Intact geomembranes are barriers to advective aqueous flow and are often a key component in the design of composite bottom liner and cover systems. During installation, the combination of solar heating, a high coefficient of expansion, and the stiffness of high density polyethylene (HDPE) causes the geomembrane to expand and buckle, forming wrinkles (waves). Up to 20 – 30% of the area of the geomembrane may be below hydraulically connected wrinkles, which could substantially increase leakage through the composite liner if there is a hole on or near a wrinkle in the connected network. To quantify wrinkles at the field scale, a technique for low altitude aerial photography and photogrammetric correction was developed. Wrinkles were quantified for nine field cases involving a variety of installation (area, geomembrane thickness and texture, orientation, subgrade) and weather conditions. The technique was used to quantify the geometry of individual wrinkles (length, width and area) and, more importantly, the length of the longest hydraulically connected wrinkle at each time. Hand measurements of height and width were conducted at five of the cases. Air temperature, solar radiation, and geomembrane surface temperature was recorded as permitted by site conditions and instrumentation. The longest measured connected wrinkle was 5330 m on a 0.61 ha slope. For a 1.5-mm-thick geomembrane, the average wrinkle width over a GCL was 0.20-0.23 m and 0.24 – 0.32 m over a CCL. The average hand-measured wrinkle height was 0.06 m, and the tallest wrinkle measured was 0.18 m. The longest connected wrinkle length was <200 m when the sum of the wrinkle lengths was < 580 m (<8% of the area of the geomembrane was wrinkles). The reported connected wrinkle lengths are significantly longer than previously reported values. When used as input into an existing theoretical leakage solution, these very long wrinkles can explain previous large field measurements of leakage. The results also suggest that simply limiting the time of day when cover soil is placed and/or reducing the area in which wrinkles can form may greatly reduce the length of connected wrinkles after covering. / Thesis (Ph.D, Civil Engineering) -- Queen's University, 2012-06-29 16:05:18.598

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M. Ing. / The overall purpose of this research project was to develop a proposed maintenance strategy for generator sets utilised in biogas applications. One specific biogas application, involving the use of landfill gas (LFG) to generate electrical energy, was the focal point of the research project. This is due to the fact that the author’s organisation is extensively involved with landfills and power generation through the use of LFG.

The main focus of the project is to tell the story of waste - to improve awareness and to help people grasp the colossal problem of landfill space running out! Currently, only 5% of the 3 million tons of waste, produced by Tshwane per year, is being recycled at landfill sites and yet 80% of the waste is recyclable! (Dekker, F. 2012) Where will we go with all of our waste when there’s no space left for landfill sites? What would happen if landfill sites start to take over our parks and green open spaces?! We need to start thinking green and recycle in order to prevent this from happening. The idea behind the design is to change the visitors’ perception of waste by allowing the visitors to go through a process of discovery in order to experience and become aware of the problem and value of waste in a fun and exciting way. The project is multifaceted with a variety of activities and spaces that contribute to the story of waste being told - educating the visitors about the endless possibilities of recycled waste and how they can make a difference by recycling and using waste as a resource. / Mini Disserration (ML(Prof))--University of Pretoria, 2013. / Architecture / unrestricted

Municipal solid waste (MSW) management strategies typically include a combination of three approaches, recycling, combustion, and landfill disposal. In the US approximately 54% of the generated MSW was landfilled in 2008, mainly because of its simplicity and cost-effectiveness. However, landfills remain a major concern due to potential landfill gas (LFG) emissions, generated from the chemical and biological processes occurring in the disposed waste. The main components of LFG are methane (50-60%) and carbon dioxide (40-50%). Although LFG poses a threat to the environment, if managed properly it is a valuable energy resource due to the methane content. Currently there are over 550 active LFG to energy (LFGTE) facilities in the US, producing renewable energy from LFG. A major challenge in designing/operating a LFGTE facility is the uncertainty in LFG generation rate predictions. LFG generation rates are currently estimated using models that are dependent upon the waste disposal history, moisture content, cover type, and gas collection system, which are associated with significant uncertainties. The objectives of this research were to:  Evaluate various approaches of estimating LFG generation and to quantify the uncertainty of the model outcomes based on case-study analysis,  Present a methodology to predict long-term LFGTE potential under various operating practices on a regional scale, and  Investigate costs and benefits of emitting vs. collecting LFG emissions with regards to operation strategies and regulations. iii The first-order empirical model appeared to be insensitive to the approach taken in quantifying the model parameters, suggesting that the model may be inadequate to accurately describe LFG generation and collection. The uncertainty values for the model were, in general, at their lowest within five years after waste placement ended. Because of the exponential nature, the uncertainty increased as LFG generation declined to low values decades after the end of waste placement. A methodology was presented to estimate LFGTE potential on a regional scale over a 25-year timeframe with consideration of modeling uncertainties. The methodology was demonstrated for the US state of Florida, and showed that Florida could increase the annual LFGTE production by more than threefold by 2035 through installation of LFGTE facilities at all landfills. Results showed that diverting food waste could significantly reduce fugitive LFG emissions, while having minimal effect on the LFGTE potential. Estimates showed that with enhanced landfill operation and energy production practices, LFGTE power density could be comparable to technologies such as wind, tidal, and geothermal. More aggressive operations must be considered to avoid fugitive LFG emissions, which could significantly affect the economic viability of landfills. With little economic motivation for US landfill owners to voluntarily reduce fugitive emissions, regulations are necessary to increase the cost of emitting GHGs. In light of the recent economic recession, it is not likely that a carbon tax will be established; while a carbon trading program will enforce emission caps and provide a tool to offset some costs and improve emission-reduction systems. Immediate action establishing a iv US carbon trading market with carbon credit pricing and trading supervised by the federal government may be the solution. Costs of achieving high lifetime LFG collection efficiencies are unlikely to be covered with revenues from tipping fee, electricity sales, tax credits, or carbon credit trading. Under scenarios of highly regulated LFG emissions, sustainable landfilling will require research, development, and application of technologies to reduce the marginal abatement cost, including:  Diverting rapidly decomposable waste to alternative treatment methods,  Reducing fugitive emissions through usage daily/intermediate covers with high oxidation potential,  Increasing the lifetime LFG collection efficiency, and  Increasing LFG energy value – for instance by producing high-methane gas through biologically altering the LFG generation pathway

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No description available.

Att gräva upp och återvinna värdefulla material från gamla deponier har en enorm miljöpotential i form av utvinning av resurser. I dagsläget innebär emellertid sådana återvinningsprojekt stora osäkerheter och därmed ekonomiska risker för företag. Anledningen är att det finns många deponier att välja mellan och dessa skiljer sig ofta åt med avseende på ålder, storlek, typ av avfall och lokalisering vilka alla är faktorer som direkt kan påverka om ett projekt blir lönsamt eller inte. För att minska de ekonomiska riskerna behöver företag i återvinningsbranschen på förhand kunna identifiera skillnader mellan olika deponier. I denna uppsats genomförs en systematisk litteraturöversikt över inventeringar av deponier. Uppsatsen syftar till att inventera tillgänglig information om deponier på nationell, regional och lokal nivå. Undersökningar har skett kring vilka uppgifter inventeringarna innehåller som finns hos Jönköpings och Linköpings kommun, Länsstyrelserna i Östergötlands och Jönköpings län samt hos Naturvårdsverket. Uppsatsen belyser även begreppet Landfill Mining och dess användning. Slutsatserna i denna uppsats är att information från inventeringarna kan användas för Landfill Mining-projekt, dock kan det behövas gå ned på objekt- eller personnivå för att få tillgång till mer detaljerad data. Uppsatsens kategorier, ålder, riskklassning och avfallstyp innehåller viktig information om deponierna som är avgörande för att besluta om ett LFM- projekt ska genomföras och utgöra en vinst.

Approximately 136,000 refuse trucks were in operation in the United States in 2007. These trucks burn approximately 1.2 billion gallons of diesel fuel a year, releasing almost 27 billion pounds of greenhouse gases. In addition to contributing to global climate change, diesel-fueled refuse trucks are one of the most concentrated sources of health-threatening air pollution in most cities. The landfills that they ultimately place their waste in are the second largest source of human-related methane emissions in the United States, accounting for approximately 23 percent of these emissions in 2007. At the same time, methane emissions from landfills represent a lost opportunity to capture and use a significant energy resource. Many landfill-gas-to-energy (LFGTE) projects are underway in an attempt to curb emissions and make better use of this energy. The methane that is extracted from these landfills can be converted into a transportation fuel, sold as a pipeline-quality natural gas, operate turbines for electricity, or be flared. The unique relationship that occurs between refuse trucks' constant visits to the landfill and the ability of the landfill itself to produce a transportation fuel creates an ability to accomplish emissions reduction in two sectors with the implementation of using landfill gas to fuel refuse trucks. Landfill owners and operators are very reluctant to invest in large capital LFGTE projects without knowing their long-term feasibility. The costs and benefits associated with each LFGTE project have been presented in such a way that owners/operators can make informed decisions based on economics while also implementing clean energy technology. Owners/operators benefit from larger economic returns, and the citizens of the surrounding cities benefit from better air quality. This research focused on six scenarios: converting landfill gas (LFG) to liquefied natural gas (LNG) for use as a transportation fuel, converting LFG to compressed natural gas (CNG) for use as a transportation fuel, converting LFG to pipeline-quality natural gas, converting LFG to electricity, flaring LFG, and doing nothing. For the test case of a 280-acre landfill, the option of converting LFG to CNG for use as a transportation fuel provided the best benefit-cost ratio at 5.63. Other significant benefit-cost findings involved the LFG-to-LNG option, providing a 5.51 benefit-cost ratio. Currently, the most commonly used LFGTE option of converting LFG to electricity provides only a 1.35 benefit-cost ratio while flaring which is the most common mitigation strategy provides a 1.21, further providing evidence that converting LFG to LNG/CNG for use as a transportation fuel provides greater economic benefits than the most common LFGTE option or mitigation strategy.

Thesis (M. Sc.)--University of Hong Kong, 1998. / Includes bibliographical references (leaf 71-73).