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1
Powell, Mark D. "The pathophysiology of chloramine-T on rainbow trout gills." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp05/nq21012.pdf.
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Simper, Jessica Mary. "Electrochemical characterization of aqueous chlorine and inorganic chloramine species." Thesis, Imperial College London, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.311946.
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Arevalo, Jorge Miguel. "MODELING FREE CHLORINE AND CHLORAMINE DECAY IN A PILOT DISTRIBUTION SYSTEM." Doctoral diss., University of Central Florida, 2007. http://digital.library.ucf.edu/cdm/ref/collection/ETD/id/3815.
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The purpose of this study was to identify the effect that water quality, pipe material, pipe size, flow conditions and the use of corrosion inhibitors would have on the rate of free chlorine and chloramine decay in distribution systems. Empirical models were developed to predict the disinfectant residual concentration with time based on the parameters that affected it. Different water treatment processes were used to treat groundwater and surface water to obtain 7 types of finished waters with a wide range of water quality characteristics. The groundwater was treated either by conventional treatment by aeration (G1) or softening (G2) or high pressure reverse osmosis (RO) and the surface water was treated either by enhanced coagulation, ozonation and GAC filtration (CSF-O3-GAC or S1) or an integrated membrane system (CSF-NF or S2). The remaining two water types were obtained by treating a blend of G1, S1 and RO by softening (S2) and nanofiltration (G4). A pilot distribution systems (PDS) consisting of eighteen (18) lines was built using old pipes obtained from existing distribution system. The pipe materials used were polyvinyl chloride (PVC), lined cast iron (LCI), unlined cast iron (UCI) and galvanized steel (G). During the first stage of the study, the 7 types of water were blended and fed to the PDS to study the effect of feed water quality changes on PDS effluent water quality, and specifically disinfectant residual. Both free chlorine and chloramines were used as disinfectant and the PDSs were operated at hydraulic retention times (HRT) of 2 and 5 days. The PDSs were periodically tested for free and combined chlorine, organic content, temperature, pH, turbidity and color. The data obtained were used to develop separate models for free chlorine and chloramines. The best fit model was a first-order kinetic model with respect to initial disinfectant concentration that is dependent on the pipe material, pipe diameter and the organic content and temperature of the water. Turbidity, color and pH were found to be not significant for the range of values observed. The models contain two decay constants, the first constant (KB) accounts for the decay due to reaction in the bulk liquid and is affected by the organics and temperature while the second constant, KW, represents the reactions at the pipe wall and is affected by the temperature of the water and the pipe material and diameter. The rate of free chlorine and chloramine decay was found to be highly affected by the pipe material, the decay was faster in unlined metallic pipes (UCI and G) and slower in the synthetic (PVC) and lined pipes (LCI). The models showed that the rate of disinfectant residual loss increases with the increase of temperature or the organics in the water irrespective of pipe material. During the second part of the study, corrosion control inhibitors were added to a blend of S1, G1 and RO that fed all the hybrid PDSs. The inhibitors used were: orthophosphate, blended ortho-polyphosphate, zinc orthophosphate and sodium silicate. Three PDSs were used for each inhibitor type, for a total of 12 PDSs, to study the effect of low, medium and high dose on water quality. Two PDSs were used as control, fed with the blend without any inhibitor addition. The control PDSs were used to observe the effect of pH control on water quality and compare to the inhibitor use. One of the control PDSs (called PDS 13) had the pH adjusted to be equal to the saturation pH in relation to calcium carbonate precipitation (pHs) while the pH of the other control PDS (PDS 14) was adjusted to be 0.3 pH units above the pHs. The disinfectant used for this part of the study was chloramine and the flow rates were set to obtain a HRT of 2 days. The chloramine demand was the same for PDS 14 and all the PDSs receiving inhibitors. PDS 13 had a chloramine demand greater than any other PDS. The lowest chloramine demand was observed in PDS 12, which received silicate inhibitor at a dose of 12 mg/L, and presented the highest pH. The elevation of pH of the water seems to reduce the rate of decay of chloramines while the use of corrosion inhibitors did not have any effect. on the rate of chloramine decay. The PDS were monitored for chloramine residual, temperature, pH, phosphate, reactive silica, and organic content. Empirical models were developed for the dissipation of chloramine in the pilot distribution systems as a function of time, pipe material, pipe diameter and water quality. Terms accounting for the effect of pH and the type and dose of corrosion inhibitor were included in the model. The use of phosphate-based or silica-based corrosion inhibitors was found to have no effect on the rate of chloramine dissipation in any of the pipe materials. Only the increase of pH was found to decrease the rate of chloramine decay. The model to best describe the decay of chloramine in the pilot distribution systems was a first-order kinetic model containing separate rate constants for the bulk reactions, pH effect and the pipe wall reactions. The rate of chloramine decay was dependent on the material and diameter of the pipe, and the temperature, pH and organic content of the water. The rate of chloramine decay was low for PVC and LCI, and more elevated in UCI and G pipes. Small diameter pipes and higher temperatures increase the rate of chlorine decay irrespective of pipe material. Additional experiments were conducted to evaluate the effect of flow velocity on chloramine decay in a pilot distribution system (PDS) for different pipe materials and water qualities. The experiments were done using the single material lines and the flow velocity of the water was varied to obtain Reynolds' numbers from 50 to 8000. A subset of experiments included the addition of blended orthophosphate corrosion inhibitor (BOP) at a dose of 1.0 mg/L as P to evaluate the effect of the inhibitor on chloramine decay. The effect of Reynolds' number on the overall chloramine decay rate (K) and the wall decay rate constant (W) was assessed for PVC, LCI, UCI, and G pipes. PVC and LCI showed no change on the rate of chloramine decay at any flow velocity. UCI and G pipes showed a rapid increase on the wall decay rate under laminar conditions (Re < 500) followed by a more gradual increase under fully turbulent flow conditions (Re > 2000). The use of the BOP inhibitor did not have an effect on the rate of chloramine decay for any of the pipe materials studied. Linear correlations were developed to adjust the rate of chloramine decay at the pipe wall for UCI and G depending on the Reynolds' number.Ph.D.
Department of Civil and Environmental Engineering
Engineering and Computer Science
Environmental Engineering PhD
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Ning, Chenxi. "Novel N-chloramine based antibacterial and non-adherent burn wound dressings." Burns, 2014. http://hdl.handle.net/1993/23890.
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A burn is a type of injury to the skin caused by fire, heat, electricity, chemicals, radiation or friction. It occurs in all age groups. Burn wound infection remains the leading cause of skin graft failure and one of the leading causes of burn injury related mortality. Dressings impregnated with silver compounds are the mainstay of treatment for burn wounds to prevent or combat the infection. However, most commercially available silver based wound dressings cause trauma upon removal because of adhesion to the wound bed. A recent study has shown that burn dressing related pain is linked to more severe depressive and posttraumatic stress symptoms. Furthermore, emerging resistance associated with silver based wound dressings is a growing concern. Organic N-chloramines have been in clinical use for over 180 years thanks to their effectiveness toward a broad spectrum of microorganisms, and no resistance has been yet reported. This study aimed to develop an “ideal” wound dressing with both antibacterial and atraumatic properties. Poly(ethylene terephthalate) (PET) fabrics are among the most representative base materials in burn wound dressings and thus were chosen as the substrate. Specifically, a very thin layer of polyacrylamide (PAm) hydrogel was deposited onto the surface of PET fabric via plasma activation and photopolymerization. The treated PET fabric (termed as “PET-PAm”) was characterized with attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectroscopy and water contact angle measurement. We adapted an in vitro wet-gelatin adherence model to evaluate the effect of hydrogel deposition on reducing the adherence of PET. The deposited hydrogel layer was found to lower the adherence of PET fabrics. The peeling energy of PET decreased drastically from 2231.5 J/m2 to nearly 250 J/m2 after the deposition of hydrogel. On the other hand, we have also synthesized a series of new “composite” biocides with both N-chloramine and quaternary ammonium (QA) moieties. Those “composite” biocides exert boosted killing efficiency against methicillin-resistant Staphylococcus aureus (MRSA) and multi-drug resistant (MDR) Pseudomonas aeruginosa. The deposited hydrogel layer can also serve as the reservoir for the loading of the novel N-chloramine based “composite” biocides, to achieve a both non-adherent and antibacterial wound dressing.
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Zhou, Xia 1953. "Inactivation of Escherichia coli and coliphage MS-2 by chloramine and copper." Thesis, The University of Arizona, 1991. http://hdl.handle.net/10150/277945.
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The efficacy of chloramine in the presence of copper chloride was evaluated for the inactivation of an indicator bacteria Escherichia coli and coliphage MS-2. Both microorganisms were exposed to chloramine with and without copper chloride. Results showed an increase in the inactivation rate of Escherichia coli and MS-2 phage with an increasing concentration of chloramine. To achieve a 99 percent reduction in the number of Escherichia coli, an exposure of 46, 21, 6, and 5 minutes was necessary for 1, 2.5, 5, and 10 mg chloramine/L, respectively. A 99 percent reduction of MS-2 phage occurred after 60 and 25 minutes of exposure to 5 and 10 mg chloramine/L. Chloramine in the presence of copper increased the inactivation rate of Escherichia coli and MS-2 phage. The time needed for 99 percent inactivation of E. coli and MS-2 phage was reduced. Copper increases the inactivation rate of bacteria and viruses by chloramine. (Abstract shortened with permission of author.)
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Salman, Noori Yousif. "Kinetics of oxidation of amino-acids by chloramine-T and related compounds." Thesis, University of Surrey, 1988. http://epubs.surrey.ac.uk/847982/.
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Studies of the kinetics and mechanism of the oxidation of amino-acids by chloramine-T, bromamine-T, di-chloramine-T, N-chlorosuccinimide and N-bromosuccinimide in the range pH 2-9 at 25 or 30°C in aqueous solution are described in this thesis. The effects of added p-toluenesulphonamide, chloride ion, or bromide ion on the rates have been studied. All the previous work on the chloramine-T oxidations of amino-acids was carried out at either pH 9 and the reactions were followed by iodometric titration. In the present work, UV spectrophotometry was used successfully to follow the reactions of all the above oxidants. Some runs were followed by iodometry for comparison. In general the kinetics of the oxidation by CAT (chloramine-T) with respect to the oxidant were first order ([CAT]=1x10[-4]M) or consecutive first order ([CAT]=3x10[-3]M). At pH's > 3 the oxidations were generally first order with respect to amino-acid, except for the oxidation of valine and arginine which showed Michaelis-Menten kinetics. Below pH 3 there was little dependence on amino-acid concentrations and it is suggested that the active species is HOCl or H[2]OCl[+] formed in a partly rate-determining step from CAT. At high pH's, the dependence of rate on pH suggests that the CAT anion is the active oxidant. Agreement was observed between the rates of the second stages of the oxidations by CAT and N-chlorosuccinimide, suggesting that these oxidations proceed via the same intermediate which is probably the chloroester. Spectroscopic evidence indicates the formation of the imine as another intermediate in the N-chlorosuccinimide reaction. In the oxidations by dichloramine-T the rate constants for the second stage agree with the rate constants for the CAT oxidations ([oxidant]=1.0x10[-4]M). Clearly CAT formed in the first stage oxidises the amino-acid in the second stage. A product analysis of the oxidations of amino-acids by CAT has been carried out by NMR and GLC. Formation of an aldehyde or a nitrile (depending on the conditions) has been confirmed. Improved calculations of the different species present in CAT solutions at various pH's have been carried out.
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El, Khatib Mazen. "Mécanisme et modélisation des réactions intervenant au cours de la synthèse d'une hydrazine d'intérêt pharmaceutique : le N-amino3-aza bicyclo [3,3,0]octane." Lyon 1, 1994. http://www.theses.fr/1994LYO18994.
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Ce travail effectué dans le cadre d'une convention de recherche avec la société Oril S. A. Présente une nouvelle synthèse du N-amino 3-aza bicyclo[3,3,0]octane utilisé dans la fabrication de médicaments hypoglycémiques. La transposition du procédé Raschig aux hydrazines supérieures induit dans le milieu le grand nombre de réactions secondaires qui sont dues à des mécanismes de transfert de chlore et de réarrangement des intermédiaires oxydés des hydrazines substituées. Elles conduisent à la formation d'hydrazones, de tétrazènes et d'organohaloamines.
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Nguyen, Caroline Kimmy. "Interactions Between Copper and Chlorine Disinfectants: Chlorine Decay, Chloramine Decay and Copper Pitting." Thesis, Virginia Tech, 2005. http://hdl.handle.net/10919/35674.
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Interactions between copper and chlorine disinfectants were examined from the perspective of disinfectant decay and copper pitting corrosion. Sparingly soluble cupric hydroxide catalyzed the rapid decay of free chlorine, which in turn, led to production of less soluble and more crystalline phases of cupric hydroxide. The catalytic activity of the cupric hydroxide was retained over multiple cycles of chlorine dosing.
Experiments with chloramine revealed that copper species could also trigger rapid loss of chloramine disinfectant. In copper pipes, loss of free chlorine and chloramine were both rapid during stagnation. Reactivity of the copper to the disinfectants was retained for weeks. Phosphate tended to decrease the reactivity between the copper pipe and chlorine disinfectants.
A novel, inexpensive and real-time test to monitor copper pitting corrosion was developed. In a normal pipe, it is not possible to measure the electron flow or pitting current from the pit anode to the cathode. But a new method was developed that can form an active pit on the tip of a copper wire, which in turn, allows the pitting current to be measured. Preliminary experiments presented herein have proven that this technique has promise in at least one water condition known to cause pitting. The method also quickly predicted that high levels of orthophosphate could stop pitting attack in this water, whereas low levels would tend to worsen pitting. Future research should be conducted to examine this technique in greater detail.Master of Science
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Parsons, Christopher Mark. "Amination of activated C-H bonds using chloramine-T trihydrate and copper (I) catalysts." Thesis, University of Warwick, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.404850.
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Stephan, Juliette. "Synthèse sous pression dans l’ammoniac liquide, d’hydrazines substituées dissymétriques, par la voie chloramine inverse." Lyon 1, 2004. http://www.theses.fr/2004LYO10030.
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Ce travail effectué dans le cadre d’un contrat avec l’Anvar a pour objectif l’étude de la synthèse d’hydrazines substituées dissymétriques, dans l’ammoniac liquide, par la voie chloramine indirecte. La synthèse d'hydrazines par le procédé Raschig direct (monochloramine/amines) est générale, sélective, peu polluante mais elle présente des limites en concentrations (2 à 5%) liées aux faibles titres des réactifs hypochlorés commerciaux et à l’instabilité de la monochloramine. Ce travail concerne l'étude du procédé inverse qui consiste à effectuer la réaction dans l’ammoniac liquide sous pression à partir de chloramines substituées, préalablement obtenues à l’état pur. L’étude a été effectuée simultanément dans l’eau, en milieu alcalin et dans l’ammoniac anhydre. Une étude cinétique systématique des réactions de formation et de dégradation en solution aqueuse a permis d’identifier les produits et d’établir un modèle cinétique. Dans le second cas, une unité de synthèse spécifique sous pression a été mise au point. Les résultats expérimentaux et leur interprétation mettent en défaut les hypothèses couramment admises dans la littérature. Les mécanismes réactionnels associés ont été élucidés et un nouveau schéma global de synthèse élaboréThe aims of this work is the synthesis of unsymmetrical substituted hydrazine by the indirect chloramine process in liquid ammonia. The hydrazine synthesis by the direct Raschig process (monochloramine/amines) is general, selective and little polluting but it presents limits in concentrations (2 to 5%) related to the low titles of the hypochlorite solution and to the instability of the monochloramine. This work studies the opposite process it’s consists to carrying out the reaction in liquid ammonia under pressure starting from pure substituted chloramines. The study was carried out in alkaline water medium and in anhydrous ammonia. - A kinetic study in aqueous medium of the formation and degradation reactions made possible the identification of the products and a kinetic model was established - In the second case, a specific unit of synthesis under pressure was developed. The experimental results and their interpretation put at fault the usually allowed assumptions in the literature. The associated reactional mechanisms were elucidated and a new total diagram of synthesis were elaborated
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Dudi, Abhijeet. "Reconsidering Lead Corrosion in Drinking Water: Product Testing, Direct Chloramine Attack and Galvanic Corrosion." Thesis, Virginia Tech, 2004. http://hdl.handle.net/10919/35417.
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The ban on lead plumbing materials in the Safe Drinking Water Act (1986) and the EPA Lead and Copper Rule (1991) have successfully reduced lead contamination of potable water supplies. The success of these regulations gave rise to a belief that serious lead contamination was an important past problem that had been solved, and that additional fundamental research was therefore unnecessary. This work carefully re-examined the lead contamination issue from the perspective of 1) new regulations causing a shift from chlorine to chloramine disinfectant, 2) assumptions guiding sampling strategies, 3) existing performance standards for brass, and 4) galvanically driven corrosion of lead bearing plumbing materals. The results were instrumental in uncovering and understanding a serious problem with lead contamination in Washington, D.C.
A critical reading of the literature indicates that chloramines can accelerate corrosion of lead bearing materials and increase lead contamination of water. When a new sampling protocol was conceived and used in Washington homes to assess the nature of the problem, hazardous levels of lead were found to be present in some drinking water samples. Contrary to the conventional wisdom, lead was not always highest in first draw samples, but often increased with flushing. This has several important implications for monitoring and public health. For instance, well-intentioned public education materials were causing consumers to drink water containing very high levels of lead in some circumstances. Laboratory and field-testing proved that chloramines were causing serious lead corrosion problems. That testing also discovered that, unbeknownst to scientists and utilities, free chlorine itself can act as a corrosion inhibitor, reducing lead solubility and contamination of water. The net result is that changing disinfectant from free chlorine to chloramine can sometimes trigger serious lead contamination of water.
While the worst problems with lead in Washington, D.C. came from the lead services, significant levels of lead were occasionally sampled from homes with solders or brass as the lead source. This prompted re-evaluation of the ANSI/NSF 61, Section 8 standard, which is relied on to protect public health from in-line brass plumbing devices that might leach excessive lead to potable water. In-depth study of the standard revealed serious flaws arising from use of a phosphate buffer in the test waters and a failure to control carbonate dissolution from the atmosphere. Due to these deficiencies, small devices made of pure lead could actually pass the performance test. The public therefore has no assurance that devices passing NSF Section 8 testing are safe and reforms to the standard are obviously needed.
Other problems arise from connecting copper pipe to lead bearing plumbing in practice. The copper is cathodic and dramatically accelerates corrosion of the lead anode via a galvanic current. Corrosion and hydrolysis of released Pb+2 can lower pH near the surface of the lead and increase its solubility. A similar galvanic effect can arise from cupric ions present in the water via deposition corrosion mechanism. In cases where part of a lead service line is replaced by copper pipe, the galvanic corrosion effect can create a serious long-term problem with lead contamination. Such partial lead service line replacements are occurring in many US cities
and the practice should be stopped. Lead contamination of potable water is not only a problem of the past but also of the present. While additional research is necessary before regulators, utilities and homeowners can anticipate and mitigate such problems with confidence, this work provides sound fundamental basis for future progress.
Master of Science
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Alexander, Matthew T. "An Integrated Field-Scale Assessment of Chloramine Dynamics, By-Product Formation, and Nitrification Modeling." University of Cincinnati / OhioLINK, 2010. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1282332632.
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Griffin, Allian Sophia. "Corrosion in New Construction:Elevated Copper, Effects of Orthophosphate Inhibitors, and Flux Initiated Microbial Growth." Thesis, Virginia Tech, 2010. http://hdl.handle.net/10919/76951.
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It is generally acknowledged that a variety of problems affecting aesthetics, health, and corrosivity of potable water can arise during installation of building plumbing systems. These include 'blue water', microbial infestation, and rapid loss of disinfectant residual, among other things. Frequently cited causes of the problems include metallic fines left in the plumbing lines from deburring, cutting and product fabrication; solder flux residuals (water soluble and petroleum based flux); and solvents for CPVC. Mechanistically, some materials such as flux contain high chloride, high ammonia and cause low pH, which can increase the corrosivity of water held in the lines. Indirect effects are also suspected to be important. For example, ammonia from flux and organic carbon from flux or PVC solvents can spur microbial growth, which in turn can reduce pH or otherwise increase corrosivity. Recent work has also demonstrated that problems with lead leaching to water from brass in modern plumbing can actually be worse in PVC/plastic than in copper systems, if certain types of microbes such as nitrifiers proliferate and drop pH. Some of the problems initiated by construction practices can persist indefinitely, causing higher levels of lead and copper in water, or longer term, contributing to failures of the plumbing system.
Blue water from high copper concentrations is a confounding problem that continues to arise in some locales of the United States. One public elementary school in Miami Dade County is experiencing blue water issues as manifested by blue ice cubes and sink staining. In addition to the aesthetic problems, copper levels are above the EPA's Copper Action Level of 1.3 ppm. Bottled water has been substituted for tap water consumption, which has created a financial burden. The pH of the school's water ranges from 7.15 - 7.5 and the school itself is located 1 ½ miles off the main distribution line resulting in a very low chlorine residual of between 0.06 mg/L Cl2 and 0.18 mg/L Cl2. On site water was shipped to Virginia Tech from Miami to be used in this study. Preliminary testing showed that an increase in the pH of the water would decrease copper leaching. Several pH's were tested which revealed that increasing the pH of the water to 8.5 would drop copper below 1.3 mg/L. When these recommendations were implemented at the school, the high alkalinity and calcium rich water caused calcite scales to form which clogged the chemical feed nozzles. Further bench scale testing indicated that adding 2 mg/L orthophosphate corrosion inhibitor would effectively decrease copper to a level that would comply with the EPA's Copper Action Limit.
Orthophosphate corrosion inhibitors are used by utilities to limit lead and copper corrosion from consumer's plumbing. An evaluation comparing the effects of both 100% orthophosphate inhibitor and orthophosphate/polyphosphate inhibitor blends was performed to study the effects they have on galvanic corrosion, metallic corrosion, microbial growth and the decay of chloramine disinfectant. On site water was sent to Virginia Tech from UNC for use in this bench scale study. The results from this study indicated that 100% orthophosphate inhibitor was the most effective corrosion inhibitor at decreasing metallic corrosion.
It has long been known that microbial activity can have significant effects on water quality. This study evaluated nitrifying and heterotrophic bacterial growth in water systems containing copper pipes, a common plumbing product, and flux which is used in soldering copper pipes together in new construction. There are several types of commercially available fluxes which are often used when soldering new pipes together. Flux ingredients vary and can include extremely high concentrations of ammonia, zinc, chloride, tin, copper and TOC. Flux containing high amounts of ammonia can be detrimental to water quality because it can accelerate the occurrence of nitrification, thus creating a cascading set of problems including, but not limited to, pH decrease and copper corrosion. The results from this case study indicated that flushing a pipe system can effectively decrease the high concentrations of flux present in a new construction system; however, high levels of ammonia from flux can create an environment in which nitrifiers may proliferate within the system.
Many water utilities in the United States are switching disinfection type from chlorine to chloramine due to the increased stability, longer residual time, and overall safety benefits of chloramine. Although chloramines have been found to be a desirable means for disinfection, chloramine decay is an issue of great concern because if the chloramine residual decays, it can leave a water system unprotected against microbial infestation. A preliminary examination of this issue was performed in a laboratory setting to evaluate the many components that effect the stability of chloramine decay, including alkalinity, phosphate, temperature, and various pipe materials. The results from this experiment revealed that temperature increase, pH increase, and aged tygon tubing all accelerated the rate of chloramine decay.Master of Science
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Goutaudier, Christelle. "Préparation électrochimique de la chloramine, élaboration d'alkylhydrazines par transfert de phases : application à la monométhylhydrazine." Lyon 1, 1993. http://www.theses.fr/1993LYO10015.
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L'etude presentee avait pour objet l'elaboration d'alkylhydrazines par adaptation du procede raschig en utilisant une reaction de transfert de phases et son application a la synthese de la monomethylhydrazine (mmh). Dans un premier temps, la monochloramine a ete preparee par action d'eau de javel sur l'ammoniaque. L'alkylhydrazine a ete ensuite formee par reaction en milieu biphasique de nh2cl sur l'amine en exces. Les differentes etapes ont ete le choix du solvant et la mesure des differents coefficients de partage, la determination des domaines d'equilibre solide-liquide-vapeur du systeme quaternaire mma-h#2o-tbme-naoh, l'etude de la synthese en milieu biphase de la mmh en discontinu puis son application en continu sur une unite pilote construite au laboratoire. Dans un second temps, la chloramine a ete preparee par electrolyse d'une solution ammoniacale d'halogenure. L'influence des divers parametres a ete etudiee et une modelisation des resultats experimentaux en fonction des densites de courant imposees a ete proposee
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Crissot-Laruade, Marjorie. "Evolution de la qualité de l'eau dans les réseaux de distribution d'eaux thermales : formation des biofilms et impact des désinfectants." Poitiers, 1999. http://www.theses.fr/1999POIT2257.
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Le transport des eaux thermales de l'emergence aux postes de soins, comporte parfois un risque d'alteration des caracteristiques de l'eau. L'objectif de ces travaux etait donc de contribuer a la maitrise de la qualite des eaux dans les reseaux des etablissements thermaux en etudiant, dans ces eaux a faible teneur en matiere organique, les mecanismes de formation des biofilms et leur resistance aux desinfectants. L'etude, realisee sur le reseau de distribution de la station thermale de saujon, montre une hausse de la densite bacterienne et du cod ainsi qu'une modification de la composition de la flore bacterienne de l'eau en sortie de reseau. Les essais menes sur simulateurs de reseau alimentes en eau thermale ont permis, apres 10 a 20 jours de colonisation, d'obtenir un biofilm a l'etat d'equilibre. L'abondance des bacteries cultivables et totales du biofilm est alors de 6 10#4 a 8 10#5 ufc cm##2 et 6 10#5 a 5 10#6 cellules cm##2. La teneur en cod du biofilm est de l'ordre de 1,8 a 3,6 gc cm##2 et sa concentration en acides amines et en sucres dissous varie respectivement de 0,6 a 1,8 gc cm##2 (20 a 50% du cod) et de 0,1 a 0,4 gc cm##2 (2 a 11% du cod). Parmi les traitements de desinfection choc testes sur le biofilm en reacteur, la monochloramine ou le traitement thermique a 70c permettent d'obtenir les meilleurs resultats d'inactivation des bacteries du biofilm. . . .
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Dickenson, Eric Reyvell Velazquez. "Short-term disinfection by-product formation in a chlorine/chloramine approach: Natural waters and model compounds." Diss., Connect to online resource, 2005. http://wwwlib.umi.com/cr/colorado/fullcit?p3190391.
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Laping, Lina Alexandra [Verfasser]. "Reaktionen primärer N-Chloramine mit Alkenen und Anwendung der Additionsprodukte als DNA-Alkylantien / Lina Alexandra Laping." Gießen : Universitätsbibliothek, 2013. http://d-nb.info/1065183712/34.
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Lee, Woo Hyoung. "Development and Use of Microelectrodes to Evaluate Nitrification within Chloraminated Drinking Water System Biofilms, and the Effects of Phosphate as a Corrosion Inhibitor on Nitrifying Biofilm." University of Cincinnati / OhioLINK, 2009. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1258489526.
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Minnis, Rochelle J. "Comparison of the use of single and multiple oxidants on the generation of particulate matter in water distribution systems derived from groundwater sources containing hydrogen sulfide and dissolved organics." [Tampa, Fla] : University of South Florida, 2005. http://purl.fcla.edu/usf/dc/et/SFE0001390.
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Goutelle, Véronique. "Synthèse de la 2-hydroxyéthylhydrazine par voie chloramine et par alkylation de l'(hydrate d'hydrazine) : mécanistique, modélisation cinétique et optimisation." Lyon 1, 2006. http://www.theses.fr/2006LYO10273.
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Ce travail, effectué avec la société ISOCHEM groupe SNPE, présente différentes voies d’accès à la synthèse de l’hydroxyéthylhydrazine. Cette molécule suscite aujourd’hui un grand intérêt compte tenu de ses applications dans le domaine l’aérospatiale, de la Défense, de l’industrie pharmaceutique et des cosmétiques. - La 1ère partie est consacrée à la voie Raschig. Une étude cinétique et mécanistique des réactions de formation et de dégradation a permis d’identifier les produits et d’établir un modèle. Les conditions optimales de synthèse ont été définies ainsi qu’une approche des opérations d’extraction. - Le 2nd volet concerne l’alkylation de N2H4 par le chloroéthanol avec et sans la présence d’une base forte. Les lois de vitesse relatives à chaque option ont été déterminées. Ce travail a été complété par une étude calorimétrique des enthalpies de solvatation et de réaction. Une modélisation globale permet de gérer l’ensemble des entités (oxyde d’éthylène…)This work was carried out with ISOCHEM (SNPE company). It presents various access roads to the synthesis of hydroxyethylhydrazine. This molecule arouses today a great interest taking into account its applications in the field aerospace, Defense, pharmaceutical and cosmetics industry. - The 1st part is devoted to the Raschig way. A kinetic and mechanistic study of the reactions of formation and degradation made it possible to identify the products and to establish a model. The optimum conditions for synthesis were defined as well as an approach of the operations of extraction. - The 2nd part relates to the alkylation of hydrazine hydrate by chloroethanol with and without the presence of a strong base. The rates laws of the mono and dialkylation relating to each option were given. This work was supplemented by a calorimetric study of the enthalpy of solvation and reaction. A total modeling makes it possible to control the whole of the reactional entities (ethylene oxide…)
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Stein, Anke [Verfasser], Wolfgang [Akademischer Betreuer] Pfister, Bernd W. Akademischer Betreuer] Sigusch, and Thomas [Akademischer Betreuer] [Hoffmann. "Die antimikobielle Wirksamkeit von Chloramin im Vergleich zu anderen Antiseptika im Wurzelkanal / Anke Stein. Gutachter: Wolfgang Pfister ; Bernd W. Sigusch ; Thomas Hoffmann." Jena : Thüringer Universitäts- und Landesbibliothek Jena, 2011. http://d-nb.info/1016391579/34.
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Bräutigam, Franziska [Verfasser], Bernd [Gutachter] Sigusch, Eike [Gutachter] Glockmann, and Holger [Gutachter] Jentsch. "In-vitro-Suppression von Enterococcus faecalis in den Dentintubuli mit Chloramin-T / Franziska Maria Bräutigam ; Gutachter: Bernd Sigusch, Eike Glockmann, Holger Jentsch." Jena : Friedrich-Schiller-Universität Jena, 2018. http://d-nb.info/1170396844/34.
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Peyrot, Laurent. "Nouvelle avancée dans le procédé Raschig : élaboration de chloramine haute teneur, extension à la synthèse d'une hydrazine à structure indolique : la N-amino-2-méthylindoline." Lyon 1, 1998. http://www.theses.fr/1998LYO10006.
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La synthese d'hydrazines par le procede raschig est la voie la plus satisfaisante pour l'environnement par rapport aux preparations passant par les nitosamines (derives cancerogenes). Cependant, elle presente des limites en concentration et rendement liees a la faible teneur de l'intermediaire de base, la chloramine, et a l'existence d'un grand nombre d'interactions secondaires. La premiere partie concerne l'elaboration de solutions concentrees de chloramine titrant plus de 2 mol l#-#1 a partir de solutions d'hypochlorite a 100 degres chlorometrique. Compte tenu de l'instabilite de l'haloamine et de la forte exothermicite des reactions mises en jeu, de nouvelles combinaisons ammoniacales quaternaires nh#4no#3 - nh#4cl - nh#3 - h#2o ont ete utilisees. Une etude des equilibres entre phases impliquant les constituants des deux reactifs a permis de definir des conditions operatoires pointues. La faisabilite de cette nouvelle voie a ete validee en discontinu puis en continu sur une unite pilote de laboratoire. Cette etude effectuee dans le cadre d'une convention de recherche avec la societe oril industrie a fait l'objet d'un depot de brevet. Le second volet traite des possibilites d'extension du procede raschig a des amines possedant une faible activite nucleophile. Dans cette optique, l'action de la chloramine sur la 2-methylindoline a ete entreprise. L'hydrazine formee est utilisee comme precurseur de medicaments antihypertenseurs. Une etude systematique des reactions de formation et de degradation en milieu aqueux a permis d'identifier les produits et d'etablir un modele cinetique global. Un traitement numerique du systeme montre que le rendement en n-amino-2-methylindoline par rapport a la chloramine est limite a 56%. L'analyse des mecanismes reactionnels montre qu'un milieu mixte eau/alcool favorise l'etape utile de la synthese au detriment de la reaction concurrente de transfert de chlore. Dans ces conditions, un rendement superieur a 75% peut etre envisage.
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Hatt, Juliette W. "Pretreatment options for municipal wastewater reuse using membrane technology." Thesis, Cranfield University, 2012. http://dspace.lib.cranfield.ac.uk/handle/1826/10200.
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Increasing freshwater scarcity across the world means that wastewater reclamation is being considered as a key method in which to meet the growing demand. Evolution of water reuse schemes where high quality product is required such as for indirect potable reuse has led to the adoption in recent years of the integrated membrane scheme using a combination of microfiltration or ultrafiltration with reverse osmosis membrane. However, despite technological advancements, these membranes are still prone to fouling resulting in increased costs through cleaning or replacement. This thesis aims to look at pretreatment to reduce the fouling propensity of the microfiltration membranes via a 600m3 /d pilot plant which was commissioned to investigate indirect potable reuse. A range of pretreatments including pre-screening, pre-coagulation, powdered activated carbon and granular activated carbon were assessed based on fouling amelioration, water quality improvement and cost analysis. Results showed that ferric sulphate dosing was the most effective in terms of reducing the reversible fouling rate especially at high turbidity loads enabling higher flux to be realised leading to a small cost benefit. Activated carbon proved the most effective pretreatment in terms of organic removal and a significant reduction in the irreversible fouling rate. However, the cost involved in using this as a pretreatment is significant compared to possible cost savings through reduced requirement for chemical cleaning. This pretreatment is only viable if it obviates the need for a separate organic removal process.
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Word, Tarah A. "Photoacoustic Calorimetry Studies of the Earliest Events in Horse Heart Cytochrome-c Folding." Scholar Commons, 2015. http://scholarcommons.usf.edu/etd/5801.
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The protein folding problem involves understanding how the tertiary structure of a protein is related to its primary structure. Hence, understanding the thermodynamics associated with the rate-limiting steps for the formation of the earliest events in folding is most crucial to understanding how proteins adopt native secondary and tertiary structures. In order to elucidate the mechanism and pattern of protein folding, an extensively studied protein, Cytochrome-c (Cc), was chosen as a folding system to obtain detailed time-resolved thermodynamic profiles for the earliest events in the protein folding process. Cytochrome-c is an ideal system for understanding the folding process for several reasons. One being that the system can unfold and refold reversibly without the loss of the covalently attached heme group. A number of studies have shown that under denaturing conditions, ferrous Cc (Fe2+Cc) heme group in the presence of carbon monoxide (CO) results in a disruption of the axial heme Methionine-80 (Met80) bond ultimately unfolding the protein. CO-photolysis of this ferrous species results in the formation of a transient unfolded protein that is poised in a non-equilibrium state with the equilibrium state being that of the native folded Fe2+Cc complex. This allows for the refolding reaction of the protein to be photo-initiated and monitor on ns - ms timescales. While CO cannot bind to the ferric form, nitrogen monoxide (NO) photo-release has been developed to photo-trigger ferric Cc (Fe3+Cc) unfolding under denaturing conditions. Photo-dissociation of NO leaves the Fe3+complex in a conformational state that favors unfolding thus allowing the early unfolding events of Fe3+Cc to be probed. Overall the results presented here involve the use of the ligands CO and NO along with photoacoustic calorimetry (PAC) to photo-trigger the folding/unfolding reaction of Cc (and modified Cc). Thus, obtaining enthalpy and molar volume changes directly associated with the initial folding/unfolding events occurring in the reaction pathways of both Fe2+ and Fe3+Cc systems that are most essential to understanding the driving forces involved in forming the tertiary native conformation. The PAC data shows that folding of proteins results from a hierarchy of events that potentially includes the formation of secondary structures, hydrophobic collapse, and/or reorganization of the tertiary complex occurring over ~ns – tens of µs time ranges. In addition, the PAC kinetic fits presented in this work is the first to report Cc folding exhibiting heterogeneous kinetics (in some cases) by utilizing a stretched exponential decay function.
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Liu, Suibing. "NITRIFICATION INVESTIGATION AND MODELING IN THE CHLORAMINATED DRINKING WATER DISTRIBUTION SYSTEM." Doctoral diss., University of Central Florida, 2004. http://digital.library.ucf.edu/cdm/ref/collection/ETD/id/4465.
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This dissertation consists of five papers concerning nitrification in chloraminated drinking water distribution systems in a one and a half year field study. Seven finished waters were produced from different treatment processes and distributed to eighteen pilot distribution systems (PDSs) that were made pipes taken from actual distribution systems. Unlined cast iron (UCI), galvanized steel (G), lined cast iron (LCI), and PVC pipes were used to build the PDSs. All finished waters were stabilized and chloraminated before entering the PDSs. This dissertation consists of five major parts. (1) System variations of nitrates, nitrites, DO, pH, alkalinity, temperature, chloramine residuals and hydraulic residence times (HRT) during biological nitrification are interrelated and discussed relative to nitrification, which demonstrated Stoichiometric relationships associated with conventional biochemical nitrification reactions. Ammonia is always released when chloramines are used for residual maintenance in drinking water distribution systems, which practically insures the occurrence of biological nitrification to some degree. Biological nitrification was initiated by a loss of chloramine residual brought about by increasing temperatures at a five day HRT, which was accompanied by DO loss and slightly decreased pH. Ammonia increased due to chloramine decomposition and then decreased as nitrification began. Nitrites and nitrates increased initially with time after the chloramine residual was lost but decreased if denitrification began. Dissolved oxygen limited nitrifier growth and nitrification. No significant alkalinity variation was observed during nitrification. Residual and nitrites are key parameters for monitoring nitrification in drinking water distribution systems. (2) Using Monod kinetics, a steady state plug-flow kinetics model was developed to describe the variations of ammonia, nitrite and nitrate-N concentrations in a chloraminated distribution system. Active AOB and NOB biomass in the distribution system was determined using predictive equations within the model. The kinetic model used numerical analysis and was solved by C language to predict ammonia, nitrite, nitrate variation. (3) Nitrification control strategies were investigated during an unexpected episode and controlled study in a field study. Once nitrification began, increasing chloramine dose from 4.0 to 4.5 mg/L as Cl? and Cl?:N ratio from 4/1 to 5/1 did not stop nitrification. Nitrification was significantly reduced but not stopped, when the distribution system hydraulic retention time was decreased from 5 to 2 days. A free chlorine burn for one week at 5 mg/L Cl? stopped nitrification. In a controlled nitrification study, nitrification increased with increasing free ammonia and Cl?:N ratios less than 5. Flushing with increased chloramine concentration reduced nitrification, but varying flush frequency from 1 to 2 weeks had no effect on nitrification. (4) HPC variations in a chloraminated drinking water distribution system were investigated. Results showed average residual and temperature were the only water quality variables shown to affect HPC change at a five day distribution system hydraulic residence time was five days. Once nitrification began, HPC change was correlated to HRT, average residual and generated nitrite-N in the distribution system. (5) Biostability was assessed for water treatment processes and distribution system pipe by AOCs, BDOCs, and HPCs of the bulk water, and by PEPAs of the attached biofilms. All membrane finished waters were more likely to be biologically stable as indicated by lower AOCs. RO produced the lowest AOC. The order of biofilm growth by pipe material was UCI > G > LCI > PVC. Biostability decreased as temperature increased.Ph.D.
Department of Civil and Environmental Engineering
Engineering and Computer Science
Civil and Environmental Engineering
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Le, Duc Minh. "Nouvelle stratégie d’élaboration de la monométhylhydrazine via le procédé Raschig en utilisant la technologie des microréacteurs : synthèse de la chloramine dans des conditions quasi-stoechiométriques et isolement en une seule étape multifonctionnelle." Thesis, Lyon 1, 2012. http://www.theses.fr/2012LYO10335.
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Ce travail effectué dans le cadre d'une collaboration avec le groupe Safran-Heraklès, a pour objectif le développement d'une nouvelle stratégie d'élaboration de la monométhylhydrazine (MMH) par intensification du procédé Raschig, en utilisant la technologie des microréacteurs. Ce composé est aujourd'hui une molécule à fort potentiel dans le domaine de la propulsion, de l'industrie pharmaceutique ainsi que dans le domaine de l'agrochimie. Ce travail a été financé par la Région Rhône-Alpes sous la forme d'une bourse doctorale CIBLE 2008-2011. La première partie de ce travail est consacrée à la synthèse de la monochloramine élaborée dans des conditions quasi-stoechiométriques et à l'étude de sa stabilité. Cette synthèse a été réalisée pour la première fois, en continu, à l'aide de la technologie des microréacteurs. Les conditions optimales de synthèse ont été déterminées ainsi que les paramètres de sécurité, en vue d'un transfert industriel rapide et sécuritaire. La deuxième partie concerne l'objectif majeur du nouveau procédé qui consiste à extraire, sous pression, la totalité des produits organiques (monométhylhydrazine et monométhylamine (MMA)), sous la forme d'une phase condensée, par démixtion des solutions brutes de synthèse. Ce phénomène est lié à l'existence d'une lacune de miscibilité à l'état liquide dans le système ternaire MMA-H2O-NaOH. L'optimisation de la démixtion a nécessité l'établissement systématique des diagrammes de phases impliqués. La dernière partie aborde l'aspect génie des procédés. Une modélisation cinétique de la synthèse de la MMH par voie Raschig a été entreprise afin d'estimer la composition des solutions de synthèse. L'exploitation thermodynamique des diagrammes de phases a permis la détermination des conditions optimales de l'isolement et l'établissement de plusieurs schémas de procédés pour la synthèse de la MMHThis work, conducted as part of a collaboration with the Safran-Heraklès group, aims at developing a new synthesis concept for the monomethylhydrazine (MMH), by process intensification using microreactor technology. The work was funded by the Rhône-Alpes region in the form of a doctoral fellowship TARGET 2008-2011. The first part of this research aims to study the stability of monochloramine solutions prepared in stoichiometric conditions. This synthesis was carried out continuously, for the first time ever, using microreactor technology. Optimal synthesis conditions as well as a set of security parameters have been established for a fast and secured transfer to industrial scale. The second part, also one of the main objectives of this work, is the extraction, under pressure, of all organic products (mostly MMH and monomethylamine) in the form of one condensed phase by demixing the crude reaction liquors. This phenomenon is related to the existence of a miscibility gap in the liquid ternary system H2O-MMA-NaOH. The optimization of the demixing step requires then the study of different solid-liquid-liquid phase diagrams involved. The last part deals with the chemical engineering aspect of the research. A kinetic modeling of the synthesis of MMH by the Raschig way was used in order to estimate the composition of the synthesis solution. These results and the application of phase diagrams allow the determination of optimal conditions for the isolation step and the establishment of process flow-sheets for the synthesis of MMH
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Orr, Wendel Byron. "Velvetleaf (Abutilon theophrasti) response to chloramben applied postemergent." 1985. http://hdl.handle.net/2097/27514.
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Knerr, Larry Dale. "Naptalam as a safener for cucumber (Cucumis sativus L.) against the phytotoxic effects of chloramben." 1987. http://catalog.hathitrust.org/api/volumes/oclc/17374690.html.
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Thesis (M.S.)--University of Wisconsin--Madison, 1987.Typescript. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 112-114).
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Venkatachalapathy, R. "Kinetic investigations of some substrates with Chloramine-T and Chloramine-B." Thesis, 1996. http://hdl.handle.net/2009/2372.
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PITHARDT, Tomáš. "Preventivní a léčebné koupele u plůdku candáta obecného (Sander lucioperca)." Master's thesis, 2017. http://www.nusl.cz/ntk/nusl-320541.
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The aim of this thesis was to test and compare the effect of four selected and in present commonly used medical treatments on other species of fish in recirculating aquaculture system (RAS). This presented work was divided into two separate experiments dealing with curative baths for fry of pikeperch.The fry was raised in ponds, feeded by natural food, with the intention of adaptating for RAS after a bath. Baths were targeted against parasitic and bacterial diseases by using Bellasav, SAVO Original, formaldehyde and Chloramine T. The curative baths took 30 minutes after which the fish were transferred to clean water where the mortality within 24 hours and the efficacy of the preparation within 24 hours was monitored. In the first experiment were used fish with an average weight of 0.23+-0.05 g and a total lenght of 31.7+-2.5 mm at the age of 35 days. The tested doses were 0.5; 1; 1.5; 2; 5; 10 and 50 ml.m-3 for Bellasav, 1; 5; 10; 20 and 50 ml.m-3 for SAVO Original, 0.5; 1; 1.5; 2.5; 5; 10; 15; 30; 45 and 50 ml.100 l-1 for formaldehyde and 10; 20; 30; 40; 50; 100; 150 and 200 mg.l-1 for Chloramine T. The best efficacy was achieved at the concentration dose 1.5 ml.m-3 for Bellasav. The concentration dose 10 ml.m-3 of SAVO Original only reduced parasitic infection by one degree. An effective dose of formaldehyde was 1 ml.100 l-1 which reduced the parasitic infection by two degrees. The most effective preparation was Chloramine T at the concentration dose of 30 mg.l-1. In the second experiment were used fish with an average weight of 1.6+-0.4 g and a total lenght of 60.4+-3.56 mm at the age of 70 days. The tested doses were 10; 20 and 50 ml.m-3 for Bellasav, 10; 20 and 50 ml.m-3 for SAVO Original, 2.5; 5 and 10 ml.100 l-1 for formaldehyde and 40; 150 and 200 mg.l-1 for Chloramine T. The best efficacy was achieved at the concentration dose 20 ml.m-3 for Bellasav and 10 ml.m-3 for SAVO Original. The most effective dose for formaldehyde was 2.5 ml.100 l-1 which reduced the bacterial infection in fish skin by two degrees. The most effective preparation was Chloramine T again at the concentration dose 40 mg.l-1.
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Umesha, K. B. "Synthetic and analytical applications of chloramine-T." Thesis, 2001. http://hdl.handle.net/2009/1929.
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Lo, Yu-lan, and 羅鈺嵐. "Study of control conditions on chloramine in water." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/50721034954733328579.
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碩士國立中山大學
環境工程研究所
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This study is focused to investigate the relations between operation conditions of chloramine and monitoring items of water quality, and could be used for increasing the efficiency of disinfection on water reusing. The major points of design on water reusing are to consider the optimal operation in membrane systems. The effects of chloramine of biological block on operation of membrane systems are found primarily considered in designing. In this study the jar tests were used in all tests. The relations between formation of chloramine and pH were observed by using high and low concentrations of ammonia solution reacted with NaOCl solutions added by us under pH = 6, 7, 8 respectively. The levels of pH were adjusted with H2SO4 and HCl in this work. Final step was conducted to study the variations of residual chlorine curves using pH and ORP. This step could obtain the control conditions of chloramine in all tests. The experimental results showed the formatting concentrations of chloramine was the highest in weight ratio 3.9:1 of Cl2/N (molar ratio was 0.76:1) when concentrations of ammonia nitrogen were high or low and pH were set on 6, 7, and 8. The concentrations of free chlorine were started to format in reaction when weight ratio 6.4:1 of Cl2/N (molar ratio was 1.27:1) was set in reaction. The reaction of ammonia nitrogen was finished when weight ratio 7.7:1 of Cl2/N (molar ratio was 1.52:1) conducted in reaction. In this study for considering chloramine formatting and avoiding free chlorine formatting, thus made the alarming point of chloramine was set on weight ratio 5.5 :1 of Cl2/N (molar ratio was 1:1) for avoiding free chlorine formatting, and made the optimal point of chloramine was set on weight ratio 3.95 :1 of Cl2/N (molar ratio was 0.76:1). It was no significant effects on formatting concentrations of chloramine under different pH by adjusting with H2SO4 and HCl in this work. Therefore, H2SO4 was primarily selected to adjust pH of raw water in influent of RO systems. For this way could raise the treatment efficiency of ammonia nitrogen in RO systems. The limited conditions of application were suggested the times for stopping added chemicals in RO systems when two controlling conditions were observed: (1) when low concentrations of ammonia nitrogen in raw water, pH were lower than 6.8 and ORP were larger than 603.7mV; (2) when high concentrations of ammonia nitrogen in raw water, pH were lower than 6.73 and ORP were larger than 625.8mV.
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Kaur, Rajbir. "Contribution of surface bound positive charge towards the conversion of N-H to N-Cl on poly (ethylene terephthalate) and the antibacterial activity of the resulting N-Cl." 2016. http://hdl.handle.net/1993/31630.
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As a continued study on combined use of different antibacterial chemistries, N-chloramine and short chain Quaternary ammonium compound (QAC) were immobilized on modified poly (ethylene terephthalate) (PET) surface in various ratios via “click” chemistry. In this study, contribution of surface bound QAC to the conversion of cyclic and acyclic N-H to N-Cl, fastest recharging chlorination as well as the most effective antibacterial efficacy was investigated. Surface bound positive charge at the density of 8.4x1016charges/cm2 achieved highest equilibrium conversion and facilitated a nine-fold increase in conversion of sterically hindered acyclic N-H to N-Cl from 0.39 to 3.92%. Within the range of 2.8x1016 to 8.4x1016charges/cm2, highest active chlorine loading within first five minutes of chlorination was observed on sample loaded with 4.6x1016charges/cm2.As it comes to PET surface grafted with a cyclic N-chloramine precursor, the presence of 2x1016charges/cm2 enabled a five-fold increase in the conversion of cyclic N-H to N-Cl. The highest biocidal efficacy was observed for sample loaded with cyclic N-chloramine/QAC 17.2:10 which presented total kill of E.coli (5.8 log reduction) in 10 minutes compared to 1.9 log reduction for other ratios (22.8/10, 75.5/10) tested at a similar level of active chlorine(223±6ppm respectively).October 2016
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Maruszczyk, Magdalene [Verfasser]. "Stereoselektive organische Synthese mit N-Chloraminen und mit Bispyrrolidin-Liganden / vorgelegt von Magdalene Maruszczyk." 2008. http://d-nb.info/990225275/34.
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Scott, Daniel. "An Investigation of Nitrification Predictors and Factors in Two Full-Scale Drinking Water Distribution Systems." Thesis, 2012. http://hdl.handle.net/10012/6450.
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The biologically-mediated process of nitrification can occur in chloraminated drinking water distribution systems. In this process, ammonia is oxidized to nitrite by ammonia-oxidizing bacteria (AOB) and archaea (AOA). In complete nitrification, nitrite is further converted to nitrate by nitrite-oxidizers; however, bacterial mediation of this step is less critical as a chemical-oxidation pathway also exists. The initial conversion of ammonia to nitrite is also more critical due to its role in the degradation of the disinfectant residual. Nitrification is affected by factors such as the concentrations of ammonia and total chlorine, the pH of the drinking water, and the temperature. The key consequence of distribution system nitrification is an accelerated decay of the disinfectant residual; it can also lead to increases in nitrite and nitrate, and a potential proliferation of heterotrophic bacteria.
The goal of this thesis is to enhance understanding of distribution system nitrification; one aspect to this goal is the evaluation of models for nitrification. The approach followed in this study was to collect water samples from two full-scale distribution systems in Southern Ontario. In the first phase, a sampling campaign was conducted at sites in these systems, with water samples being analyzed for parameters considered relevant to nitrification, such as the concentrations of nitrogen species affected by nitrification, the disinfectant residual, and the levels of ammonia-oxidizing microorganisms. In the second phase, batch tests were conducted with water from these same distribution systems.
In the course of the field sampling campaign some indications of nitrification were detected, but there were no severe nitrification episodes as indicated by major losses of the disinfectant or prolonged elevations in nitrite levels. On some occasions at some sites there were small rises in nitrite above baseline levels; moderate declines in total chlorine residual were also seen. Nitrifying microorganisms were present in most samples, as detected by both culture-based and molecular methods (PCR). The latter was able to distinguish AOA from AOB; both were detected in the systems included in this study, with AOB gene counts outnumbering those of AOA at most sites. Using Spearman non-parametric correlations, significant correlations were found between some parameters relevant to nitrification. Notably, AOB were found to be positively correlated with heterotrophic plate counts (HPC), reinforcing the latter's role as a useful indicator of microbial regrowth conditions in a distribution system. Also of interest is the negative correlation between total chlorine residual and levels of microorganisms, reminding drinking water professionals of the value of maintaining a stable disinfectant residual.
Batch testing investigations compared total chlorine decay curves between inhibited and uninhibited samples to provide insight into the microbial contribution to disinfectant decay. Four types of decay curves were identified, with qualitative differences in the microbial contribution to the disinfectant residual decay. Liquid chromatography with organic carbon detection (LC-OCD) was applied to investigate changes in the character of the dissolved organic carbon over the course of the batch tests. Based on the results of this study, it is recommended to evaluate the results of nitrification batch tests based on a visual identification of the curve type and calculation of the decay rates and critical threshold residual (CTR), rather than relying on the microbial decay factor alone to express the results.
An application of this work was in making comparisons to some models for nitrification proposed in the literature. The ultimate goal of these models is to provide drinking water system operators with a prediction of when nitrification episodes will occur so that action may be taken to avert them. The models considered in this study differ in their degree of complexity and in whether they are based on mechanistic considerations. The differences in the underlying principles and data required for analysis make these models suitable for different applications. The results of this evaluation support the use of the model of Fleming et al. (2005) in full-scale distribution systems and the use of the model by Yang et al. (2008) for research applications, while the other models considered can still offer some useful insights.
The results of this research can be applied to monitoring and operational practices in chloraminated distribution systems where nitrification is a potential concern. The correlations between parameters that have significance to distribution system nitrification that were found in this study, along with the modelling and batch testing evaluated in this work, can provide insight into predicting conditions favourable to nitrification and avoiding or averting nitrification episodes.
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Bone, Christopher C. "Ammonia release from chloramine decay implications for the prevention of nitrification episodes in distribution systems /." 1999. http://catalog.hathitrust.org/api/volumes/oclc/48160177.html.
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Thesis (M.S.)--University of Wisconsin--Madison, 1999.Typescript. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 118-122).
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Kgorane, Nomathemba. "Adsorption modelling of desulphurisation of light diesel fuel using Chloramine T and Polymer Supported Imidation Agent." Thesis, 2017. https://hdl.handle.net/10539/24856.
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A research report submitted to the Faculty of Engineering and the Built Environment, University of the Witwatersrand, Johannesburg, in partial fulfilment of the requirements for the degree of Master of Science in Engineering (Metallurgy and Materials Engineering) October 2017In petroleum industry, sulphur compounds are undesirable due to potential corrosions and environmental challenges associated with these compounds. Sulphur occurs in varies forms in crude oil and petroleum products such as, marcaptans, disulphide, sulphides, disulphide H2S and thiophenes. Commercial scale refineries utilises hydrodesulphurisation to reduce the sulphur content in fuels, though this technology is associated with high operating and capital cost. Extractive, adsorptive, oxidative, membrane separation and bio desulphurisation are some of the alternative technology being investigated which have proven not to be as efficient and/or cost effective as compared to hydrodesulphurisation. Adsorption desulphurisation has been effective in separation processes where the sorbate concentrations are low and this technology was used to evaluate the performance of the polymer supported imidation agent (Sodium N-chloro-polystyrene sulphonamide) as an adsorbent in diesel fuel desulphurisation. A mathematical model simulating adsorption on a fixed was developed. This model incorporates internal mass transfer assuming laminar flow, constant interstitial velocity and an isothermal system. To represent liquid solid equilibrium the Langmuir isotherm was used. The model contains partial differentiate equation that were linearised by using the Euler’s forward implicit method, this enabled simulating the model using Microsoft Excel Visual Basic. The obtained simulation results were compared against experimental data. The impact of varying parameters such as initial sulphur concentration, adsorbent bed porosity and external bed surface area per particle volume was studied in detail. Existing isotherms and kinetics were discussed by using experimental data from Fadhel’s study. It was found that the adsorbate residence time is reduced by smaller adsorbent bed porosity resulting in increased adsorption rate. By decreasing the adsorbent particle diameter and an increase in initial sulphur concentration, the breakthrough time is decreased. The experiment data agreed with the simulation results and this validate that the proposed model is applicable to study the performance of fixed bed adsorption processes under isothermal conditions, no axial mixing and constant interstitial velocities. The results from the analysed Fadhel’s data showed that the modelled light oil can be desulphurise to the Euro 5 level requirements, Sulphur <500ppm, by both Chloramine T and Synthesis PI, a complete sulphur removal was achieved using both adsorbents. The desulphurisation rate proved to be faster with Chloramine T as an adsorbent as compared to Synthesis PI. Modelled light oil adsorption obeyed the pseudo-first-order kinetics and the overall adsorption rate was controlled by the chemisorption process. The diesel fuels study by Fadhel could not be desulphurised to the Euro 5 level. The diesel fuel 1 sulphur concentration was reduced from 12 354 to 11 200ppm and diesel fuel 2 from 1 900 to 800ppm. It was observed that the rate of desulphurisation proved to be faster with diesel fuel 1 as compared to that of diesel fuel 2. The Freundlich isotherm was found to be a best fit in the adsorption of diesel fuel 1, the attained R square values was 0.881 and 0.435 for Freundlich and Langmuir, respectively. Also the obtained Langmuir separation factor, RL , of 1 confirmed the that the Langmuir adsorption was unfavourable. This implies that the adsorption rate was controlled by a physisorption process. The diesel fuel 2 desulphurisation process did not fit the studied adsorption isotherms, the attained R square values was 0.433 and 0.218 for Freundlich and Langmuir, respectively. The Langmuir separation factor confirmed in-favourability at 1 and the Freundlich adsorption strength was 6.052, which is very low as compared to that pf diesel fuel 1 at 272.41. Diesel fuel 1 adsorption reaction obeyed the pseudo-second and pseudo-first order kinetics when reacted with Chloramine T and Synthesis PI, respectively. The obtained R squared values were 0.694 and 0.999 for pseudo-second and pseudo-first order, respectively. Diesel fuel 2 obeyed the third order kinetics with both Chloramine T and Synthesis PI, with R squared values calculated at 0.889 and 0.774 for Chloramine T and Synthesis PI reaction, respectively.
XL2018
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Kandou, Alicia Irene. "Ammonia release from chloramine decay implications for the prevention and control of nitrification episodes in distribution systems /." 2000. http://catalog.hathitrust.org/api/volumes/oclc/44688003.html.
Full textAbstract:
Thesis (M.S.)--University of Wisconsin--Madison, 2000.Typescript. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 93-96).
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Nihemaiti, Maolida. "Formation of emerging DBPs from the chlorination and chloramination of seawater algal organic matter and related model compounds." Thesis, 2014. http://hdl.handle.net/10754/316699.
Full textAbstract:
Limited studies focused on reactions occurring during disinfection and oxidation processes of seawater. The aim of this work was to investigate disinfection by-products (DBPs) formation from the chlorination and chloramination of seawater algal organic matter and related model compounds. Simulated algal blooms directly growing in Red Sea, red tide samples collected during an algal bloom event and Hymenomonas sp. monoculture were studied as algal organic matter sources. Experiments were conducted in synthetic seawater containing bromide ion. A variety of DBPs was formed from the chlorination and chloramination of algal organic matter. Brominated DBPs (bromoform, DBAA, DBAN and DBAcAm) were the dominant species. Iodinated DBPs (CIAcAm and iodinated THMs) were detected, which are known to be highly toxic compared to their chlorinated or brominated analogues. Algal organic matter was found to incorporate important precursors of nitrogenous DBPs (N-DBPs), which have been reported to be more toxic than regulated THMs and HAAs. Isotopically-labeled monochloramine (15N- NH2Cl) was used in order to investigate the nitrogen source in N-DBPs. High formation of N-DBPs was found from Hymenomonas sp. sample in exponential growth phase, which was enriched in nitrogen-containing organic compounds. High inorganic nitrogen incorporation was found from the algal samples enriched in humic-like compounds. HAcAms formation was studied from chlorination and chloramination of amino acids. Asparagine, aspartic acid and other amino acids with an aromatic structure were found to
be important precursors of HAcAms and DCAN. Factors affecting HAcAms formation (Cl2/ amino acid molar ratio and pH) were evaluated. Studies on the formation kinetics of DCAcAm and DCAN from asparagine suggested a rapid formation of DCAcAm from organic nitrogen (amide group) and a slower incorporation of inorganic nitrogen coming from monochloramine to form DCAN. High amounts of DCAN and DCAcAm were detected from the chloramination of aromatic compounds (i.e., phenol and resorcinol) indicating that N-DBPs can also be formed from organic compounds without any organic nitrogen through the incorporation of inorganic nitrogen from monochloramine. Moreover, results from Hymenomonas sp., aromatic amino acids, and phenolic compounds suggested that aromatic compounds are highly reactive with monochloramine and a major fraction of DBP precursors.
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Chen, Sz-Chin, and 陳思親. "Enhancement of Chemiluminescence by cationic surfactant for the Oxidation of Luminol with Pottasium Iodide/Chloramine-T and Its Applications." Thesis, 2006. http://ndltd.ncl.edu.tw/handle/48844631733087541893.
Full textAbstract:
碩士國立臺灣大學
化學研究所
94
This study applied stopped-flow spectrometry to investigate the enhancement of chemiluminescence (CL) from the oxidation of luminol with KI/Chloramine-T (CT) by cationic surfactant cetyltrimethyl-ammonium chloride (CTAC). Various factors, including pH, concentration of reagents (KI, CT, and CTAC), that affect the CL intensity were also discussed and optimized. The CL of this system increased with increasing pH and the maximum enhancement occurred at pH 10.0. The optimized condition for this CL system is 20 mM CTAC, 0.025 mM luminol, 0.025 mM KI and 0.025 mM CT at pH 10.0; the CL intensity was thereby enhanced about 80-fold. It is suggested that the negatively charged luminol, iodide and CT will all be attracted around the positively charged micelle surface. In addition, the iodine produced from the oxidation of CT and KI is hydrophobic and easily enters the micelle. The proximity of the reagents involved in the CL reaction will largely improve the overall CL efficient, leading to a dramatic enhancement in CL emission. Other cationic surfactants enhance the intensity of CL system to various extents: 70-fold for 50 mM DTAC, only 2-fold for 1 mM HPC. The results indicate that the CL enhancement is related to the size of micelle. In addition, anionic surfactant SDS and β-cyclodextrin exhibit essentially no enhancement. The antioxidants destroy the radicals involved in the CL reaction, causing a decrease in CL emission. Thereby, the CL system has been applied to determine several antioxidants such as trolox (0~19 μM), BHA (0~5 μM), BHT (0~14 μM), GSH (0~16 μM), ascorbic acid (0~30 μM), cysteine (0~14 μM), tyrosine(0~50μM), and flavonoids (3,6-dihydroxyflavone:0~20 μM ; 3,7-dihydroxyflavone:0~50 μM).
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Chen, Chia Hsing, and 陳佳杏. "Zinc-Catalyzed Chloroamination reaction of Ynamides and Chloramine-T And Gold-Catalyzed Regiocontrolled [2+2+2]-Cycloadditions of Two Terminal Ynamides with Vinyl ether." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/58596739301259081805.
Full textAbstract:
碩士國立清華大學
化學系
104
PART 1 The synthesis of (Z)-2,2-dichloro-N-methyl-N-(methyl-sulfonyl) -2-phenyl-N'-tosylacetimidamide, an efficient zinc catalyzed reaction enhancing the reactivity for the chloroamination of alkynes with Chloramine-T at room temperature, is described with moderate to good yields. The electron-deficient character of the azomethine group of polyhalogenaldimines promotes their interactions with numerous nucleophiles, which could be used for further reactions. PART 2 This part of the dissertation deals with the gold-catalyzed regiocontrolled [2+2+2]cycloadditions of two ynamides and vinyl ether constructing polysubstituted benzene derivatives. The utility of this new cycloaddition is manifested in the excellent regioselectivity with a wide range of scope of applicable ynamides as well as vinyl ether. And there are few examples using alkene for [2+2+2]cyclization reactions.
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Lin, Li Shuan, and 林立軒. "Gold-Catalyzed Divergent Addition and Cyclization Reaction of Ynamide with Allylic and Propargyl Alcohol and Zinc-Catalyzed Chloroamination reaction of 3-En-1-Ynamide and Chloramine-T." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/96949094186258609407.
Full textAbstract:
碩士國立清華大學
化學系
104
Chapter 1 We developed the gold-catalyzed reaction with allylic alcohol and propargyl alcohol delivering variety of product such as Claisen rearrangement’s type product, 1,4 addition’s type product and undergo cyclization followed by 1,4 addition’s type product. Chapter 2 An efficient Zinc catalysis enhances the reactivity of the Chloramine-T, and Chloramine-T react with the ynamides which has the vibration’s olefin. The reaction will undergo the chloroamination of ynamides with Chloramine-T at room temperature. The reaction will get the Polyhalogenaldimes in the moderate to good yields. The products will include one primary C-Cl bond and one secondary C-Cl bond, with these good leaving group, it can promote their interaction with divergent nucleophiles to form numerous novel compounds.
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Shoker, Tharallah A. "Synthesis of Novel Extremely Sterically Hindered Tertiary Alkylamines." 2018. https://monarch.qucosa.de/id/qucosa%3A21109.
Full textAbstract:
Three advanced methodologies for the preparation of extremely sterically hindered tertiary alkyl amines have been developed. The syntheses of 28 novel tertiary alkylamines that accommodate unusual steric hindrance are detailed.
The electrophilic amination of alkyl Grignard reagents with N-chlorodialkylamines, in the presence of N,N,N′,N′-tetramethylethylenediamine (TMEDA) as a key additive, gives a variety of unprecedentedly sterically hindered tertiary alkylamines in good yields. Alternative strategy to 1-adamantyl-substituted (1-Ad) sterically hindered tertiary amines, which involved instead an SN1 reaction between 1-Ad cation with various secondary amines, is described. A complementary strategy to 1-Ad-based sterically hindered tertiary amines, which involves an iminium salt intermediate, is also reported.
Salient features of the three protocols that are detailed here include unusual tolerance of steric hindrance, mild reaction conditions employed, ease of product isolation-purification, and absence of catalysts/transition metals.
The molecular structures of two faithful examples of extremely sterically hindered tertiary alkylamines were determined by single crystal X-ray diffraction, and the height “h” of nitrogen pyramid of these compounds were measured. The NMR spectra show a restriction in rotation at room temperature among many hindered tertiary amines, and some of them exhibit two complete sets of peaks for two non-equivalent rotamers at room temperature. 15N NMR has been applied to study the structural changes in highly sterically hindered tertiary amines. Most of these compounds have been shown to undergo Hofmann type elimination reaction upon thermolysis at 100 degree in inert solvents, like toluene.In der vorliegenden Arbeit wurden drei Methoden zur Synthese von tertitären Aminen mit extremer sterischer Hinderung entwickelt und zur Synthese von 28 neuen tertiären Alkylaminen mit entsprechender sterischer Hinderung angewendet. Die elektrophile Aminierung von Grignard-Reagenzien mit N-Chlordialkylaminen, unter Zusatz von N,N,N′,N′-Tetramethylethylendiamin (TMEDA) als Schlüsselkomponente, ermöglicht einen einfachen Zugang zu einer Vielzahl von tertiären Aminen mit extremer sterischer Hinderung mit guten Ausbeuten. Eine alternative Synthesestrategie unter SN1-Bedingungen führt zu sterisch-gehinderten 1-Adamantyl-substituierten (1-Ad) tertiären Aminen durch die Reaktion eines 1-Ad-Kations mit unterschiedlichen sterisch-gehinderten sekundären Aminen. Angelehnt an die zuvor beschriebene Reaktion können auch sterisch gehinderte Imine über eine Iminium-Salz-Zwischenstufe zu sterisch-gehinderten 1-Ad-substituierten tertiären Aminen umgesetzt werden. Auch in diesen Fall zeichnet sich die Reaktion durch eine bemerkenswerte Toleranz gegenüber sterischer Hinderung, milden Reaktionsbedingungen, leichte Produktisolierbarkeit und die Abwesenheit von Übergangsmetallkatalysatoren aus. Die molekulare Struktur zweier repräsentativer tertiärer Alkylamine mit extremer sterischer Hinderung wurde mittels Röntgeneinkristallstrukturanalyse untersucht und die Höhe “h” ihrer Stickstoff-Pyramide bestimmt. Die NMR-Spektren zeigen bei RT eine Einschränkung der freien Rotation um die N-C-Bindungsachse, teilweise führt dies zu vollständig getrennten Signalsätzen für die einzelnen Rotamere. 15N-NMR-Spektroskopie wurde ebenfalls zur Untersuchung von Strukturveränderungen genutzt. In inerten Lösungsmitteln, wie Toluol, zeigen die Verbindungen bei 100 °C in den meisten Fällen eine Hofmann-Eliminierung.