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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.
151

Evaluation of landfill leachate treatability in a modified Ludzack Ettinger activated sludge system

Marickovich, Donald C. 18 April 2009 (has links)
The purpose of this study was to investigate treatment alternatives for a leachate from a municipal landfill in Roanoke County, Virginia. A continuous flow, laboratory scale, single sludge waste treatment system utilizing the Modified Ludzack Ettinger (MLE) nitrification/denitrification process with the addition of phosphorus and methanol was operated to determine its effectiveness in removing total nitrogen, organic compounds and metals from the leachate. The system was compared with the effectiveness of a totally aerobic activated sludge system operated in various configurations and at different mean cell residence times (MCRT’s) with and without the addition of methanol. The ability of activated carbon to remove organics from the leachate was briefly examined. The early results from this study indicated that the MLE process could successfully treat the leachate by removing up to 84% of the total nitrogen present while operating at high MCRT’s (eight days or greater). The MLE process removed as much as 56% of the total nitrogen at the lowest MCRT operated (1.5 days), By comparison, a maximum removal of only 30% was achieved for the completely aerobic activated sludge system operating under the same conditions. The MLE process and the completely aerobic process were not effective in removing the organics from the leachate as evidenced by a leachate COD removal of only 2% to 5%. Limited studies with activated carbon proved successful in substantially reducing the COD from the effluent of the biological treatment systems. The MLE process consistently reduced the iron concentration in the leachate from the average level of 18.6 mg/l to levels below 1.0 mg/l. Towards the end of this 584-day study, there were indications that toxic agents were intermittently entering the leachate from the landfill as evidenced by two episodes of severe nitrification inhibition during operating periods when nitrification should have been essentially complete. This raises doubts concerning the ability of biological nitrification/denitrification to successfully treat the Dixie Caverns landfill leachate on a long-term basis without special treatment for the removal of the unknown toxic components. / Master of Science
152

Study of addition of non-hazardous industrial and municipal wastewater to bioreactor landfills

Dhesi, Parminder Singh 01 October 2003 (has links)
No description available.
153

A comparison & contrast of Hong Kong and overseas practices in landfill gas management

Kam, Chung-hau, Brian., 甘忠校. January 1998 (has links)
published_or_final_version / Environmental Management / Master / Master of Science in Environmental Management
154

Determining suitable locations for landfill development

Chan, Zenith., 陳仕廉. January 1997 (has links)
published_or_final_version / Environmental Management / Master / Master of Science in Environmental Management
155

Treatment of landfill leachate via advanced oxidation

Unknown Date (has links)
A landfill is in a reserved space on land used for the disposal of refuse by utilizing the principles of engineering to confine the refuse to the smallest practical area to prevent the creation of nuisances to public health or safety (Andersen et al. 1967). However, because landfills are open to the atmosphere, rainfall can saturate them, resulting in a liquid called leachate. Leachate generated within the landfill contains suspended solids, soluble components of the waste and by-products from the degradation of the waste by various micro-organisms. Treatment of leachate is an emerging area of need. In this manuscript the main purpose is to investigate a laboratory scale batch reactor that is able to detoxify and treat leachate by using an advanced oxidation process (i.e. TiO2). Based on the results obtained from this ground breaking research, it appears that the process investigate has the potential to radically change the way landfill leachate is treated. Scale up may provide direction that can be used to improve the efficiency of the different stages of toxicity of leachate during the entire life of a landfill. / by Andrâe McBarnette. / Thesis (M.S.C.S.)--Florida Atlantic University, 2011. / Includes bibliography. / Electronic reproduction. Boca Raton, Fla., 2011. Mode of access: World Wide Web.
156

Optimization of TiO2 photocatalyst in an advanced oxidation process for the treatment of landfill leachate

Unknown Date (has links)
Since the United States Environmental Protection Agency (USEPA) began requiring landfills to implement a leachate collection system in 1991, the proper disposal of leachate has become a growing concern. The potential toxicity of landfill leachate will contaminate groundwater and soil if not managed properly. Research has been made in efforts to manage leachate in a cost-effective, single treatment process. Photocatalytic oxidation is an advanced oxidation process (AOP) which has shown ability to reduce toxicity of an array of leachate constituents including organics, inorganics and heavy metals. The purpose of this manuscript is to scale up the batch scale study of TiO2 photocatalytic degradation of leachate utilizing a pilot scale falling film reactor. In this research project, the use of UV/TiO2 for the removal of chemical oxygen demand (COD), ammonia, alkalinity and color will be studied in order to optimize catalyst dosage, determine pH effects and reaction kinetics and develop preliminary cost estimates. / by Frank Youngman. / Thesis (M.S.C.S.)--Florida Atlantic University, 2013. / Includes bibliography. / Mode of access: World Wide Web. / System requirements: Adobe Reader.
157

Predicting Seepage of Leachate from the St. Johns Landfill to Ground and Surface Water Systems

Schock, Kevin A. 11 June 1993 (has links)
Determination of the vertical and horizontal groundwater hydraulic gradient within a landfill is the first step in determining the potential of groundwater contamination from the landfill leachate. The length of a study and the frequency at which measurements are recorded can greatly affect the description of the local groundwater environment. A more comprehensive analysis can be preformed for longer periods of study and greater measurement frequency. The intent of this study was to install a continuous groundwater level monitoring system around the st. Johns Landfill for a minimum study length of one year. This would allow a more thorough study of the seasonal character and behavior of the groundwater system beneath the landfill than in previous studies. Particular interest was paid to groundwater level changes resulting from seasonal weather changes. Additional attention was paid to other forcing mechanisms which could be perturbing groundwater levels, and variations in the geochemical groundwater constituents. Included throughout this report is a literature review of various studies pertinent to the analysis of groundwater level variations. Seasonal variations in vertical groundwater hydraulic gradients were reviewed and time averaged vertical seepage rates were estimated. Areal plots of groundwater levels were used to view expected horizontal groundwater hydraulic gradients during seasonal maximum and minimum groundwater levels. A computer model was developed to study the effects temporal variations in slough water levels had on groundwater seepage rates through the perimeter dike separating the landfill from the sloughs. The modeling provided an estimate of the average horizontal leachate seepage rate into the sloughs. Comparison plots of monitoring well groundwater levels were used to analyze potential swash zones beneath the landfill and potential effects of lowered water levels in Bybee Lake. Spectral analysis techniques were imployed to determine the dominant frequencies observed in the groundwater levels, allowing determination of the type of forcing mechanism driving the fluctuations. Geochemical groundwater constituents were statistically analyzed to determine the significance of observed trends in the data: areal plots of chloride concentrations and electrical conductivity were made to view constituent distributions within the underlying aquifers. Estimated vertical and horizontal groundwater seepage rates into the local waters showed that horizontal leachate seepage is insignificant compared to vertical leachate seepage. Groundwater level comparison plots indicated no significant swashing beneath the landfill occurred. The statistical studies on groundwater forcing mechanisms indicated that either the slough or the Columbia River water levels could be perturbing groundwater levels. Trend analyses on the geochemical groundwater constituents indicated significant, positive trends in chloride concentrations, and undeterminable trends in electrical conductivity.
158

Production and assessment of modified clay for organic contaminant containment

Richards, Sarah A. January 2003 (has links)
Abstract not available
159

Ground water contamination from an abandoned landfill site in Delaware County, Indiana

Day, Stephen Wayne 03 June 2011 (has links)
Groundwater contamination by landfill generated leachate is a problem that is increasingly addressed for proposed and existing landfill sites.This thesis examines groundwater contamination movement from the abandoned Delaware County Municipal landfill. The site is located in the crest of a highly permeable sand and gravel glacial esker which allows for rapid movement of ground water and any contaminants introduced into it.The landfill site was originally investigated in the late 1970's by Ed Lusch, a graduate student at the Ball State University Geology Department. That study showed some indications of ground water contamination movement to about 400 feet west of the site, in the direction of ground water flow. This indicated position of a contamination plume suggested that leachate, generated from the landfill site, had moved to that position since (or possibly before) the closing of the landfill in 1971.The present study, using a combination of surface resistivity methods, on-site test wells, and chemical analyses of ground water, attempted to determine the degree of contamination movement from the site since the original study and the extent to which the local aquifer had been affected. Results of this investigation revealed an apparent slow movement of leachate from the landfill westward towards the Mississinewa River, also in the direction of ground water flow. Surface resistivity methods of this study revealed the plume of contamination (indicated by resistivity "low" area) to now exist at approximately the same location as indicated in the earlier study, but to have expanded laterally. This investigation also found indications of the contamination plume well into the underlying fractured dolostone.Chemical analyses of nearby residential wells also revealed slightly elevated amounts of chloride, ammonia and specific conductivity in the ground water of the glacial esker south of the abandoned landfill site. The presence of three other dump sites, including a sludge dump, along the esker south of the landfill, offers questions as to the source of ground water contamination.Ball State UniversityMuncie, IN 47306
160

Soil genesis and vegetation growth in pulverized fuel ash and refuse landfills capped by decomposed granite

Ngai, Yuen-yi, Helen., 魏婉儀. January 1998 (has links)
published_or_final_version / Geography and Geology / Master / Master of Philosophy

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