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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.
231

Exploring the Presence and Characteristics of Antibiotic Resistance Genes and Bacteria Present in Water Environments of Uppsala, Sweden

Herrera Rodríguez, Daniel January 2020 (has links)
Antibiotics are one of the greatest discoveries in medicine, and emerged resistances have become a global threat. It is theorized that a big part of the antibiotic resistance genes come from the environment, and wastewater treatment plants and hospitals are considered a great breeding ground for the spread of these. The aim of this project is to analyse the microbiome and resistome of the wastewater of Uppsala and to evaluate the efficiency in the elimination of antibiotic resistance genes and bacteria. Samples from the University Hospital and the influents, sand filter and effluent of the Wastewater Treatment Plant were collected, DNA was extracted and sequenced to be analysed through metagenomics to explore them taxonomically and looking for resistance genes. Bacteria were also isolated, and their resistances were analysed. Taxonomical differences became noticeable in Order, Family, Genus and Species, with an increase of diversity in the Effluent samples. A total of 233 resistance genes were found in all the samples. There was a clear reduction in the number of resistance genes in the Effluent samples. However, there was an important number of genes carried in these and some prevail through all the path. Within all the isolates collected, from a total of 11, three E. coli isolates, one C. freundii and one E. cloacae presented resistances. Our study shows that the effluent of the wastewater treatment plant of Uppsala is potentially causing a negative impact on the environment, flushing out water not completely free of antibiotic resistance genes and resistant bacteria.
232

Mejoramiento de las PTAR de uso minero usando un sistema integrado de clarificación de agua de 3 procesos, mina Coimolache - Cajamarca / Improvement of the WWTP for mining use using an integrated 3-process water clarification system, Coimolache mine - Cajamarca

Villalta Yupanqui, Danny Willer, Lévano Lévano, William César 17 November 2021 (has links)
La minería es considerada un motor clave para el desarrollo económico de un país. En este sector, el mejoramiento en la eficiencia de usos del agua es un punto crítico desde el punto de vista económico y ambiental, por ello se siguen implementando nuevos procesos en el tratamiento del agua en el sector minero. Por tal motivo, el objetivo de esta investigación es demostrar que es posible mejorar las PTAR (planta de tratamiento de aguas residuales) de uso minero, lo que implica el mejor funcionamiento del sistema, usando de la mejor forma los recursos que se tienen. Esta investigación se desarrolló bajo los lineamientos de una metodología experimental, donde se diseñó el coagulador, floculador y clarificador de agua de rastras y el diseño del sistema integrado de clarificación de agua de 3 procesos que lo reemplazaría. El propósito de esto es realizar un análisis comparativo entre ambos sistemas usado en la mina “Coimolache” Con los resultados de los cálculos realizados para ambos diseños, tanto el clarificador de rastras y el sistema integrado de clarificación de agua de 3 procesos se demostrará que es posible una reducción en área (m2) a ocupar en el terreno, y de volumen (m3) de movimiento de tierra para contribuir la reducción del impacto ambiental. Así mismo, se evaluó la variación de los costos de implementación, operación y mantenimiento. Finalmente se busca dar a conocer, documentar y demostrar que el uso del sistema integrado de clarificación de agua de 3 procesos tiene múltiples ventajas para promover su implementación al nivel nacional. / Mining is considered a key for the economic development of a country. In this sector, improvement in water use efficiency of use is a critical point from the economic and environmental point of view, is because this reason, new processes are being implemented in the treatment of water in the mining sector. For this reason, the principal objective of this research is to demonstrate that it is possible to optimize the WWTP (wastewater treatment plant) for mining even to get the best operation of the system using in the right way the resources that we have. This research was developed under the guidelines of an experimental methodology, where coagulator, flocculator, and dredge water clarifier were designed and the design of the integrated 3-process water clarification system that would replace them. The purpose is to realize a comparative analysis between these systems used in the "Coimolache" mine. With the results of the calculations carried out for both designs, dredge water clarifier and integrated 3-process water clarification system, it will demonstrate that a reduction in area (m2) to be occupied on the ground and volume (m3) of earth movement is possible to contribute to the reduction of environmental impact. Likewise, the variation in implementation, operation and maintenance costs it was evaluated. Finally, this research intends to make known, document, and demonstrate that the use of the integrated 3-process water clarification system has multiple advantages to promote its implementation at the national level. / Tesis
233

Développements d’échantillonneurs passifs pour l’étude de la contamination des eaux par les micropolluants organiques / Development of passive sampling tools to monitor organic micropollutants in water

Wund, Perrine 09 December 2013 (has links)
Préserver les ressources en eau est l’une des problématiques environnementales majeures du 21è siècle. Pour faire face à cette nécessité, il est essentiel de mettre en place une surveillance réglementée de la qualité des eaux et des rejets se déversant dans le milieu aquatique et de développer de nouveaux outils d’échantillonnage. L’échantillonnage ponctuel est la technique la plus facile à mettre en œuvre. Toutefois, elle n’est pas toujours représentative d’un milieu hétérogène parfois soumis à des variabilités spatiales et temporelles importantes. L’échantillonnage passif, notamment avec l’outil POCIS (Polar Organic Chemical Integrative Sampler), est une approche complémentaire aux techniques traditionnelles, qui permet de concentrer des molécules organiques semi-polaires directement sur site. La pertinence du résultat obtenu (la concentration moyennée sur la durée d’exposition), couplée à la simplicité de sa mise en œuvre en font a priori un outil de choix pour suivre des hydrosystèmes complexes.Dans ce contexte, des familles des composés diversifiées ont été sélectionnées : pesticides, composés pharmaceutiques, hormones stéroïdiennes et composés perfluorés. Au sein de chaque famille, plusieurs composés traceurs, présents dans l’environnement, comportant des propriétés physico-chimiques variées et aux statuts règlementaires différents (Directive Cadre sur l’Eau notamment), ont été choisis.Des essais d’optimisation de design du POCIS (quantité et nature de phase réceptrice, nature de la membrane) ont été conduits, menant à la validation de la configuration classique dans le cas général. L’influence de différents paramètres environnementaux pertinents : débit, température, matrice, présence de biofilm et dispositif de déploiement a été évaluée lors de calibrations de l’outil réalisées dans des systèmes de complexité croissante : au laboratoire, sur pilote et sur site.Les différents déploiements sur site (effluent de STEP et rivière) ont permis de valider l’utilisation de cet outil de prélèvement passif dans le cadre d’un suivi environnemental. Le potentiel du POCIS a été pleinement confirmé, tant en termes de logistique que de résultats (justesse par rapport aux concentrations mesurées par des techniques classiques, intégration d’événements ponctuels, limite de quantification…). / The protection of water resources is one of the major environmental stakes of 21st century. Regulation concerning water quality and effluents is therefore definitely needed, as well as new approaches regarding water sampling. Spot sampling is the easiest strategy. However, it may not be representative of a heterogeneous matrix, with sometimes important spatial and temporal variability. Passive sampling, including POCIS (Polar Organic Chemical Integrative Sampler) is a complementary approach, which enables an on-site pre-concentration of semi-polar organic compounds. The relevance of the result (time-weighted average concentrations) and the ease to implement POCIS make it an appropriate tool to monitor complex hydrosystems.Within this work, various compound classes were selected: pesticides, pharmaceuticals, steroid hormones and perfluorinated compounds. Among each family, several tracer molecules, widely encountered in the environment, with different physic-chemical properties and regulatory status (particularly in the Water Framework Directive), were chosen.POCIS design optimization (amount and nature of sorbent, nature of membrane) was carried out, leading to the validation of the standard configuration for general purposes. The impact of different relevant environmental parameters (flow-rate, temperature, matrix, biofouling and deployment device), was assessed during calibrations of POCIS conducted in systems of increasing complexity: in the laboratory, at pilot-scale and on-site.All on-site deployments (WWTP effluent and river) enabled to validate the use of this passive sampling tool in the framework of an environmental monitoring. The potential of this tool was fully confirmed, both logistically and in terms of results (trueness compared to concentrations measured with traditional techniques, integration of punctual events, quantification limit…).
234

Hodnocení kvality vody v úpravně pitné vody Mokošín / Evaluation of water quality in water treatment plant Mokošín

Vosáhlo, Jan January 2012 (has links)
The theme of this thesis is " Evaluation of water quality in water treatment plant Mokošín". The source of water supply are 4 artesian wells. The paper first describes the supply area and water treatment plant with individua water treatment technologies. In the practical section there is the specification of contaminating elements required to be separated at the water treatment plant. Since it is an underground source of water, there is an increased amount of iron and manganese. Increased attention is given to arsenic, which occurs in two water sources in recent years. There are also offered the possibilities of removing arsenic at water treatment plant and two filter materials tested in the laboratory. Monitoring of water quality takes place always in resources and after treatment in the time period of five years, the arsenic values are reported for ten years.
235

Poruchovost městských čistíren odpadních vod / Failure rate wastewater treatment plants

Boryśová, Michaela January 2012 (has links)
This thesis deals with the sludge management in wastewater treatment plants. It provides a basic overview of methods for modifying risk material in sludge ending. The main goal of this work is to create a fault trees based on faults which occurred in the sludge management facilities. Furthermore, it was created frequency of failures assessment of the objects on wastewater treatment plant in Hodonín. Provided information were obtained during excursions of WWTP Hodonín and Zbýšov.
236

Výzkum regenerace filtračního materiálu zemních filtrů a kořenových čistíren odpadních vod / The Research on Regeneration of the Filter Material, used in the Soil Filters and Constructed Wetlands

Burešová, Hana January 2012 (has links)
The thesis consists of two basic parts. The first research part creates an introduction to the root zone wastewater treatment plants. It contains mainly causes of filter environment colmation and its theoretical solution methods, which are further solved in the laboratory. The master’s thesis attempts to find a simple way, which would in future be possible to evaluate the rate of sedimentation of the sludge material, which causes filtration environment colmation. Results of developed methodology will be used in practice by washing colmated filtration material, respectively colmatant separation in sedimentation tank. The thesis focuses to verify the possibility flocculation and mineralization of sludge, which adheres to the surface of the filtration material. The solution lies in the observation of sedimentation rate (after previous dilution) using by the turbidimetric method, based on the beam-column passage through muddy water. The results show that it is not critical ambient temperature, but the time effect of natural mineralization in combination with moisture (dry matter concentration, the amount of water). The present thesis evaluates the possibilities and application method, leading to the natural regeneration of the filtration material exposed to natural climatic conditions.
237

nádrž ČOV / Cast-in-place tank of sewage plant

Sivčák, Jozef Unknown Date (has links)
The master’s thesis designs and checks the reinforced concrete tanks of sewage plant. Part of this thesis are also drawings. Tanks are designed as a watertight underground structure with aspect on standards and watertight function. Foundation slab and concrete walls were designed according to ultimate and serviceability limit states. The thesis includes design of reinforcement according to non-force effects in early stage. The structure is checked also to loss of equilibrium of a structure due to uplift by vertical actions from water pressure.
238

Numerisk förstudie av industriell symbios mellan fiskodling och pappers och massaindustrin : Med fokus på möjligheter och begränsningar / Numerical feasibility study of industrial symbiosis between fish farming and the paper and pulp industry : With a focus on opportunities and limitations

Meldgaard, Susanna January 2022 (has links)
I många år har linjär ekonomi tillämpats i samhället men det börjar ske en förändring. Nu börjar det bli intressant att skapa ett ekonomiskt värde i restprodukter genom att bilda cirkulära ekonomier, som dessutom minskar utarmningen av jordens resurser och skapar hållbarhet. En kritisk ändlig naturresurs för alla levande organismer är mackronäringsämnet fosfor. Den bryts i stora dagbrott men börjar bli mer svåråtkomlig och utspädd vilket kan leda till att det blir en resursbrist i framtiden. De skogsindustriella reningsverken behöver näringsämnen för att kunna rena avloppsvatten från organiskt material. Där tillsätts bland annat kväve och fosfor vars utvinning är energikrävande och bidrar till miljöföroreningar. Inne i reningsverket sker många biologiska processer som är beroende av flera faktorer för att uppnå en hög reningsgrad. En faktor är temperatur. Pappers och massabruken har ofta varma flöden som behöver kylas ner innan de går till reningsverket, därav fås ett stort överskott av lågvärdig energi som ej används (spillvärme). Under de senaste åren har både ett politiskt och privat driv uppstått att utöka det svenska vattenbruket med akvatiska produkter, exempelvis fisk. Fiskar kan odlas i öppna kassar i sjöar/hav men det finns risker så som övergödning och spridning av sjukdomar. Därav är intresset stort för landbaserade fiskodlingar med Recirculating Aquaculture Systems. En landbaserad fiskodling har dock ett stort värmebehov för att bibehålla rätt vattentemperatur för fisken. Avloppsvattnet har även ett högt innehåll av kväve och fosfor som behöver renas innan det släpps ut. Med hjälp av programmet Simulink byggdes en simuleringsmodell över ett skogsindustriellt reningsverk i symbios med en fiskodling. Syftet var att undersöka möjligheter och begränsningar för symbiosen med ett extra fokus på reningsverket. Målen var att ta reda på hur mycket mindre kväve och fosfor som behövs i reningsverket, utföra en miljöanalys av symbiosen, identifiera begränsande faktorer och hitta lösningar samt ta reda på om spillvärmen räcker för att värma fiskodlingen De erhållna resultaten var att reningsverket kan spara 82 ton fosforsyra och upp till 817 ton ammoniak per år. Reningsverket klarar belastningen från en fiskodling med en årlig produktion på 2200 ton fisk utan överskrida sin dåvarande utsläpp år 2021, vilket motsvarar 2,9 kg odlad fisk per ton producerad massa. Det kan reducera reningsverkets och fiskodlingen koldioxidutsläpp med 471,1 ton respektive 485,7 ton per år. Under året infaller ett processtop i pappers och massaindustrin. Det leder till strypt värmetillförsel för fiskodlingen som resulterar i för kall fiskvattentemperatur samt för höga utsläpp närsalter vid uppstart av reningsverket. En lösning är att lägga på fem centimeters isolering på fiskpoolerna. För att minimera närsaltsutsläppen kan fasta närsalter ur fiskavloppsvattnet filtreras bort och en kolkälla tillsättas. För att maximera användningen av spillvärme kan en icke isolerad 3000 ton fiskodling byggas. Värmningsbehovet per år blir då runt 16000 MWh vilket motsvarar cirka 4,7 % av spillvärmen. / For many years, linear economics has been applied in society, but it is changing. Instead, it is now interesting to create an economic value in residual products by forming circular economies, which also reduces the depletion of the earth's resources and promote sustainability. A critical finite natural resources for all living organisms is the macronutrient phosphorus. It is mined in large open pits but is becoming diluted and difficult to access, which may lead to a lack of resource in the future. The forest industry wastewater treatment plants need nutrients to be able to treat wastewater from organic material. Among other things, nitrogen and phosphorus are added, the extraction of which is energy-intensive and contributes to environmental pollution. Inside the treatment plant, many biological processes take place that depend on several factors to achieve a high degree of treatment. One factor is temperature. Paper and pulp mills often have warm streams of water that needs to be cooled down before being sent to the treatment plant, which results in a large surplus of waste heat that is not used. In recent years, both a political and private drive has arisen to expand Swedish aquaculture with aquatic products such as fish. Fish can be grown in open net pens in lakes / seas, but there are risks such as eutrophication and the spread of diseases. As a result, there is great interest in land-based fish farms with Recirculating Aquaculture Systems. However, a land-based fish farm has a great need for heat to maintain the right water temperature for the fish. The wastewater also has a high content of nitrogen and phosphorus that needs to be treated before it is discharged. With the help of the program Simulink, a simulation model was built describing a forest industry treatment plant in symbiosis with a fish farm. The purpose was to investigate possibilities and limitations for the symbiosis with an extra focus on the treatment plant. The goals were to investigate how much less nitrogen and phosphorus is needed in the treatment plant, perform an environmental analysis of the symbiosis, identify limiting factors, find solutions and find out if there is enough waste heat to heat the fish farm The results obtained were that the treatment plant can save 82 tonnes of phosphoric acid and up to 817 tonnes of ammonia per year. The treatment plant manages the load from a fish farm with an annual production of 2200 tonnes of fish without exceeding its equivalent discharge pollution levels of 2021, which is equal to 2,9 kg farmed fish per tonne produced pulp. It can reduce the treatment plant's and fish farm's carbon dioxide emissions by 471.1 tonnes and 485.7 tonnes per year, respectively During the year, a process stop occurs in the paper and pulp industry. This leads to a restricted heat supply for the fish farm, which results in a too cold water temperature for the fish and too high discharges of nutrients in to receiving lake at the start-up of the treatment plant. One solution to this issue is to put five centimetres of insulation on the fish pools. To minimize nutrient discharges, the solid nutrients from the fish wastewater can be filtered out and a carbon source added. To maximize the use of waste heat, a non-insulated 3000 ton fish farm can be built. The heating demand per year will then be around 16,000 MWh, which corresponds to approximately 4.7% of the waste heat.
239

Research on model-based calculation of greenhouse gas emissions from domestic wastewater treatment systems in Vietnam

Nguyen, Thi Van Anh, Dang, Xuan Hien, Nguyen, Duc Toan 07 January 2019 (has links)
There are three important greenhouse gases: carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O), which are generated from the domestic wastewater treatment systems, including on-site and off-site sources. On-site emission of greenhouse gases occurs during process of wastewater treatment, while the off-site emission of greenhouse gases occurs during energy using and other supporting activities of the treatment system. The research established model to calculate greenhouse gas emissions from the domestic wastewater treatment systems, was named No.0 MTH model. The No.0 MTH model was based on balance equations of substrate and biomass, biochemical reactions and Monod kinetics equations for biological treatment reactors and writen by programing Scalable language. Model was calibrated and applied on the Yen So wastewater treatment plant, Ha Noi and the results were obtained at 22oC as follows: off-site GHG emission is 29,560 kgCO2-eq/day; on-site GHG emission is 13,534 kgCO2-eq/day, and the rate of on-site emission is 2.506 kgCO2-eq/ kg BOD. Maybe using the No.0 MTH model to calculate greenhouse gas emissions from the domestic wastewater treatment systems with similar biological methods. / Có 3 khí nhà kính quan trọng là khí Cacbonic (CO2), khí Mêtan (CH4), và khí Đinitơ monoxit (N2O) được phát sinh từ hệ thống xử lý nước thải sinh hoạt gồm cả nguồn trực tiếp và gián tiếp. Phát thải trực tiếp khí nhà kính (KHK) xảy ra trong suốt quá trình xử lý còn phát thải gián tiếp khí nhà kính xảy ra trong quá trình sử dụng năng lượng và các hoạt động phụ trợ bên ngoài hệ thống xử lý. Nghiên cứu đã thiết lập mô hình tính toán phát thải khí nhà kính từ hệ thống xử lý nước thải sinh hoạt, được đặt tên là mô hình MTH số 0. Mô hình MTH số 0 đã dựa trên các phương trình cân bằng khối lượng cơ chất và sinh khối, các phản ứng hóa sinh và phương trình Monod đối với các thiết bị xử lý sinh học và được viết trên ngôn ngữ lập trình scala. Mô hình đã được hiệu chỉnh và được áp dụng tính toán tại nhà máy xử lý nước thải sinh hoạt Yên Sở, thành phố Hà Nội và kết quả thu được tại 22oC như sau: phát thải KNK gián tiếp là 29.560 kgCO2-tđ/ngày và phát thải KNK trực tiếp là 13.534 kgCO2-tđ/ngày với tỷ lệ phát thải khí nhà kính trực tiếp là 2,506 kgCO2-tđ/ kgBOD. Có thể sử dụng mô hình MTH số 0 để tính toán phát thải khí nhà kính từ hệ thống xử lý nước thải sinh hoạt bằng phương pháp sinh học tương tự.
240

Modeling of the primary sludge thickening process at a wastewater treatment plant with the use of machine learning / Modellering av förtjockningsprocessen av primärslam på ett avloppsreningsverk

Bröndum, Eric January 2022 (has links)
This thesis focuses on modeling the primary sludge in the thickening process at Henrikdals wastewater treatment plant in Stockholm, Sweden. The thickening process is one of the core processes at the wastewater treatment plant, where the goal is to thicken a residual product called primary sludge. Two thickener belts are used to thicken the sludge gravimetrically. Polymer is also added to increase the dewaterability and to thicken the sludge. The thickness of the sludge is measured by the total solids content (TS) in the sludge and is measured with total solid measurement sensors. These sensors have, however, been shown to be inaccurate. A long short-term memory network (LSTM) and a feed-forward neural network were compared by using sensor and instrument data to predict the TS in the thickened primary sludge. To validate the performance of the models, manual laboratory testing samples were compared with the predictions of the models. Simulations in Simulink were also performed with the intent of simulating the thickening process. By using a machine learning model that could predict the TS, hypotheses regarding reductions in the polymer dosage were explored. A feed-forward and feedback control strategy in combination with the LSTM architecture were used and it was shown that the TS of the thickened sludge could be controlled by regulating the polymer dosage. Thus, using a feedback control strategy gives further opportunities for the wastewater treatment plant to choose whether a lower polymer consumption or a higher TS is preferred, as these two variables correlate with each other. / Syftet med detta arbete var att ta fram maskininlärningsmodeller av primärslamsförtjockningen på Henriksdals avloppsreningsverk i Stockholm, Sverige. Förtjockningsprocessen är en av de viktigaste delerna i avloppsreningsverk, där målet är att förtjocka en restprodukt som kallas primärslam. Förtjockningen sker i två separata linjer. Polymer tillsätts och slammet förtjockas genom gravimetrisk avvattning på ett silband. Slammets torrsubstanshalt (TS) är ett mått på slammets tjockhet och beräknas med hjälp av att använda sensorer. Dessa sensorer har dock visats sig vara opålitliga. Genom att använda tillgänglig process-, maskin- och instrumentdata så har en long short-term memory (LSTM) arkitektur och ett framkopplat neuralt nätverk jämförts för att uppskatta torrsubstansen i primärslammet. Manuell provtagning och labbanalys utfördes för att validera prestandan i de två modellerna. Hypoteser kring att kunna optimera TS-halten eller minska polymerförbrukningen utforskades genom att simulera processen i Simulink. Resultaten visade att användandet av en fram och återkopplingsregulator tillsammans med en LSTM arkitektur kan minska polymerförbrukningen och kan ge en jämnare TS-halt i det förtjockade slammet. Däremot måste en avvägning mellan hög TS-halt och låg polymerförbrukning göras, då dessa två variabler korrelerar med varandra

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