This course describes chemical leaching tests and biological assays to measure the sulfate content of a solid waste and to estimate its hydrogen sulfide production potential. A number of chemical leaching tests were compared to evaluate the most effective test to measure both sulfate and solid phase sulfide. In addition, both small (160 mL) batch reactors and larger 8-L reactor systems were evaluated to measure the rate and extent of sulfate conversion to hydrogen sulfide. Laboratory-measured first order decay constants were used to estimate decay rate constants applicable to MSW landfills. Recommended decay rates and hydrogen sulfide yields will be presented for 5 fly ash samples from coal combustion, two ash samples from MSW combustion, and C&D fines. Limitations of the laboratory tests will also be presented.
Upon completion of this course, the attendee will be able to:
- Become familiar with the types of waste that may contain sulfate and the limitations of various chemical test methods
- Learn methods to estimate the hydrogen sulfide production potential of a waste from chemical leaching data and from biological assays
- Understand the implications of sulfide toxicity on biological tests
- Develop an appreciation for the uncertainty in using a first model and decay rate constant to predict hydrogen sulfide production
Dr. Morton A. Barlaz is Distinguished University Professor and Head of the Department of Civil, Construction, and Environmental Engineering at North Carolina State University. He received a B.S. in Chemical Engineering from the University of Michigan and an M.S. and Ph.D. in Civil and Environmental Engineering from the University of Wisconsin. He has been involved in research on various aspects of solid waste since 1983. Over this time, he has conducted research on biological and chemical processed in landfills, waste decomposition and methane production in landfills, and the behavior of hazardous wastes in landfills. He has participated in two state-of-the-practice reviews of bioreactor landfills. His research forms the basis for much of the work done to assess the impact of landfills on methane emissions inventories. Dr. Barlaz is also recognized for his research on the use of life-cycle analysis to evaluate environmental emissions associated with alternate solid waste management strategies. Dr. Barlaz is the author of over 125 peer-reviewed publications and has made over 200 presentations at conferences throughout the world.
Dr. Barlaz has served as an Associate Editor for two journals (Waste Management and Journal of Environmental Engineering), as co-chair of the bi-annual Intercontinental Landfill Research Symposium for 12 years, and on the Science Advisory Committee for the International Waste Working Group. He has also served as chair of the Government Affairs Committee and the Lectures Committee for the Association of Environmental Engineering and Science Professors.