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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.
81

An Arduino Based Control System for a Brackish Water Desalination Plant

Caraballo, Ginna 08 1900 (has links)
Water scarcity for agriculture is one of the most important challenges to improve food security worldwide. In this thesis we study the potential to develop a low-cost controller for a small scale brackish desalination plant that consists of proven water treatment technologies, reverse osmosis, cation exchange, and nanofiltration to treat groundwater into two final products: drinking water and irrigation water. The plant is powered by a combination of wind and solar power systems. The low-cost controller uses Arduino Mega, and Arduino DUE, which consist of ATmega2560 and Atmel SAM3X8E ARM Cortex-M3 CPU microcontrollers. These are widely used systems characterized for good performance and low cost. However, Arduino also requires drivers and interfaces to allow the control and monitoring of sensors and actuators. The thesis explains the process, as well as the hardware and software implemented.
82

Sources, Transport, Measurement and Impact of Nano and Microplastics in Urban Watersheds

Birch, Quinn T. January 2019 (has links)
No description available.
83

XENOKAT – Biofilter für Xenobiotika in der Ressource Wasser

Werner, Anett, Bley, Thomas, Wick, Justus, Hauser, Ralf January 2016 (has links)
Aus der Einleitung: "Xenobiotika werden durch den Menschen in die Stoffkreisläufe der Natur eingebracht, sie sind dort ursprünglich nicht anzutreffen. Dazu zählen auch Medikamente, die der menschliche Körper in kurzer Zeit wieder ausscheidet ohne diese abzubauen. Die bestehenden Abwasserreinigungsanlagen sind derzeit nicht in der Lage diese Frachten vollständig zu eliminieren, sodass sie unweigerlich in die Umwelt gelangen und dort undefiniert Einfluss nehmen. Xenobiotika können bereits in den großen Wasserreservoirs der Erde detektiert werden, die Prognose für die nächsten Jahre zeigt eine 30% Steigerung der Emissionen auf. In Deutschland gelangen z.B. jährlich 63 Tonnen des Schmerzmittels Diclofenac in die Flüsse (Bundesumweltamt 2014). Der Mensch hinterlässt regelrechte anthropogene Fußabdrücke, bestehend aus Schmerzmitteln, Antibiotika und Hormonen. Die problematischen Emissionen einiger Xenobiotika treten anhand von Folgeerscheinungen weltweit immer gravierender zutage (Bundesumweltamt 2014). So müssen das globale Artensterben (Geier in Indien), die Verweiblichung von Tierpopulationen in aquatischen Systemen und Krebserkrankungen mit partiell hohen Xenobiotika-Belastungen in der Umwelt in Zusammenhang gebracht werden. Die Entfernung von Xenobiotika insbesondere aus den Wasserkreisläufen stellt eine große ökonomische als auch ökologische Herausforderung zum Schutz der Lebensräume dar. ..."
84

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.
85

Perfluorinated compounds, bishenol a and acetaminophen in selected waste water treatment plants in and around Cape Town, South Africa

Adeleye, Adeola Patience January 2016 (has links)
Thesis (MTech (Chemistry))--Cape Peninsula University of Technology, 2016. / The release of wastewater to the aquatic environment is most likely to introduce some trace levels of organic contaminants, some of which may be toxic, carcinogenic, or endocrine disruptors, as well as, persistent in the environment. Additionally, increasing contamination of surface waters by wastewater effluents has made water treatment processes more challenging and expensive. The presence of these pollutants in the receiving water body may have negative effects on aquatic species and often pose potential human health risks through the reuse of treated wastewater for drinking purposes and other household use. In countries like South Africa, Namibia, USA, Singapore and Australia, water agencies are intensifying wastewater reclamation/wastewater reuse as part of their water resource agenda: in order to meet the demands of the growing populations. Nowadays, water reuse is generally considered as a viable method of water supply management. This study focused on the identification of the occurrence, quantification of emerging contaminants and evaluation of removal efficiency in wastewater treatment processes of three classes of emerging contaminants (ECs) in wastewater: 1) six types of perfluorinated compounds (PFCs), namely; perfluorooctanoic acid (PFOA), Perfluorooctane sulphonate (PFOS), perfluoroheptanoic acid (PFHpA), perfluorononanoic acid (PFNA), perfluorodecanoic acid (PFDA), and perfluoroundecanoic acid (PFUDA); 2) bisphenol A (BPA); and 3) Acetaminophen (ACP). These contaminants were identified and quantified in four wastewater treatment plants in the Western Cape. These treatment plants include three WWTPs in Cape Town, namely: Bellville WWTP, Scottsdene WWTP and Zandvliet WWTP and one WWTP in the central Karoo (Beaufort West wastewater reclamation plant).
86

Renovering av betongkonstruktioner i vattenverk

Landin, Johan January 2019 (has links)
Omkring 1970 byggdes och renoverades många vattenverk i Sverige. Dessa beräknadesdå att ha en livslängd på mellan 50-60 år, vilket i de flesta fall nu har passerat.Det har hittills saknats enhetlig information gällande hur renovering av enbassängkonstruktion i ett vattenverk bäst går till. Detta motiverade tillkomsten av följandearbete. Syftet är att undersöka vilka renoveringsmetoder som finns samt sammanställaoch utvärdera dessa. Målet är att presentera vilka riktlinjer som bör följas vid renoveraringav betongkonstruktioner i vattenverk.Arbetet ger svar på vilka skador som är vanliga i vattenverk och vad de beror på, vilkarenoveringsmetoder som är bäst lämpade, vilka material som kan användas samt vilkakrav som ställs på slutresultatet.Litteratur som behandlar betongrenovering har tjänat som utgångsmaterial. Intervjuer harskett med betongexperter, vattenverkspersonal och entreprenörer som utför denna typ avarbete.Problem i vattenverk är främst sprickor, urlakning, mekanisk erosion, korrosionsskador,kemiskt angrepp, biologisk nedbrytning och frostskador. Dessa skador renoveraslämpligen genom att ta bort den skadade betongen och ersätter den med ny, utifrån denexponeringsklass som gäller för det aktuella objektet.Borttagning av den dåliga betongen ska mot slutet göras med försiktighet för att undvikafickor vid armering och mikrosprickor i kvarvarande betong. För att få ett bra resultatkrävs både uppruggning av ytan som ska pågjutas samt fukthärdning efteråt. Vatten är ettlivsmedel så det ställs hårda renhetskrav på arbetare och maskiner samt krav på att allaprodukter som används är livsmedelsgodkända.Den slutsats som dras är att det idag inte finns någon generell och exaktrenoveringsmetod för betongkonstruktioner i vattenverk. Många olika faktorer spelar in.Det skulle dock fylla en kunskapslucka och underlätta framtida renoveringar omvattenverken gjorde en gemensam sammanställning av sina erfarenheter och lärdomar.Likaså är det ett stort värde att utbilda sin personal. / Around 1970 many water treatment plants were built and renovated in Sweden. Thesewas calculated to have a service life of between 50-60 years, which in most cases nowhave passed.The aim is to investigate which renovation methods exist and compile and evaluate these.The goal is to present which guidelines should be followed when renovating concretestructures in water treatment plants.The work gives answers to what damage is common in water treatment plants and whatthey depend on, which renovation methods are best suited, which materials can be usedand which requirements are set on the result.Problems in water treatment plants are mainly cracks, leaching, mechanical erosion,corrosion damage, chemical attack, biodegradation and frost damage. These damages arepreferably renovated by removing the damaged concrete and replacing it with new, basedon the exposure class that applies to the object in question.The conclusion is that today there is no general and exact renovation method for concretestructures in water treatment plants. Many different factors are involved.However, it would fill a gap of knowledge and facilitate future renovations if the watertreatment plants made a joint compilation of their experiences and lessons learned. It isalso a great value to educate the personnel.
87

The Microbial Community Composition of Cincinnati Wastewater Treatment Plants and Eutrophic Freshwater Lakes

Icardi, Keely Marie 10 January 2019 (has links)
No description available.
88

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
89

Method Development for the Synthesis of Anaerobic Digester Biogas with the Laboratory Environment

Freitas, Andrew Daniel Sanchez 12 February 2015 (has links)
Biogas, a gaseous mixture produced during decomposition of organic matter, is a renewable, easily generated and common byproduct of anaerobic digestion at wastewater treatment plants (WWTP), landfills and agricultural operations. There is growing interest in researching and utilizing the energy potential associated with its combustion. Siloxanes, a family of volatile organic silicon compounds, pose large impediments to biogas usage due to the formation and precipitation of silicon dioxide within combustion devices. Removal of siloxanes prior to combustion is therefore a growing endeavor. Research was performed to synthesize a representative gas stream produced from anaerobic digesters within WWTP. Methane, carbon dioxide and hydrogen sulfide were combined with humidity and gaseous siloxane in levels characteristically seen exiting anaerobic digesters. A methanol impinger train was utilized to sample the biogas composite. Gas chromatography-mass spectrometry (GC-MS) was used to determine gas-phase siloxane concentrations in the gas stream effluent for the purposes of confirming the generation of a consistent and reproducible biogas stream. / Master of Science
90

Regeneration of Lanthanum Following Precipitation of Phosphates from Waste-Waters

Wasserlauf, Mark 03 1900 (has links)
<p> Government programs now underway in Ontario aim at removing phosphates from waste-waters at sewage treatment plants. At present, removal of phosphates is commonly accomplished by chemical precipitation with lime, alum, or iron. Lanthanum, a rare earth element, has been found to be an effective precipitant of phosphates. If lanthanum precipitate can be collected, and the lanthanum then regenerated so that it could be recycled for further phosphate precipitation, a very advantageous alternative to the above schemes would result.</p> <p> In this study, phosphates were precipitated from both distilled water and secondary effluent using lanthanum. For the two cases, a regeneration scheme for lanthanum was examined. The basic regeneration reactions were carried out to evaluate the kinetics and equilibria for different ratios of reactants and different reaction temperatures. Techniques for phase separation of reacted reagents were studied. Process design calculations were carried out to obtain order of magnitude figures for amounts and costs of chemicals required, amounts of sludge produced, and reactor sizes.</p> / Thesis / Master of Engineering (MEngr)

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