INTRODUCI N G THE BIOREACTOR LANDFILL NE X T GENE R A TI O N LANDFI L L TECHNOLO G Y ® Bioreactor Program The Bioreactor Landfill: The Future of Landfill Management Small Changes in Landfill Operation Today will Yield Large Environmental Benefits Tomorrow ASTE MANAGEMEN T Conventional landfill after 30 years • Leachate recirculation reduces W has prepared this brochure to leachate management costs while share our vision of the future of landfill improving leachate quality. management and to describe the steps • Provide an environmentally sound that we are taking to realize this vision. alternative to the land application of Looking to the future, we see that as a certain liquid wastes. society we will need to continuously improve the way that we manage our WASTE MANAGEMENT’S BIOREACTOR wastes. Source reduction and recycling Bioreactor landfill after 10 years LANDFILL RESEARCH AND efforts will take on increasingly DEVELOPMENT EFFORTS INCLUDE: important roles, but landfill disposal will • Building on our own experience with remain an essential component of could be accelerated to occur within bioreactors and leachate recirculation integrated waste management strategies years instead of decades, and that this projects, we have begun an ambitious for the foreseeable future. could be achieved while enhancing program to evaluate multiple full-scale We believe there are significant environmental protection. This is the bioreactor projects. environmental and economic benefits to concept behind bioreactor landfill • Establishing relationships with leading be gained by making small changes in technology and it is the basis for researchers from academia and industry the way that we operate landfills. We see our optimism. to further the understanding of bioreactor the potential to revolutionize landfills processes and the development of new from secure waste repositories to waste BIOREACTOR LANDFILL TECHNOLOGY tools for investigating landfill treatment systems, to significantly Bioreactor technology accelerates the processes. reduce or even eliminate long-term risk biological decomposition of food, • Cooperatively working with federal to the environment while simultaneously greenwaste, paper and other organic and state regulatory agencies. extracting further value. We are wastes in a landfill by promoting • Economics of full-scale bioreactor optimistic that these things can be conditions necessary for the operations. accomplished. Here is why. microorganisms that degrade the waste. The single most important factor in AREAS OF FOCUS: LEADING-EDGE INNOVATION promoting waste decomposition is the • Bioreactor process types and AND TECHNOLOGY ACCELERATES moisture content of the waste. operational implementation WASTE DECOMPOSITION Liquids must be added to the waste • Impacts of geography and climate on The engineered landfill is an environ- mass to obtain optimal moisture bioreactor performance mentally sound system for solid waste content, which ranges from 35 to 45 • Nitrogen management in landfills disposal. At Waste Management, we are percent water by weight. Liquids that • Alternative sources of moisture proud that we were at the forefront in are added include: landfill leachate, gas • Landfill gas production and emissions developing and implementing many of condensate, water, storm water runoff, • Landfill stability (geotechnical) the practices, such as leachate and gas and wastewater treatment sludges. • Regulatory change collection and management, that now constitute the standards for environ- BIOREACTOR LANDFILL BENEFITS BIOREACTOR LANDFILL PROCESSES mentally responsible landfill design • Accelerated waste stabilization. Waste Management is evaluating four and operation. Stabilized landfills can be converted types of bioreactor technology: From a pollution prevention to other useful purposes years sooner standpoint, the control features oft he with greater assurance of environ- • Aerobic-Anaerobic modern landfill have been an mental safety. • Anaerobic unqualified success. But we have also • Recovery of 15 to 35 percent of • Aerobic learned that these same control features landfill space as waste decomposes • Facultative retard the natural decomposition and is converted to gas extends the processes in the landfill by making it a useful life of landfills, reducing the Waste Management is evaluating these dry tomb. Under these conditions waste need to site new facilities. bioreactor types at existing landfills decomposes over a period of decades, • Expanded and concentrated (retrofit) and at those that are being slowly producing gas and settling until production of methane gas favors constructed (as built). The following the waste is biologically stable. beneficial gas use projects while pages describe such technologies and Now imagine that the natural decreasing greenhouse gas emissions applications. decomposition of waste in the landfill over the life of the landfill. Aerobic-Anaerobic Bioreactor (US Patent 6,283,676 B1) Leachate and Liquids Addition Gas Collection Air Injection Liquids Storage Gas Collection To Generate Electrical Energy Air Injection Groundwater Monitoring The Aerobic-Anaerobic Bioreactor is designed to accelerate waste degradation by combining attributes of the aerobic and anaerobic bioreactors. The objective of the sequential aerobic-anaerobic treatment is to cause the rapid biodegradation of food and other easily degradable waste in the aerobic stage in order to reduce the production of organic acids in the anaerobic stage resulting in the earlier onset of methanogenesis. Bioreactor Program In this system the uppermost lift or layer of waste is aerated, while the lift immediately below it receives Waste Management Bioreactor Program liquids. Landfill gas is extracted from each lift below the lift receiving liquids. Horizontal wells that are installed 2956 Montana Avenue in each lift during landfill construction are used convey Cincinnati, OH 45211 the air, liquids, and landfill gas. Phone 513-389-7370 The principle advantage of the hybrid approach is that Fax 513-389-7374 it combines the operational simplicity of the anaerobic process with the treatment efficiency of the aerobic process. Added benefits include an expanded potential for destruction of volatile organic compounds in the waste mass. Leachate/Liquids Addition Anaerobic Bioreactor Gas Collection Liquids Storage Gas Collection to Generate Electrical Energy Groundwater Monitoring The Anaerobic Bioreactor seeks to As the moisture content of the waste accelerate the degradation of waste by optimizing approaches optimal levels, the rate of waste conditions for anaerobic bacteria. In landfills, moisture, are required. degradation increases, this in turn leads to an consortia of anaerobic bacteria are responsible for Moisture is typically added in the form of increase in the amount of landfill gas produced. the conversion of organic wastes into organic acids leachate through a variety of delivery systems. Also observed is an increase in the density of the and ultimately into methane and carbon dioxide. However, the amount of leachate produced at many waste. While the rate of gas production in an Anaerobic conditions develop naturally in nearly sites is insufficient to achieve optimal moisture anaerobic bioreactor can be twice as high as a all landfills without any intervention. The waste in conditions in the waste. Additional sources of normal landfill, the duration of gas production is typical landfills contains between 10 and 25 moisture such as sewage sludge, storm water, and significantly shorter. Because of this accelerated percent water. It is generally accepted that to other non-hazardous liquid wastes may therefore be production, gas collection systems at bioreactor optimize anaerobic degradation moisture conditions necessary to augment the leachate available for landfills must be capable of handling a higher peak at or near field capacity, or about 35 to 45 percent recirculation. volume but need do so for a shorter period of time. Leachate/Liquids Addition Aerobic Bioreactor Air Injection Liquids Storage Air Injection Groundwater Monitoring The Aerobic Bioreactor seeks to In landfills aerobic activity is promoted through accelerate waste degradation by optimizing injection of air or oxygen into the waste mass. It is conditions for aerobes. Aerobes are organisms also possible to apply a vacuum to the waste mass that require oxygen for cellular respiration. In respiration is more efficient at generating energy and pull air in through a permeable cap. Liquids are aerobic respiration, energy is derived from organic than anaerobic respiration. One consequence of typically added through leachate recirculation, with molecules in a process that consumes oxygen and this is that aerobic degradation can proceed faster the need for additional sources of moisture even produces carbon dioxide. than anaerobic degradation. Another consequence more acute than for anaerobic reactors. The aerobic Aerobes require sufficient water to function just is that aerobic respiration can generate large process does not generate methane. as anaerobes do. However, aerobic organisms can amounts of metabolic heat, which requires grow more quickly than anaerobes because aerobic significant quantities of water. Leachate / Liquids Addition Facultative Bioreactor Gas Collection (US Patent 6,398,958 B1) Leachate Nitrification Treatment Gas Collection to Generate Electrical Energy Groundwater Monitoring The Facultative Bioreactor combines production of nitrogen gas (N2), which conventional anaerobic degradation