Thesis (Ph. D.)--University of Texas at Austin, 1998. / Vita. Includes bibliographical references (leaves 135-139). Available also in a digital version from Dissertation Abstracts.

Thesis (Ph. D.)--Civil & Environmental Engineering, Georgia Institute of Technology, 2006. / Pennell, Kurt, Committee Chair ; Lawrence Bottomley, Committee Member ; James Mulholland, Committee Member ; Carolyn Ruppel, Committee Member ; D. Webster, Committee Member. Includes bibliographical references.

Thesis (M.Eng.)--Memorial University of Newfoundland, 2004. / Bibliography: leaves 114-118.

Thesis (M.A.)--University of Central Florida, 2008. / Adviser: Brent Marshall. Includes bibliographical references (p.60-69).

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.

The industrial history of the Great Lakes basin has left its mark on the landscape with more than 4,500 known hazardous waste sites on both sides of the Canada-United States border. The vast majority are closed and no longer accept wastes, but they still pose potential risks to the environment and nearby communities. For the past several years, state and provincial governments have proposed new "state-of-the-art" facilities as a way to allow industries continued access to waste disposal capacity, but with far stricter controls than most older sites have provided. Publicity of contamination incidents at existing waste sites, and also the institution of formal administrative reviews and public hearings for the location of new ones, have complicated the facility siting process considerably and led to the not-in-my-backyard (NIMBY) syndrome. Additionally, issues related to environmental equity and justice often arise, especially in cases where local residents are racial minorities or low-income (social equity). The problem also has a spatial dimension when one region is expected to receive wastes from, and for the benefit of, industries in other areas (spatial equity), or when a heavily industrialized community becomes slated for yet another facility (cumulative equity). Cross-boundary and local autonomy issues heighten the controversies as well. This thesis reviews ten hazardous waste siting disputes in communities on the Canada-U.S. border in terms of their environmental justice implications. In the majority of cases, opponents of new hazardous waste facilities based their concerns on spatial equity and a variety of procedural matters. Racial minority groups tended to base their arguments on cumulative equity rather than social equity. In some cases, local and regional disputes became international matters given the geographic setting along the Canada-U.S. border.

Thesis (M.S.)--University of Missouri-Columbia, 2007. / The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from title screen of research.pdf file (viewed on November 6, 2007) Includes bibliographical references.

Thesis (Ph. D.)--University of California, San Diego, 1998. / Vita. Includes bibliographical references.

Thesis (M.S.)--Michigan State University. Dept. of Resource Development, 2008. / Title from PDF t.p. (viewed on July 27, 2009) Includes bibliographical references (p. 105-106). Also issued in print.