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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.
21

Influence of dissolved organic matter (DOM) on mercury speciation and reactivity in rainwater

Manley, Sarah D. January 2008 (has links) (PDF)
Thesis (M.S.)--University of North Carolina Wilmington, 2008. / Title from PDF title page (viewed May 27, 2009) Includes bibliographical references (69-71)
22

Aqueous photochemical cycling of formaldehyde and hydrogen peroxide in rainwater

Smith, Jeremy Daniel January 2009 (has links) (PDF)
Thesis (M.S.)--University of North Carolina Wilmington, 2009. / Title from PDF title page (February 23, 2010) Includes bibliographical references (p. 73-77)
23

Quality assessment of domestic harvested rainwater in the peri-urban region of Kleinmond, Western Cape and the optimisation of point-of-use treatment systems

Dobrowsky, Penelope Heather 04 1900 (has links)
Thesis (MSc)--Stellenbosch University, 2014. / ENGLISH ABSTRACT: Domestic rainwater harvesting (DRWH) refers to the collection and storage of rainwater for domestic purposes and in an effort to achieve the Millennium Development Goals (MGD), the South African government has started an initiative where DRWH tanks are financed in sustainable housing schemes in an aim to provide an additional water source directly to households. Although many provinces, including parts of the Eastern Cape and KwaZulu Natal, have been using harvested rainwater as a potable water source, there are a limited number of studies indicating the quality of harvested rainwater in South Africa. However, many studies, internationally, have indicated that while the practice of harvesting rainwater is gaining popularity, rainwater quality is not within potable standards (Chapter 1). During the first phase of the study, rainwater samples were collected from the Kleinmond Housing Scheme (Western Cape, South Africa). From a cluster of 411 houses, the DRWH tanks connected to 29 houses were selected for monitoring the microbial and physico-chemical properties of harvested rainwater. Drinking water guidelines stipulated by SANS 241 (2005), DWAF (1996), ADWG (NHMRC and NRMMC, 2011) and WHO (2011) were used throughout the study to monitor the quality of rainwater. Eight sampling sessions were then conducted from March to August 2012, during a high and low rainfall period. Overall, the physico-chemical parameters of the rainwater samples were within the respective drinking water guidelines. However, the microbiological analysis verified results obtained in international studies, and showed that the indicator bacteria numbers present in the DRWH samples exceeded the stipulated guidelines (Chapter 2 and 3). Species specific primers were also used to routinely screen for the virulent genes, aggR, stx, eae and ipaH found in Enteroaggregative E. coli (EAEC), Enterohaemorrhagic E. coli (EHEC), Enteropathogenic E. coli (EPEC) and Enteroinvasive E. coli (EIEC), respectively, in the rainwater samples. The virulent pathogenic E. coli genes were then detected in 3% (EPEC and EHEC) and 16% (EAEC) of the 80 rainwater samples collected routinely during the sampling period from ten DRWH tanks (Chapter 3). Bacterial isolates selected during the high rainfall period (June to August 2012), as well as PCR assays performed on total genomic DNA extraction from the rainwater samples, confirmed the presence of numerous pathogenic bacteria including Legionella spp. Klebsiella spp. and Shigella spp. Yersinia spp. were also isolated and detected for the first time in DRWH tanks (Chapter 4). Based on the results obtained in the first phase and as many studies have indicated the poor quality of rainwater, the second phase of the project was aimed at designing and monitoring point of use treatment systems. Three polyethylene DRWH tanks (2000 L) were installed at the Welgevallen Experimental farm, Stellenbosch University, South Africa. Various treatment systems, such as activated carbon and slow sand filtration, solar pasteurization and a combined activated carbon/PVA nanofibre filtration column, were then intermittently connected to the three DRWH tanks during the high rainfall period (June to October 2013). Results for slow sand filtration and activated carbon filters indicated that the biological layer that had developed on the filtration media had not matured and for this reason chemical and microbial parameters were not reduced to within drinking water guidelines. A polyvinyl (alcohol) (PVA) nanofibre membrane without activated carbon in a column filtration system was analysed and results indicated that this system was also not effective in reducing the microbial numbers to within drinking water guidelines. Lastly, by utilising a PVA nanofibre membrane with activated carbon in a column filtration system, one litre of potable water was produced and all heterotrophic bacteria, E. coli and total coliform counts were reduced to zero and were within drinking water guidelines (Chapter 5). For the solar pasteurization system (Chapter 6), at treatment temperatures of greater than 72°C, all heterotrophic bacteria, E. coli and total coliforms were reduced to zero and were within drinking water guidelines. However, PCR assays confirmed the presence of Yersinia spp., Legionella spp., and Pseudomonas spp., at temperatures greater than 72°C. Results for chemical analysis also indicated all cations were within the international and national drinking water guidelines, with the exception of iron, aluminium, lead and nickel, which were detected in the pasteurized rainwater samples and were above the respective guidelines. It is hypothesised that these elements could have leached from the stainless steel storage tanks of the pasteurization system and it is therefore recommended that the storage tank of the pasteurization system be manufactured from an alternative material, such as a high grade polymeric material, which is able to withstand the high temperatures yet will not negatively influence the quality of harvested rainwater. / AFRIKAANSE OPSOMMING: Reënwater versameling vir huishoudelike gebruik verwys na die versameling en berging van reënwater vir huishoudelike doeleindes. In 'n poging om die Millennium Ontwikkelingsdoelwitte (MOD) te bereik het die Suid-Afrikaanse regering ‘n inisiatief begin om finansiële bystand aan huishoudings te verleen vir die implementering van reënwater tenke, in ‘n poging om ‘n addisionele water bron direk aan huishoudings te verskaf. Hoewel baie provinsies, insluitend dele van die Oos-Kaap en KwaZulu-Natal, reënwater gebruik as ‘n drinkbare water bron, is daar 'n beperkte aantal studies beskikbaar oor die gehalte van versamelde reënwater in Suid-Afrika. Baie studies internasionaal het egter al aangedui dat, alhoewel die praktyk van die versameling van reënwater besig is om in gewildheid toe te neem, die kwaliteit van reënwater nie binne drinkbare standaarde is nie (Hoofstuk 1). Tydens die eerste fase van die studie is reënwater monsters geneem van die Kleinmond Behuisings Skema (Wes Kaap, Suid Afrika). Van ‘n kompleks van 411 huise, is reënwater tenke van 29 huise geselekteer vir die monitering van die mikrobiese en fisiese-chemiese eienskappe van versamelde reënwater. Drinkwater riglyne soos gestipuleer deur SANS 241 (2005), DWAF (1996), AWDG (NHMRC en NRMMC, 2011) en WHO (2011) was regdeur die studie gebruik om die kwaliteit van reënwater te monitor. Reënwater monsters is tydens agt geleenthede geneem vanaf Maart tot Augustus 2012, tydens die hoë en lae rëenval periode. Oor die algemeen was die fisiese-chemiese parameters van die reënwater monsters binne die onderskeie riglyne vir drinkwater. Mikrobiese analises het egter die resultate van internasionale studies bevestig en het aangedui dat die getal indikator bakterieë teenwoordig in the reënwater die gestipuleerde riglyne oorskry (Hoofstuk 2 en 3). Spesies spesifieke inleiers was gebruik om die virulensie gene aggR, stx, eae en ipaH, teenwoordig in onderskeidelik Entero-aggregatiewe E. coli (EAEC), Entero- hemorragiese E. coli (EHEC), Entero-patogeniese E. coli (EPEC) and Entero-indringende E. coli (EIEC), in die reënwater monsters op te spoor. Die virulente pathogeniese E. coli gene was in 3% (EPEC en EHEC) en 16% (EAEC) van die 80 reënwater monsters, geneem van 10 reënwater tenke tydens die studie, waargeneem (Hoofstuk 3). Bakteriese isolate geselekteer tydens die hoë reenval periode (Junie tot Augustus 2012), so wel as PKR (polymerase ketting reaksie) ontledings uitgevoer op genomiese DNS wat van die reënwater monsters ge-ekstraheer was, het die teenwoordingheid van verskeie patogeniese bakterieë, insluitend Legionella spp., Klebsiella spp. en Shigella spp., bevestig. Dit is ook die eerste keer wat Yersinia spp. in versamelde reënwater waargeneem is (Hoofstuk 4). Die doel van die tweede fase van die projek was om water behandeling sisteme by die punt van gebuik te ontwerp en te monitor aangesien die resultate wat gedurende die eerste fase verkry is, sowel as vele ander studies, aangedui het dat die kwaliteit van versamelde reënwater swak is. Drie poli-etileen reënwater tenke (2000 L) was geïnstalleer op die Welgevallen Eksperimentele plaas van die Universiteit van Stellenbosch, Suid Afrika. Verskeie water behandeling sisteme, soos geaktiveerde koolstof en stadige sand filters, sonkrag pasteurisasie en ‘n gekombineerde geaktiveerde koolstof/PVA nanovesel filtrasie kolom, was met tye gekonnekteer aan verskeie reënwater tenke gedurende die hoë reënval periode (Junie to Oktober 2013). Resultate van die stadige sand en geaktiveerde koolstof filters het aangedui die biologiese laag nog nie ver genoeg ontwikkeld het nie en daarom was die chemiese en mikrobiese parameters nie verminder to binne die riglyne vir drinkwater nie. ‘n Polyviniel (alkohol) nanovesel membraan sonder geaktiveerde koolstof binne ‘n kolom filtrasie sisteem, was geanaliseer en resultate het aangedui dat hierdie sisteem ook nie die mikrobiese getalle verminder het tot drinkwater standaarde nie. Laastens, deur gebruik te maak van ‘n PVA nanovesel membraan met geaktiveerde koolstof in ‘n kolom filtrasie sisteem, was een liter drinkbare water geproduseer met alle heterotrofiese bakterieë, E. coli en totale koliform getalle verminder tot nul en was binne die riglyne vir drinkwater (Hoofstuk 5). Vir die sonkrag pasteurisasie sisteem (Hoofstuk 6), by behandelings temperature van groter as 72°C, was alle heterotrofiese bakterieë, E. coli en totale koliform getalle verminder tot nul en was binne die riglyne vir drinkwater. Maar PKR ontledings het die teenwoordigheid van Yersinia spp., Legionella spp., en Pseudomonas spp. by temperature groter as 72°C bevestig. Resultate van die chemiese analises het ook aangedui dat alle katione binne die drinkwater riglyne was, met die uitsondering van yster, aluminium, lood en nikkel. Hierdie elemente was in die gepasteuriseerde reënwater monsters waargeneem met konsentrasies wat die onderskeie riglyne oorskry het. Dit word gehipoteseer dat hierdie elemente uit die vlekvrye staal van die bergings tenk van die pasteurisasie sisteem kon uitgeloog het. Daarom word dit aanbeveel dat die bergings tenk van die pasteurisasie sisteem geproduseer moet word van ‘n alternatiewe materiaal, soos ‘n hoë graad polimeriese material, wat hoë temperature kan weerstaan maar nie ‘n negatiewe invloed sal hê op die kwaliteit van versamelde reënwater nie.
24

The impacts of rainfall runoff on tidal creek algal and bacterial production /

Ortwine, Michelle L. January 2007 (has links) (PDF)
Thesis (M.S.)--University of North Carolina Wilmington, 2007. / Includes bibliographical references (leaves: 65-70)
25

Evaluating rainwater harvesting and conservation techniques on the Towoomba/Arcadia Ecotope

Ngwepe, Mantlo Richard January 2015 (has links)
Thesis (MSc .(Agronomy)) -- University of Limpopo, 2015 / The changes in climate, especially poor rainfall patterns and distributions are key issues posing major agricultural challenges for food security and threaten the rural livelihoods of many communities in the Limpopo Province. Rainfall (P) is low and limited. These limited P is mostly lost through runoff and evaporation, which result in low soil moisture availability and possible crop failure. Therefore, techniques that reduce these water losses are important for improving dryland crop production and rainwater productivity (RWP). The objectives of this study were to determine the potential and effectiveness of rainwater harvesting and conservation techniques (RWH&CT’s) to conserve and improve plant available water (PAW) for dryland maize production and also determine the efficiency of the RWH&CT’s to improve dryland maize yield and RWP compared to conventional tillage (CON). The study was conducted over a period of two growing seasons (2008/09; 2009/10) using maize as indicator crop at the Towoomba Research Station of the Limpopo Department of Agriculture in the Limpopo Province of South Africa, on an Arcadia ecotope. The experiment was laid out in a randomized complete block design, with four replications and five treatments. The five treatments used in the study were; conventional tillage (CON), No-till (NT), In-field rainwater harvesting (IRWH), Mechanized basins (MB) and Daling plough (DAL). The IRWH and DL were classified as rainwater harvesting techniques (RWHT’s), whilst MB and NT were classified as water conservation techniques. Two access tubes were installed at each treatment to measure the soil water content (SWC) at four different soil depths of 150, 450, 750 and 1050 mm using the neutron water meter. The data collected included climatic data, soil and plant parameters. The data were subjected to analysis of variance through NCSS 2000 Statistical System for Windows and GENSTAT 14th edition. Mean separation tests were computed using Fisher's protected least significant difference test. The SWC of IRWH, DAL and MB were about 510 and 490 mm higher compared to CON and NT treatment during the 2008/09 and 2009/10 seasons, respectively. The PAWT of the IRWH, MB and DAL was significantly different from the CON treatment during the 2008/09 season. For both seasons the biomass yield of the IRWH treatment was significantly different from the NT treatment, producing 23 and 50% more biomass in the 2008/09 and 2009/10 growing seasons, respectively. The grain yield under IRWH was significantly different from the NT treatment during both 2008/09 and 2009/10 seasons. The highest maize grain yield of IRWH was achieved during the 2009/10 season with 56% higher grain yield than the NT treatment. RWP from various RWHT’s were significantly different from the NT treatment. These results indicate that IRWH and DAL were 12 and 2% more effective in converting rainwater into harvestable grain yield than the CON treatment. R2 values of 68.6 and 78.4% for SWC and transpiration (Ev) were obtained when correlated with maize grain yield respectively. This indicates the importance of moisture conservation for improved dryland maize production under low P areas. Therefore, the use of appropriate RWHT’s by smallscale farmers maybe crucial to improve dryland maize production. IRWH outperformed all other treatments in terms of the soil parameters and plant parameter measured during the period of this study. Therefore, these results suggest IRWH has potential of sustaining maize yields under low rainfall conditions. Key words: Rainwater harvesting, conservation techniques, ecotope, rainwater productivity, maize yield, precipitation use efficiency.
26

Estudo da viabilidade do aproveitamento de água de chuva para consumo não potável em edificações. / Rainwater catchment feasibility study for non-potable consumption in buildings.

May, Simone 13 May 2004 (has links)
Para a conservação de água existem medidas convencionais e medidas não convencionais. O sistema de aproveitamento de água da chuva para consumo não potável é uma medida não convencional. Atualmente o aproveitamento de água da chuva é praticado em países como Estados Unidos, Alemanha, Japão, entre outros. No Brasil, o sistema é utilizado em algumas cidades do Nordeste como fonte de suprimento de água. A viabilidade do uso de água da chuva é caracterizada pela diminuição na demanda de água fornecida pelas companhias de saneamento, tendo como conseqüência a diminuição dos custos com água potável e a redução do risco de enchentes em caso de chuvas fortes. No processo de coleta de água da chuva, são utilizadas áreas impermeáveis, normalmente o telhado. A primeira água que cai no telhado, lavando-o, apresenta um grau de contaminação bastante elevado e, por isso, é aconselhável o desprezo desta primeira água. A água de chuva coletada através de calhas, condutores verticais e horizontais é armazenada em reservatório podendo ser de diferentes materiais. A água armazenada deverá ser utilizada somente para consumo não potável, como em bacias sanitárias, em torneiras de jardim, para lavagem de veículos e para lavagem de roupas. Este trabalho trata da avaliação da qualidade da água da chuva, juntamente com o estudo da viabilidade econômica da utilização de um sistema de coleta e aproveitamento da água da chuva. A partir de um sistema experimental, análises da composição física, química e bacteriológica da água da chuva foram realizadas para caracterizar a água e verificar a necessidade de tratamento, diminuindo riscos à saúde de seus usuários. A viabilidade do sistema depende basicamente de três fatores: precipitação, área de coleta e demanda. O reservatório de água da chuva, por ser o componente mais dispendioso do sistema, deve ser projetado de acordo com as necessidades do usuário ecom a disponibilidade pluviométrica local para dimensioná-lo corretamente, sem inviabilizar economicamente o sistema. Baseado nos resultados das análises realizadas e na utilização do sistema de coleta e aproveitamento de água da chuva, seu uso para fins não potáveis deve ser estimulado. / There are conventional and non-conventional ways for water conservation. The rainwater catchment system for non-drinking use is a non-conventional way. Nowadays, the exploitation of the rainwater is found in the United States, Germany, Australia and Japan, among others. In Brazil, the system is used in some northeast cities as water supplement supply source. The feasibility of rainwater use is characterized by the reduction of the demand on water supplied by the sanitation company and, as a consequence, the reduction of costs and the reduction of flood risk in case of storm rain. In the process of rainwater catchment impermeable areas are used, in most of cases, the roof. The first water that falls and washes the roof has sufficiently high degree of contamination and therefore it is a advisable to discharge it. The rainwater caught by gutters, vertical and horizontal conductors, is stored in a rainwater reservoir, which can be made of different materials. The stored rainwater should be used only for non-drinking consumption like in the toilet, in garden taps, in car washing and in clothes laundering. This paper evaluates the rainwater quality and develops the feasibility study for rainwater catchment for non-drinking use. From an experimental system, physical, chemical and microbiological analyses of the rainwater were made to qualify and verify the need of treatment avoiding the risk of illness to users. The feasibility of the system depends firstly on three factors: precipitation, catchment area and demand. The rainwater reservoir, as the most expensive part of the system, should be designed accordingly to the consumption and the local precipitation availability to set it accordingly, without making it economically unfeasible. Based on the results of the analysis and on the rainwater catchment system, its application for non-drinking use should be stimulated.
27

Estudo da viabilidade do aproveitamento de água de chuva para consumo não potável em edificações. / Rainwater catchment feasibility study for non-potable consumption in buildings.

Simone May 13 May 2004 (has links)
Para a conservação de água existem medidas convencionais e medidas não convencionais. O sistema de aproveitamento de água da chuva para consumo não potável é uma medida não convencional. Atualmente o aproveitamento de água da chuva é praticado em países como Estados Unidos, Alemanha, Japão, entre outros. No Brasil, o sistema é utilizado em algumas cidades do Nordeste como fonte de suprimento de água. A viabilidade do uso de água da chuva é caracterizada pela diminuição na demanda de água fornecida pelas companhias de saneamento, tendo como conseqüência a diminuição dos custos com água potável e a redução do risco de enchentes em caso de chuvas fortes. No processo de coleta de água da chuva, são utilizadas áreas impermeáveis, normalmente o telhado. A primeira água que cai no telhado, lavando-o, apresenta um grau de contaminação bastante elevado e, por isso, é aconselhável o desprezo desta primeira água. A água de chuva coletada através de calhas, condutores verticais e horizontais é armazenada em reservatório podendo ser de diferentes materiais. A água armazenada deverá ser utilizada somente para consumo não potável, como em bacias sanitárias, em torneiras de jardim, para lavagem de veículos e para lavagem de roupas. Este trabalho trata da avaliação da qualidade da água da chuva, juntamente com o estudo da viabilidade econômica da utilização de um sistema de coleta e aproveitamento da água da chuva. A partir de um sistema experimental, análises da composição física, química e bacteriológica da água da chuva foram realizadas para caracterizar a água e verificar a necessidade de tratamento, diminuindo riscos à saúde de seus usuários. A viabilidade do sistema depende basicamente de três fatores: precipitação, área de coleta e demanda. O reservatório de água da chuva, por ser o componente mais dispendioso do sistema, deve ser projetado de acordo com as necessidades do usuário ecom a disponibilidade pluviométrica local para dimensioná-lo corretamente, sem inviabilizar economicamente o sistema. Baseado nos resultados das análises realizadas e na utilização do sistema de coleta e aproveitamento de água da chuva, seu uso para fins não potáveis deve ser estimulado. / There are conventional and non-conventional ways for water conservation. The rainwater catchment system for non-drinking use is a non-conventional way. Nowadays, the exploitation of the rainwater is found in the United States, Germany, Australia and Japan, among others. In Brazil, the system is used in some northeast cities as water supplement supply source. The feasibility of rainwater use is characterized by the reduction of the demand on water supplied by the sanitation company and, as a consequence, the reduction of costs and the reduction of flood risk in case of storm rain. In the process of rainwater catchment impermeable areas are used, in most of cases, the roof. The first water that falls and washes the roof has sufficiently high degree of contamination and therefore it is a advisable to discharge it. The rainwater caught by gutters, vertical and horizontal conductors, is stored in a rainwater reservoir, which can be made of different materials. The stored rainwater should be used only for non-drinking consumption like in the toilet, in garden taps, in car washing and in clothes laundering. This paper evaluates the rainwater quality and develops the feasibility study for rainwater catchment for non-drinking use. From an experimental system, physical, chemical and microbiological analyses of the rainwater were made to qualify and verify the need of treatment avoiding the risk of illness to users. The feasibility of the system depends firstly on three factors: precipitation, catchment area and demand. The rainwater reservoir, as the most expensive part of the system, should be designed accordingly to the consumption and the local precipitation availability to set it accordingly, without making it economically unfeasible. Based on the results of the analysis and on the rainwater catchment system, its application for non-drinking use should be stimulated.
28

Servitudes of light and stillicide in Roman law

Rodger, A. F. January 1970 (has links)
No description available.
29

Harvesting Rainwater for Landscape Use

Waterfall, Patricia 10 1900 (has links)
52 pp. / In the arid Southwest, rainfall is scarce and evapotranspiration rates are high. Only natives and some desert-adapted plants can live on 10 or 11 inches of annual rainfall. Other plants require some supplemental irrigation and harvesting rainwater can reduce the use of drinking water for landscape irrigation. This publication discusses the water requirements for some plants and the way to collect rainwater. Its topics include: - Water Harvesting System Components - Simple Water Harvesting System Design and Construction - Complex Water Harvesting Systems
30

Canopy Change Assessment and Water Resources Utilization in the Civano Community, Arizona

Pan, Yajuan 12 1900 (has links)
The Civano community of Tucson, Arizona, is built for sustainability. Trees and plants are precious resources in the community and balancing human needs and natural resources. The design of rainwater harvesting systems and the usage of reclaimed water inside the community effectively irrigate plants and save drinking water. This project estimates canopy changes over time and explores the effect of water resources on plant growth for developed areas and natural areas, respectively. This project generates land cover classifications for 2007, 2010, and 2015 using supervised classification method and measures canopy cover change over time. Based on City of Tucson Water “harvesting rainwater guide to water-efficient landscaping”, this project discusses if water supply meets plant water demand in the developed areas of the community. Additionally, the normalized difference vegetation index (NDVI) data for developed area and natural area over ten years are compared and provide a correlation analysis with water sources. The results show that canopy cover across the entire community decreased from 2007 to 2010, then increased from 2010 to 2015. Water supply in the developed areas is sufficient for plant water demand. In natural areas plant growth changes dramatically as a result of precipitation fluctuation. In addition, it’s proved that 2011 National Land Cover Database (NLCD) tree canopy underestimates canopy cover in the Civano community. The final products not only provide the fundamental canopy cover data for other studies, also serve as a reference of water efficient landscaping within a community.

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