense, to validate the use of the δ15N of particulate organic matter and identify the nitrogen source fueling a dinoflagellate bloom and its toxicity. The effects of N chemical form on isotope fractionation, toxin content, and toxicity, were investigated using isolates in single-N and mixed-N experiments. Growth on NO3-, NH4+, or urea, resulted in isotope fractionation of 2.761.48‰, 29.019.32‰, or 0.340.19‰, respectively, with the lowest cellular toxicity and toxin quotas reported during urea utilization. Toxin composition and growth rates, however, remained constant across all N treatments, showing no effects of NO3-, NH4+, or urea utilization. Alexandrium fundyense was then preconditioned to either NO3-, NH4+, or urea, and abruptly inoculated into mixed-N medium containing all three chemical forms. All treatments initially utilized NH4+ and urea upon inoculation into mixed medium, suggesting no effect of preconditioning. Cells only began utilizing NO3- after NH4+ decreased below 2-4 M in the medium. During the inhibition of NO3- uptake by NH4+ utilization, the cellular δ15N was at its lowest (-5‰), and through the course of the experiment, the δ15N continuously changed to mimic the isotope value of the most recent N source(s) being utilized. When utilizing multiple sources, the isotope signature of the cells fell between the signal of the two N sources. Together this suggests that in NO3- and urea rich environments, the 15NPOM would reliably look like the source or sources of nitrogen utilized, but that caution should be taken in NH4+ rich environments where the large value could lead to misinterpretation of the signal. Nutrients are only one factor influencing bloom dynamics, but information about the relative importance of natural or anthropogenic nutrients in the development and toxicity of bloom events is necessary to predict future shifts in phytoplankton species composition, density, and toxicity.
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Zaidi, Syed Faraz Ali, and Juthatip Sudthanom. "To Analyze The Relationship between BOD, Nitrogen And Phosphorus Contents at Constant Dissolved Oxygen Concentration In Municipal Wastewater Treatment." Thesis, Mälardalens högskola, Akademin för hållbar samhälls- och teknikutveckling, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:mdh:diva-12524.
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In this report, the application of Principle Component Analysis (PCA) and Partial Least Square (PLS) regression analyzing methods used to understand the relationship of interdependent loads in municipal wastewater treatment plant. Two different wastewater treatment plants were chosen for analysis of the relationship between interdependent loads. Firstly, the collected data of incoming wastewater and outgoing water from both Västerås and Eskilstuna wastewater treatment plants were analyzed to find some relationship or correlation between contents and compare the data of both the plants. Secondly, the correlated contents were used to generate the regression model for predicting the value in the future, in this report we have focussed only on ammonium nitrogen value for regression model. The PCA study shows the variation between incoming and outgoing wastewater’s characteristics given by Västerås and Eskilstuna plant.<br>BOD, ammonium nitrogen, nitrogen, phosphorus
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Pribadi, Tri Dewi K. [Verfasser], Kai [Akademischer Betreuer] Bischof, and Christian [Akademischer Betreuer] Wiencke. "Macroalgal Ecophysiology in Response to High Ammonium Concentrations and Different Irradiances / Tri Dewi K. Pribadi. Gutachter: Kai Bischof ; Christian Wiencke. Betreuer: Kai Bischof." Bremen : Staats- und Universitätsbibliothek Bremen, 2012. http://d-nb.info/1071994107/34.
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Buffet-Bataillon, Sylvie. "Relation épidémiologique et génétique entre la résistance aux antibiotiques et des concentrations minimales inhibitrices élevées d'Escherichia coli isolés de bactériémies vis-à-vis d'ammoniums quaternaires." Rennes 1, 2011. http://www.theses.fr/2011REN1B085.
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Les ammoniums quaternaires (AQs) sont utilisés comme conservateur, rentrant dans la composition des produits cosmétiques et pharmaceutiques. Ils sont également largement utilisés comme détergents-désinfectants. L’utilisation croissante des AQs pourrait être un des facteurs responsable de l’émergence de la multirésistance de souches bactériennes cliniques. Une étude prospective a été ainsi menée chez 153 patients atteints de bactériémies à Escherichia coli au CHU de Rennes. Cette étude a montré un lien épidémiologique entre des valeurs elevés de concentrations minimales inhibitrices (CMI) d’E. Coli aux AQs et la résistance aux antibiotiques (ATB). Secondairement, les mécanismes de co-résistance ont été étudié montrant l’implication cumulée des intégrons de classe 1, de la pompe d’efflux AcrAB-TolC et du régulon mar chez des souches d’E. Coli à la fois résistantes aux ATB et présentant des CMI élevées aux AQs. Une revue a enfin rapporté le rôle des AQs dans l’acquisition de la résistance aux antibiotiques. Il apparait important que ce mécanisme puisse être mis en évidence par les laboratoires de microbiologie<br>Quaternary ammonium compounds (QACs) are used as a preservative in the composition of cosmetics and pharmaceuticals products. They are also widely used as detergents, disinfectants. The increasing use of AQs may be one factor responsible for the emergence of multidrug resistance in clinical bacterial strains. A prospective study was conducted in 153 patients with Escherichia coli bacteremia at the University Hospital of Rennes. This study showed an epidemiological link between high values of minimum inhibitory concentrations (MIC) of QACs in E. Coli and resistance to antibiotics (ATB). Secondarily, the mechanisms of co-resistance has been studied showing the involvement of the Class 1 integrons, the AcrAB multi-drug efflux pump and mar regulon in E. Coli strains resistant to ATB and with high MICs of QACs. A review finally reported the role of QACs in the acquisition of antibiotic resistance. It appears important that this mechanism can be identified by microbiology laboratories
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Skėrytė, Neringa. "Dirvinio ir karčiojo kiečių biologinės charakteristikos nevienodos amoniakinės taršos vietose." Master's thesis, Lithuanian Academic Libraries Network (LABT), 2009. http://vddb.library.lt/obj/LT-eLABa-0001:E.02~2009~D_20090615_114507-84848.
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Magistro darbe tiriama dirvinio ir karčiojo kiečių biologinės cherakteristikos nevienodos amoniakinės taršos vietose.
Darbo tema: Dirvinio ir karčiojo (pelyno) kiečių biologinės charakteristikos nevienodos amoniakinės taršos vietose
Darbo objektas - dirvinis kietis ir pelynas - paplitę Lietuvoje augalai, pasižymintys gausiomis vaistingomis medžiagomis - eteriniais aliejais ir flavonoidais.
Darbo tikslas - nustatyti skirtingų (AB "Achema" atžvilgiu) vietų karčiojo kiečio, pelyno (Artemisia absinthum L.) ir dirvinio kiečio (Artemisia campestris L.) fiziologines-biochemines savybes.
Darbo metodai - Kjeldalio metodas azoto nustatymui, atominės absorbcijos spektroskopija sunkiųjų metalų nustatymui. Salsburo ir sojos agaras mikroorganizmų auginimui.
Darbo rezultatai - ištirtos tokios dviejų rūšių kiečių fiziologinės-biocheminės savybės: dirvožemio azoto ir sunkiųjų metalų koncentracija, kiečių įvairių organų masė, kiečių įvairių organų azoto koncentracija, kiečių antžeminių organų flavonoidų koncentracija, kiečių epifitinių mikroorganizmų skaičius, įvertinta kaip oro amoniakinė tarša ir dirvožemio tarša sunkiaisiais metalais reikšmingai įtakoja ištirtus kiečių fiziologinius rodiklius. Atlikti tyrimai parodė, kad dirvožemio ir abiejų rūšių augalų azoto koncentracija išsidėsto tokia tvarka: dirvožemio < stiebų < lapų < žiedų < skrotelių. Tirtos vietos pagal dirvožemio ar organų azoto koncentraciją nesiskyrė. Didžiausios dirvožemio sunkiųjų metalų koncentracijos nustatytos abiejų... [toliau žr. visą tekstą]<br>Topic of the master degree diploma: Various biological parameters of Artemisia absinthum L. and Artemisia campestris L. growing in the areas effected by different level pollution by ammonia. Artemisia absinthum L. and Artemisia campestris L. are common wild growing species in Lithuania. Despite these species are rich in flavonoids and essential oils till now in our country biology and biochemistry of these species have not received bigger attention.
Present work aimed at evaluation of Artemisia absinthum L. and Artemisia campestris L. physiological-biochemical parameters depending on sampling site distance from the nitrogen fertilizer factory.
Methods. Following physiological-biochemical parameters of these species were analysed: soil nitrogen and heavy metal concentrations, dry mass and nitrogen concentration of various organs of selected plant species, abundance of epiphytic microflora.
Results. During vegetation period sampling was performed three times: in July, 2; July, 24, and September, 24. Obtained parameters were evaluated in respect of aerial ammonia pollution and heavy metal pollution of the soil. Present study showed that nitrogen concentration of the soil and various organs of both Artemisia species fell into following ascending order: soil < stems < leaves < inflorescences and fruits < rosettes. Between selected sites no differences were observed according to the soil and plant nitrogen concentration. The highest concentrations of heavy metals were observed... [to full text]
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El, Rhess Es-Saïd. "Synthèse, mode de croissance et caractérisations physico-chimiques de microparticules monodispersés de silice dans le système SI(OC : :(2)h::(5))::(4)-nh::(3)-h::(2)o-roh." Besançon, 1988. http://www.theses.fr/1988BESA2023.
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Preparation de microparticules de silice a partir du precurseur organometallique si(oc::(2)h::(5))::(4). Etude de l'influence de la temperature et de la concentration en nh::(3) et roh sur la dimension des particules
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Nyström, Stephanie, and Elias Bäckström. "Ämnestransport i Tomtaåns avrinningsområde : Inverkan av Hovgårdens avfallsanläggning och diffusa utsläpp." Thesis, Uppsala universitet, Institutionen för geovetenskaper, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-296195.
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The chemistry of a stream is the result of different transport routes of the precipitation and the processes it undergoes in the catchment area to the stream. The transport route can involve natural processes in the ground, called diffuse sources, or some more anthropogenic sources titled point sources. In the stream, this chemistry is affected by dilution and different sources and sinks of substances. From Hovgårdens waste facility, a point source situated in Tomtaåns water catchment (20 km NE of Uppsala), waste water is released in the nearby Hovgårdsbäcken stream, bringing various metals, salts and nutrient salts. This is then transported to Lissån stream and further on to Tomtaån stream. Before connecting to Lissån, Tomtaån flows through a rural landscape without known larger point sources. This project has two purposes, one is to investigate if substance concentrations in the water changes on its transport along Hovgårdsbäcken, Lissån and Tomtaån streams and why. The other is to determine whether the mass transport from Tomtaån stream is significant for the water chemistry compared to Lissån stream. This project is based on substance concentrations measured by Uppsala Vatten AB from 2009-2014 and the writers’ own measurements from spring of 2016. The substances concerned in this project are N-tot, P-tot, NH4+, PO43-, Fe, SO42-, NO3-. The samplings made by Uppsala Vatten AB does not include Tomtaån upstream the inflow from Lissån. To obtain the size of the mass transport of Tomtaån, modelled substance concentrations along with surface types from GIS have been used. A mass balance was then calculated. The reliability of these values are then discussed. The own measurements included discharge measurements and water sampling to carry out analysis of pH, alkalinity as well as anions Cl-, SO42- and NO3-. The results showed that for Fe, P-tot and PO43-, the values were peaking after the inflow of Lissån to Tomtaån, meaning that these ones come in higher values from Tomtaån than Hovgården. N-tot, NH4+ and SO42- decrease in concentration along the transport which indicates the opposite for Fe, P-tot and PO43-. The mass transport calculated with the modelled values indicates an absurd deficit, which brings the conclusion that these are not reliable.<br>Ett vattendrags kemi är ett resultat av nederbördens olika transportvägar och dess processer i avrinningsområdet. Transportvägen kan innefatta naturliga processer i mark, så kallade diffusa utsläpp, och mer antropogena källor som har en bestämd utsläppspunkt, vilka benämns som punktkällor. Väl i vattendraget påverkar utspädning, källor och sänkor ämnenas halter. Från Hovgårdens avfallsanläggning, en punktkälla som ligger i Tomtaåns avrinningsområde (2 mil nordost om Uppsala), rinner avfallsvatten ut i den närliggande Hovgårdsbäcken med en rad olika typer av metaller, salter och närsalter. Detta transporteras vidare till Lissån vars flöde går ihop med Tomtaån. Tomtaån rinner innan sammanflöde med Lissån genom ett jordbrukslandskap utan större kända punktkällor men där diffusa utsläppskällor kommer till uttryck. Projektet har två syften, det ena är att undersöka om ämneshalterna i vattnet på sin transport längsmed Hovgårdsbäcken, Lissån och Tomtaån förändras och varför. Det andra är att slå fast om masstransporten från Tomtaån är betydande för vattenkemin jämfört med Lissån. Till grund för projektet ligger ämneshalter tagna vid olika punkter av Uppsala Vatten AB år 2009-2014 respektive prover tagna av författarna våren 2016. Ämnen som ligger i fokus är; N-tot, P-tot, NH4+, PO43-, Fe, SO42-, NO3-. Uppsala Vattens provtagningar innefattar inte Tomtaån uppströms. För att få fram storleken på Tomtaåns masstransport, har istället schablonvärden och markanvändningsareor tagna ur GIS använts. Med dessa schablonvärden och de empiriskt uppmätta halterna från Uppsala Vatten har massbalansberäkningen sedan gjorts. Vi kommer föra en diskussion om denna metod var tillförlitlig eller ej. Av författarna mättes vattenföring och vattenprover togs, vilka analyserades för pH och alkalinitet såväl som anjonerna: Cl-, SO42- and NO3-. Resultatet visade att ämneshalterna för Fe, P-tot and PO43- var högst efter Lissåns inflöde med Tomtaån. Vilken betyder att vattenkemin påverkas mer av Tomtaån än Hovgården. Resterande ämnen minskar i halt längsmed transporten, Hovgården bidrar med högst ämneshalt och Tomtaån påverkar vattenkemin genom utspädning. Masstransporten beräknad med schablonvärden indikerar ett massivt orimligt underskott, bedömningen är att schablonhalter ej är tillförlitliga.
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Berlot, Isabelle. "Synthèse, caractérisation et étude électrochimique de tensioactifs dérivés du pyrrole." Université Joseph Fourier (Grenoble), 1998. http://www.theses.fr/1998GRE10087.
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Ce memoire est consacre a la synthese, la caracterisation et l'etude electrochimique de nouveaux tensioactifs derives du pyrrole, analogues du dodecyltrimethylammonium et associes aux contre-ions br#-, no#-#3, tso#-, bf#-#4. La plupart forment des micelles en solution aqueuse. Une electrode selective du cation dodecyltrimethylammonium a ete utilisee pour determiner leurs concentrations micellaires critiques (cmc). Nous avons aussi montre que la voltammetrie cyclique permet dans certains cas de determiner la cmc en milieu electrolytique, en depit du caractere irreversible de l'oxydation de la sonde redox que constitue le pyrrole. On constate que l'introduction d'un motif pyrrole a l'extremite de la chaine hydrocarbonee (series a1 et a2) ne modifie pas la cmc de ces tensioactifs par rapport a leurs analogues sans pyrrole. Par contre si le pyrrole est situe sur la tete polaire (serie b1), leur cmc est plus basse. L'etude par rmn#1h a eclaire ces constatations, en precisant la localisation des divers groupements dans la micelle : le pyrrole se place dans le cur hydrophobe dans le cas des a1 et a2, alors qu'il se replie vers l'interieur de la micelle pres de la tete polaire pour les b1. Dans le cas particulier des tensioactifs associes a l'anion tosylate, nous avons constate que le tosylate penetre dans la micelle et s'intercale entre les groupes ammonium. L'etude electroanalytique a montre que ces composes s'adsorbent fortement sur carbone et que des films de polypyrrole peuvent croitre sur ces electrodes par electrooxydation de solutions micellaires. Ces films sont electroinactifs, mais d'epaisseurs significatives (20 a 1000 couches monomoleculaires). Les rendements de depots sont faibles (5 a 10%) dans le cas des a1 et a2, mais nettement plus importants (50%) dans le cas des b1. L'electropolymerisation de solutions micellaires des series a1 et a2 conduit majoritairement a la formation d'oligomeres solubles, de type polypyrrole suroxyde.
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Bate, Bate. "Engineering behavior of fine-grained soils modified with a controlled organic phase." Diss., Georgia Institute of Technology, 2010. http://hdl.handle.net/1853/39627.
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Organic materials are ubiquitous in the geologic environment, and can exert significant influence over the interfacial properties of minerals. However, due to the complexity in their structure and interaction with soil solids, their impact has remained relatively unquantified. This study investigated the engineering behaviors of organoclays, which were synthesized in the laboratory using naturally occurring clay minerals and quaternary ammonium compounds of controlled structure and density of loading. Organic cations were chosen to study the effects of functional group structure and size.
The laboratory investigation showed that the presence of the organic cations on the mineral surfaces led to increased hydrophobicity of all clays tested. Conduction studies on the electrical, hydraulic, and thermal properties of the organoclay composites suggested that increasing the total organic carbon content resulted in decreased electrical and thermal conductivity, but increased hydraulic conductivity, due to the reduced swelling of the base clay mineral phase. Electrokinetic properties of the organoclays illustrated that compared with the clay's naturally occurring inorganic cations, exchanged quaternary ammonium cations were more likely bound within a particle's shear plane. Consequently, organoclays had less negative zeta potential than that of unmodified bentonite. Increasing the length of one carbon tail was more effective at binding organic cations within the shear plane than increasing the size of the cation, when compared on the basis of total organic carbon content.
In terms of large strain strength, the modified organic clays exhibited increased shear strength, in part owing to the reduction in water content caused by the presence of the hydrophobic organic layering. Shear strength increased with single carbon tail length or with cation size, although the latter effect tended to reach a plateau as the length of the four short cation tails increased from 2 to 4. In terms of small strain behavior, the shear modulus was shown to be a function of the total organic carbon content. It is believed that number of particle contacts increased as the organic carbon content increased. Stiffness increased as either the size of the cation or the total organic carbon content was increased. Damping also increased as the organic loading was increased, with the organic phase acting as an energy dissipation mechanism.
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Nordström, Albin. "Denitrification in a Low Temperature Bioreactor System : Laboratory column studies." Thesis, Uppsala universitet, Institutionen för geovetenskaper, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-226585.
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Denitrification is a microbially-catalyzed reaction which reduces nitrate to N2 through a series of intermediate nitrogen compounds. Nitrate is a nutrient and its release into the environment may lead to eutrophication, depending on the amount that is released and the state of the recipient. The release of nitrate from the mining industry in Kiruna (Sweden) has been identified as an eutrophication risk, and a denitrifying bioreactor is to be constructed at the site to reduce the nitrate release.Since the denitrification rate decreases with temperature and the temperature in Kiruna during large parts of the year drops below 0˚C, the denitrifying bioreactor therefore has to be designed for the site-specific environment in terms of flow rate and hydraulic residence time. Laboratory column studies are used to study and determine the nitrate removal rate in a low temperature environment (5˚C) with pine wood chips as reactive matrix/ electron donor; the input solution had an average concentration of 35 mg NO3-N/L and a high sulfate concentration. Nitrate removal was studied as a function of hydraulic residence time and temperature. Parameters that were monitored include pH, alkalinity and concentrations of ammonium, nitrite and sulfate in the effluent from the columns. On three occasions, samples were gathered along the flow path in the columns (concentration profiles) such that changes in nitrate, nitrite, and occasionally ammonium concentration could be studied in relation to each other. The study concluded that a denitrifying bioreactor utilizing pine wood chips as the reactive matrix is a suitable option for nitrate treatment in a low temperature (5˚C) environment. Under the conditions of the study, effluent nitrate, nitrite, and ammonium concentrations are below limits established in legislation. Nitrate removal rates are given for zero-order nitrate reduction and overall first-order nitrate reduction, as the concentration profiles revealed a decrease in nitrate removal rate as nitrate concentration dropped below 3 mg NO3-N/L.<br>Nitrat är ett näringsämne som kan orsaka övergödning vid utsläpp, beroende på halterna och recipienten. Växterna som tar upp kväve kommer så småningom att dö och sjunka mot botten där de förmultnar. Förmultningen kräver syre, och vid ökad växtlighet så ökar även konsumtionen av syre då det finns mer organiskt material att bryta ned. Detta leder i slutändan till syrefria områden, där djurliv och växtlighet är mer begränsade. Nitratutsläpp från gruvindustrin i Kiruna har blivit identifierad som en potentiell övergödningsrisk och en denitrifierande bioreaktor ska därmed installeras för att minska utsläppen. Denitrifikation är en mikrobiell reaktion som reducerar nitrat till kvävgas genom en serie av intermediära kväveföreningar. En denitrifierande bioreaktor använder sig utav denitrifikation för att minska nitratkoncentrationer i vatten som passerar genom bioreaktorn som består av huvudsakligen; (1) bakterierna som sköter denitrifikationen, och (2) en kolkälla som fungerar som ”mat” till de denitrifierande bakterierna, Hastigheten varvid nitrat omvandlas till kvävgas genom denitrifikation, minskar med temperatur och den denitrifierande bioreaktorn måste därmed anpassas till omgivningen där den ska placeras med avseende på uppehållstid i reaktorn. Uppehållstiden måste vara tillräcklig för att minska nitratkoncentrationen till önskad nivå, men samtidigt så får uppehållstiden inte vara för lång då andra ämnen kan reagera och bilda ofördelaktiga produkter vid låga nitratkoncentrationer. Kolonnstudier i en låg-tempererad miljö (5˚C) är ett första steg för att studera hastigheten av nitratförbrukning i en sådan omgivning, och används i detta arbete med träflis av tall som kolkälla. Parametrar som påverkar, och varierar som ett resultat av, denitrifikation (exempelvis pH och sekundära föroreningar) övervakas. Hastigheten av nitratförbrukning som fås från kolonnstudierna kan sedan används som riktlinjer för konstruktionen av en denitrifierande bioreaktor i fältskala i Kiruna. Studiens slutsats är att en denitrifierande bioreaktor med träflis av tall som reaktivt medium är ett fungerande alternativ för nitrat reducering i en lågtempererad miljö (5˚C) då nitrat effektivt reduceras till under gränsvärden fastslagna i lag. Även andra potentiella biprodukter (exempelvis nitrit och ammonium) som kan resultera från den miljö som den denitrifierande bioreaktorn ger upphov till är under de gränsvärden som finns fastslagna i lag.
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Konarik, Stephen Brian. "Trends in agricultural ammonia emissions and ammonium concentrations in precipitation over the southeast and midwest United States." 2006. http://www.lib.ncsu.edu/theses/available/etd-09102006-215638/unrestricted/etd.pdf.
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Hou, WeiNi, and 侯瑋妮. "Treatment of Waste Solutions Containing High Concentrations of Ammonia Using the Physico-Chemical Method." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/67117281860316763089.
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碩士<br>國立聯合大學<br>環境與安全衛生工程學系碩士班<br>102<br>This study adopts two chemical treatment procedures to explore the impact factors related to the treatment of waste solutions containing high concentrations of ammonia. In addition to forming ammonium alum through the reaction between aluminum sulfate and the high concentrations of ammonia in the waste solution, it also seeks for methods of preparing ammonium alum by utilizing water treatment sludge and waste solutions with high concentrations of ammonia. This study explores the impacts of different operating conditions on the crystallized amount of ammonium alum, including ammonium/aluminum molar ratio, removal of residual acid and aluminum ion, removal of concentration of ammonia in waste solution, impacts of rotational speed of mixer and time of mixing of ammonium alum; besides, it reckons the theoretical crystallization of ammonium alum based on the changes of ammonia concentration before and after the reaction, then calculates the ratio between the theoretical and actual crystallization, so as to obtain the recovery rate of ammonium alum crystal, which is served as the basis of efficiency evaluation. The results show that the reasonable crystallization conditions of ammonium alum include the ammonium/aluminum molar ratio of about 1.2, sulfuric acid of 100mL, and sludge volume of 300g/L, whereby the removal rate of ammonium ion is up to 69% and the recovery rate of ammonium alum crystal is up to 93%. Moreover, the mixing time and speed also will affect the recovery rate of ammonium alum crystal, in which the recommended mixing time is 5-30 minutes, and the recommended mixing speed is based on the velocity gradient (G) at about 100. The ammonium alum crystal recovered by filtering and settling for crystallization after mixing is quite lower than that obtained by directly crystallizing in sludge solution after mixing. In addition, the rise of crystal temperature will also reduce the crystallization rate of ammonium alum, however, in terms of the sludge solution after filtering, the research results indicate that a second mixing still can remove the ammonium ion. Moreover, a small amount of aluminum sulfate is added in the sludge, which can facilitate the removal of ammonium ion significantly, so as to reduce the treatment costs effectively.
Moreover, this study also conducts a preliminary research on the treatment of ammonia-containing waste solution by methods of diaphragm electrolysis and electro dialysis. The results show that the chlorine generated through electrolysis with a two-slot electrode can remarkably conduct the oxygenolysis for the ammonium ion in the waste solution. However, the three-slot electro dialysis can noticeably dialyze the ammonium ion in the waste solution to the negative slot and then recover the ammonium solution through gasification; relatively, it can also dialyze the chlorine ion in waste solution into the positive slot, so as to produce chlorine by electrolytic oxidation.
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"Comparison of Ammonia and Particulate Matter Air Sample Concentrations at Task-Locations Within Swine Confinement Buildings." East Tennessee State University, 2009. http://etd-submit.etsu.edu/etd/theses/available/etd-1116109-154833/.
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Armstrong, Kenneth A. "An analysis of liquid aluminum sulfate (alum) use in broiler production houses to control in-house ammonia (NH₃) concentrations and naturally-occurring Salmonella and Campylobacter the development of an NH₃ emission factor for a typical Tennessee broiler house /." 2003. http://etd.utk.edu/2003/ArmstrongKenneth.pdf.
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Thesis (M.S.)--University of Tennessee, Knoxville, 2003.<br>Title from title page screen (viewed Mar., 19, 2004). Thesis advisor: Robert T. Burns. Document formatted into pages (xiv, 148 p. : ill. (some col.)). Vita. Includes bibliographical references.
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Pan, Yi-Ta, and 潘奕達. "Purge-and-Trap preconcentrator system for the determination of ammonia in wide range of concentrations and its Henry's law constant." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/26916004299694463294.
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碩士<br>國立清華大學<br>生醫工程與環境科學系<br>97<br>The ammonia purge-and-trap (P&T) preconcentrator system is a device to separate ammonia from complicated matrices, which combining the concept of purge-and-trap and ammonia stripping. After the P&T pretreatment, the collected sample from trap vessel would be analyzed by ortho- Phthaldialdehyde (OPA) fluoresce derivatization or ion chromatography. The main research purpose of this thesis is to widen the P&T preconcentrator’s linear range under the same efficiency to previous work. And to measure ammonia’s Henry’s law constant under different temperature and different sodium hydroxide concentration. To extend the linear range under the same efficiency, the following parameters should take into account：affect of ultrasound, purging time, volume of trap solution, the composition of trap solution and its concentration. The advanced system broaden its linear range about 3 order to 20 ppb~100 ppm, make it possible to deal with wide ammonia concentration samples. Furthermore, directly ammonia measurement in the purge vessel can verify this system is keep mass balance. Both measurements of ammonia’s KH from purge vessel and trap vessel are very close to the theoretical value and the reference ones. Therefore, this system can not only apply to the pretreatment of wide ammonia concentration samples but also measure ammonia’s KH precisely.
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Ricke, Steven Clarence. "Characterization of hen egg yolk antibodies made to Selenomonas ruminantium, and growth and metabolic response of Selenomonas ruminantium HD₄ in high concentrations of ammonia." 1989. http://catalog.hathitrust.org/api/volumes/oclc/22269780.html.
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Thesis (Ph. D.)--University of Wisconsin--Madison, 1989.<br>Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.
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Chen, Jiann-Ming, and 陳建名. "Effects of nitrogenous excretions and the specific activities of arginase and glutamate dehydrogenase in the tissues of Penaeus monodon exposed to different ambient ammonia concentrations." Thesis, 1997. http://ndltd.ncl.edu.tw/handle/33509114195123643995.
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Avrahami, Sharon [Verfasser]. "Effects of temperature, soil ammonium concentration and fertilizer on activity and community structure of ammonia oxidizers / by Sharon Avrahami." 2003. http://d-nb.info/972815201/34.
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Shen, Wei-Chun, and 沈暐鈞. "Low concentration ammonia micro sensor with polypyrrole coated graphene." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/47403408502664504837.
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碩士<br>國立中興大學<br>機械工程學系所<br>104<br>This study presents a micro NH3 sensor. An NH3 sensing chip with a thermometer is fabricated through the commercial 0.18 μm CMOS-MEMS process of TSMC (Taiwan Semiconductor Manufacturing Company). Chemically reduced graphene oxide, polypyrrole coated graphene (PPy/RGO), is prepared by the oxidation-reduction method. We use different reductant dosage and reducing time to prepare different PPy/RGO. All sensing films are characterized by elemental analyzer (EA), field emission scanning electron microscope (FE-SEM), electron spectroscope for chemical analysis (ESCA) and high resolution X-ray diffraction (HR-XRD). In order to obtain the best sensing film, we compare their gas sensing properties. The sensing circuit board is made by photolithography. The SMD resistor and amplifier are bonded on the sensing circuit board. The sensing chip is attached on the sensing circuit board, and connected to each other by wire bonding.
The results reveal that PPy/RGO-8 is the best ammonia sensitive film. Therefore, this study adopts PPy/RGO-8 as the sensing film. PPy/RGO-8 sensing film is coated on the sensing electrodes of the sensing chip. The micro NH3 gas sensor can detect low concentration NH3 gas at room temperature. The sensing mechanism of the gas sensor is chemoresistor. The measurement results show that the NH3 gas sensor has a response of 1.83 % and 16 mV with the NH3 concentration of 0.1 ppm. The sensor has a good repeatability and selectivity to NH3. The sensor has the benefits of small size, low cost, low power consumption and easy fabrication.
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Liang, Chia-Jui, and 梁家瑞. "Observation and Simulation Analysis of Ammonia Concentration in Taiwan." Thesis, 2019. http://ndltd.ncl.edu.tw/cgi-bin/gs32/gsweb.cgi/login?o=dnclcdr&s=id=%22107NCHU5087045%22.&searchmode=basic.
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碩士<br>國立中興大學<br>環境工程學系所<br>107<br>In Taiwan and many countries, particulate matter with radius ＜2.5 μm (PM2.5) is one of the major pollutants which exceeds the WHO standard. A Gaussian trajectory transfer-coefficient model (GTx) has been developed for the simulation of PM2.5. It determines secondary sulfate aerosol and nitrate aerosol from the oxidations of gaseous SO2 and NOx emissions. This model has been used in many studies. It uses a constant oxidation rate for SO2 at 7.8 %h-1, and that for NOx at 0.75 %h-1 and 3.75％h-1. It also assumes that ammonia is abundant. Hence, the oxidized SO2 is present as (NH4)2SO4, and the oxidized NOx is present as NH4NO3. Nonetheless, these assumptions are too simplified.
A more sophisticated mechanism for the formations of secondary sulfate aerosol and nitrate aerosol used in CALLPUFF has been implemented into GTx recently. In addition, the ammonia concentration is calculated according to the emission data of Taiwan Emission Data System (TEDS10) with scavenging coefficients at 1.3*10-4 s-1 and the Pseudo-first-order reaction rate at 28.8% h-1.
The original version (v027) as well as the new version (v029) of GTx are used to simulate the concentrations of various pollutants (NH3, PM2.5, SO2, NOx, etc.) at 72 stations throughout Taiwan Island in 2017 and March 2018. The results show that in terms of spatial distribution map, the simulated high value of ammonia appears in accordance with TEDS10. However, the ammonia concentration for v029 is overestimated at Xinzhuang and Qianzhen stations and is underestimated at Lunbei station. The results also show that nitrate aerosol as well as PM2.5 simulation by v029 is better correlated to observation. It can also be seen from the performance evaluation table, the correlation coefficient of the new version v029 is increased.
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Chi, Shang-Hung, and 紀尚宏. "Photocatalytic decomposition of low-concentration aqueous ammonia over Pt/TiO2." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/35557883573360611372.
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碩士<br>國立臺灣科技大學<br>化學工程系<br>104<br>In the waste water, ammonia is a general pollutant, which severely endanger the aquatics. There are several methods to deal with ammonia, such as stripping an ion exchange. However, the necessary operation in basic conditions of these methods is the major disadvantage for practical application, resulting in the generation of new contaminants.
In this work, the photocatalytic process was carried out by using Pt/TiO2. The morphologies of the Pt on this photocatalyst were obtain by HRTEM and the Pt content was analyzed by ICP-OES. A glass reactor containing variant concentration of ammonia was used to simulate an aquarium. Under UVA irradiation at room temperature, the ammonia was degraded over Pt/TiO2 from 10 to 3 ppm, which is the safe situation for regular fish. The change in concentration of ammonia and other derivatives during reaction was measured by an ion chromatography. The result indicates the degradation rate of ammonia is increased with the increase in Pt content on titania. With the optimization of reaction parameters, total ammonia could be completely converted to the less toxic component, nitrate.
The designed catalyst was immobilized on a porous supports as practical filter. The deactivation phenomenon of this filter was observed after long-time reaction. This filter was further applied in an fish bowl containing 8 Cardinal tetra to evaluate the photocatalytic activity for ammonia degradation.
The result from fish bowl indicates the generation rate of ammonia is suppressed with using this photocatalytic system. Even though the fish bowl equipped photocatalytic system was two times the amount of fish in the control one, the concentration of ammonia in the photocatalytic fish bowl was still lower than that in control one. The increase in the nitrate concentration in the photocatalytic fish bowl resulted from the photocatalytic degradation of ammonia over the prepared filter, meanwhile, the survival rate is also improved.
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Rogers, James William. "Surface hydrophobicity manipulation through ammonium sulfate concentration." 1988. http://hdl.handle.net/1993/16816.
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Wei, Hao-Ting, and 魏豪廷. "Effects of ammonia concentration on the performance of phototrophic microbial fuel cells." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/68802594005086449391.
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碩士<br>國立臺灣海洋大學<br>河海工程學系<br>104<br>Ammonia nitrogen, a major pollutant in domestic wastewater, usually caused oxygen drop in the water body, which should be effectively removed before the wastewater is discharged to a receiving water body. Using phototrophic microbial fuel cell (Photo-MFC) to treat domestic wastewater containing ammonia is promising because Photo-MFC not only can remove the pollutant but also recover bioenergy. An experimental Photo-MFC (termed as MFC-P) was employed in this study, loaded with 1000 Ω external resistance, operated at diurnal illumination of 12 h light/12 h dark (L/D) cycles. Real sewerage effluent containing ammonia nitrogen (NH4+-N) amended with ammonia chloride (covering 25, 50, and 150 mg/L) was continuously fed into the anodic chamber of MFC-P at flow rate of 1.5 L/day. After 170 days of operation, the electricity generation in MFC-P was founded decreased as ammonia concentration increased. The maximum power output of 76 mW/m3 was founded at 25 mg NH4+-N/L, while the oxygen supply by microalgae reached 126 mg/d which was adequate for nitrification. The ammonia concentration also affects ammonia removal efficiency, contribution of suspended growth in removing ammonia, and chlorophyll a production. Specifically, when influent ammonia concentration increased from 25 to 150 mg NH4+-N /L, the ammonia removal efficiency decrease from 99 % to 9%, the contribution of suspended grown in removing ammonia decreased from 28 % to 7 %, and chlorophyll a concentration from cathode chamber decreased from 446 μg/L to 1.8 μg/L. In addition, the effect of light on Photo-MFC performance was significant, for example, from light to dark periods, the electricity generation decreased from 0.19 mW to 0.08 mW and dissolved oxygen decreased from 1.3 mg/L to 0.1 mg/L. This study demonstrated that influent ammonia concentration is an important process parameter to Photo-MFC, in which the ammonia loading rate should be carefully designed in order to achieve optimal operation in pollutant removal and bioenergy recovery.
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Chen, Mei-Ching, and 陳玫菁. "Polymer Coated Surface Acoustic Wave Sensor for Low Concentration Ammonia Detection and Clustering Analysis." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/92970229566140248379.
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碩士<br>國立清華大學<br>奈米工程與微系統研究所<br>98<br>Abstract
The detection results for organic vapors and ammonia gas by different polymer deposited on 128° YX-LiNbO3 surface acoustic wave (SAW) delay lines are studied in this work. The gas sensor array is based on 2×2 non-continuously working oscillators equipped with differently polymer-coated surface acoustic wave sensors. The SAW detection system which is employed to detect various organic molecules in a static system was prepared using 117.4 MHz two-port SAW resonators and a computer for signal acquisition and data process. This gas sensor array system consists of SAW sensors, polymers with different polarity and function groups, and signal readout electronics. The appropriate coating materials on to the SAW crystal would be used for gas detection, e.g. poly(N-vinylpyrrolidone), poly(4-vinylphenol), poly(vinyl acetate), poly-ethylene-glycol, poly-styrene-co-maleic anhydride, polystyrene and poly-sulfone. The frequency shift of SAW was measured to detect the presence of ammonia and organic vapors. Therefore a simple database would be created by different gas detection. Detecting at an ammonia concentration of 32.9 ppm, the frequency shift was 78.9Hz with a response time of less than 90 s. The good result of tree-view from the two-way hierarchical clustering analysis is studied in this work after comparing the correlation between the 6 coating materials and 6 organic vapors. Furthermore, the SAW detection system can distinguish unknown gas or mixed gas by the database of pattern recognition in the future.
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TSAI, CHENG-CHE, and 蔡承哲. "Nano-flower Structure-based Sensing Modules Applied for Measuring Hydrogen Sulfide and Ammonia Concentration." Thesis, 2019. http://ndltd.ncl.edu.tw/handle/a4v2qp.
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碩士<br>逢甲大學<br>自動控制工程學系<br>107<br>The research develops ZnO-based nanoporous metal oxide multilayer sturctures of gas microsensor using hydrothermal to improve sensitivity and selectivity for detecting ammonia and hydrogen sulfide gases . Sensitivity can be obtained by measuring the variation of sensed resistance when detected gas reacts on the surface of sensing films under cycled different gas concentration at specified temperature.The optimal parameters of the hydrothermal processes were applied to fabricate better distribution of nanometer-scale flower structures. After high temperature calcination, the fabricated nanoflower structur-based gas sensing film can increase reaction contact area to improve the sensitivity of target gas.The gas sensing properties of the material have been improved by doping copper oxide, silver and reducing graphene oxide respectively.Material topographic structure and properties were discussed and the relationship between operation temperature and gas response was analyzed. Developed gas sensing module has shown great performance with low detection limit and high responsibility. The sensing resistance variation and sensitivity as well as temperature dependence of the metal oxide doped zinc oxide nano-flower structure have been analyzed in contact with different concentrations of ammonia and hydrogen sulfide gases. The resistance change rate was 29 at an ammonia concentration of 50 ppm with response time and recovery time 12 and 18 s respectively. The resistance change rate was 15 at a hydrogen sulfide concentration of 10 ppm with response time and recovery time 18 and 42 s respectively.