Thesis (M.S.)--University of Wisconsin--Madison, 1983. / Typescript. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 67-71).

Thesis (Ph. D.)--University of Hong Kong, 2000. / Includes bibliographical references (leaves 99-122).

Thesis (Ph.D.)--University of Delaware, 2009. / Principal faculty advisor: Paul T. Imhoff, Dept. of Civil & Environmental Engineering. Includes bibliographical references.

Thesis (Ph. D.)--Ohio State University, 2004. / Title from first page of PDF file. Document formatted into pages; contains xvii, 342 p.; also includes graphics. Includes bibliographical references (p. 164-171). Available online via OhioLINK's ETD Center

The discharge of a landfill leachate to a receiving water body can cause a serious pollution problem. One component of leachate that can have a severe impact on a receiving water body is ammonia and its oxidized form, nitrate. This study investigated the biological treatibility of a high ammonia leachate, with specific regard to nitriification and denitrification. A continuous-feed, single sludge denitrification system with recycle was used. Leachate ammonia concentrations of up to 288 mg/L-N were reduced to less than 1 mg/L. The ammonia was removed by nitrification and bacterial uptake. About 25% of the incoming ammonia was taken up by the bacteria in the anoxic reactor; the rest was subsequently nitrified in the aerobic reactor. The nitrates produced in the aerobic reactor were recycled back to the anoxic reactor to undergo denitrification. Glucose was added directly to the anoxic reactor to aid denitrification. The degree of denitrification was dependent on the glucose loading to the anoxic reactor; however, 100% denitrification was achieved on several occasions. The influent leachate COD removal was 20%; however after the addition of glucose to the system, a mean COD removal of 74% was obtained. Of the COD removed across the system, 85% was used in the anoxic reactor for denitrification, and the remaining 15% was used by the heterotrophs in the aerobic reactor. The four metals monitored regularly, zinc, manganese, nickel and iron were removed by the biomass, but not to the same extent During the latter part of the study, the system was first spiked with manganese, and then - zinc, to try and induce an inhibitory effect on the nitrification process. The manganese had no detectable effect on the system. However, total zinc (>95% soluble) levels of between 14.9 and 17.6 mg/L caused substantial inhibition of the nitrification process, resulting in approximately 70 mg/L ammonia in the effluent (feed = 216 mg/L). This inhibition was also evident from the lower percent nitrification values and the unit nitrification rates. This high influent zinc concentration also caused deflocculation, resulting in the loss of significant quantities of biomass with the effluent. The high zinc concentrations also inhibited the denitrifiers, resulting in a decrease in the ammonia uptake, as well as an increase in the COD (used)/Nitrate+Nitrite (NOT) (reduced) ratios in the anoxic reactor. The zinc levels were then lowered to allow the system to return to normal; after this state had been reached, the influent total zinc (>95% soluble) levels were again increased up to 19.5 mg/L. This concentration of zinc did not result in any ammonia appearing in the effluent; thus, it is possible that the bacteria had acclimatized to these high influent zinc concentrations. / Applied Science, Faculty of / Civil Engineering, Department of / Graduate

No description available.

Per- and polyfluoroalkyl substances (PFAS) are highly persistent compounds in nature and have been shown to have adverse health effects. Residents in Kallinge, Sweden, were exposed to PFAS through contaminated ground water used for drinking, resulting in the highest globally measured concentrations of PFAS in their blood. While active landfills in Sweden have been well-documented regarding PFAS, thousands inactive landfills in Sweden remain unexamined. This study examines the presence and temporal trends of PFAS in the leachate of one active landfill and the groundwater surrounding 36 closed landfills. Additionally, this study suggests which PFAS compounds should be monitored at landfills and in surrounding groundwater. PFAS concentration in the leachate of the active landfill differed between the snow period and the snow-free period. This may be attributed to differences in landfill treatment, as a chemical treatment is used during the snow period, and biological treatment during the snow-free period. A significant difference between short- and long chained PFAS was found in the active landfill.However, no significant differences were found year-over-year during the 5-year period examined. PFAS were detected in 31 of the 36 investigated inactive landfills, with 6 sites exceeding current guidelines for contamination. Approval of a new proposal would mean that an additional 15 landfills would exceed the guidelines. Typical PFAS analysis currently includes PFAS11, it is however recommended that broader analysis is implemented to comply with future guidelines based on PFAS24. Overall, the results highlight the risk of PFAS-contaminated groundwater spreading from landfills to drinking water sources.

This report reviews the state of the art with respect to permeability determination and sanitary landfills. Characteristics of the soil which determine the permeability are given. Processes which can change the permeability are discussed. Darcy's Law, the mathematical basis of permeability and its validity are discussed. Laboratory and field methods for determining the permeability are also discussed. Applications of determined permeability for design and management of landfills are also indicated.

No description available.

published_or_final_version / Environmental Management / Master / Master of Science in Environmental Management