• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 72
  • 58
  • 30
  • 21
  • 15
  • 14
  • 5
  • 3
  • 3
  • 3
  • 2
  • 1
  • 1
  • 1
  • 1
  • Tagged with
  • 291
  • 291
  • 127
  • 38
  • 37
  • 36
  • 33
  • 32
  • 27
  • 27
  • 26
  • 26
  • 25
  • 22
  • 21
  • 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

Περιβαλλοντικός σχεδιασμός για την ασφαλή επαναχρησιμοποίηση επεξεργασμένων λυμάτων και ιλύος βιολογικών καθαρισμών νομού Αιτωλοακαρνανίας σε εδάφη

Αραμπατζής, Χρήστος 04 December 2012 (has links)
Στην παρούσα μελέτη εξετάζεται η δυνατότητα επαναχρησιμοποίησης των επεξεργασμένων αστικών λυμάτων και ιλύος από Εγκαταστάσεις Επεξεργασίας Λυμάτων του νομού Αιτωλ/νίας σε γεωργικές εκτάσεις του νομού. Στο πρώτο μέρος της εργασίας γίνεται μια εισαγωγή στην επαναχρησιμοποίηση των αστικών λυμάτων στην γεωργία. Περιγράφονται τα χαρακτηριστικά των λυμάτων, οι διεργασίες που συντελούνται στις Εγκαταστάσεις Επεξεργασίας Λυμάτων, τα κριτήρια ποιότητας που πρέπει να πληρούν τα λύματα (προκειμένου να χρησιμοποιηθούν για άρδευση). Αναλύονται τα αγρονομικά κριτήρια και τα κριτήρια για την διασφάλιση της δημόσιας υγείας, που πρέπει να τηρούν τα επεξεργασμένα λύματα, ώστε να εφαρμόζονται στα εδάφη με ασφάλεια. Επίσης, στο πρώτο μέρος αναλύονται τα κριτήρια επιλογής θέσεων για την εφαρμογή των λυμάτων, καθώς και το νομοθετικό πλαίσιο που ισχύει στην Ελλάδα σχετικά με την επαναχρησιμοποίηση. Τέλος, γίνεται μια επισκόπηση της διεθνούς πρακτικής σχετικά με την επαναχρησιμοποίηση και περιγράφεται και η κατάσταση που επικρατεί στον Ελλαδικό χώρο. Στο δεύτερο μέρος γίνεται αναφορά στους υδατικούς πόρους του νομού Αιτωλ/νίας. Περιγράφεται το υδατικό δυναμικό του νομού Αιτωλ/νίας, οι ανάγκες νερού για διάφορες χρήσεις στον νομό, καθώς και οι υποδομές δικτύων άρδευσης σην Αιτωλ/νία. Το τρίτο μέρος αναφέρεται στην χρήση της ιλύος στην γεωργία. Γίνεται περιγραφή των χαρακτηριστικών της λυματολάσπης, του νομικού πλαισίου που ισχύει κατά την χρήση της στην γεωργία και τονίζονται τα κρίσιμα σημεία ελέγχου κατά την εφαρμογή της λάσπης στα γεωργικά εδάφη. Στο τέταρτο μέρος γίνεται η οριοθέτηση και η περιγραφή των περιοχών μελέτης και παρουσιάζεται ο τρόπος, με τον οποίο προσδιορίζονται οι καλλιεργούμενες εκτάσεις μέσα σε κάθε περιοχή μελέτης, ώστε στην συνέχεια να εκτιμηθούν οι υδατικές απαιτήσεις. Οι Εγκαταστάσεις Επεξεργασίας Αστικών Λυμάτων, που εξετάζονται στην παρούσα μελέτη, είναι αυτές των Δήμων Μεσολογγίου, Αιτωλικού, Θέρμου, Αγρινίου και Ναυπάκτου. Ενώ οι επιλεγείσες περιοχές μελέτης βρίσκονται πλησίον των ανωτέρω εγκαταστάσεων. Γίνεται επίσης σύντομη αναφορά στον τρόπο λειτουργίας της κάθε ΕΕΛ. Στο πέμπτο μέρος γίνεται αναφορά στους παράγοντες που επηρεάζουν την υδατοκατανάλωση των καλλιεργειών, αναλύεται η μεθοδολογία με την βοήθεια της οποίας προσδιορίζονται οι υδατικές απαιτήσεις των καλλιεργειών σύμφωνα με την εξίσωση των Penman Monteith κατά FAO. Προσδιορίζονται οι υδατικές απαιτήσεις των καλλιεργειών και οι συνολικές ανάγκες σε αρδευτικό νερό για κάθε περιοχή μελέτης, ακολουθεί η συσχετισή του με τις ετήσιες εκροές της κάθε ΕΕΛ, ώστε να προκύψει το ποσοστό κάλυψης των αρδευτικών αναγκών με επεξεργασμένες εκροές για την κάθε περιοχή. Τέλος, στο έκτο μέρος γίνεται μια προσπάθεια εκτίμησης της δυνατότητας χρήσης της λυματολάσπης στα εδάφη του νομού Αιτωλ/νίας. / This study examines the potential reuse of treated municipal wastewater and sludge from Waste Water Treatment Plants (WWTPs) in agricultural areas of Aitoloakarnania prefecture. The first part of the study is an introduction to the reuse of urban wastewater in agriculture. Describes the characteristics of wastewater, the processes occurring in the wastewater treatment plants, the quality criteria that wastewater should have for safe use in irrigation. Also, the first part analyzes the criteria for selecting areas to apply wastewater. The legislative framework in Greece for waste water reuse is also analyzed. Finally, a review of international and domestic practices on agricultural reuse is given. The second part refers to the water resources of the Aitoloakarnania prefecture. The third part refers to the use of sludge in agriculture. Describes the characteristics of the sludge, the legal framework applicable for use in agriculture and highlights the critical control points in the application of sludge on soils. The fourth part describes each study area and shows how we can specify in each area the cultivated species (crops) in order to calculate the water requirements of the crops. The study areas are sited near by the WWTPs of Messolongi, Aitoliko, Thermo, Agrinio, Naupaktos. The fifth part refers to the factors affecting water requirements of the crops, and analyzes the methodology used to calculate water requirements of crops (FAO Penman – Monteith equation). At the end of the part there is a correlation between the water requirements of the crops and the annual output of each WWTP, resulting in the percentage of coverage of irrigation demands of crops in each studied area. Finally, the sixth part is an attempt to assess the usability of sludge to soils of the Aitoloakarnania prefecture.
82

Environmentální bezpečnost systému odpadních vod / Protection of the untreated sewage water environmental

BELEŠOVÁ, Petra January 2015 (has links)
The topic "Environmental Security of Wastewater System" was selected for the creation of my thesis by several fundamental reasons.The main one is the vital importance of water for the functioning of human society.Drinking water sources are limited and the current relatively easy access to good quality water leads to irresponsible waste of this commodity.Besides wasting there is another big problem with environmental pollution,which is closely related to the degradation of sources of drinking water.With the increase of human population,environmental conditions began to worsen rapidly and this issue became to be discussed by multinational organizations.The so-called Environmental Security is currently very topical subject.It is introduced gradually into school curricula.Large amounts of funds have been invested to the environmental safety of water management in the past few years.An especially,there have been build many waste water treatment plants.The thesis is oriented locally on the municipality of Příbram.Its administrative area covers 74 municipalities and military training area of Brdy.The administrative area is mostly formed by smaller communities that are self-sustaining in water management.It is necessary to ensure sufficiently good conditions of the environment to prevent its degradation.The aim of this thesis is mainly to map the impacts of failure of sewage system and eventual propose of appropriate interim solutions of such failure.The research question is closely related to it: What is the current level of environmental safety of water? To achieve the set objectives,primarily I applied the method of literary research,through which was described the basic information necessary to understand the issue.It was also used method of qualitative research,which was carried out on the basis of interviews with experts in that field.The collected data were organized in a logical survey and analyzed by the a SWOT analysis.The thesis is divided into two main sections.The first one is a theoretical part,which describes the water cycle,explains what is infrastructure and,consequently,it highlights the importance of critical infrastructure.It also explains the concept of water management and presents the basic characteristics and methods of processing and treatment of drinking and waste water.It also states the basic legislation governing the issue of water and ultimately defines the concept of environmental security.The second part describes the sewage system in the area of Příbram and maps the ways of creation and the subsequent magnitude of failure of analyzed wastewater treatment plants.In direct relation to this,it assesses the possible emergence of environmental impact.Waste water can be divided into several groups according to where and how they arise.Taking account of their origin,wastewater may contain a wide variety of harmful substances.A failure of the wastewater system would be not only a current problem of environmental pollution at the site where the waste water was getting into the nature,but a long term adverse effect,which would be later manifested in the form of,for example,contamination of soil and groundwater,which would subsequently mix with drinking water resources.It could also lead to the death of some animals,disabling eating crops in that location and spread of various infectious diseases.This condition is highly undesirable and therefore it is necessary to implement preventive measures to prevent environmental safety.From this research,it was found that the formation of potentially serious impacts on the environment due to the failure of the sewage disposal plants in the area of Příbram is not expected.The operators are ready to remove immediately and quite efficiently incurred defects in order to avoid serious long-term failure.In relation to this,the environmental safety of the sewage disposal plants in the area of Příbram can be evaluated as very good.
83

Quantifying the energy consumption of the water use cycle

Trujillo, Iliana Cardenes January 2017 (has links)
The management and delivery of water and wastewater consume significant amounts of energy, mostly in the form of electricity. With increasing populations, climate change, water quality issues and increasing energy prices, it is more important than ever to understand energy consumption patterns. Energy usually represents the largest operational cost in water utilities around the world, yet there is limited work aiming to quantify the specific relationship between water and its associated energy, and understand its implications for future decision-making. This thesis presents variousmethodological approachesto quantify and understand energy use in water infrastructure systems, as well as how to incorporate them in decision-making processes. The main hypotheses are as follows: firstly, a detailed understanding of the use of energy in water infrastructure systems can facilitate more efficient and sustainable water infrastructure systems and, secondly, that incorporating energy into planning for water and wastewater resources can help understand the impacts of decisions and establish trade-offs between actions. To test these hypotheses, the thesis presents an analytical approach to various areas. Firstly, it identifies, maps and quantifies the energy consumption patterns within a water infrastructure system. This is then used to identify inefficiencies and areas of potential energy saving. Secondly, it incorporates detailed energy costs into short and long-term water resources management and planning. Thirdly, it evaluates trade-offs between energy costs and changing effluent quality regulations in wastewater resources. The Thames River basin, in the south-east of England, is used as a case study to illustrate the approach. The results demonstrate that a systematic approach to the quantification of energy use in a water infrastructure system can identify areas of inefficiencies that can be used to make decisions with regards to infrastructure planning. For example, water systems have significant geo-spatial variations in energy consumption patterns that can be addressed specifically to reduce negative trade-offs. The results also show that incorporating detailed energy information into long-term water resources planning can alter the choices made in water supply options, by providing more complete information. Furthermore, methodologically, they show how several methodological approaches can be used to support more complete decision-making in water utilities to reduce short and long-term costs. In this particular case study, the results show that there are important differences in energy consumption by region, and significant differences in the seasonal and energy patterns of water infrastructure systems. For example, water treatment was shown to be the largest consumer of energy within the whole system, compared with pumping or wastewater treatment; but wastewater treatment energy consumption was shown to be the fastest growing over time due to changes in water quality regulatory frameworks. The results show that more stringent effluent standards could result in at least a doubling of electricity consumption and an increase of between 1.29 and 2.30 additional million tonnes of CO2 a year from treating wastewater in large works in the UK. These are projected to continue to increase if the decarbonisation of the electricity grid does not occur fast enough. Finally, the thesis also shows that daily energy consumption can be reduced by up to 18% by optimally routing water through a water network. optimization of water networks, and that a change in discount rates could change the daily operating costs by 19%, that in turn leads to a resulting different set of optimal investment options in a water supply network.
84

Aplicação de tratamentos biológico e físico-químico em efluentes de lavanderia e tinturaria industriais do município de Toritama no estado de Pernambuco

Andréa Fernanda de Santana Costa 29 May 2008 (has links)
Os corantes presentes em efluentes industriais são poluentes recalcitrantes que apresentam toxicidade aos seres vivos e são de difícil remoção por tratamentos convencionais. O processo de beneficiamento de jeans utiliza grande volume de água e produtos químicos diversos, incluindo os corantes sintéticos. O presente estudo investigou a influência de fatores biológicos e físico-químicos na remoção de cor e turbidez em tratamentos de efluentes de lavanderia e tinturaria industriais. Planejamentos fatoriais com ponto central foram empregados em biodegradações e em tratamentos por coagulação-floculação, utilizando delineamento experimental com análise de interação entre os fatores investigados. As variáveis independentes foram consórcio microbiano, aeração, agitação, concentrações de tanino e do polímero auxiliar de floculação (POLICAP - 32) sobre as variáveis respostas, cor e turbidez. O consórcio microbiano com capacidade de descolorir corantes foi obtido a partir do efluente na ausência de nutrientes, a 28 - 30 C, sob agitação de 150 rpm e aeração de 1 vvm. No tratamento biológico, a aeração e o aumento da agitação desfavoreceram significativamente a descoloração; a maior remoção de cor foi obtida no ponto central do planejamento - concentração do consórcio a 1,25 % v/v e agitação de 50 rpm. Nessa condição experimental, a cor média atingiu aproximadamente 138 mgPt/L, correspondendo a uma descoloração do efluente não tratado de cerca de 90 %. No tratamento físico-químico, o aumento da concentração de tanino e a interação entre as concentrações de tanino e do polímero favoreceram significativamente a descoloração do efluente. A maior remoção de cor e redução de turbidez foram obtidas no ponto central do planejamento - concentração do tanino 0,3 g/mL, polímero auxiliar de floculação 15 ppm em pH 7,5 durante 20 minutos. Nessa condição experimental, a cor média foi aproximadamente 50 mgPt/L e a turbidez média, aproximadamente 4 UNT. A descoloração atingiu 96 % e a redução de turbidez, 79 % do efluente não tratado no tratamento físico-químico / The industrial effluents with dyes are recalcitrant pollutants exhibiting toxicity to the living being and are difficult to remove by conventional processes. The treatment process of jeans uses large volumes of water and various chemicals, including synthetic dyes. This study investigated the influence of biological and physico-chemical factors in the removal of color and turbidity in the effluent treatment from laundry and dyeing industries. Factorial designs with central point were used in biodegradation and coagulation-flocculation treatments using analysis of interactions between the investigated factors. The independent variables were microbial consortium, aeration, agitation, tannin and the floculation polymer (POLICAP - 32) concentrations, whereas the response variables were color and turbidity. The microbial consortium with capacity of dye decolorization was obtained from the effluent in the absence of nutrients at 28 to 30 C, aeration of 1 vvm under agitation of 150 rpm. The biological treatment of the effluent occurred during 48 hours. In the experimental design of the biodegradation, the aeration and the increase of the agitation unfavored significantly the decolorization. The higher removal of color was obtained from the central point of the factorial design 1.25 % v/v consortium concentration and 50 rpm agitation. In this condition, the color average reached approximately 138 mgPt/L, corresponding to a decolorization of the untreated effluent of approximately 90 %. In the physico-chemical treatment, the increase of the tannin concentration and the interactions between tannin and polymer concentrations significantly favored the decolorization of the effluent. The higher removal of color and further reduction of turbidity were obtained at the central point of the factorial design 0.3 g/mL tannin concentration, 15 ppm polymer floculation at pH 7.5 for 20 minutes. In this experimental condition, the average color was approximately 50 mgPt/L and the average turbidity, approximately 4 NTU. The decolorization reached 96 % and the turbidity reduction, 79 % of the untreated effluent in the physical-chemical treatment
85

Tratamento de efluentes da carcinicultura por flotação em coluna e flotação

José Francisco de Araújo Melo 00 December 2010 (has links)
A elevada produtividade nos criadouros de camarão torna necessária a abordagem de alguns aspectos para sua sustentabilidade, principalmente do ambiente aquático dos viveiros. Dessa forma, o tratamento de efluentes originados da carcinicultura torna-se de fundamental importância, considerando a necessidade de minimizar os impactos ambientais gerados por essa atividade produtiva. O presente trabalho investiga os usos das flotações dos tipos por coluna e ar dissolvido para o tratamento de efluentes da carcinicultura. O efluente utilizado foi proveniente da fazenda Tabatinga, localizada no litoral norte do Estado de Pernambuco. Foi realizada a caracterização físico-química e microbiológica dos efluentes, sendo obtidos parâmetros condizentes com os encontrados na literatura. Uma coluna de flotação de bancada foi utilizada nos ensaios experimentais, sendo empregado um planejamento experimental com duas variáveis (pH e vazão de ar) visando avaliar a remoção de turbidez do efluente. O efeito da adição de um floculante(Bozefloc CE 340 líquido) também foi investigado. Os experimentos em célula FAD foram realizados com valores de pressão de 3 e 6 bar, e pH de 5,8 e 9,8, e experimentos adicionais foram realizados utilizando um coletor aniônico. Os resultados de flotação em coluna para o efluente do início do cultivo demonstraram que a turbidez diminui com o aumento da vazão e com a diminuição do pH após 40 minutos de processo, sendo obtido como melhor ajuste um modelo linear com interação. A presença do floculante na concentração de 0,1% (p/v) a pH 7,8 demonstrou uma remoção de turbidez de apenas 25% para a condição de menor vazão de ar. Para o tratamento do efluente do fim do cultivo, a remoção de turbidez também aumentou com o aumento da vazão de ar e com a diminuição do pH, atingindo um valor máximo de remoção de cerca de 40% após 35 minutos de processo, com um ajuste quadrático do modelo. Na flotação por ar dissolvido do efluente do fim do cultivo, os maiores percentuais de remoção de turbidez foram obtidos a pH 5,8, atingindo valores de 52 e 47% para pressões de operação de 3 e 6 bar, respectivamente. Na presença de um coletor aniônico(Flomin-C-5435), observou-se um aumento na remoção da turbidez para valores entre 56 e 65% / The high productivity in the breeding of shrimp makes it necessary to approach some aspects to their sustainability, particularly the aquatic environment of the nursery. Thus, the treatment of effluents originating from the shrimp becomes of fundamental importance, considering the need to minimize the environmental impacts generated by this productive activity. This study investigates the uses of flotation types of column and dissolved air to the treatment of shrimp effluent. The effluent used was from the farm Tabatinga, located on the north coast of Pernambuco State. Was performed physical-chemical and microbiological characterization of effluent being obtained parameters consistent with those found in the literature. A column flotation bench was used in experimental trials, being employed an experimental design with two variables (pH and air flow) to evaluate the removal of turbidity of the effluent. The effect of adding a flocculant was also investigated. The FAD cell experiments were performed with pressure values of 3 and 6 bar, and a pH of 5.8 and 9.8, and additional experiments were performed using an anionic collector. The results of column flotation for the effluent from the beginning of culture showed that the turbidity decreases with increasing air flow and the decrease in pH after 40 minutes of the proceedings, was obtained as best fit a linear model with interaction. The presence of flocculant concentration of 0.1% (p / v) at pH 7.8 showed a removal of turbidity of only 25% for the condition of lower air flow. For the treatment of effluent from the end of cultivation, the turbidity removal also increased with increasing air flow and with decreasing pH, reaching a maximum removal of about 40% after 35 minutes of the proceedings, with an adjustment quadratic model. In dissolved air flotation effluent end of the cultivation, the highest percentage of turbidity removal were obtained at pH 5.8, reaching values of 52 and 47% for operating pressures of 3 and 6 bar, respectively. In the presence of an anionic collector, there was an increase in the removal of turbidity values between 56 and 65%
86

Separacao e recuperacao de cromio e outros elementos de valor em solucoes de trabalho e residuos industriais de galvanoplastia por troca ionica

CHEPCANOFF, VERA 09 October 2014 (has links)
Made available in DSpace on 2014-10-09T12:45:26Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T13:59:37Z (GMT). No. of bitstreams: 1 07174.pdf: 7729112 bytes, checksum: 448b0bbb9302347b89a39b90929d3bf4 (MD5) / Dissertacao (Mestrado) / IPEN/D / Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP
87

Tratamento de esgoto sanitario com o uso de acelerador de eletrons

BORRELY, SUELI I. 09 October 2014 (has links)
Made available in DSpace on 2014-10-09T12:25:25Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:03:05Z (GMT). No. of bitstreams: 1 06048.pdf: 4286403 bytes, checksum: 125c0216eea47b9a749977ad0ec8b66a (MD5) / Dissertacao (Mestrado) / IPEN/D / Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP
88

Avaliação da toxicidade em água e sedimento do Rio Cubatão-SP / Assessment of toxicity in water and sediment from Cubatão River - SP

GARCIA, VANESSA S.G. 09 October 2014 (has links)
Made available in DSpace on 2014-10-09T12:34:48Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:03:28Z (GMT). No. of bitstreams: 0 / Dissertação (Mestrado) / IPEN/D / Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP
89

Caracterização química de hormônios sexuais em águas de poço da região da USP via cromatografia a gás acoplada a espectrometria de massas CG/EM / Chemical characterization of sex hormones in water from wells in the region of the USP by gas chromatography coupled to mass spectrometry GC/MS

GONSCHOROWSKI, GRACIELE P. da C. 09 October 2014 (has links)
Made available in DSpace on 2014-10-09T12:41:24Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:03:40Z (GMT). No. of bitstreams: 0 / Dissertação (Mestrado) / IPEN/D / Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP
90

Ensaios de toxicidade empregados na avaliacao de efeitos no sistema de tratamento de esgotos e efluentes, Ete Suzano, e seu entorno, utilizando organismos aquaticos / Toxicity assays applied for the evaluation of the effects of Suzano wastewater treatment system, Ete Suzano, and its surroundings, using aquatic organisms

HAMADA, NATALIA 09 October 2014 (has links)
Made available in DSpace on 2014-10-09T12:26:27Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:04:05Z (GMT). No. of bitstreams: 1 11715.pdf: 1156737 bytes, checksum: 41ad845cca81dbf4069b69b67a1aa3f3 (MD5) / Dissertacao (Mestrado) / IPEN/D / Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP

Page generated in 0.0801 seconds