• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 8
  • 4
  • 2
  • 2
  • 1
  • 1
  • Tagged with
  • 22
  • 22
  • 7
  • 7
  • 4
  • 4
  • 3
  • 3
  • 3
  • 3
  • 3
  • 3
  • 3
  • 3
  • 3
  • 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

Planning and Management Modeling For Treated Wastewater Usage

Ahmadi, Leila 01 May 2012 (has links)
Two computational models, including several calculation and analysis submodels, were developed to create a tool for assessing the impact of different treated wastewater reuse options on irrigated agriculture. The models consider various aspects of treated wastewater availability (past, present, and future), wastewater quality, agricultural water demand, and the economics of conveying wastewater from treatment plants to farms. The two models were implemented using Visual BASIC.NET in a GIS environment to facilitate visualization of some of the features of an area under study, and to provide a convenient interface for user application. One of the models is for treated wastewater availability calculations, and the other is for wastewater reuse. The water availability model has sub-models including urban population predictions, agricultural land use changes, residential water demand, agricultural water demand (evapotranspiration) for over 40 crop types, and treated wastewater analysis. The water reuse model is composed of three sub-models, including soil water and salt balance calculations, nutrient calculations, and pumping and conveyance costs calculations. The nutrient calculationssub-model is based on an existing model, but was completely rewritten and modified in some parts to accommodate the needs and features of the water reuse model presented herein. A sample application of the models is presented for Cache Valley, Utah. The results show a comparison of treated wastewater reuse schemes for the study area, highlighting how irrigated agriculture would best benefit from the total or partial use of treated wastewater. Two wastewater reuse scenarios were considered. The water availability model shows good agreement with other sources of information in terms of population forecast and calculation of future residential and agricultural water demand. However, according to the results from the model, the rate of increase of the urban area was much higher than the rate of decrease of the agricultural areas between the years 1992 and 2001.The future population growth and water demand increases for urban areas was calculated and validated for Logan City. Also, in the case study the model was shown to be a good tool for wastewater influent analysis for Logan City.
2

Chitobiase as a tool in water quality monitoring

MacKenzie, Scott 11 March 2016 (has links)
Time-consuming and expensive benthic surveys are currently the most common means of determining impacts on invertebrates and fish habitat in lotic systems. We propose using the rate of chitobiase production by benthic invertebrates as a complement for determining impacts on freshwater systems. We successfully modified the existing assay to a microplate approach for high throughput analysis of chitobiase activity. Next we conducted two case studies in: 1) the Dead Horse Creek, Manitoba, to determine if changes in chitobiase could detect impacts on the benthic community from wastewater effluent and; 2) in Snake and Kinch Creeks, Manitoba to see if chitobiase could be used to assess fish habitat quality. In both cases, we observed no strong relationships between chitobiase and traditional metrics (e.g., abundance, biomass, diversity). We recommend further studies concerning the timing of chitobiase release in lotic systems and assessments of its use in mesocosm and microcosm toxicity studies / May 2016
3

Microbiological Water Quality in Irrigation Water, Treated Wastewater, and Untreated Wastewater and Its Impact on Vegetables in Sonora, Mexico

Gortares-Moroyoqui, Pablo January 2007 (has links)
In Mexico, wastewater recycling is an important alternative source of water, particularly in arid regions like the state of Sonora, Mexico. In El Valle del Yaqui, Sonora, Mexico, where 500 million m3 per year of wastewater is available for recycling in agriculture activities . The main objective of the three studies presented in this dissertation was to assess the microbial water quality of surface water, untreated wastewater, and treated wastewater for produce irrigation, as well as the impact of microbial water quality on vegetable contamination. The results suggest that the three sources of water meet Mexican and international guidelines for use in production of food crops.Despite wide differences in the concentration of bacterial indicators (Escherichia coli, Clostridium perfringens) and enteric pathogens (Cryptosporidium, Giardia, and enteroviruses) in the various types of water studied there was little impact on contamination of the produce studied (carrots, lettuce, tomatoes, and peppers) at harvest. Apparently, the time between the last irrigation event and harvesting was sufficient to allow for die-off of enteric organisms that may have contaminated the produce.
4

Systematic Framework for Evaluating Treated Wastewater Usage in Agricultural Irrigation

Nazzal, Yasser Kamal 01 May 2005 (has links)
A general systematic framework with several sub-frameworks was developed to help managers make informed decisions related to the reuse of treated wastewater in agricultural irrigation. The framework involves the identification and evaluation of the short- and long-term effects of using treated wastewater with some common constituents of concern ( e.g. salts and some specific ions, nutrients, heavy metals, organic compounds, and microorganisms) on the environmental elements ( crop , soils, surface water, and groundwater), and on the public health. Local and/ or international standards, criteria, and guidelines related to agricultural reuse are applied to the evaluation of the effects. Based on the evaluation results, decisions are made and management alternatives are proposed. The management alternatives include improving the wastewater treatment level , blending treated wastewater with good-quality water, using an appropriate irrigation method, using different reuse schemes, and zero discharging from specific industries. The framework demonstration includes the data input, information processing, output, evaluation, and decision-making phases. Data related to the plant-soil system (crop, soil, and any other assimilation pathway), and the behavior and fate of treated wastewater constituents are necessary for the identification of the effect on the environmental elements. Jordan was selected as a case study for the demonstration of the general systematic framework. Due to the lack of data related to the different constituents, some of the hazardous heavy metals were considered in the demonstration with the worst condition of accumulating the whole quantity of metals in the soil. The demonstration results showed that, at least for the coming 40 years Jordan can practice the reuse of the treated wastewater for agricultural irrigation without exceeding the maximum allowable limits in the agricultural soils based on the USEPA for biosolid application. With regard to blending and system efficiency, the demo result s also showed that they do not have an effect on the long-term accumulation of the hazardous metals in the soil. The general systematic framework is a decision tool, which is able to answer questions related to water treatment level and type , when to blend with freshwater, the recommended blending ratio, the recommended irrigation method, selection of the optimum reuse scheme, as well as providing answers to questions related to industrial wastewater constituents.
5

Diseño y evaluación de concreto estructural de f’c 280 kg/cm2 elaborado con aguas residuales domésticas tratadas mediante procesos biológicos como alternativa al uso de agua potable en Lima Metropolitana

Catanzaro Mesía, Gianfranco, Zapana Gago, Oscar Anthony 01 August 2019 (has links)
El tema de esta investigación se centra en el diseño y la evaluación de concreto elaborado a partir de aguas residuales domesticas tratadas mediante dos tipos diferentes de procesos biológicos (lodos activados y humedales artificiales) como alternativa al uso de agua potable en Lima Metropolitana. Actualmente, se conoce que la disponibilidad de agua potable en la ciudad de Lima no es abundante y las proyecciones a futuro indican que la demanda por el incremento poblacional generará problemas de escasez de este recurso. Debido a ello, es importante tomar medidas al respecto que permitan ahorrar este valioso recurso en industrias que consumen más agua como la de producción de concreto. Ante esta problemática, el uso de aguas residuales tratadas se muestra como una posible opción para reemplazar al agua potable en la elaboración de concreto. La presente tesis se desarrolla en 7 capítulos detallados a continuación: En Capítulo 1, se presenta el marco teórico, el cual incluye las principales bases teóricas utilizadas. En el Capítulo 2 se definen las características de los materiales empleados y la metodología de la investigación. En el Capítulo 3 se muestran los resultados de los ensayos y evaluaciones realizadas. En el Capítulo 4 se realiza la verificación de los resultados y luego la discusión de los mismos. En el Capítulo 5 se presentan las conclusiones y en el Capítulo 6 se detallan las recomendaciones. Finalmente, en el Capítulo 7 se muestran las referencias de otras investigaciones citadas en la presente Tesis y, adicionalmente, se muestran los anexos de la investigación. Al final de la investigación, se determinó que el concreto elaborado con aguas residuales domesticas tratadas mediante el proceso biológico de lodos activados si es una alternativa factible al uso de agua potable al presentar resultados similares a los del grupo de control. / The subject of this research focuses on the design and evaluation of concrete made from domestic wastewater treated by two different types of biological processes (activated sludge and artificial wetlands) as an alternative to the use of drinking water in the city of Lima. Currently, it is known that the availability of drinking water in the city of Lima is not abundant and future projections indicate that the demand due to population increase will generate water shortage problems. Because of this, it is important to take measures to save this valuable resource in industries that consume more water, such as concrete production. Given this problem, the use of treated wastewater is shown as a possible option to replace drinking water in concrete production. This thesis is developed in 7 chapters detailed below: In Chapter 1, the theoretical framework is presented, which includes the main theoretical bases used. Chapter 2 defines the characteristics of the materials used and the methodology of this investigation. Chapter 3 shows the results of the tests and evaluations carried out. In Chapter 4, the results are verified and then discussed. In Chapter 5 the conclusions are presented and in Chapter 6 the recommendations are detailed. Chapter 7 shows the references of other research cited in this Thesis and, finally the annexes of the thesis are shown. At the end of the investigation, it was determined that concrete made with domestic wastewater treated by the biological process of activated sludge is a feasible alternative to the use of potable water when presenting results similar to those of the control group. / Tesis
6

Effluent-Dominated Waterways in the Southwestern United States: Advancing Water Policy through Ecological Analysis

January 2011 (has links)
abstract: Over the past century in the southwestern United States human actions have altered hydrological processes that shape riparian ecosystems. One change, release of treated wastewater into waterways, has created perennial base flows and increased nutrient availability in ephemeral or intermittent channels. While there are benefits to utilizing treated wastewater for environmental flows, there are numerous unresolved ecohydrological issues regarding the efficacy of effluent to sustain groundwater-dependent riparian ecosystems. This research examined how nutrient-rich effluent, released into waterways with varying depths to groundwater, influences riparian plant community development. Statewide analysis of spatial and temporal patterns of effluent generation and release revealed that hydrogeomorphic setting significantly influences downstream riparian response. Approximately 70% of effluent released is into deep groundwater systems, which produced the lowest riparian development. A greenhouse study assessed how varying concentrations of nitrogen and phosphorus, emulating levels in effluent, influenced plant community response. With increasing nitrogen concentrations, vegetation emerging from riparian seed banks had greater biomass, reduced species richness, and greater abundance of nitrophilic species. The effluent-dominated Santa Cruz River in southern Arizona, with a shallow groundwater upper reach and deep groundwater lower reach, served as a study river while the San Pedro River provided a control. Analysis revealed that woody species richness and composition were similar between the two systems. Hydric pioneers (Populus fremontii, Salix gooddingii) were dominant at perennial sites on both rivers. Nitrophilic species (Conium maculatum, Polygonum lapathifolium) dominated herbaceous plant communities and plant heights were greatest in effluent-dominated reaches. Riparian vegetation declined with increasing downstream distance in the upper Santa Cruz, while patterns in the lower Santa Cruz were confounded by additional downstream agricultural input and a channelized floodplain. There were distinct longitudinal and lateral shifts toward more xeric species with increasing downstream distance and increasing lateral distance from the low-flow channel. Patterns in the upper and lower Santa Cruz reaches indicate that water availability drives riparian vegetation outcomes below treatment facilities. Ultimately, this research informs decision processes and increases adaptive capacity for water resources policy and management through the integration of ecological data in decision frameworks regarding the release of effluent for environmental flows. / Dissertation/Thesis / Ph.D. Plant Biology 2011
7

Aspectos SanitÃrios e AgronÃmicos do Uso de Esgotos Tratados na IrrigaÃÃo do Capim TanzÃnia (Panicum Maximum Jacq. Cv. TanzÃnia)-Aquiraz, CearÃ. / Sanitary and Agronomic Aspects of the use of treated wastewater in the Irrigation of TanzÃnia grass (Panicum maximum Jacq. cv. TanzÃnia) - Aquiraz, CearÃ.

Regis Meireles Benevides 09 August 2007 (has links)
nÃo hà / Nesta pesquisa procurou-se avaliar os aspectos sanitÃrios e agronÃmicos da utilizaÃÃo de esgotos tratados na irrigaÃÃo do capim TanzÃnia (Panicum Maximum Jacq. cv. TanzÃnia). Os experimentos foram realizados no Centro de Pesquisa sobre Tratamento de Esgotos e ReÃso de Ãguas da Companhia de Ãgua e Esgoto do Cearà em Aquiraz, CearÃ. A cultura de capim TanzÃnia foi irrigada com Ãgua de poÃo e esgoto tratado adubado com diferentes dosagens de fertilizante. Foi utilizado o mÃtodo de irrigaÃÃo por microaspersÃo, dividida em blocos, e aplicados quatros tratamentos diferentes. Os tratamentos utilizados foram: irrigaÃÃo com Ãgua de poÃo (T1), irrigaÃÃo com esgoto tratado (T2), irrigaÃÃo com esgoto tratado mais adubaÃÃo completa recomendada (T3) e irrigaÃÃo com esgoto tratado mais metade da adubaÃÃo recomendada (T4). Foram realizadas anÃlises fÃsico-quÃmicas e microbiolÃgicas na Ãgua do poÃo e no efluente da Ãltima lagoa de estabilizaÃÃo da EstaÃÃo de Tratamento de Esgoto (ETE) de Aquiraz, utilizados na irrigaÃÃo, onde se constatou diferenÃas significativas, mas os valores encontravam-se dentro de nÃveis aceitÃveis para esse uso. Na cultura do capim TanzÃnia foi coletada amostras para as anÃlises microbiolÃgicas e quÃmico-bromatolÃgicas. Os resultados das anÃlises microbiolÃgicas no capim TanzÃnia apresentaram valores aceitÃveis em todos os tratamentos aplicados. Observou-se um decaimento menor da presenÃa de microorganismos patogÃnicos no tratamento irrigado com esgoto mais adubaÃÃo completa recomendada (T3). A qualidade para consumo e digestibilidade do capim TanzÃnia pelos animais foi avaliada por meio das anÃlises quÃmico-bromatolÃgicas, com base em parÃmetros como: matÃria seca (MS), proteÃna bruta (PB), extrato etÃreo (EE), resÃduo mineral (RM), fibra em detergente Ãcido (FDA) e fibra em detergente neutro (FDN). Os tratamentos irrigados com esgoto tratado (T2, T3 e T4) apresentaram valores melhores que o tratamento irrigado com Ãgua do poÃo (T1). / This research evaluated the sanitary and agronomic aspects of the use of treated wastewater in the irrigation of TanzÃnia grass (Panicum maximum Jacq. cv. TanzÃnia). The experiments had been carried through in the Center of Research on Wastewater Treatment and Reuse of the Company of Water and Wastewater of the Cearà in Aquiraz, CearÃ. The culture of TanzÃnia grass was irrigated with water of well and treated wastewater with different dosages to fertilizer. The method of irrigation for microaspersion, divided was used block-type, and applied four different treatments. The used treatments had been: irrigation with well water (T1), irrigation with treated wastewater (T2), irrigation with treated wastewater more complete fertilization recommended (T3) and to irrigation with treated wastewater more half to the recommended fertilization (T4). Analyses had been carried through physicist-chemistries and microbiological in the water of the well and the effluent one of the last lagoon of stabilization of the Station of Wastewater Treatment (ETE) of Aquiraz, used in the irrigation, where if it contacted significant differences, but the values met inside of acceptable levels for this use. In the culture of TanzÃnia grass it was collected samples for the microbiological analyses and chemical and bromatologic. The results of the microbiological analyses in TanzÃnia grass had presented acceptable values in all the applied treatments. A lesser decline of the presence of pathogenic microorganisms in the treatment irrigated with wastewater more recommended complete fertilization (T3) was observed. The quality for consumption and digestibility of TanzÃnia grass for the animals was evaluated by means of chemical and bromatologic analysis, on the basis of parameters as: dry substance (MS), rude protein (PB), etereo extract (EE), mineral residue (RM), fiber in acid detergent (FDA) and fiber in neutral detergent (FDN). The treatments irrigated with treated wastewater (T2, T3 and T4) had presented better values that the treatment irrigated with water of the well (T1).
8

Využití přečištěných odpadních vod pro kapkovou závlahu / Utilization of treated wastewater in a drip irrigation system

Šalanda, Pavel January 2020 (has links)
Drought has an increasing importance in the Czech republic. It is necessary to look for potential irrigation water sources, which are important for agriculture. Treated wastewater can be one of them. It has potentially negative impact on soil physico-chemical properties, which is well-known from many researches in arid regions. The aim of this diploma thesis was to investigate, if the drip irrigation with treated wastewater (from constructed wetland) also has a potentially negative impact on two soils in the Czech republic. In one year experiment drip irrigation with treated wastewater was carried out in the greenhouse. Four treatments of irrigation was used for both soils - irrigation with treated wastewater, irrigation with groundwater, irrigation with treated wastewater + rainwater, irrigation with groundwater + rainwater. An amount of rainwater correspond with total precipitation of two locations, where the soils were brought from (Kostelec nad Ohří - Ústí nad Labem region and Hostětín - Zlín region). pH and electrical conductivity of soil leachate, total concentration of Na, K, Ca, Mg a P, bulk density, particle density and porosity was measured in both soils in 5 and 10 centimeters from source of irrigation. Values of pH of soil leachate fluctuated in every treatment in both soils during the...
9

Análisis Técnico Económico de una Planta de Tratamiento de Aguas Residuales en la Ciudad de Cajamarca, implementada bajo la modalidad de Obra por Impuestos

Azañedo Quilcate, Vicente Michael, Guerrero Ocas, Luis Angel, Rojas Pérez, David Gustavo, Ruiz Moncada, Oscar Modesto, Vásquez Sánchez, Álvaro Ramón 09 June 2020 (has links)
El presente trabajo de investigación ha sido desarrollado como ayuda para la ejecución de proyectos bajo la modalidad de Obras por Impuestos, toda vez que esta modalidad, es mejor que otras alternativas de financiamiento en nuestro país, como las Asociaciones Público Privadas (APP’s), en cuanto a costos, recorte de plazos y eficiencia en los procesos. Esto permitirá usar los resultados obtenidos como herramienta de consulta para dar inicio a proyectos de Plantas de Tratamiento de Agua Residual – PTAR en el ámbito local y nacional, bajo esta modalidad, cabe indicar que este tipo de obras han sido declaradas de interés nacional por el Estado bajo el Decreto Supremo que aprueba el Plan de Saneamiento 2017 – 2021 (D.S. N° 018 - 2017 – Vivienda). Los estudios realizados han sido hechos para la ciudad de Cajamarca, ciudad que a la fecha no cuenta con una PTAR, por el colapso de su actual infraestructura en el año 2005, generando malestar a la población y faltando al derecho fundamental de la población de vivir en un ambiente sano y saludable. El proyecto consiste en la construcción de una PTAR, con una tecnología de Bioreactores de Membranas (MBR), el monto estimado para la construcción asciende a los S/. 86, 634,096.49 y el plazo de ejecución son de 20 meses. Cabe señalar que esta alternativa tecnológica ha sido seleccionada tras un análisis comparativo de ingeniería económica, con la alternativa tecnológica de Filtros Percoladores. La tecnología elegida nos mostró resultados favorables por su impacto económico para el erario nacional, además de un impacto costo-eficiente menor, tomando en cuenta la población beneficiaria de la ciudad de Cajamarca. Por otro lado, cabe recalcar que todos los permisos deberán estar aprobados y saneados por las entidades públicas. / This research work has been developed as an aid for the execution of projects under the Works for Taxes modality, since this modality is better than other financing alternatives in our country, such as Public Private Partnerships (PPPs), in in terms of costs, shortening deadlines and efficiency in the processes. This will allow the use of the results obtained as a consultation tool to initiate projects of Waste Water Treatment Plants - PTAR at the local and national level, under this modality, it should be noted that these types of works have been declared of national interest by the State under the Supreme Decree that approves the 2017-2021 Sanitation Plan (DS N ° 018 - 2017 - Housing). The studies carried out have been made for the city of Cajamarca, a city that to date does not have a WWTP, due to the collapse of its current infrastructure in 2005, generating discomfort for the population and lacking the fundamental right of the population to live In a healthy and healthy environment. The project consists of the construction of a WWTP, with a technology of Membrane Bioreactors (MBR), the estimated amount for construction amounts to S /. 86, 634,096.49 and the execution period is 20 months. It should be noted that this technological alternative has been selected after a comparative analysis of economic engineering, with the technological alternative of Percolator Filters. The chosen technology showed favorable results due to its economic impact on the national treasury, as well as a lower cost-efficient impact, taking into account the beneficiary population of the city of Cajamarca. On the other hand, it should be emphasized that all permits must be approved and sanitized by public entities. / Trabajo de investigación
10

Production Of Fermentable Sugars And Lipids By Microalgae From Secondarily Treated Municipal Wastewater

Liu, Jen Chao 30 April 2011 (has links)
In this paper, replacing complete or partly of growth mediums with secondarily wastewater was studied. Lipid content of Neochloris oleoabundans grown in a 0.3 X SE medium and autoclaved secondarily treated wastewater mixture was 22.27 % (w/w). The maximum biomass concentration of N. oleoabundans grown in wastewater with no additional nutrients was 0.636 g/L with 33% (w/w) glucose. Two culture lines, MA, and NA were isolated within our laboratory and could grow in secondarily treated wastewater with no additional nutrients. The maximum biomass concentration of MA in batch culture was 0.860 g/L and the sum of glucose and xylose was 40% (w/w). The maximum biomass concentration of NA was 1.562 g/l and the sum of glucose and xylose was 33.8% (w/w). The maximum specific growth rates of NA and MA were determined to be 0.0566 and 0.0337 per hour.

Page generated in 0.0636 seconds