This award is to North Carolina State University at Raleigh to support the activity described below for 36 months. The proposal was submitted in response to the Partnerships for Innovation Program Solicitation (NSF 05-556).
Partners North Carolina State University at Raleigh (NCSU) (lead institution), University of Wisconsin- Madison (UW-M), Waste Management, Inc., Allied Waste Industries, Inc., Republic Services Corporation, Onyx Waste Systems, Inc., Buncombe County, NC, Delaware Solid Waste Authority, Yolo County, CA, Camp Dresser & McKee, CH2Mhill, GeoSyntec Consultants, SCS Engineers, US Environmental Protection Agency, NY Department of Environmental Conservation, Wisconsin Department of Natural Resources, National Solid Waste Management Association, Solid Waste Association of North Carolina, and Environmental Research and Education Foundation.
The primary objective of the proposal follows: To increase the use of bioreactor landfills to manage waste. Bioreactor landfills in contrast to dry-tomb landfills are a more holistic approach to landfilling of solid waste in which the landfill is operated as a biological system to enhance waste decomposition. Dry tomb landfills inhibit waste decomposition by robbing the system of air needed for decomposition of the solid waste in the landfill. Bioreactor landfills have several advantages including (1) more rapid settlement and reuse of airspace for addition water and therefore revenue, (2) increased volumes of methane that can be recovered as a ?green? source of domestic energy, (3) in-situ leachate treatment, and (4) reduced post-closure maintenance and monitoring costs. Currently, it is estimated that 5-10% of all landfills are operated as bioreactors. More widespread adoption of the technology is limited by a lack of quantitative methods to predict landfill performance and economics. This proposal will develop quantitative, field-validated engineering methods to improve the design and operation of bioreactor landfills. Hopefully, also the reclamation of the methane which is one of the most important factors.
Potential Economic Impact
Over 482 million tons of solid wastes are generated in the US annually from households, institutions, businesses, and industry, with approximately 65% being disposed of in landfills. This reliance on landfills is expected to continue for the foreseeable future. Thus, the US benefits by improving the economics and environmental signature of landfills via technologies such as the bioreactor landfill. In addition, the solid waste industry is massive, consisting of large publicly traded and privately held corporations, as well as of public solid waste authorities. Industry-wide revenue is approximately $40 billon annually, and the annual contribution to the US economy is approximately $96 billon. More than 367,000 people are directly employed in the solid waste industry in the US, and ultimately the industry contributes nearly 1 million jobs to the economy due to multiplier effects. Thus, research that makes solid waste management more economical is good for the US economy. Conservative assumptions indicate that research on bioreactor landfills, such as that proposed in this study, could transfer more than $1 billion annually into other sectors of the US economy.
The intellectual merit of the project follows. Three thrust areas have been identified where research can directly contribute to improvements in bioreactor technology by reducing cost and increasing predictability: (1) landfill hydrology, (2) solids decomposition, and (3) settlement prediction. In landfill hydrology, research will be conducted to understand flow patterns and residence times for leachate and other liquids injected into landfills. This research is needed to develop operational guidelines for leachate injection and to evaluate the behavior of liquid waste streams that may be added to bioreactor landfills. Work on solids decomposition will relate fundamental information on the biodegradation of individual waste components to settlement and airspace recovery, as well as improve the accuracy of national greenhouse gas inventories. Finally, a predictive model will be developed that relates moisture, solids decomposition, and waste settlement that will improve the predictability of airspace utilization, the industry?s ultimate metric. In all areas, fundamental laboratory-scale studies are tightly coupled to models and field-scale work at bioreactor landfills operated by industrial partners.
The broader impacts of the activity follow. The technology developed will contribute to both the economic and environmental wellbeing of the US. The partnership will provide a pipeline of highly skilled technical personnel to the solid waste industry. Diversity will be addressed by recruiting students from under-represented groups. Both NCSU and UW-Madison participate in NSF?s Summer Undergraduate Research Experience program, which will be used as a source to recruit undergraduate students from under-represented groups. Students at K-12 schools will be informed of the project via presentations by faculty to inform young students about career opportunities and the importance of environmental engineering and solid waste management.
