• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 6
  • 1
  • 1
  • Tagged with
  • 11
  • 11
  • 4
  • 4
  • 3
  • 3
  • 3
  • 3
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 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

Biosolids Land Use in Arizona

Artiola, Janick 04 1900 (has links)
8 pp. / The land application (non-hazardous sewage sludge) biosolids has been in practice in Arizona since the 60s.
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

Numerical modeling of machine-product interactions in solid and semi-solid manure handling and land application

Landry, Hubert 13 April 2005
The general objective of the research effort reported in this thesis was to develop the knowledge required to optimize the design and operation of solid and semi-solid manure handling and land application equipment. Selected physical and rheological properties of manure products deemed to have an influence on the performances of manure handling and land application equipment were measured and general trends were identified among the measured properties. Relationships were also established between the measured properties and the type of manure as well as its total solids concentration. Field experiments were carried out to evaluate the effects of selected mechanical configurations, operating parameters and product properties on the discharge of manure spreaders. The influence of the type of conveying system (scraper conveyor and system of four augers) and the velocity at which it is operated, the geometry of the holding system and the position of a flow-control gate were all included in the analysis. The discharge rates of the machines as well as the specific energy required by the unloading operations were measured. A numerical modeling method called discrete element method (DEM) was used to create virtual manure, a numerical model of the real product. The measured physical and flow properties were used to develop and validate the virtual manure models. It was found that manure products could successfully be represented in a DE framework and that several parameters defining the contact constitutive model in the DEM had an influence on the behaviour of the virtual products. The DEM was then used to study machine-product interactions taking place in handling and land application equipment. Results from field experiments carried out using various land application equipment were used in the development and validation of the interaction models. The predicted flow rates and power requirements were in good agreement with measured data. The results obtained allowed for a better understanding of the flow of manure products in manure handling and land application equipment. It was found that the constitutive model used for the product influenced the results of the machine-product interactions models. A precision banded applicator under development at the University of Saskatchewan was also modeled. The discharge rate of this equipment is influenced by a number of parameters. The predicted mass distribution across the width of the banded applicator was well correlated to the experimental results. The models developed in this thesis have the potential to become powerful engineering tools for the design of improved machines for the handling and land application of solid and semi-solid manure.
4

Health Risk Assessment For The Land Application Of Biosolids In Ankara, Turkey

Kendir, Ece 01 January 2013 (has links) (PDF)
Biosolids are valuable products which can be beneficially used in land application. However, the possibility of serious health effects on humans due to several pollutants in biosolids creates a big concern. To address this issue, risk-based methodologies are commonly used to evaluate health effects associated with the land application of biosolids. This study aims to investigate the health risks associated with ingestion of biosolids or soil mixed with biosolids by a child. This study is the first health risk assessment study in Turkey for land application of biosolids. Monthly sludge samples taken from Ankara Central Wastewater Treatment Plant (ACWWTP) in 2012 were analyzed for seven heavy metals (Cd, Cr, Cu, Hg, Ni, Pb, and Zn), and two organic contaminants (PCB and NPE) concentrations. To calculate health risks, methodologies developed by U.S. Environmental Protection Agency (U.S. EPA) and French National Institute for Industrial Environment and Risks (INERIS) were used. With both methods, cancer and non-cancer risks for the ingestion by a child pathway were determined and found to be below the acceptable cancer and non-cancer risk levels suggested by U.S. EPA and INERIS. Additionally, same health risk calculations were conducted for sludge and soil limit values provided in Turkish Regulation for the Use of Sewage Sludge in Agriculture (2010) to determine what the maximum health risk would be for the worst case scenario in Turkey. According to the results, even if the concentrations are at the maximum possible regulatory levels, the health risks are still low.
5

Numerical modeling of machine-product interactions in solid and semi-solid manure handling and land application

Landry, Hubert 13 April 2005 (has links)
The general objective of the research effort reported in this thesis was to develop the knowledge required to optimize the design and operation of solid and semi-solid manure handling and land application equipment. Selected physical and rheological properties of manure products deemed to have an influence on the performances of manure handling and land application equipment were measured and general trends were identified among the measured properties. Relationships were also established between the measured properties and the type of manure as well as its total solids concentration. Field experiments were carried out to evaluate the effects of selected mechanical configurations, operating parameters and product properties on the discharge of manure spreaders. The influence of the type of conveying system (scraper conveyor and system of four augers) and the velocity at which it is operated, the geometry of the holding system and the position of a flow-control gate were all included in the analysis. The discharge rates of the machines as well as the specific energy required by the unloading operations were measured. A numerical modeling method called discrete element method (DEM) was used to create virtual manure, a numerical model of the real product. The measured physical and flow properties were used to develop and validate the virtual manure models. It was found that manure products could successfully be represented in a DE framework and that several parameters defining the contact constitutive model in the DEM had an influence on the behaviour of the virtual products. The DEM was then used to study machine-product interactions taking place in handling and land application equipment. Results from field experiments carried out using various land application equipment were used in the development and validation of the interaction models. The predicted flow rates and power requirements were in good agreement with measured data. The results obtained allowed for a better understanding of the flow of manure products in manure handling and land application equipment. It was found that the constitutive model used for the product influenced the results of the machine-product interactions models. A precision banded applicator under development at the University of Saskatchewan was also modeled. The discharge rate of this equipment is influenced by a number of parameters. The predicted mass distribution across the width of the banded applicator was well correlated to the experimental results. The models developed in this thesis have the potential to become powerful engineering tools for the design of improved machines for the handling and land application of solid and semi-solid manure.
6

Characterization of Pollutants in Florida Street Sweepings for Management and Reuse

Jang, Yong Chul, Jain, Pradeep, Tolaymat, Thabet, Dubey, Brajesh, Townsend, Timothy 01 November 2009 (has links)
Disposal and beneficial-use options for street sweeping residuals collected as part of routine roadway maintenance activities in Florida, USA, were assessed by characterizing approximately 200 samples collected from 20 municipalities. Total concentrations (mg/kg or μg/kg) and leachable concentrations (mg/L or μg/L) of 11 metals and a number of organic pollutant groups (volatile organics, semi-volatile organics, pesticides, herbicides, carbamates) in the samples were measured. The synthetic precipitation leaching procedure (SPLP) was performed to evaluate the leachability of the pollutants. From the total metal analysis, several metals (e.g., arsenic, barium, chromium, copper, nickel, lead, and zinc) were commonly found above their detection limits. Zinc was found to have the highest mean concentration of all metals measured (46.7 mg/kg), followed by copper (10.7 mg/kg) and barium (10.5 mg/kg). The metal with the smallest mean concentration was arsenic (0.48 mg/kg). A small fraction of the total arsenic, barium, lead, and zinc leached in some samples using the SPLP; leached concentrations were relatively low. A few organic compounds (e.g., 4,4′-DDT, endrin, and endosulfan II) were detected in a limited number of samples. When the total and leaching results were compared to risk-based Florida soil cleanup target levels and groundwater cleanup target levels, the street sweepings were not found to pose a significant human-health risk via direct exposure or groundwater contamination.
7

Persistent Organic Pollutants in Australian Sewage Sludge: Environmental Monitoring and Land Application Risk Assessment

Clarke, Bradley, Bradley.clarke@student.rmit.edu.au January 2008 (has links)
Presented is a study of persistent organic pollutants in Australian sewage sludge, focusing on environmental monitoring and a sewage sludge land application human health risk contaminated with these compounds. The chemicals of concern were: • Polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs) and
8

Avaliação de diferentes técnicas de pulverização com base em agricultura de precisão / Evaluation of different spraying techniques based on precision agriculture

Jobim, Lucas dos Santos 05 September 2017 (has links)
The Precision Agriculture process proposes and implements spraying automation and control systems in agricultural machines, a system widely used and universal in the most diverse agricultural cultures. This work evaluates the efficiency of the application among the different spraying techniques that use Precision Agriculture technology, such as tractors (terrestrial), self-propelled (terrestrial) and aircraft (aerial), with a comparative purpose of items such as precision of application, speed of work, drops deposition and operational cost. The research region is located in the Municipality of Cachoeira do Sul, central region of Rio Grande do Sul, where agricultural activity has intense participation. The project was developed in an experimental area located in the interior of the Municipality of Cachoeira do Sul. Applications of chemical pesticides were made using three different techniques, all of which are based on the use of Precision Agriculture technology. The spraying techniques that are being evaluated are the terrestrial tratorized, terrestrial self-propelled and aerial, being the methodology based on evaluation of the accuracy of the GPS system, drop drops on the target (hydrosensitive cards), working time, cost of acquisition of machines and outsourcing (based on local budget research). The accuracy results of the navigation systems were more favorable for the self-propelled sprayer, followed by the tractor and in the airplane sequence, but both evaluated systems maintained the standardized average of precision of each navigation system. Regarding droplet deposition on the target, self-propelled spraying was more efficient (greater target arrival and less drift). In relation to the working time, aerial spraying showed much higher speed, followed by self-propelled and lastly the tratorized system. As for the equipment acquisition costs, they were sequentially expressed in decreasing order starting with the agricultural aircraft, self-propelled sprayer and tractor, and the average cost of outsourcing services remained tied between the self-propelled and aerial application and the tractor system if it showed more expensive than the others. In this way, it is concluded that the best spray system is that it adapts to the field condition and expenditure of financial investment, according to the reality of the producer. / O processo de Agricultura de Precisão propõe e implementa sistemas de automação e controle de pulverização em máquinas agrícolas, sistema utilizado de forma generalizada e universal nas mais diversas culturas agrícolas. Este trabalho avalia a eficiência da aplicação entre as diferentes técnicas de pulverização que utilizam a tecnologia de Agricultura de Precisão, como a tratorizada (terrestre), autopropelida (terrestre) e com aeronaves(aérea), com finalidade comparativa de itens como precisão de aplicação, velocidade de trabalho, deposição de gotas e custo operacional. A região de pesquisa situa-se no Município de Cachoeira do Sul, região Central do Rio Grande do Sul, onde a atividade agropecuária tem intensa participação. O projeto foi desenvolvido em uma área experimental situada no interior do Município de Cachoeira do Sul. Foram realizadas aplicações de defensivos químicos utilizando-se de três diferentes técnicas, sendo que todas têm como base a utilização da tecnologia de Agricultura de Precisão. As técnicas de pulverização que estão sendo avaliadas são a terrestre tratorizada, terrestre autopropelida e aérea, sendo a metodologia baseada em avaliação da acurácia do sistema de GPS, deposição de gotas no alvo (cartões hidrossensiveis), tempo de trabalho, custo de aquisição de máquinas e terceirização (baseado em pesquisas orçamentárias locais). Os resultados de acurácia dos sistemas de navegação mostraram-se mais favoráveis para o pulverizador autopropelido, seguido pelo tratorizado e na sequencia o avião, mas ambos os sistemas avaliados mantiveram a média padronizada de precisão de cada sistema de navegação. Em relação à deposição de gotas no alvo a pulverização autopropelida se mostrou mais eficiente (maior chegada ao alvo e menor deriva). Em relação ao tempo de trabalho, a pulverização aérea de mostrou muito superior em velocidade, seguida pelo autopropelido e por ultimo o sistema tratorizado. Quanto aos custos de aquisição de equipamento expressaram-se sequencialmente em ordem decrescente iniciando pela aeronave agrícola, pulverizador autopropelido e tratorizado, sendo o que o custo médio de terceirização de serviços se mantiveram empatados entre o autopropelido e aplicação aérea e o sistema tratorizado se mostrando mais caro que os demais. Dessa forma conclui-se que o melhor sistema de pulverização é aquele se adapta à condição de campo e dispêndio de investimento financeiro, de acordo com a realidade do produtor.
9

The fate and effects of sewage-derived pharmaceuticals in soil

Gielen, Gertruda Jacqueline Hariette Petronella January 2007 (has links)
The behaviour and impact of pharmaceuticals in the environment are still poorly understood. Pharmaceuticals are widely used and continually released into the environment causing increasing concerns about their impact on the environment beyond the intended human or veterinary use. Prescribed pharmaceuticals, typically, enter the environment either through excretion after human use or disposal of surplus medication. Sewage treatment plants do not completely remove pharmaceuticals and their metabolites and these have been detected in sewage treatment plant effluent and receiving waters. Land application of treated sewage effluent is widely practiced in New Zealand as an alternative to surface water discharge. Methods were developed to determine selected pharmaceuticals in environmental matrices such as sewage effluent, sewage solids, soil, and soil water. From these, pharmaceutical removal efficiencies were determined for three common sewage treatment processes; activated sludge, composting and land application of sewage effluent. The impacts of some common pharmaceuticals on soil microbial communities, together with the effect of prolonged exposure to sewage effluent on these communities were examined. Additionally, toxicity of sewage effluent, and toxicity mechanisms of specific pharmaceuticals were investigated using luminescent micro-organisms and lettuce seedlings. Pharmaceuticals were successfully detected in sewage effluent, sewage solids, compost, soil and soil water. The sewage treatment processes investigated, including land application, were able to remove or reduce pharmaceutical concentrations in sewage. In case of land application, volcanic soils were more efficient than sandy soils in pharmaceutical removal while irrigation rate and level of sewage pre-treatment also showed some effect on removal efficiency. Pharmaceuticals were not acutely toxic at environmental levels currently detected. Exposure of microbial communities to unnaturally high levels of pharmaceuticals did demonstrate that most pharmaceuticals were potentially able to induce stress in the microbial community although microbes were able to metabolise some of these pharmaceuticals. Twelve years of effluent irrigation resulted in microbial adaptation to aspirin, acetaminophen and tetracycline, indicating that these pharmaceuticals had an effect on microbial community. Presently, land application of treated sewage waste may be a suitable treatment for additional pharmaceutical removal provided that land application schemes are designed appropriately, and pharmaceutical accumulation in the soil is occasionally monitored. It would be prudent to recognise the potential risk that could be caused by chronic exposure to pharmaceuticals such that continued vigilance may lead to future indications of chronic effects at an early stage.
10

The fate and effects of sewage-derived pharmaceuticals in soil

Gielen, Gertruda Jacqueline Hariette Petronella January 2007 (has links)
The behaviour and impact of pharmaceuticals in the environment are still poorly understood. Pharmaceuticals are widely used and continually released into the environment causing increasing concerns about their impact on the environment beyond the intended human or veterinary use. Prescribed pharmaceuticals, typically, enter the environment either through excretion after human use or disposal of surplus medication. Sewage treatment plants do not completely remove pharmaceuticals and their metabolites and these have been detected in sewage treatment plant effluent and receiving waters. Land application of treated sewage effluent is widely practiced in New Zealand as an alternative to surface water discharge. Methods were developed to determine selected pharmaceuticals in environmental matrices such as sewage effluent, sewage solids, soil, and soil water. From these, pharmaceutical removal efficiencies were determined for three common sewage treatment processes; activated sludge, composting and land application of sewage effluent. The impacts of some common pharmaceuticals on soil microbial communities, together with the effect of prolonged exposure to sewage effluent on these communities were examined. Additionally, toxicity of sewage effluent, and toxicity mechanisms of specific pharmaceuticals were investigated using luminescent micro-organisms and lettuce seedlings. Pharmaceuticals were successfully detected in sewage effluent, sewage solids, compost, soil and soil water. The sewage treatment processes investigated, including land application, were able to remove or reduce pharmaceutical concentrations in sewage. In case of land application, volcanic soils were more efficient than sandy soils in pharmaceutical removal while irrigation rate and level of sewage pre-treatment also showed some effect on removal efficiency. Pharmaceuticals were not acutely toxic at environmental levels currently detected. Exposure of microbial communities to unnaturally high levels of pharmaceuticals did demonstrate that most pharmaceuticals were potentially able to induce stress in the microbial community although microbes were able to metabolise some of these pharmaceuticals. Twelve years of effluent irrigation resulted in microbial adaptation to aspirin, acetaminophen and tetracycline, indicating that these pharmaceuticals had an effect on microbial community. Presently, land application of treated sewage waste may be a suitable treatment for additional pharmaceutical removal provided that land application schemes are designed appropriately, and pharmaceutical accumulation in the soil is occasionally monitored. It would be prudent to recognise the potential risk that could be caused by chronic exposure to pharmaceuticals such that continued vigilance may lead to future indications of chronic effects at an early stage.

Page generated in 0.1331 seconds