Page 272 - Materials Chemistry, Second Edition

CAT3525_C08.qxd 1/29/2005 10:03 AM Page 243
Composting MSW 243
SUGGESTED READINGS
Anderson, J., Ponte, M., Biuso, S., Brailey, D., Kantorek, J., and Schink, T., Case study of a selection process,
The Biocycle Guide to In-Vessel Composting, JG Press, Inc., Emmaus, PA, 1986. pp. 39–47.
Barlaz, M.A. and Ham, R.K., Methane production from municipal refuse: A review of enhancement techniques
and microbial dynamics, Crit. Revi. Environ. Control, 19, 557–584, 1990.
Broda, P., Biotechnology in the degradation and utilization of lignocellulose, Biodegradation, 3, 219–238, 1992.
Daniels, L., Biological methanogenesis: physiological and practical aspects, Trends Biotechnol., 2, 91–98, 1984.
DeBaere, L., Van Meenen, P., Debroosere, S., and Verstraete, W., Anaerobic fermentation of refuse, Resour.
Conserv. 14, 295–308, 1987.
Gillis, A.M., Shrinking the trash heap, BioScience. 42, 90–93, 1992.
Goldstein, N., States regulations on MSW composting, Biocycle, 30, 50–53, 1989.
Goldstein, N. and Steuteville, R., Biosolids composting strengthens its base, Biocycle, 35, 48–57, 1994.
Horan, N. J., Biological Wastewater Treatment Systems, Wiley, New York, NY, 1990.
Kashmanian, R.M. and Taylor, A.C., Costs of composting yard wastes vs. landfilling, Biocycle, 30, 60–63, 1989.
Segall, L., In-vessel composting for low volume generators, Biocycle, 35, 61–66, 1994.
Segall, L. and Alpert, J., Compost market strategy, Biocycle, 31, 38, 1990.

QUESTIONS
1. It is undesirable to land-apply raw solid wastes to soil because undesirable reactions may
occur which could inhibit plant growth. Explain.
2. When a waste possessing a high (200:1) C:N ratio waste is land-applied:
(a) microbial growth is relatively unchanged; (b) agricultural plants cannot compete with
soil microbes for soil N; (c) N is converted into ammonia gas (NH ) and lost to the atmos-
3
phere; (d) nitrogen is converted into N gas
2
3. During composting of MSW, a series of complex N transformations, including immobi-
lization, nitrification, mineralization, and others occur. Explain how the C:N ratio
declines during composting. What are the fates of N and C? Provide specific reactions
and compounds.
4. Microbial succession is important to bring the composting process to completion. Explain.
5. Explain how fire could be generated in an actively composting pile. How could such a
scenario be prevented?
6. Compare the dynamics of microbial populations and oxygen levels over time with the
turned pile method of composting vs. aerated static piles.
7. Discuss the pH requirements for optimizing composting. Why, from a biochemical or
microbiological perspective, is this pH range most effective?
8. Composting of sewage sludge poses different management concerns compared with
composting of MSW. Describe how the process may differ in terms of pathogen control,
odor control, leachate control, and aeration.
9. Explain how anaerobic reactions may occur in a compost pile that contains 15-20%
oxygen in the interstitial spaces.
10. What is the relationship between pile temperature and microbial growth and activity?
What is an ideal compost temperature range? Why is this range considered optimal?
11. The city of Pristine, Illinois, in developing their comprehensive waste management program,
will establish a composting facility adjacent to the transfer station. What attributes should be
considered when screening potential locations for a composting site? Consider size of area,
soils, drainage and slope, land-use compatibility, and controls for runon and runoff.
12. The land area of the selected compost site is smaller than optimum. Based on practical
issues, the following compost method should be used: (a) turned pile; (b) static pile with