Dissertations / Theses: 'Discharges of pollutants'

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Уберман, В. И., та Людмила Антоновна Васьковец. "Сверхнормативные сбросы загрязняющих веществ: методика судебной экспертизы причиненных убытков". Thesis, Національний технічний університет "Харківський політехнічний інститут", 2014. http://repository.kpi.kharkov.ua/handle/KhPI-Press/45255.

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Рассматриваются основные особенности и алгоритмы методики для проведения судебной экспертизы убытков, причиненных государству сбросами загрязняющих веществ с возвратной водой. Приводятся структура и примеры практического использования методики. Basic aspects of the methodology and main algorithms for forensic examination of economic losses caused for state from excessive discharges of pollutants in sewage waters are considered. The structure of the methodology and some practical examples of usage the techniques are given.

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Yuan, Ye [Verfasser], W. Kirk [Gutachter] Junker, and Stephan [Gutachter] Hobe. "A Comparative Study: China’s Water Pollutants Discharge Permit System with Reference to the National Pollutants Discharge Elimination System of the United States of America / Ye Yuan. Gutachter: W. Kirk Junker ; Stephan Hobe." Köln : Universitäts- und Stadtbibliothek Köln, 2016. http://d-nb.info/1103134884/34.

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Yuan, Ye [Verfasser], W. Kirk Gutachter] Junker, and Stephan [Gutachter] [Hobe. "A Comparative Study: China’s Water Pollutants Discharge Permit System with Reference to the National Pollutants Discharge Elimination System of the United States of America / Ye Yuan. Gutachter: W. Kirk Junker ; Stephan Hobe." Köln : Universitäts- und Stadtbibliothek Köln, 2016. http://nbn-resolving.de/urn:nbn:de:hbz:38-67123.

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Zabitytė, Jurgita. "Radioaktyviųjų teršalų paplitimo atmosferoje įvertinimas." Master's thesis, Lithuanian Academic Libraries Network (LABT), 2007. http://vddb.library.lt/obj/LT-eLABa-0001:E.02~2007~D_20070816_165005-33201.

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Šio darbo pagrindinis tikslas − įvertinti radioaktyviųjų teršalų paplitimą atmosferoje ir nusėdimą, bei įvertinti teršalų žalą aplinkai ir žmonėms. Tam tikslui pasiekti, šiame darbe buvo: 1.išanalizuoti pagrindiniai radioaktyviųjų teršalų paplitimo būdai; 2.supažindinta su teisės aktais ribojančiais radionuklidų išmetimą į aplinką; 3.įvertinti labiausiai žmonių sveikatą įtakojančių radionuklidų ir sklidimą atmosferoje ir nusėdimą. In Lithuania we have a very important object from the point of energetics. It’s atomic power − station of Ignalina. It is work safety aspects worry so the themes of the graduate work have been chosen for this clean reason. The base of the work is to evaluate the damage of the radiological nuclides and to the environment and people and their discharge amounts the atmosphere, if it doesn’t exceed allowable norms, witch are regulated by the laws of Lithuania Republic. Willing to introduce you to this theme the following objectives were defined: 1.The main ways of radiological pollutants discharge into the atmosphere have been analyzed; 2.Have been familiarized with the main norms of radiological safety and the limitation of the discharge of radio nuclides into the atmosphere from the objects of atomic energetics; 3.According to the push − button program of environment pollution “ Hysplit ” the distribution of the radiological nuclides in the atmosphere has been denoted; 4.According to the results having been done by the program “ Hysplit “, the diagram of the dependence of the nuclides and on time has been delineated. It is clear that the atmosphere doesn’t exceed allowable norms of the laws of Lithuania Republic. It’s even lower than allowable norms per day. In conclusion, having all the objectives of this work analyzed it becomes clear that the amounts of the nuclides and witch gets into the atmosphere doesn’t damage our organisms and environment.

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Kumar, Alok. "Optimum Allocation of Discharged Pollutant Loads from Nonpoint Sources in a Watershed using GIS." Kyoto University, 2003. http://hdl.handle.net/2433/148983.

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Kyoto University (京都大学) 0048 新制・課程博士 博士(農学) 甲第10257号 農博第1329号 新制||農||867(附属図書館) 学位論文||H15||N3778(農学部図書室) UT51-2003-H678 京都大学大学院農学研究科地域環境科学専攻 (主査)教授河地利彦, 教授青山咸康, 教授高橋強 学位規則第4条第1項該当

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Weiner, Ellen Rebecca. "Evaluation of Impacts Resulting from Home Heating Oil Tank Discharges." Thesis, Virginia Tech, 2018. http://hdl.handle.net/10919/84395.

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Diesel #2 is used to heat nearly 400,000 dwellings in Virginia. Home heating oil released from leaking underground tanks located adjacent to homes and residing in unsaturated soil adjacent to houses poses a potentially serious health risk. Specifically, the migration of hazardous vapors into buildings, known as vapor intrusion, can negatively impact indoor air quality in homes and public buildings (USEPA 2015). In this look-back study, we assessed the potential for petroleum vapor intrusion by sampling soil vapor at 25 previously remediated spill sites. Residual contaminants, in particular total petroleum hydrocarbons (TPH) and naphthalene, were detected in approximately 1/3 of the samples. Concentration levels were correlated to site variables (building type, remediation time, physiographic region) including previous abatement measures. Spill category as assigned by the remediation contractor was investigated in conjunction with these three site variables. Remediation time was the most promising predictive site variable, with visible trends downward in DEQ Category 2 sites with increased remediation time. Higher contaminant concentrations were found near basement-style dwellings, which we hypothesize is due to the wall of the basement blocking horizontal migration of contaminants and the flow of oxygen to the release source zone. We found that many sites exceeded the sub-slab risk target threshold in naphthalene concentration, which has negative implications on previous abatement strategy efficacy. Master of Science

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Mouele, Emile Salomon Massima. "Degradation of persistent organic pollutants (pharmaceuticals & dyes) by combined dielectric barrier electrohydraulic discharge system and photo catalysts." University of the Western Cape, 2019. http://hdl.handle.net/11394/6976.

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Philosophiae Doctor - PhD Water pollution problems have continued to increase not only in South Africa but worldwide due to human activities. The presence of organic toxins and bacteria in water sources is mostly due to population growth, industrial development and agricultural run-off. The accumulation of persistent organic pollutants (POPs) in water and wastewater sources has raised various questions on the safety of potable water used for drinking, households and other activities. Traditional mechanical, biological, physical, and chemical methods such as flocculation, coagulation, reverse osmosis, filtration, ultrafiltration, adsorption and active sludge treatment methods have failed to remove these new xenobiotic from aquatic media. This is due to the fact that instead of degrading the toxins, the methods listed above often transform organic contaminants from one form another. Also, the post treatment of by-products resulting from these methods is costly. In addition, this new generation of contaminants, often referred to as compounds of emerging concern (CECs), exist in tiny concentrations (ng) and conventional techniques have not been designed for these low levels of pollutants which consequently pass through during treatment processes and end up in the treated effluents at minute concentrations (ug/L to ng/L). However, complete remediation of chemical toxins in wastewater treatment plants has not been achieved. A better option involves the direct oxidation of the pollutants in the effluent but so far their complete mineralisation has not been achieved. Advanced oxidation processes (AOPs) have emerged in recent years as adequate techniques for the complete removal of POPs. AOPs focus more on the production of non-selective hydroxyl radicals (OH.) which have been considered as the most powerful oxidants (2.8 V) that directly or indirectly mineralise the organic pollutant into dissolved CO2, H2O and harmless end-products. However, the use of excessive chemicals, corrosion of catalyst supports, wasted UV, ozone escapes and the cost associated with AOPs often limit their application for the removal of POPs from water and wastewater treatment facilities. The principal aim of this study was to optimise a double cylindrical barrier discharge (DBD) system for the removal of low concentration persistent organic pollutants (POPs). The efficiency of the DBD system was initially confirmed by quantification of three main reactive oxygen species including ozone (O3), hydrogen peroxide (H2O2) and hydroxyl radicals (.OH) among others. These three active species were successfully detected and quantified using indigo, per titanyl sulphate and terephthallic acid (TA) spectroscopy methods, respectively. Thereafter, the DBD reactor was optimised by assessing the effect of electrophysico-chemical parameters on the removal efficiencies of two selected pollutants including orange II sodium salt dye (O.II) and sulfamethoxazole (SMX), a pharmaceutical, as model persistent organic pollutants. 2020-09-02

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Peacock, Steven. "Storm Water System Monitoring for the Small Municipality Under Phase II of the National Pollutant Discharge Elimination System." Thesis, University of North Texas, 2003. https://digital.library.unt.edu/ark:/67531/metadc4298/.

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Storm water quality can have a significant impact on receiving water bodies. The chief recipients of these impacts are aquatic life in the receiving water body and downstream water users. Over the last few decades, legislation, regulations, institutions and facilities have evolved to recognize the impact of urban storm water on receiving streams. This increased emphasis has caused contaminants in storm water to be identified as a major concern. This developing concern has generated an increased interest in the water quality of our streams and lakes and emphasized the need for more monitoring efforts. With the passage of the National Pollutant Discharge Elimination System (NPDES) Phase II requirements, small municipalities are responsible for storm water impacts on receiving waters within their jurisdiction. For the purposes of NPDES Phase II requirements, small municipalities are identified as these municipalities that are typically composed of 10,000 but less than 100,000 in population. The purpose of this dissertation is to develop a manual for use by the staff of small municipalities in meeting the requirements prescribed by changes initiated in the NPDES Phase II regulations. Attempts were made to comply with these requirements within a very limited manpower and budget framework and to develop procedures that would allow for permit compliance using testing equipment that was both reliable and robust. The users' manual provides valuable guidance in the establishment of a knowledge base for characterization of the watersheds selected for study. Chapter 3 of the dissertation contains a users' manual, designed for use by municipal staff members in their efforts to comply with the NPDES Phase II requirements. Using the techniques and equipment capabilities developed during the writing of the users' manual a characterization of three watersheds within Denton County, Texas was developed. Non-storm water samples were taken from each of the streams and a baseline analysis was established. The three watersheds represented agricultural, suburban and urban settings. Storm water samples were obtained from multiple storms within all three watersheds and data analysis used to determine the character and impact of urban runoff. Determination of the constituents for analysis was based on monitoring requirements of the NPDES Phase I and II requirements for owners and operators of municipal separate storm sewer systems (MS4) and on the Texas Pollutant Discharge Elimination System (TPDES) Multi-Sector General Permit (MSGP). The three watersheds were determined to have multiple statistically significant differences for some parameters between their Base Flows and Storm Flows. The impact of urban runoff on the receiving waters of these three drainage systems was clearly demonstrated throughout the testing period.

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Guckian, Jacqueline. "Ohio Environmental Protection Agency: An Internship Report." Miami University / OhioLINK, 2007. http://rave.ohiolink.edu/etdc/view?acc_num=miami1196169547.

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Gosset, Antoine. "Evaluation de l’écotoxicité des rejets urbains par temps de pluie : Développement d’une batterie de bioessais et application à la conception de biocapteurs." Thesis, Lyon, 2018. http://www.theses.fr/2018LYSEI027/document.

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Les Rejets Urbains par Temps de Pluie (RUTP) représentent une pollution très complexe et variable de par la diversité des évènements pluvieux et des bassins versants lessivés. Les RUTP sont, dans la majorité des cas, rejetés dans des milieux récepteurs aquatiques péri-urbains tels que les lacs, rivières ou eaux souterraines, sans traitement d’épuration. La pollution déversée, qui peut être très diluée, est le plus souvent liée à des évènements relativement courts et difficiles à prévoir. L’impact écotoxique des RUTP peut donc s’avérer difficile à évaluer, en particulier par des mesures directes in situ. Parmi les organismes utilisés en écotoxicologie, les microalgues sont extrêmement intéressantes. En effet, elles constituent la base des réseaux trophiques, sont sensibles à une large gamme de polluants et sont très sensibles à la présence de substances exogènes. C’est la raison pour laquelle nous avons développé dans un premier temps une batterie de biomarqueurs cellulaires sur microalgue (perturbation de la physiologie (comme la photosynthèse) de Chlorella vulgaris), afin de montrer leur intérêt pour détecter rapidement et sensiblement l’impact toxique d’échantillons de RUTP collectés sur la région Lyonnaise. La réponse de ces biomarqueurs a été comparée en laboratoire à une batterie de bioessais écotoxicologiques monospécifiques classiques sur microalgues et microcrustacés (e.g. essais de croissance, reproduction). Dans un second temps, nous avons travaillé à l’adaptation de ces biomarqueurs afin de créer des outils de détection in situ. Des biocapteurs à cellules entières, basés sur une mesure de la perturbation de la photosynthèse (fluorescence chlorophyllienne) de microalgues, ont été développés. Pour leur création, deux techniques de mise en contact bio-récepteur/transducteur ont été testées : (i) la double encapsulation des microalgues dans des hydrogels alginate/silice utilisant un procédé sol-gel, et (ii) l’inclusion des microalgues dans des puces microfluidiques fabriquées par xurographie. Une station portative autonome de terrain a été élaborée et testée avec efficacité pour effectuer des mesures in situ de la toxicité des RUTP, et des milieux aquatiques urbains contaminés. Ce travail de thèse présente de nombreuses perspectives concernant une meilleure connaissance de l’impact des RUTP sur les organismes aquatiques. Il apporte également des réponses à la problématique du développement des biocapteurs à cellules algales entières pour la surveillance environnementale Urban Wet-Weather Discharges (UWWD) represent a very complex and variable pollution due to the diversity of the rainfall events and leached watersheds. In most cases, UWWD are released without, or after very low treatments only, in suburban aquatic environments such as lakes, rivers or groundwaters. Spilled pollution is often linked to relatively short and difficult to predict events, and can be very diluted. Thus, it may be complicated to assess the ecotoxic impact of UWWD, and particularly in situ. Among the organisms used in ecotoxicology, microalgae are particularly interesting because they are the basis of trophic networks, are sensitive to a wide range of pollutants found in UWWD and can react very quickly to their presence. It’s why, first, we developed and used a battery of microalgae (Chlorella vulgaris) cellular biomarkers (e.g. photosynthesis disturbance) to demonstrate their utility in detecting the toxic impact of UWWD samples collected in the Lyon city area in a rapid and sensitive way, in comparison with a battery of monospecific bioassays on microalgae and microcrustaceans (e.g. growth or reproduction inhibition assays). In a second phase, we worked on the adaptation of these biomarkers for the creation of ecotoxicological field tools, biosensors. We developed two types of whole-cell biosensors based on the microalgal photosynthesis (chlorophyll fluorescence) disturbance. We particularly worked on the microalgal immobilization processes in the aim to design biosensors, using mainly two techniques: a double-encapsulation in alginate/silica hydrogels using a sol-gel process and an inclusion in microfluidic chips created by xurography. Finally, we were able to create an autonomous portative biosensor able to conduct in situ measurements of UWWDs toxicity and contaminated urban aquatic environments in general. This thesis project presents many perspectives concerning the deeper understanding of the UWWDs impact on aquatic organisms, and also on the development of whole-cell biosensors for the environmental monitoring

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Brankatschk, Robert, and Klaus-Peter Lange. "Risikoabschätzung für Stoffausträge aus Ackerflächen." Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2014. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-139473.

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In der Broschüre wird ein neues Verfahren vorgestellt, welches zur Bewertung und Minderung von Stoffausträgen aus Ackerflächen in Oberflächengewässer entwickelt wurde. Dazu werden in einem ersten Schritt Gewässer und angrenzende Ackerschläge hinsichtlich Nutzung, Schutzstreifen und Gefahrenpunkte erfasst. In einem zweiten Schritt werden ein N- und ein P-Index berechnet, die das Stoffaustragsrisiko angeben. Die beiden Indices basieren auf einfach zu erhebenden Daten und auf einfachen Berechnungen. In einem dritten Schritt werden Maßnahmen zur Risikominderung empfohlen und deren Wirksamkeit prognostiziert. Anhand dieser Prognose können passende Schutzmaßnahmen ausgewählt werden. Das Verfahren wurde an zwei Oberflächenwasserkörpern in Sachsen erprobt. Es kann ebenso die Identifikation von Flächen mit hohem Stoffaustragsrisiko unterstützen.

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Hannouche, Ali. "Analyse du transport solide en réseau d’assainissement unitaire par temps de pluie : exploitation de données acquises par les observatoires français en hydrologie urbaine." Thesis, Paris Est, 2012. http://www.theses.fr/2012PEST1134/document.

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Cette thèse valorise les données de mesure en continu de pluie de débit et de turbidité, ainsi que les bases de donnée de résultat d'analyse et les connaissances acquises dans le cadre des trois observatoires français en hydrologie urbaine, OPUR-Paris, OTHU-Lyon et ONEVU Nantes, pour valider et améliorer les connaissances sur les flux et les sources de particules vectrices de contaminants, en réseaux d'assainissement unitaire. Les données provenant de 6 sites expérimentaux drainés par un réseau d'assainissement unitaire ont été exploitées : Marais, Quais et Clichy à Paris, Cordon Bleu et Saint-Mihiel à Nantes et Écully à Lyon, avec sur chaque site des bases de données de longue durée qui ont permis des études statistiques sur des échantillons de plusieurs dizaines d'événements pluvieux et de journées de temps sec. Cette thèse a permis : 1- d'évaluer la représentativité de la turbidité pour analyser du transport solide en réseau ; 2- d'analyser et de modéliser statistiquement les concentrations et les masses de particules à l'échelle événementielle ; 3- d'étudier la dynamique des flux et des concentrations à l'échelle intra-événementielle. Les résultats obtenus indiquent d'une part, que la turbidité permet de décrire les dynamiques intra-événementielles des flux et des concentrations à condition d'exprimer ceux-ci sous forme relative, normalisée par les valeurs moyennes événementielles. En revanche, ces valeurs événementielles sont attachées par des erreurs systématiques non négligeables induites par les variations inter-événementielles de la relation MES-Turbidité (intervalle de confiance de l'ordre de 30% de la moyenne). Ils confirment d'autre part que la contribution des dépôts aux flux de temps de pluie est importante mais variable (entre 20 et 80% de la masse à l'exutoire selon l'événement), y compris sur un site réputé exempt de dépôts (grossiers). Autrement dit, les problématiques d'ensablement et de pollution de temps de pluie ne sont pas nécessairement liées. L'autre contribution majeure est celle des eaux usées « de temps sec ». De plus, ils nous ont permis de progresser dans la compréhension des phénomènes de décalage temporel entre hydrogramme et pollutogramme et d'effet piston This thesis exploits continuous measurement of rainfall, discharge and turbidity data and the knowledge acquired by three French observatories in urban hydrology, OPUR-Paris, OTHU Lyon and ONEVU-Nantes, to validate and improve knowledge on suspended solids discharges and sources of particles, which are major vectors of contaminants in combined sewer systems. Data from six experimental sites served by a combined sewer system were used: Marais, Quais and Clichy in Paris, Cordon Bleu and Saint-Mihiel in Nantes and Ecully in Lyon. At each site, a long duration databases enabled statistical studies on samples of several tens of rainfall events and dry weather days. This thesis allowed: 1-to assess the representativeness of turbidity to analyze sediments transport in network; 2-to analyze and model concentrations and masses of particles at the scale of rain events; 3-to study the dynamics of fluxes and concentrations at intra-event scale. Results show that turbidity can describe the dynamics of intra-event fluxes and concentrations provided these are expressed in a relative form, normalized by the event mean values. However, these mean values are attached by significant systematic errors induced by variations of the inter-event TSS-turbidity relationship (95% confidence interval about 30% of average). The contribution of sewer deposits to wet weather suspended solids discharges is important but variable (between 20 and 80% of the mass at the outlet depending on the event), including for a site allegedly free of (coarse) sewer deposits. In other words, the problems of silting and contribution from deposits to wet weather pollution are not necessarily related. The other major contribution is from “dry weather” wastewater. In addition, they we made some progress in understanding the lag-time phenomena between hydrograph and pollutograph and the piston effect

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Sámano, Celorio María Luisa. "Desarrollo e integración de modelos numéricos de calidad del agua en un Sistema de Información Geográfica." Doctoral thesis, Universidad de Cantabria, 2011. http://hdl.handle.net/10803/35687.

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En la presente tesis se aborda el desarrollo de un modelo de calidad del agua orientado al estudio de sustancias prioritarias y peligrosas teniendo en cuenta los efectos de la dinámica sedimentaria a fin de facilitar la gestión de zonas estuarinas. Además, con el objeto de poder llevar a cabo la integración del modelo desarrollado dentro de un Sistema de Información Geográfica, se establecen los procedimientos metodológicos necesarios. La conjugación de estas tareas permitirá fusionar los beneficios de ambos instrumentos bajo un único entorno a fin de obtener una herramienta de gestión de vertidos que aporte respuestas técnicas tomando en consideración las exigencias legislativas de la normativa vigente. This thesis tackles the development of a water quality model devoted to priority and hazardous substances considering, as well, the effects derived from the sedimentary dynamics with the aim to simplify the management of estuarine areas. Moreover, with the aim to integrate this model into a Geographical Information System, the required methodological procedures are established. The combination of both tasks will allow the integration of the benefits from both tools within a unique environment that will allow the discharges management providing technical answers taking into consideration the legislative requirements.

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Chung, Rui-Yean, and 鍾瑞源. "Studies on the Improvement of Gaseous Pollutant Discharges for." Thesis, 1998. http://ndltd.ncl.edu.tw/handle/85663706907261964121.

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博士 淡江大學 水資源及環境工程學系 86 No.6 fuel oil, commonly refereed to as "Fuel Oil", is a main fuel to power industrial boiler. After combustion, the exhaust gas contains significant amount of pollutants such as particulates, carbon black, CO2, NOx and SOx, etc. that have tremendous adverse impact on the environmental quality. Studies with the objective of improving the combustion of No.6 fuel oil and abating the pollution have been initiated on formulating the No.6 fuel oil with addition of water, solvent and activating agents. Emul The hemogenized No.6 fuel oil are mixed with the used of a "static mixed", This creates emulsified No.6 fuel oil of micro droplet, smaller than 5μm, with water sealed inside using emulsified No.6 fuel oil is a "Y type multijet twin fluid atomizers" burner produces double varporization and micro explosions during combustion, reducing emission pollution. This study can be concluded as following: 1.Homogenized oils have 8.8~45% more CO2 in the exhaust bas, calculated with unit weight of emulsified oils reduce CO2 emission by 7~12%. 2.Reduce NOX emission by 13.9~45%. 3. Reduce SOX emission by 38.2~51.7%. 4.Homogenized oils have CO concentration within 4~100 ppm. 5.Creare equal or better level furl oil combustion efficiency. 6.Reduce inner boiler and the exhaust gas temperature by 10~180%℃. 7.Reach goal of low oxygen combustion though coefficient of excess air reduction.

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Shieh, Wen-Shyang, and 謝文祥. "Numerical Study on the Diffusion of Drilling Pollutants Discharge in the Sea." Thesis, 1995. http://ndltd.ncl.edu.tw/handle/78387400469277001636.

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碩士 國立海洋大學 河海工程學系 83 The present study is to investigate the discharge of drilling muds and produced water from oil drilling platform.The results can be used as references for marine environment protection. The short-term diffusion of the discharge can be catalogued into three phases:jet convective descent, dynamic collapse and bottom encounter.By using the conservation laws,a set of ordinary differential governing equations are derived.The set of govering equations incorporating with proper initial conditions are solved by the Forth order Runge-Kutta Method.The variations of the discharged muds of their trace centerline path and dilution rate are calculated and discussed.The calculated trace centerline path of the discharge is in good agreement with the experimental data of Davis et al.Also the discharge radius is smaller as in comparison with Teeter''s result.

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Wang, Bo-Yo, and 王博右. "Wind tunnel study on the vertical discharge of airborne pollutant dispersion around the set-up canyon." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/93243687380164597655.

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碩士 國立臺灣海洋大學 河海工程學系 103 This study was to explore the dispersion characteristics of airborne pollutant around the set-up cayon. Experiment are conducted in the Environmental Wind Tunnel of Nation Taiwan Ocean University. Spire arrays roughness elements were deployed to simulate a turbulent boundary layer as the approaching flow. Cases of different building heights, different cayon spaces and source heighs are run in the experiments.Results are summarized as follows: (1) The neutral atmospheric turbulent boundary layer flow was simulated as the approaching flow which had the power-law mean velocity profile with exponent n=0.27. This exponent value is within the range of urban type of atmospheric boundary layer flow proposed by Counihan(1975). (2) When the canyons spacing becomes narrow,due to the the rear of the building of the barrier, the flow upward reflux causes aggregation concentration situation. The concentration of trace gases accumulate more readily around the canyon. As canyon spacing becomes broader, airflows in the canyon are the greater mobility. Therefore trace concentrations are transported in downstream. (3) When the canyon spacing becomes small, while the rear building with height 2H(H is the front building height),a significant uplift flow phenomenon has occurred. This caused the tracer pollution accumulating around the apper position of rear building.

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Lee, Bo-Jun, and 李柏駿. "Wind tunnel study on the horizontal discharge of airborne pollutant dispersion around the step up canyon." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/06263280181730265886.

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碩士 國立臺灣海洋大學 河海工程學系 103 This study was to explore the dispersion characteristics of elevated point source discharging horizontally into step up street canyons. Experimental results are summerized as: (1)Spries and roughness elements are used to simulate a turbulent boundary layer flow which is expressed power law profoile with an exponent of 0.27. This value is found to within the range of urban type of atmospheric boundary layer flow proposed by Counihan(1975) (2)As the pollutant was discharging horizontally into the canyon,accumulation of pollutants occurred in different regions for changing the canyon width.The windward side of step up canyon has found pollution accumulation when the windward side building height increases. (3)The dispersion parameters variations are proportional to the elevated source heights which is located in the leeward side of step up canyon. (4)The measurd horizontal concentration distributions are found to close to the prediction of Gaussian diffusion equation.

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Chen, Cheng-Chun, and 陳振鈞. "Wind tunnel study on the vertical discharge of airborne pollutant dispersion around the step down canyon." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/50183051468036458385.

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碩士 國立臺灣海洋大學 河海工程學系 104 The study was to investigate the dispersion of elevated source which discharged vertically into the step down canyon. The urban type of neutral atmospheric turbulent boundary layer was simulated in the wind tunnel. The mean velocity profile was expressed in power-law with the exponent n=0.27. The simulation results are found in agreement with the results proposed by Counihan(1975). Measurement results show that the pollutants are accumulated in the street canyon when the width of canyon becomes narrow. As the width of canyon is wider, the pollutants diffuse better. When the step down steepness for canyon increases, the dispersion becomes better in the canyon. The effect on the pollution dispersion for canyon width is more significant than that of for canyon step down steepness.

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Yan, Hong-Ming, and 顏鴻名. "Wind tunnel study on the vertical discharge of airborne pollutant dispersion for parallel wind direction to the street canyon." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/71196201053009510955.

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碩士 國立臺灣海洋大學 河海工程學系 104 This study employed the wind tunnel to investigate the flow and dispersion characteristics of elevated point source discharging into street canyon. Spire arrays and roughness elements were deployed to generate a thick turbulent boundary layer in the wind tunnel. The neutral atmospheric turbulent boundary layer flow was simulated as the approaching flow which had the power-law mean velocity profile with exponent n=0.27. The simulated turbulent boundary layer with turbulence intensity close to the ground is about 0.2~0.24. The simulation of approaching flow is found in agreement with the results proposed by Counihan(1975). The effect of width of street canyon and building height difference of two sides in canyon on the pollution dispersion were explored. Results show that the wind flow smoothly and it is favorable to pollution dispersion when the width of street canyon becomes wider. The in crease of building height difference results in the better dispersion of pollution in the street canyon.

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Sinha, Dipanwita. "Towards Achieving Better NOx Removal In Discharge Plasma Treatment Of Diesel Engine Exhaust." Thesis, 2007. http://hdl.handle.net/2005/648.

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In India, the expansion of industries and two-fold increase in motor vehicles over the last decade are posing a serious environmental crisis in the form of urban air pollution. Common pollutants include carbon monoxide, sulfur dioxide, chlorofluorocarbons (CFCs), and nitrogen oxides produced by industry and motor vehicles. Air pollution results from a variety of sources. The natural sources include volcanoes, forest fire, scattering soil, biological decay, lightning strikes, dust storms etc. and man-made sources include thermal power plants, vehicular exhausts, incinerators and various other industrial emissions. More than 60% of the air pollution is contributed by these man-made sources. Amongst the gaseous pollutants, the major concern and a challenging task is to control oxides of nitrogen, commonly referred to as NOx. In case of diesel engines, despite the modification in engine design and improvement in after treatment technologies, large amount of NOx continues is get emitted and attempts to develop new catalyst to reduce NOx have so far been less successful. Further, with the emission standards becoming more stringent, estimates are that NOx and particulate matter emission must be reduced by as much as 90%. In this context, the emergence of electrical discharge plasma technique in combination with the few existing technologies is providing to be economically viable and efficient technology. In this thesis emphasis has been laid on the discharge based non-thermal plasma for NOx removal. NOx from simulated gas mixture and actual diesel engine exhaust has been treated. The thesis mainly addresses the following issues. . • Performance evaluation of pipe-cylinder and wire-cylinder reactor for NOx removal . • Study of effect of plasma assisted adsorbent reactor on NOx removal . • Study of effect of adsorption and plasma based desorption using different adsorbent material and electrode configuration The first chapter provides introduction about the air pollutants and the existing NOx control technologies, a brief history of electric discharge plasma, a detailed literature survey and scope of the work. A detailed experimental setup consisting of voltage sources, gas system (simulated flue gas and diesel exhaust), gas analyzers, adsorbent materials are discussed in the second chapter. In the third chapter, NOx is treated by three different methods and are described in separate parts. In first part we have done a comparative study of NO/NOx removal using two different types of dielectric barrier discharge electrodes: a) wire-cylinder reactor, b) pipe-cylinder reactor. Investigations were first carried out with synthetic gases to obtain the baseline information on the NO/NOx removal with respect to the two geometries studied. Further, experiments were carried out with raw diesel exhaust under loaded condition. A high NOx removal efficiency 90% was observed for pipe-cylinder reactor when compared to that with wire-cylinder reactor, where it was 53.4%. In second part an analysis has been made on discharge plasma coupled with an adsorbent system. The cascaded plasma-adsorbent system may be perceived as a better alternative for the existing adsorbent based abatement system in the industry. During this study the exhaust is sourced from a diesel generator set. It was observed that better NO removal in a plasma reactor can be made possible by achieving higher average fields and subsequent NO2 removal can be improved using an adsorbent system connected in cascade with the plasma system. This part describes the various findings pertaining to these comparative analyses. The third and last part of chapter 3 consists of gas desorption from an adsorbent by non-thermal plasma, which is an alternative to conventional thermal desorption, has been studied in relation to diesel engine exhaust. In this process saturated adsorbent material is regenerated using high energetic electrons and excited molecules produced by non thermal plasma. The last Chapter lists out the major inferences drawn from this study.

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Kumar, Bijendra. "No/Nox Removal In Diesel Engine Exhaust Under Different Energizations And Reactor Configurations." Thesis, 2008. http://hdl.handle.net/2005/716.

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In India, with the increase in the number of industries and vehicles the environment is getting more and more polluted. More than industries it is the rapid growth of vehicles which causes serious environmental crisis in the form of air pollution and has become alarming particularly in cities. The industrial and vehicular growth cannot be neglected, as the country’s economic and social well being is largely dependent on them. But this should not come at the cost of our health and eco system. The industrial and vehicular emissions must be controlled in order to keep our air clean. Continued efforts in this direction are being taken up across the globe to investigate an efficient and economical technique. There are many air pollutants being emitted from both natural and manmade sources. The major air pollutants identified as hazardous to human health are nitrogen oxides (NOx), carbon monoxide (CO), particulate matter (PM), volatile organic compounds (VOC), and sulfur dioxides (SOx). Among these, nitrogen oxides are considered to be difficult to remove. The sources of NOx are thermal power plants, stationary and mobile diesel engines, gasturbine engine, ironore sintering plants and various other smallscale utilities. There are conventionally available technologies to remove NOx such as chemical scrubbing, catalysis etc. But these techniques are either difficult to operate or do not bring down the level of NOx to the required norms imposed by the government. The failure of conventional techniques to remove NOx to the expected limit led to the development of alternative nonconventional techniques. Prominent among these new alternative techniques is electric discharge plasma, where the gas is partially ionized and temperature of electrons is considerably higher than that of ions and background gas molecules. Diesel engines are getting popular due to their inherent merits and their number is increasing considerably. Unfortunately, the exhaust of diesel engine being complex with high oxygen content makes the existing pollution control techniques insufficient particularly with regard to removal of NOx. So there is a need for investigating better technology which can effectively abate the pollutants from diesel engine exhaust. Electric Discharge plasma is one such alternative technique which has been very successful in large volumes of flue gas cleaning and hence, its potential is being explored in the cleaning of small volumes of vehicular exhausts, in particular, diesel engine exhaust. In the present work we investigated the relative performance of different electric discharge plasma reactors, with different type of voltages like AC, DC and pulse. The reactors were evaluated for NOx removal efficiency and NO conversion. This research work is a feasibility study to find whether electric discharge plasma can be used more effectively as an alternative technology for the after treatment of diesel engine exhaust in cascade with some cheaper adsorbents, if necessary. The scope of this qualitative experimental study can briefly be summarized as below: . • To study different reactors for NO conversion and NOx removal . • To study the effect of dielectric pellets in enhancing the radical production which in turn will have a bearing on the chemical reactions . • To study the effect of different types of voltages on the cleansing process . • To propose an efficient reactor system subject to the experimental conditions studied.

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Dissertations / Theses on the topic 'Discharges of pollutants'

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