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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

The study of household wastewater treated by artificial wetlands¡GA case study

WENG, SHIH-CHIEH 02 July 2009 (has links)
Artificial wetland treatment system is an economical water purification system which has high potential in water purification ecology method. Many countries utilized this natural treatment system to solve their waste problems (for example, wastewater and solid waste) and well results were found with proven efficient. Recently, Taiwan has started developing the natural treatment system utilizing the self-purifying function of the natural surrounding by using the physical, chemical and biological reactions in soil, plants and microorganisms, to reduce the concentrations of pollutants produced by wastes. Eventually, all the pollutants can be eliminated to the harmless level to the environment and its organisms. For better understanding the feasibility of artificial wetlands, we study the performance of artificial wetland system with its raw wastewater produced from its community household wastewater at Liao-Luo Village. Artificial wetland system is a natural purification system, no additional chemicals are needed. In addition, it can be easily operated and maintained, and can be used to treat wastewater with simple pollutants in school. Wetlands not only can be utilized to treat wastewater, but also for can be used for educational purposes. The investigation periods in this work is from May 2008 to Dec.2008. The average of removal efficiency were as follows: BOD (52%), E-colis (79%), NH3 (74%). Total N (61%) and Total P (72%). In comparison with related literatures, we operated with higher removal due to the facts containing the lower organic loading and longer water retention time to decompose pollutants in solution. To keep the Liao-Luo Village wetland¡¦s wastewater treatment function, periodical maintenance is performed. Besides moving grass and removing garbage, proper vegetables are planted in each treatment area are needed.
2

The efficiency of the Zeekoegat artificial wetland as a biological filter of waste water

11 September 2013 (has links)
M.Sc. (Aquatic Health) / Located largely in a semi-arid part of the world, South Africa’s water resources, in global terms are extremely scarce and limited. (South Africa is one of the 30 driest countries of the world). South Africa is already categorised as water stressed with annual freshwater availability of less than 1700 mm³ /person (the index for water stress) (Blignaut and Van Heerden, 2009). South Africa is a water scarce country due to low rainfall (less than 500 mm per annum, some parts less than 200 mm: the average of 475 mm is well below the global average of 860 mm p/a.) and due to the uneven distribution of its water resources (more than 60% of the river flow arising from only 20% of the land area) which is a direct result of the climate and topography of the country (Davis and Day, 1998). South Africa is a large piece of land, far larger than for instance Germany (population of 82.7 million- Bergman and Renwick, 2003). When compared, Germany has 2169 cubic meters of water available per person while South Africa has only 1208 (Bergman and Renwick, 2003). Compared with another arid country, Australia has a population of 19.1 million and freshwater resources of 18 722 cubic meters per person (Bergman and Renwick, 2003). South Africa has close to the lowest conversion of rainfall to usable run-off from rivers of all the countries in the world (South Africa 8.6%, Australia 9.8%, and Canada 66%) (Bergman and Renwick, 2003). South Africa will also be negatively impacted by both changes in climate and the prevalence and spread of alien invasive species (Blignaut and Van Heerden, 2009). Prosperity for South Africa depends upon the sound management and utilisation of many resources, with water playing a pivotal role. Any decrease in the quality and therefore the usability of water in South Africa by 1% may result in the loss of 200 000 jobs, a drop of 5.7% of disposable income per capita, and an increase of 5% or R18.1 billion in government spending. This will further result in a 1% decrease in the GDP growth rate (Du Toit, 2010). This is reiterated by a number of other studies.
3

A Comparative Sustainability Study for Treatment of Domestic Wastewater: Conventional Concrete and Steel Technology vs. Vegetated Sand Beds (VSB’s) and Their Relative Differences in CO2 Production

Milch, Alicia M 13 July 2016 (has links)
Conventional wastewater treatment in the U.S. is an energy dependent and carbon dioxide emitting process. Typical mechanical systems consume copious amounts of energy, which is most commonly produced from fossil fuel combustion that results in the production of CO2. The associated organic load is also metabolized by microorganisms into CO2 and H2O. As the desire to reduce CO2 output becomes more prominent, it is logical to assess the costs of conventional treatment methods and to compare them to alternative, more sustainable technology. Vegetated Sand Bed (VSB) and Reed Bed (RB) systems are green technologies that provide environmentally superior treatment to conventional systems at a fraction of the cost both environmentally and economically. Using mass balance equations the net CO2 produced from wastewater treatment at 3 conventional facilities, (Amherst, MA, Ithaca, NY and Shelburne-Buckland, MA) and 3 VSBs, (Lloyd, NY, Shushufindi Slaughterhouse, Ecuador and Shushufindi Municipal Facility, Ecuador), will be estimated. Carbon dioxide sources considered are BOD5 microbial respiration, power demand, and sludge treatment. Using the BOD5 reduction and the average daily flow from each of the conventional facilities, hypothetical VSB and RB systems will be sized for the 3 conventional systems. The land area for each hypothetical VSB and RB and the CO2 reduction for equal treatment are estimated for each conventional facility. Estimates of annual CO2 production for Amherst, Ithaca, and Shelburne-Buckland, are 3,021 metric tons, 5,575 metric tons, and 158 metric tons of, respectively. The annual CO2 reduction potential for the conventional facilities Amherst, Ithaca, and Shelburne-Buckland, when compared to VSB and RB technology is estimated to be 74.0%, 83.2%, and 86.3% respectively. VSB and RB technology also provide promising results for sustainable wastewater treatment and reuse. Ammonium and nitrate reduction at the Joseph Troll Turf Plot VSBs were 72% and 88% respectively. The mean ammonium microbial growth rate constant was – 0.14 d-1 and the mean nitrate microbial growth rate constant was – 0.23 d-1. The implications are ammonium and nitrate reduction is possible with VSB and RB technology. Further investigation to understand the processes and fate of nitrogen including separate testing of ammonium and nitrate reduction are recommended.
4

Mejora de las condiciones de vida de las familias porcicultoras del Parque Porcino de Ventanilla, mediante un sistema de biodigestión y manejo integral de residuos sólidos y líquidos, Lima, Perú

Ruiz Ríos, Albina 09 June 2010 (has links)
El present treball constitueix el producte de la recerca d'una solució integral al greu problema social, econòmic i ambiental en què viuen dia a dia centenars de famílies assentades al Parc Porcí de Ventanilla, a Lima-Perú.S'analitza, s'adapta i fa viable l'aplicació de les tecnologies existents a la utilització de les excretes i orins dels porcs i de les aigües residuals dels habitatges com a matèria primera per a la producció de biogàs i altres subproductes, que serveixin com a: font d'energia, de matèries primeres per a la producció orgànica, per a l'ús racional de l'aigua, la planificació del territori i sobretot per la millora dels ingressos de les famílies, tot prioritzant l'ús dels recursos locals i que sigui assumible per les famílies per la seva operació, manteniment i rèplica, la qual cosa va significar treballar en una metodologia participativa involucrant a les famílies en tot el procés. / El presente trabajo constituye el producto de la búsqueda de una solución integral al grave problema social, económico y ambiental en que viven día a día cientos de familias asentadas en el Parque Porcino de Ventanilla, en Lima-Perú.Se analiza, se adapta y hace viable la aplicación de las tecnologías existentes a la utilización de las excretas y orines de los cerdos y de las aguas residuales de las viviendas como materia prima para la producción de biogás y otros subproductos, que sirvan como: fuente de energía, de insumos para la producción orgánica, para el uso racional del agua, la planificación del territorio y sobre todo para la mejora de los ingresos de las familias, todo ello priorizando el uso de los recursos locales y que sea asumible por las familias para su operación, mantenimiento y réplica, lo cual ha significado trabajar en una metodología participativa involucrando a las familias en todo el proceso. / This work results from the search of an integral solution to the very serious social, economical and environmental problems faced by hundreds of families settled in the Porcine Park of Ventanilla in Lima, Peru.The existing technologies have been analyzed, adapted and applied to use with pigs' excreta and urine, as well as with households´ wastewater as a feedstock for the production of biogas and other sub products. These will be used as: source of energy; organic production inputs; better management of water, spatial planning; and above all, for the improvement of households' incomes. This process prioritizes the use of local resources and is designed to be self managed by the families in terms of operation, maintenance and replication. These two objectives required working in a participatory approach that involved all the families throughout the complete process.

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