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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Numerical modelling of wind-induced circulation and pollution transport in the Thermaikos Gulf using a curvilinear coordinate system

Volakos, Nikolaos Panagiotou January 2002 (has links)
No description available.
2

Higiene e segurança nas estações de tratamento de esgotos / Hygiene and safety at sewage treatment plants

Loureiro, Reginaldo Vello 04 May 1982 (has links)
A poluição dos recursos hídricos vem agravando-se a cada ano, em quase todos os países, inclusive no Brasil. Providências vêm sendo tomadas, principalmente nas grandes cidades, no sentido de combatê-la. Dentre os meios utilizados para a proteção da qualidade da água, destacam-se as Estações de Tratamento de Esgotos - ETE.s. Nestas ETEs trabalham diversos profissionais, dentre os quais os operadores. Estes, exercem variadas atividades, geralmente em todas as suas unidades. Com o aumento progressivo do número de Estações de Tratamento de Esgotos, a quantidade de operadores, anteriormente pouco significativa, tende a se tornar cada vez maior no Brasil, e deverá atingir um número considerável, em futuro bem próximo. Estes trabalhadores, como os de qualquer outra atividade industrial, estão expostos a riscos os mais variados, os quais são agravados ainda mais, devido à presença dos esgotos no local de trabalho. Procurou-se, neste trabalho, levantar os riscos existentes nas unidades das ETEs pesquisadas, e fazer recomendações, no sentido de minimizá-los. Aplicou-se, para tal fim, um questionário em 11 Estações de Tratamento de Esgotos, levantando-se dados relacionados com as condições sanitárias do ambiente de trabalho; hábitos higiênicos dos operadores; medidas preventivas, de caráter individual e coletivo, para evitar a ocorrência de acidentes nas ETEs; atividades do Serviço Especializado em Segurança e em Medicina do Trabalho; e Segurança Patrimonial nas ETEs. Foi feita, ainda, uma avaliação dos veis de iluminamento, à noite; ruído; explosividade; e concentração do gás sulfídrico, em algumas unidades das ETEs incluídas na pesquisa. / The pollution of water resources has become worse every year in almost every country of the world, including Brasil. Among the measures taken to correct it, installation of Sewage Treatment Plants, specially in big cities, stand out. Many professionals work at these Sewage Treatment Plants, among these are operators performing a variety of activities. With the increasing number of Sewage Treatment Plants installed, the number of operators, of little significance at the beginning, tends to become greater and greater in Brazil and it is antecipated that in the near future it will become considerable. These workers, like those in any other industrial activity, are exposed to a great variety of risks, that in this case are increased even more by the existence of sewage at their place of work. This paper intends to survey the existing risks in the Sewage Treatment Plants units studied as well as to make recommendations that may minimize them. In this sense, a questionnaire was applied at eleven Sewage Treatment Plants, collecting data regarding sanitary conditions of the work environment, higienic habits of the workers, preventive measures - individual and collective - to avoid the occurrence of accidents, activities of the Specialized Safety Service and Labour Medicine and Patrimonial Safety. At the same time an evaluation was carried out to assess the levels of night illumination, noise, explosiveness and the concentration of hydrogen sulfide in some of the Sewage Treatment Plants units covered in this study
3

Higiene e segurança nas estações de tratamento de esgotos / Hygiene and safety at sewage treatment plants

Reginaldo Vello Loureiro 04 May 1982 (has links)
A poluição dos recursos hídricos vem agravando-se a cada ano, em quase todos os países, inclusive no Brasil. Providências vêm sendo tomadas, principalmente nas grandes cidades, no sentido de combatê-la. Dentre os meios utilizados para a proteção da qualidade da água, destacam-se as Estações de Tratamento de Esgotos - ETE.s. Nestas ETEs trabalham diversos profissionais, dentre os quais os operadores. Estes, exercem variadas atividades, geralmente em todas as suas unidades. Com o aumento progressivo do número de Estações de Tratamento de Esgotos, a quantidade de operadores, anteriormente pouco significativa, tende a se tornar cada vez maior no Brasil, e deverá atingir um número considerável, em futuro bem próximo. Estes trabalhadores, como os de qualquer outra atividade industrial, estão expostos a riscos os mais variados, os quais são agravados ainda mais, devido à presença dos esgotos no local de trabalho. Procurou-se, neste trabalho, levantar os riscos existentes nas unidades das ETEs pesquisadas, e fazer recomendações, no sentido de minimizá-los. Aplicou-se, para tal fim, um questionário em 11 Estações de Tratamento de Esgotos, levantando-se dados relacionados com as condições sanitárias do ambiente de trabalho; hábitos higiênicos dos operadores; medidas preventivas, de caráter individual e coletivo, para evitar a ocorrência de acidentes nas ETEs; atividades do Serviço Especializado em Segurança e em Medicina do Trabalho; e Segurança Patrimonial nas ETEs. Foi feita, ainda, uma avaliação dos veis de iluminamento, à noite; ruído; explosividade; e concentração do gás sulfídrico, em algumas unidades das ETEs incluídas na pesquisa. / The pollution of water resources has become worse every year in almost every country of the world, including Brasil. Among the measures taken to correct it, installation of Sewage Treatment Plants, specially in big cities, stand out. Many professionals work at these Sewage Treatment Plants, among these are operators performing a variety of activities. With the increasing number of Sewage Treatment Plants installed, the number of operators, of little significance at the beginning, tends to become greater and greater in Brazil and it is antecipated that in the near future it will become considerable. These workers, like those in any other industrial activity, are exposed to a great variety of risks, that in this case are increased even more by the existence of sewage at their place of work. This paper intends to survey the existing risks in the Sewage Treatment Plants units studied as well as to make recommendations that may minimize them. In this sense, a questionnaire was applied at eleven Sewage Treatment Plants, collecting data regarding sanitary conditions of the work environment, higienic habits of the workers, preventive measures - individual and collective - to avoid the occurrence of accidents, activities of the Specialized Safety Service and Labour Medicine and Patrimonial Safety. At the same time an evaluation was carried out to assess the levels of night illumination, noise, explosiveness and the concentration of hydrogen sulfide in some of the Sewage Treatment Plants units covered in this study
4

Assessment of the biological quality of raw and treated effluents from three sewage treatment plants in the Western Cape, South Africa

Hendricks, Rahzia January 2011 (has links)
<p>The aim of this study was to compare the water quality of raw wastewater and treated sewage effluents from three different sewage treatment plants in the Western Cape, South Africa. The treatment plants investigated are on the same river system. Sewage treatment plant 1 and 2 use older technologies, while sewage treatment plant 3 has been upgraded and new technologies (membrane bioreactor) were incorporated in the treatment processes. The first objective was to determine the occurrence of total coliforms, Escherichia coli (E. coli) and fluoroquinolone and sulfamethoxazole antibiotic residues in raw wastewater and treated sewage effluents. Bacteria in treated sewage effluents can result in diseases such as dysentery, gastroenteritis, and typhoid upon exposure. A chromogenic test was used to screen for coliforms and E. coli. Enzyme linked Immunosorbent Assays (ELISA) were used to quantitate antibiotic residues (fluoroquinolones and sulfamethoxazole) in raw wastewater and treated sewage effluents. This study showed that bacteria are present in raw wastewater and residual bacteria are released with treated sewage effluents from sewage treatment plants.</p>
5

Determination of Antibiotics in the Swedish Environment with Emphasis on Sewage Treatment Plants

Lindberg, Richard January 2006 (has links)
Metoder har utvecklats för att kunna bestämma tolv antibiotikasubstanser, vanliga inom human medicin, i miljöprover. Fokus lades på trimetoprim samt substanser från följande grupper: fluorokinoloner, sulfonamider, penicilliner, cefalosporiner, nitroimidazoler, tetracykliner samt makrolider. Vid extraktion användes fast-fas extraktion för vattenprover och ultraljuds-assisterad fast-fas/vätske extraktion för fasta prover. För separering och bestämning användes vätskekromatografi tandemmasspektrometri. Interna standarder nyttjades för att öka noggrannhet och precision. Extraktionsutbyte låg mellan 50% och 100% för vattenfaser och 14% och 100% för fasta faser. Koncentrationer och massflöden bestämdes för antibiotikasubstanser i inkommande och utgående vatten och slam, från fem avloppreningsverk i Sverige, samt i avloppsvatten från ett sjukhus. I sjukhusavloppsvattnet så påträffades ciprofloxacin (en fluorokinolon) och metronidazol (en nitroimidazol) i höga halter (µg/L nivå). Screening-studien vid de fem avloppsreningsverken visade att norfloxacin, ofloxacin, ciprofloxacin och doxycyklin ofta förekom i inkommande och utgående vatten och slam. Trimetoprim och sulfametoxazol påvisades inte i slam men förekom i snarlika koncentrationer i det utgående vattnet relativt det inkommande. I vattenfasen så förekom de sex antibiotikasubstanserna i ng/L nivån och i slam förekom norfloxacin, ofloxacin, ciprofloxacin, och doxycyklin i låga mg/kg nivån. En studie genomfördes där beteendet hos antibiotikasubstanser under avloppsrening studerades. De två fluorokinolonerna, norfloxacin och ciprofloxacin, adsorberade till slam och mindre än 5% av den totala mängd som kommer till avloppsreningsverket påvisades i det utgående vattnet. I slam var motsvarande andel 70%. Resultat från en process som värmebehandlar rötat avvattnat slam antyder att cirka 50% av de två fluorokinolonerna bryts ner. Trimetoprim adsorberade inte till slam och 100% av total mängd återfanns i det utgående vattnet. Teoretiska beräkningar av koncentrationer och massflöden visade god korrelation till kvantitativa resultat. Ökad noggrannhet i beräkningarna fås genom att beakta stabilitet och fasfördelning. Effekten av antibiotikasubstanser i miljön är idag okänd. Resultat från testprotokoll där deras toxicitet bedöms är i många fall irrelevanta. Tester där organismer är kroniskt exponerade av biologiskt aktiva substanser vid låga koncentrationer är få. Dessutom så fokuserar de ej på de stora potentiella effekterna såsom utveckling eller bevaring av resistenta stammar av bakterier i miljön. Ytterligare studier av förekomst, öde och effekt av antibiotikasubstanser i miljön är nödvändiga. / Methods were developed for determining levels in environmental samples of twelve antibiotics that are commonly used in human medicine: trimethoprim and substances from the following groups: fluoroquinolones, sulfonamides, penicillins, cephalosporines, nitroimidazoles, tetracyclines and macrolides. These substances were extracted from liquid and solid samples by solid phase extraction and ultrasonic-assisted liquid/solid extraction, respectively. Liquid chromatography tandem mass spectrometry was then used to separate and quantify them, and internal standards were added to improve the accuracy and precision of the determinations. Extraction yields from aqueous and solid phases were in the ranges 50 - 100% and 14 - 100%, respectively. Concentrations and mass flows of antibiotic substances were determined in a hospital effluent and in the raw sewage water, final effluent, and sludge from five sewage treatment plants (STPs) scattered across Sweden. High levels (in the µg/L range) of ciprofloxacin (a fluoroquinolone) and metronidazole (a nitroimidazole), were found in the hospital effluent. The screening study of the five sewage treatment plants revealed that norfloxacin, ofloxacin, ciprofloxacin, and doxycycline were frequently present in the raw sewage water, final effluent and sludge. Trimethoprim and sulfamethoxazole were not detected in the sludge, but these substances were present in the final effluents at concentrations close to those of the raw sewage water. In the aqueous phase, these six antibiotics were present in the ng/L range and in the solid phase, norfloxacin, ofloxacin, ciprofloxacin, and doxycycline were present in the low mg/kg range. The behaviour of the antibiotic substances during sewage water treatment was also investigated in one of the STPs. The two fluoroquinolones, norfloxacin and ciprofloxacin, sorbed to sludge, and less than 5% of the total amounts that entered the STP were found in the final effluent. In sludge, the corresponding figure was 70%. Results from a process in which digested dewatered sludge was treated with heat (producing pellets) indicated that approximately 50% of the two fluoroquinolones had been degraded. Trimethoprim did not sorb to sludge and 100% of its total amount was found in the final effluent. Theoretical calculations of concentrations and mass flows correlated well with quantitative results for the antibiotics that were frequently detected, but not for the others. In order to increase the accuracy of the calculations, the stability and phase distribution of the antibiotics should be considered. The effects of antibiotics present in the environment are currently unknown. Results of test protocols to assess their toxicity are often irrelevant, and there have been few tests in which organisms have been chronically exposed to biologically active substances at low concentrations. In addition, these tests have not addressed the immense potential of antibiotics in the environment to induce the development of resistant strains of bacteria and to maintain populations of resistant strains. Further studies of the occurrence, fate, and, effects of antibiotic substances in the environment are required.
6

Assessment of the biological quality of raw and treated effluents from three sewage treatment plants in the Western Cape, South Africa

Hendricks, Rahzia January 2011 (has links)
<p>The aim of this study was to compare the water quality of raw wastewater and treated sewage effluents from three different sewage treatment plants in the Western Cape, South Africa. The treatment plants investigated are on the same river system. Sewage treatment plant 1 and 2 use older technologies, while sewage treatment plant 3 has been upgraded and new technologies (membrane bioreactor) were incorporated in the treatment processes. The first objective was to determine the occurrence of total coliforms, Escherichia coli (E. coli) and fluoroquinolone and sulfamethoxazole antibiotic residues in raw wastewater and treated sewage effluents. Bacteria in treated sewage effluents can result in diseases such as dysentery, gastroenteritis, and typhoid upon exposure. A chromogenic test was used to screen for coliforms and E. coli. Enzyme linked Immunosorbent Assays (ELISA) were used to quantitate antibiotic residues (fluoroquinolones and sulfamethoxazole) in raw wastewater and treated sewage effluents. This study showed that bacteria are present in raw wastewater and residual bacteria are released with treated sewage effluents from sewage treatment plants.</p>
7

Behavior of antibiotics and antiviral drugs in sewage treatment plants and risk associated with their widespread use under pandemic condition / 下水処理場での抗生物質と抗ウイルス剤の挙動とパンデミック発生時のその多様に伴うリスク / ゲスイ ショリジョウ デ ノ コウセイ ブッシツ ト コウウイルスザイ ノ キョドウ ト パンデミック ハッセイジ ノ ソノ タヨウ ニ トモナウ リスク

GHOSH, Gopal Chandra 24 September 2009 (has links)
The concern for pharmaceutically active compounds (PhACs) as contaminants in the environment and the need to assess their environmental risk have greatly increased since the early nineties. Among PhACs, antibiotics and antiviral drugs are of important concern due to their role in growing antibiotic and antiviral drugs resistance among pathogenic bacteria and influenza viruses, respectively. Besides resistance issue, the compounds may upset sensitive ecosystems as they are designed to be highly bioactive. Clinically-important antibiotics are virtually ubiquitous contaminants in sewage water and surface water. Notably, recent emergence of novel influenza and use of anti-influenza drugs (specially Tamiflu®) during seasonal influenza、 influenza epidemics and for future pandemic are of emerging concern. Every year seasonal influenza epidemic causes tens of millions of respiratory illnesses and 250, 000 to 500, 000 deaths worldwide. WHO (World Health Organization) recommend the use of antiviral drug Tamiflu® during pandemic, as they are easy to use. Currently only Japan uses over eighty percent of Tamiflu® prescribed globally during common seasonal influenza. It is a fact that a huge amount of antiviral drugs and antibiotics ( for post infection cure of respiratory illness) will be used during an influenza pandemic and will arrive to sewage treatment plants (STPs).Unfortunately, these compounds behaviors are mostly unknown in both conventional and advanced STPs. The exposure of antiviral drug in the wild fowl gut and its implications for hastening the generation of antiviral-resistance in avian influenza viruses are also an emerging issue. The major objective of this thesis work was to investigate the occurrence of antibiotics and antiviral drugs in sewage treatment plants and their fate in different sewage treatment plants. The specific objectives were as follows: (a) to established appropriate analytical method for the selected antibiotics and antiviral drugs in sewage treatment plants, (b) to investigate the occurrence and removal of antibiotics and antiviral drugs in sewage treatment plants differ in technology and operation conditions; and (c) to predicts environmental concentration of the target compounds during a pandemics and appraisal of appropriate technology to reduce the risk associated with widespread use under pandemic conditions. In this study we selected twenty antibiotics: one beta-lactam: ampicillin; four macrolides: azithromycin, clarithromycin and roxithromycin; five quinolones: ciprofloxacin, enrofloxacin, levofloxacin, nalidixic acid and norfloxacin; two tetracycline: tetracycline and oxytetracycline; five sulfonamides: sulfadimethoxine, sulfadimizine, sulfamerazine, sulfam- ethoxazole and sulfamonomethoxine; and four others: lincomycin, novobiocin, salinomycin and trimethoprim. Oseltamivir Carboxylate (OC), the active metabolite of oseltamivir phosphate (Tamiflu®) and amantadine (AMN) were selected as antiviral drugs. This dissertation consists of nine chapters: Chapter I describe the background and objective of the study and chapter II represent a brief literature review. In Chapter III, analytical methods for selected antibiotics and antiviral drugs (for the first time) in water and wastewater were described. In Chapter IV, the occurrences and fate of antibiotics in sewage treatment plants were investigated in Japan and China. Clarithromycin was detected in the highest concentration in influent (1129 to 4820 ng/L), followed by azithromycin (160 to 1347 ng/L), levofloxacin (255 to 587 ng/L) and norfloxacin ( 155 to 486 ng/L) and sulfamethoxazole (159 to 176ng/L) in Japan. Ozonation as tertiary treatment of secondary effluent for wastewater reclamation provided significant elimination of antibiotics. Fifty present of the selected antibiotics were removed over eighty percent during ozonation. There was no elimination of antibiotics in dissolve phase during ultra filtration. From Chapter IV a hypothesis was drawn on antibiotics removal and its relation with longer sludge retention time (SRT) in STPs and in Chapter V the role of nitrifier in antibiotics removal was evaluated to verify the hypothesis established from Chapter IV. Nitrifying activated sludge (NAS) can biodegrade the tested antibiotics with different biodegradation rate between 2.74 to 9.95 L/gSS/d. Sulfamethoxazole and sulfamerazine degraded faster than trimethoprim, clarithromycin and enrofloxacin. In Chapter VI, occurrence of antiviral drugs in sewage water discharge and in river water in Japan was conducted during seasonal influenza epidemic and their fate in different sewage treatment facilities were evaluated in Chapter VII. This is the fist findings of antiviral (anti-influenza) drugs in the environment in the world and for the first time the removal mechanism in STPs was elucidated. Finally, it was observed that only primary and secondary treatment processes in STPs were not sufficient to remove these compounds significantly. Overall OC and AMN removal in STP with ozonation as tertiary treatment was 90% and 96% respectively. In ozonation batch experiment, Chapter VIII, ( feed ozone gas concentration 4.0mg/L, ozone gas flow rate 0.23L/min to maintain ozone feed rate of 0.6 mg/L/min), it was observed that AMN and OC concentration decreased linearly with time in all the experiments conducted and it can be, therefore, said that the degradation reactions follow pseudo first-order reaction. The k'O3 (pseudo first-order rate constant for O3) of AMN was 0.596/min (0.00993/sec), and OC was 0.524 /min (0.008725/sec) and over 99% removal within 10min. Chapter VIII described the predicted OC and antibiotics concentration in STPs influent, secondary effluent, after advance tertiary treatment (ozonation) and receiving water during a pandemic with three expected infection scenario ( according to US CDC FluAid model 2.0) in Kyoto city. Both antiviral drugs and antibiotics pose an environmental risk associated to there widespread use during a future pandemic. Ozonation as tertiary treatment can provide a technological solution to reduce the ecotoxicological effect of antibiotics and antiviral drugs uses during a pandemic. In a full scale STP, the antiviral drugs (OC and AMN) reduction were over 90% from secondary effluent after ozonation during seasonal influenza outbreak in Kyoto city in 2008/2009. Finally, (1) analytical methods for commonly used antibiotics and antiviral drugs in water sample was developed with an excellent precision and accuracies, (2) both antibiotics and antiviral drugs were detected in environmental sample, and their behavior in STPs were elucidated. Antivirals in this study were the first time findings in sewage water. This study will provide a surrogate for planning a pandemic preparedness action plan for sewage treatment pants for ecotoxicological risk management. / Kyoto University (京都大学) / 0048 / 新制・課程博士 / 博士(工学) / 甲第14931号 / 工博第3158号 / 新制||工||1474(附属図書館) / 27369 / UT51-2009-M845 / 京都大学大学院工学研究科都市環境工学専攻 / (主査)教授 田中 宏明, 教授 伊藤 禎彦, 教授 藤井 滋穂 / 学位規則第4条第1項該当
8

Assessment of the biological quality of raw and treated effluents from three sewage treatment plants in the Western Cape, South Africa

Hendricks, Rahzia January 2011 (has links)
Philosophy of Doctor - PHD / The aim of this study was to compare the water quality of raw wastewater and treated sewage effluents from three different sewage treatment plants in the Western Cape, South Africa. The treatment plants investigated are on the same river system. Sewage treatment plant 1 and 2 use older technologies, while sewage treatment plant 3 has been upgraded and new technologies (membrane bioreactor) were incorporated in the treatment processes. The first objective was to determine the occurrence of total coliforms, Escherichia coli (E. coli) and fluoroquinolone and sulfamethoxazole antibiotic residues in raw wastewater and treated sewage effluents. Bacteria in treated sewage effluents can result in diseases such as dysentery, gastroenteritis, and typhoid upon exposure. A chromogenic test was used to screen for coliforms and E. coli. Enzyme linked Immunosorbent Assays (ELISA) were used to quantitate antibiotic residues (fluoroquinolones and sulfamethoxazole) in raw wastewater and treated sewage effluents. This study showed that bacteria are present in raw wastewater and residual bacteria are released with treated sewage effluents from sewage treatment plants. / South Africa
9

A study of pharmaceutical residues in wastewater from small municipalities in Northern Sweden : E-peroxone as a complementary tertiary removal technique

Hägglund, Mathias January 2021 (has links)
The conventional treatment processes used in Swedish sewage treatment plants (STPs) are not designed to remove micropollutants such as pharmaceuticals and biocides. This leads to STPs being a major source of pharmaceuticals in the environment including surface waters, coastal waters, and groundwaters all over the world. The occurrence of these compounds combined with their adverse ecological effects makes them problematic. This study aims to investigate the removal of pharmaceuticals and biocides from six conventional STPs from small municipalities in Northern Sweden. It also aims to evaluate the suitability and potential of an advanced treatment process called electro-peroxone (E-peroxone) as an additional tertiary treatment step complementing the current STPs configurations, through batch experiments. The removal of pharmaceuticals and biocides in the studied STPs showed great variability. The occurrence of pharmaceuticals was mainly in line with previous research apart from caffeine and paracetamol concentrations. Several pharmaceuticals were detected above their respective critical environmental concentration (CEC) in effluent wastewaters. The removal of pharmaceuticals was heavily influenced by paracetamol. When excluding paracetamol, the total removal of pharmaceuticals ranged from -23% to 80% in the conventional processes. After E-peroxone treatment, removals, excluding paracetamol, ranged from 61% to 93%, and no average effluent concentrations exceeded their respective CEC. In this study, E-peroxone was conducted in not optimized batch-experiments due to time constraints, but still with promising results. In a full-scale application, water matrix specific optimizing should be performed. Therefore, the removal efficiencies of pharmaceutical residues by the E-peroxone process in a plant-specific configuration would most likely be significantly increased.
10

Consumption-based estimation of discharge of human-used antibiotics from sewage treatment plants (STPs) to the aquatic environment and risk assessment / 消費量をもとにしたヒト用抗生物質の下水処理場から水環境への流出量の推定とリスク評価

MIAO, JIA 23 March 2022 (has links)
京都大学 / 新制・課程博士 / 博士(工学) / 甲第23869号 / 工博第4956号 / 新制||工||1774(附属図書館) / 京都大学大学院工学研究科都市環境工学専攻 / (主査)教授 藤原 拓, 准教授 西村 文武, 講師 中田 典秀 / 学位規則第4条第1項該当 / Doctor of Philosophy (Engineering) / Kyoto University / DFAM

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