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

NONPOINT SOURCE WATER POLLUTION CONTROL: INCENTIVES THEORY APPROACH

Pushkarskaya, Helen N. 29 January 2003 (has links)
No description available.
2

Release and Transport of Bacteria and Nutrients from Livestock Manure Applied to Pastureland

Soupir, Michelle Lynn 03 September 2003 (has links)
Transport of fecal bacteria and nutrients from point and nonpoint sources to surface water bodies is of significant concern in Virginia and the United States. In Virginia, 4,320 river miles are impaired for one or more beneficial use and 72% of the streams are impaired due to pathogen indicators (VDEQ, 2002). Land applications of manure from confined animal systems and by direct deposit by grazing animals are both major sources of fecal bacteria and nutrients in runoff. Therefore, an understanding of the overland transport mechanisms for fecal bacteria and nutrients is very important for the development of best management practices to reduce loading of pathogens and nutrients to surface water bodies. The objectives of this study were to quantify the release and transport potential of three fecal bacterial indicators: E. coli, Enterococcus, and fecal coliforms; and nitrogen and phosphorus from land applied manure during runoff events. Another objective was to identify the Enterococcus species present in dairy manure and determine which species have the highest potential to be transported by runoff. Release plots were established to study the in-field bacteria and nutrient release. The bacteria and nutrients released from the plots are available to be transported to the edge of the field in runoff. Four manure treatments (turkey litter, liquid dairy manure, cowpies, and none or control) and three land type treatments: pasture with a history of poultry litter application (Turkey Farm), pasture with a history of liquid dairy manure application (Dairy Farm), and pasture with no prior manure application (Tech Research Farm) were studied. During a short but intense rainfall event, the highest bacterial release was measured under the cowpie treatment (E. coli concentrations ranging from 37,000 to >300,000 and FC concentrations ranging from 65,000 to >300,000). Pasturelands with a history of previous manure applications did not release higher bacteria concentrations compared with pasturelands which had never received manure applications. Pasturelands with a history of land application of liquid dairy manure and turkey litter had 143% and 94% higher TSS concentrations available to be transported off the field during overland flow events because of the build up of organic material on the soil surface. TP concentrations released from the cowpie, liquid dairy, and turkey litter treatments were 3.12 mg/L, 3.00 mg/L, and 1.76 mg/L, respectively. Transport plots were developed to measure the concentrations of fecal bacteria and nutrients present in overland flow at the edge of the field. The bacteria flow-weighted concentrations were highest in runoff samples from the plots treated with cowpies (200,000 CFU/100 mL of E. coli and 234,000 CFU/100 mL of FC). The turkey litter had the highest concentration of dissolved phosphorus in runoff from pasturelands (1.22 mg/L), but the cowpie treatment had the highest concentrations of sediment bound phosphorus in runoff (0.73 mg/L). All three treatments investigated in this study contributed to phosphorus loading in surface waters and could potentially increase the risk of eutrophication. Total nitrogen concentrations from the transport plots exceeded the threshold for likely eutrophication problems for all treatments and the total nitrogen concentrations from plots treated with cowpies exceeded the threshold for severe eutrophication problems. The Biolog System, a method of bacterial source tracking, was used to identify the different species of Enterococcus present both in the cowpie source manure and in the runoff collected from the transport plots treated with cowpies. The source manure is dominated by the Enterococcus mundtii (55%), Enterococcus gallinarum (20%), Enterococcus faecium (10%), and Enterococcus faecalis (10%). Enterococcus faecalis had the highest percentage of isolates present in runoff with a total of 37%, followed by Enterococcus mundtii which was present in 21% of the runoff events and Enterococcus gallinarum and Enterococcus faecium (11%). Improvements in understanding the bacterial release and overland processes will enhance modeling of bacteria and nutrient transport, and provide a basis for a more realistic evaluation of the impacts of management practices implementation. The data from this study will serve as a baseline to model the release and transport of fecal bacteria and nutrients from agricultural watersheds to surface waters. / Master of Science
3

Assessment of a Countywide Stormwater Pond Improvement Project: Impacts of the Hillsborough County Adopt-A-Pond Program

Betts, Anthony Thomas 01 January 2011 (has links)
Comparative research was conducted to assess the environmental impacts of the Adopt-a-Pond program, which operates throughout Hillsborough County, Florida. The Adopt-a-Pond program was established in 1992 and designed to address nonpoint pollution through outreach and stormwater pond enhancement. However, the program had never been thoroughly and scientifically evaluated. Therefore, assessments of water quality and vegetative characteristics were made at ninety Adopt-a-Pond participants and eleven control ponds to explore the potential impacts of the program on measurable environmental parameters. Statistical analysis of the results failed to demonstrate any statistically significant environmental improvements associated with the Adopt-a-Pond program, and measures of program activity did not illustrate a consistently positive relationship. These results indicate a need to readdress the policies and implementation of the program. Poor compliance by program volunteers, evident by the limited span of group participation (mean = 2.5 years) and relatively low percentage of actively involved residents, is the most likely culprit for the unremarkable improvements in pond quality, as pond enhancement techniques are firmly established in the literature. Overall, these conclusions underline the need for an integrated evaluation component in policymaking and an adaptive management approach to environmental management. A more detailed analysis is warranted to provide time series data, which examines ponds both before and after entry to the program and after implementing landmark improvement measures. In the end, the results of the study have provided a better understanding of the AAP and other similar restoration programs, and hopes to allow for enhancement of AAP program restoration practices.
4

Theoretical and Empirical Essays on the Effects of Proposed and Existing Environmental Policies

Jones, Luke Robert 01 December 2011 (has links)
This dissertation consists of three chapters that explore environmental policy. Chapter 1 empirically investigates the potential for incentives to encourage the adoption of low-emission alternatives to gasoline motorcycles. Hanoi, Vietnam, like many Asian cities, is experiencing rapid growth in the ownership of personal gasoline-powered motorcycles and scooters, and along with this heightened air quality issues. Electric scooters have the potential to reduce air pollution as an alternative to gasoline-powered motorcycles; however, electric scooters have yet to penetrate the Vietnamese and other large Asian markets. This study uses a choice experiment survey to elicit the demand for electric scooters, with focus on the effects that economic incentives and technology improvements have on adoption. Chapter 2 takes the first steps toward incorporating point sources into the theoretical discussion on nonpoint pollution ambient taxes. Previous investigations into the use of ambient taxes for nonpoint source pollution have not addressed the role of point sources, even though many watersheds have both source types. This paper examines the use of taxes for jointly regulating point and nonpoint sources. A model of point-nonpoint pollution is developed, and within this framework taxes are applied to achieve different regulatory objectives, including implementing optimal emissions reductions, as well as meeting exogenously specified environmental goals at least cost. Discussion centers on comparison of the point and nonpoint taxes in each scenario. Chapter 3 is an experimental economics examination of the design of markets for water quality trading. Water quality trading is endorsed by policymakers as a tool for reducing pollution in watersheds in a cost-effective manner, and many watersheds in the U.S. have established water quality trading programs. As a whole, these programs have not been successful. It is hypothesized that common features of these programs, such as the market institutions in place, may contribute to the limited success. As a first step in empirically investigating water quality trading markets, this study uses laboratory experiments to isolate how different institutions affect economic efficiency. In particular, we compare cap-and-trade, two forms of baseline-and-credit institution, and a tax/subsidy regulation, and examine the effect of introducing fixed technology costs with these four institutions.
5

ESTUDO DA DISTRIBUIÇÃO DE POLUENTES EM SUPERFÍCIES URBANAS / STUDY OF POLLUTANT DISTRIBUTION IN URBAN SURFACE

Silva, Ana Roberta Victoria 27 February 2009 (has links)
Conselho Nacional de Desenvolvimento Científico e Tecnológico / This paper aimed to quantify pollutants connected to sediments of different sizes in impermeable surfaces in three sampling campaigns. Dry sediments collections were dane on Marquês do Herval ad Rigoberto Duarte streets, both located on the Cancela Creek basin in Santa Maria county, RS, as well as hidrosedimental monitoring at the drainage system escape on Marquês do Herval St. Dry sediments samples prior to rainfall, as well as surface runoff sediment samples during rainfall, were separated into 4 granulometric bands (≤63μm, 63-250μm, 250-500μm e ≥500μm). Organic pollution, nutrient and heavy metal contents were evaluated for each granulometric band by determining the concentration of the following parameters: oxygen chemical demand, ammonia, nitrite, nitrate, phosphate, sulphate, chloride, fluoride, copper, nickel, zinc and lead. Granulometry lower than 63μm represented on average 2,6% of the total sediment content for Marquês do Herval St. and 3,5% for Rigoberto Duarte St. Granulometry above 250μm represented on average 70% of the sediment content for both streets. Heavy metal samples showed higher concentrations in granulometry below 63μm. In dry sediment samples, the highest sulphate, phosphate and chloride contents were found in granulometry above 500μm. Ammmonia, nitrate, lead and zinc are associated with the 63-250μm granulometric band. / Este trabalho teve como objetivo quantificar os poluentes ligados aos diversos tamanhos de sedimentos em superfícies impermeáveis em três campanhas de amostragem. Foram realizadas coletas de sedimento seco nas ruas Marquês do Herval e Rigoberto Duarte, ambas localizadas na bacia do arroio Cancela no município de Santa Maria-RS; e monitoramento hidrossedimentológico na saída da canalização da rua Marquês do Herval. As amostras de sedimento seco dos dias anteriores a precipitação, bem como as de sedimento ligado ao escoamento superficial, durante a precipitação, foram separadas em 4 faixas granulométricas (≤63μm, 63-250μm, 250-500μm e ≥500μm). Para cada faixa granulométrica foi avaliada a carga de poluição orgânica, de nutrientes e de metais pesados, através da determinação das concentrações dos seguintes parâmetros: demanda química de oxigênio, amônia, nitrito, nitrato, fosfato, sulfato, cloreto, fluoreto, cobre, níquel, zinco e chumbo. A granulometria menor que 63μm representa em média 2,6% da carga total de sedimentos para a rua Marquês do Herval e 3,5% para a rua Rigoberto Duarte. A granulometria maior que 250μm representa em média 70% da carga de sedimentos em ambas as ruas. As amostras de metais pesados apresentaram maiores concentrações na granulometria menor que 63Sm. Nas amostras de sedimento seco, as maiores cargas de DQO, sulfato, fosfato e cloreto foram encontradas na granulometria maior que 500μm. A amônia e o nitrato, chumbo e zinco estão associados a faixa granulométrica de 63-250μm.
6

Development of Effective Procedures for Illicit Discharge Risk Mapping

Bender, Paul Ryan 23 June 2016 (has links)
Authorities of municipal separate storm sewer systems (MS4s) are required to address illicit discharges as part of the National Pollutant Discharge Elimination System (NPDES) stormwater program. Field reconnaissance is an effective measure to detect and identify illicit discharges, but requires substantial staff and financial resources to conduct. While risk analysis techniques and guidelines have been developed to facilitate MS4 prioritization of field operations, neither a standard set of indicators nor a standard operating procedure has been adopted. This study investigates the relationships among indicators of illicit discharge potential (IDP) and the locations of illicit discharges in two Virginia MS4s. Results of the study indicate that certain risk factors are statistically more effective at predicting IDP, suggesting that a core set of factors can be used to map illicit discharge risk. The results also show that risk mapping tools are significantly impacted by uncertainty in model inputs. Recommendations are provided for MS4s interested in pursuing IDP risk mapping as a tool to improve cost-effectiveness and guide illicit discharge program implementation. / Master of Science
7

Desarrollo de un sistema de tratamiento del agua de escorrentía superficial procedente de aparcamientos impermeables usando flujo ascendente y geotextiles

Fernández Barrera, Andrés H. 18 February 2010 (has links)
Esta tesis doctoral presenta la investigación del desarrollo de un prototipo de laboratorio de un sistema de captación, pretratamiento y tratamiento (SCPT) de la escorrentía proveniente de aparcamientos con firmes impermeables. El prototipo de SCPT fue estudiado en condiciones de funcionamiento inicial y a largo plazo. Las respuestas analizadas son las concentraciones de aceites y sólidos en el efluente y las eficiencias de depuración de dichos contaminantes. Finalmente, se analizó la capacidad del sistema de filtrado del SCPT para albergar colonias de microorganismos depuradores de hidrocarburos. Los niveles de depuración alcanzados por el prototipo de SCPT son superiores al 80% para el caso de los sólidos y al 90 % para los aceites, tanto en condiciones de inicio de operación, como a largo plazo tras catorce eventos de lluvia consecutivos. Además, se demostró que el sistema de filtrado es capaz de albergar colonias de microorganismos degradadores de hidrocarburo
8

Managing agriculture and water quality : four essays on the control of large-scale nitrogen pollution /

Brady, Mark January 2003 (has links)
Diss. (sammanfattning) Uppsala : Sveriges lantbruksuniv., 2003. / Härtill 4 uppsatser.
9

Optimal allocation of stormwater pollution control technologies in a watershed

Chen, Wei-Bin B. 22 September 2006 (has links)
No description available.
10

Recuperação de córregos urbanos através do controle de cargas pontuais e difusas - estudo de caso: Córrego Ibiraporã e do Sapé. / Recovery of urban streams by point and nonpoint pollution control - case study: Stream Ibiraporã and Thatch.

Silva, Juliana Caroline de Alencar da 12 December 2013 (has links)
Com a consolidação do saneamento em algumas bacias urbanas, um novo desafio surge: o da recuperação dos corpos dágua. O que a principio parece ser uma consequência do processo, na realidade se mostra uma tarefa muito mais complexa e que envolve diversos fatores, tornando o processo de recuperação lento e dispendioso. Muito se diz a respeito da despoluição dos corpos dágua através da eliminação da carga pontual, mas o que se observa na prática é que, mesmo diante do controle das cargas pontuais, os corpos dágua continuam poluídos devido às cargas difusas. A preocupação com a poluição por carga difusa já é um assunto muito estudado em locais onde a poluição por cargas pontuais já possui um controle efetivo, mas este assunto ainda é um grande desafio em países como o Brasil, onde o controle da carga pontual ainda não constitui uma realidade palpável. Atualmente, na região metropolitana de São Paulo, há diversos programas atuando na despoluição de corpos dágua através do controle de cargas pontuais, dentre eles o programa Córrego Limpo se destaca por agir na otimização de sistemas de esgotamento sanitário, e apesar dos bons resultados obtidos, como o programa se baseia no controle de cargas pontuais, estas bacias não se encontram completamente despoluídas. Considerando o caso brasileiro, o programa é pioneiro no que se refere à adoção de medidas que integram a população no processo de recuperação, pois implanta em algumas de suas bacias um programa de governança colaborativa, que, através da mobilização da população, promove a integração desta com o corpo dágua. Diante deste panorama, o presente estudo, tem como intuito, através da análise de córregos de interesse do programa Córrego Limpo, contribuir para a melhor compreensão dos desafios envolvidos no processo de recuperação de corpos dágua urbanos através do controle de cargas pontuais e difusas. No estudo empregou-se o método da Unidade de carga para quantificação da geração de cargas difusas nas bacias e identificação do seu potencial poluidor, resultando na criação de um índice de qualidade da superfície da bacia; Avaliou-se também a qualidade ambiental destes corpos dágua através de indicadores físicos, químicos e biológicos, o que revelou a importância do uso conjunto destes indicadores, já que obteve-se resultados distintos para cada um destes indicadores; com base nos resultados obtidos nestes estudos foi possível avaliar o quão complexo é o processo de recuperação de corpos dágua em áreas urbanas. / With the consolidation of sanitation in some urban watersheds, a new challenge arises: the recovery of bodies of water. What at first appears to be a consequence of the process, in fact it shows to be a much more complex task and involves several facts, making the recovery process slow and costly. Much is said about the remediation of water bodies by removing point charge, but what we notice in practice is that even after controlling of point charge, they remain polluted because nonpoint pollution. The concern with nonpoint pollution is much studied in places where pollution by point charge already has an effective control, but this issue is still a challenge in countries like Brazil, where the control point charge does not constitutes a tangible reality. Currently, the São Paulo metropolitan area there are several programs working on recovering of water bodies through the control of point charge, including the Córrego Limpo that acts optimizing sewage systems, and is notorious the improvement in the quality of water bodies covered its actions. However, as the program based on controlling of point charge, the streams are not completely unpolluted. Considering the Brazilian case, the program is a pioneer when it comes to the adoption of measures that integrate the population in the recovering process. It deploys in some watersheds a program of collaborative governance that, through the people mobilization, promotes the body of water, resulting in reduction of the potential pollution in the watersheds and rendering more effective the process. The present study has the intention, through the analysis of streams of interest to the program Córrego Limpo, contribute to a better understanding of the challenges involved in the recovery process of urban water bodies through the control of the point and nonpoint pollution. In the study was used the method of unit load to quantify the generation of diffuse loads in basins and identification of their pollution potential, resulting in the creation of an index of quality of the surface of the basin, also evaluated the environmental quality of these bodies of water through physical, chemical and biological indicators, which revealed the importance of the combined use of these indicators, since we obtained different results for each of these indicators, the results of this study showed how complex is the recovery process of water bodies in urban areas.

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