Water, flowing through beds of refuse in a sanitary landfill, will leach organic and inorganic substances from the fill. These leached substances may be a source of pollution for receiving surface or ground waters. The leachate, before it is diluted by the receiving water, can usually be classed as a very strong waste water; that is, the levels of the waste water parameters COD, Suspended Solids, low dissolved oxygen and turbidity are many times those found in normal, municipal waste water. Added to these foregoing parameters are possible high levels of toxic chemicals and metals. It is now generally recognized that the leachate from refuse landfills should be controlled, and in some recently designed landfills, leachate collection is incorporated into the overall design. Toxic chemicals and metals are not adequately removed from waste waters by the standard biological sewage treatment processes; thus, the collected landfill leachate often requires pretreatment before it can be discharged to a municipal sewer system. If it is to be discharged to a natural receiving water, it requires more complete treatment. It was the purpose of this research to attempt to develop a physical-chemical treatment system for landfill leachate, such that the effluent might be safely discharged to a biological treatment plant or a natural receiving water. To deal with the extremely large number of possible chemical reagents, and to a lesser extent, physical methods available-, it was first necessary to select a number of primary candidates from prior information and theory available in the literature; secondly, it was advantageous to use a statistically designed experimental programme for screening those candidates chosen. In the screening process, no changes in the physical parameters screened, such as duration and speed of mixing or duration of settling, were found to be significant, if normal minimum times and usual speeds were used. Four chemical reagents, lime, ozone, ferric sulfate, and alum were indicated as having a potentially significant effect on the leachate-contained Total Solids (TS), Total Carbon (TC), Turbidity (Turb), Cadmium (Cd), Copper (Cu), Iron (Fe), Zinc (Zn), Potassium (K), Calcium (Ca), Sodium (Na), Phosphorus and the acid-base relationship as expressed by the term pH. The follow-up experiments determined that only two of the above four reagents were significantly effective in removal of the afore-named pollutants, as well as Manganese (Mn), Lead (Pb), Colour, Chemical Oxygen Demand (COD), the components of Total Carbon (TC) Total Inorganic Carbon (TIC) and Total Organic Carbon (TOC), and the components of Total Solids (TS)—Suspended Solids (SS) and Dissolved Solids (DS). All of the multivalent metals, except Calcium, were significantly removed from this wastewater by pH adjustment with lime, with additional minor removals by oxidation with ozone. Dissolved organic materials were not removed by pH adjustment and only removed in approximate stoichiometric amounts by reaction with ozone. In these experiments, the polymers tested were not effective in the removal of the named pollutants. Ozone is indicated to be an effective disinfectant, but highly sensitive to the COD of the leachate. An ozone-COD ratio, which determines the quantity of applied ozone necessary for the oxidation of some of the dissolved metals and for disinfection, as a function of the contained COD, is proposed for this leachate. The possibility of the application of this ozone-COD ratio is put forth, subject to further investigation. / Applied Science, Faculty of / Civil Engineering, Department of / Unknown

Each year a large number of wooden pallets are disposed of in US landfills, representing a significant portion of total wood usage. The purpose of this research was to gain an understanding of the numbers of pallets reaching landfills, specifically Municipal Solid Waste (MSW) and Construction & Demolition (C&D) landfills. Also, the research was conducted to determine what, if anything, was done with the pallets once they were received by landfills.Mail questionnaires were sent to every state licensed MSW and C&D landfill identified in the US, except Alaska. Alaska was omitted because it is known to have many small landfills each representing a single small village. It was thought that these small landfills could skew the results. The questionnaire mailed to the landfills was based on a questionnaire used in a Virginia Tech study of landfills in 1995. Only minor changes were made to the previously used questionnaire so that the data collected would be comparable to previous results.This study found that, on average, MSW landfills received 138,000 tons of waste and C&D landfills received 36,000 tons of waste in 1998. This amounted to a total of 239 million tons of waste at MSW facilities and 40 million tons of waste at C&D facilities. Average tipping fees at MSW and C&D landfills were $29.31 and $16.84 per ton, respectively. Pallets represented 2.8 percent of waste at MSW facilities and 3.3 percent of waste at C&D facilities. This amounts to 138 million pallets reaching MSW landfills and 40 million pallets reaching C&D landfills in 1998. Of these pallets reaching landfills 22 million were recovered from MSW landfills and 16 million were recovered from C&D landfills. Recovered pallets from both types of landfills were typically ground and used for mulch, animal bedding, compost or boiler fuel. Infrequently, pallets were used as-is. But this was infrequent. When pallet material was sold by MSW and C&D facilities, it received between ten and twenty dollars per ton depending on end use and region of the country. / Master of Science

No description available.

Despite the many models of American federalism in the literature, the principal model of American federalism is one of relationships between two distinct sovereigns - the federal and state governments. Yet, a third sovereign exists, the many Alaska Native and American Indian tribes in this nation. Tribes are sovereigns, having their own governance structures, and are dealt with on a government-to-government relationship by the United States. At the nexus or intersection where federalism and tribal governance meet, numerous relationships often occur between these sovereigns and other entities, some of which may be cooperative or conflicting in scope. Under the federal Resource Conservation and Recovery Act of 1976, the issue of solid waste management in what is known as Indian country is used as a lens to examine the multiple relationships among these multiple sovereigns. Interviews were conducted with forty-five key informants from tribes, tribal organizations, federal/state/local agencies, and universities. Specific information about tribal solid waste management programs was obtained from thirty-five tribes, tribal organizations and other sources. Analysis of the research data revealed three patterns of relationships that emerged: (1) uncooperative, (2) cooperative formal, and (3) cooperative informal. These patterns of relationships point to tribal sovereignty as an embedded theme for solid waste management by Indian tribes because of its emphasis on the rights and responsibilities of their members to participate in decisions affecting the community as a whole. Finally, the study advocates better relationships among all sovereigns not only in solid waste management but also for public policy in general. / Ph. D.

Bioreactor landfills have become a feasible alternative to the typical "dry tomb" landfill. By recirculating leachate and/or adding additional liquid wastes, bioreactor landfills operate to rapidly degrade and transform organic wastes. The reactions within a bioreactor landfill create elevated temperatures. The intent of this study was to determine the effect of elevated temperature on the degradation of lignocellulose compounds. In order to observe the effects of temperature on lignin, small bioreactors were created in the laboratory. Several experiments were performed by the authors. Solubility of lignin based on temperature and time of thermal exposure were conducted. In addition, degradation studies were conducted based on biological treatment of lignin as well as a combination of biological and thermal treatment. Samples were collected at specified intervals to determine the amount of water soluble lignin (WSL), volatile fatty acids (VFAs), lignin monomers, and/or methane present. Lignin solubility increased as temperature rose in the thermal solubility experiments. The rate of solubility increased 15 times for office paper and 1.5 times for cardboard in the biological experiments when compared to the thermal treatment. The thermal and biological study indicates that as lignin is solubilized, it breaks down into lignin monomers, which can be converted easily by anaerobic bacteria into VFAs and subsequently, methane. These experiments indicate that temperature is crucial to the degradation of lignin compounds in a bioreactor landfill. / Master of Science

No description available.

Thesis (Ph. D.)--West Virginia University, 2001. / Title from document title page. Document formatted into pages; contains ix, 160 p. : ill. (some col.). Vita. Includes abstract. Includes bibliographical references (p. 102-107).

Thesis (M. Arch.)--University of Hong Kong, 1995. / Includes special study report entitled: Planting on landfill. Includes bibliographical references.

This report examines the potential benefits from the redevelopment of landfills into parks in Houston, Texas. Many Park and Recreation (P&R) Departments are unable to acquire and develop parkland at a rate on par with new residential construction. Parks provide economic, environmental, public health and aesthetic benefits. Despite these benefits, P&R Departments are often the target of budget cuts when city governments grapple with funding shortfalls. P&R Departments must pursue low value lands to meet parkland needs. Closed Municipal Solid Waste (MSW) landfills are a source of low value land in, and surrounding urban areas. New regulatory framework in the form of the U.S. EPA’s Municipal Solid Waste Landfill Criteria ensures closed landfills may be safely and cost effectively redeveloped for recreational use with limited liability concerns for the P&R Department. This regulatory framework is discussed and Best Management Practices (BMPs) are outlined. These BMPs focus on accommodating the dynamic nature of landfills to minimize park development and Operation and Maintenance (O&M) costs. The substantial parkland deficit in the City of Houston is quantified. The findings of the needs assessment in the City’s Parks Master Plan are presented. A multi-tiered Geographic Information Systems (GIS) based analysis is utilized to evaluate the potential benefits from the redevelopment of existing landfills in the City into parks. The GIS analysis identified 8 landfills that, if redeveloped, will increase the distributional equity of City parkland holdings. Of these 8, the 4 landfills with the lowest expected total development costs and the highest expected savings over traditional greenfield development were identified. It is recommended the City adopt a thorough site characterization and planning process and pursue landfill redevelopment as a cost effective and beneficial way to increase parkland holdings. / text

Despite improved liner design, there are still reported incidences of landfill leachate, rich in heavy metals, percolating through to groundwater and threatening ecosystems. This thesis introduces the concept of segregating municipal solid wastes (MSW) according to their major heavy metals and their metal's adsorption compatibility. Each segregated portion can be disposed in a different landfill compartment to minimize leaching of these heavy metals with the greatest bioactive impact. The validity of the concept was evaluated by batch and column retention mobility studies using copper (Cu) alone or with either lead (Pb) or cadmium (Cd) in solutions bearing various pHs. This was supported by selective sequential extraction (SSE) to determine the affinity to specific liner fractions. The following summarizes the procedure used. / Beforehand, a soil column test using sand with 5 and 10% bentonite was conducted to develop an equation predicting liner permeability, k , under simulated field conditions. The column permeability test revealed that a liner with 5% bentonite resulted in a k value which respected the North American criteria of 10-5 m/s. / In the batch experiments, solutions with Cu alone or with Cd or Pb, adjusted to pH of 3.7, 5.5 or 7.5, were applied to sand liners with 0%, 5% or 10% bentonite, having CEC's of 2.0, 6.4, and 10.8 (cmol(+) kg-1 ), respectively. Bentonite, pH and Pb significantly affected Cu adsorption. Cu was adsorbed by the liners at pH <6.5 whereas Cu precipitated at pH >6.5. Cu retention was higher in the presence of Cd than in that of Pb, at all combinations of CEC and pH. Competition between metals was greater in liners with lower CEC and therefore fewer adsorption sites. Limiting Pb in a landfill compartment can improve Cu adsorption at pH's below the precipitating threshold. / In the SSE procedure, the liner samples were centrifuged, decanted from their solutions and each adsorption fraction analyzed for Cu content. Results indicated that the carbonate fraction adsorbed more Cu, and that Pb significantly increased the mobility of Cu due to competition for exchangeable sites. / In the final soil column test using a sand liner with 5% bentonite, the leachate had an initial pH of 3.7. The leaching test confirmed the compatibility of Cu with Cd. The leaching of Cu was greater in the presence of Pb. Total metals in leachate was greater for the Cu-Cd solutions than for the Cu-Pb, because of Cd's relatively high mobility. The sequential extraction results showed again that the carbonate fraction dominated metal adsorption. Total heavy metal leaching followed the order of Cu/Cd > Cu/Pb > Cu alone. / Thus, disposing MSW in landfill compartments based on their heavy metal compatibility can minimize migration of heavy metals.