Page 315 - Materials Chemistry, Second Edition

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286 Waste Management Practices: Municipal, Hazardous, and Industrial
U.S. Environmental Protection Agency, Risk Assessment for the Waste Technologies Industries (WTI)
Hazardous Waste Incineration Facility (East Liverpool, Ohio), EPA-905-R97-002a, U.S.
Environmental Protection Agency Region 5, Chicago, IL, 1997.
U.S. Environmental Protection Agency, Emissions Test Results from the Stanislaus County, California,
Resource Recovery Facility, International Conference on Municipal Waste Combustion, Hollywood,
FL, U.S. Environmental Protection Agency Washington, DC, 1989.
Walsh, P., O’Leary, P., and Cross, F., Residue disposal from waste-to-energy facilities, Waste Age, April 1988.
WASTE, Waste Analysis, Testing and Evaluation: The Fate and Behavior of Metals in Mass Burn Incineration,
A.J Chandler Associates Ltd., Willowdale, ON, 1993.

QUESTIONS
1. MSW combustion involves physical and chemical transformations in which solid materials are
converted into gases and some solid residues. What factors affect the types of gases pro-
duced? What factors will influence the amount of solid residues, both carbonaceous and
inorganic?
2. Compare the operation of a mass-burn incinerator with that of RDF, in terms of: fuel types;
waste processing and equipment; convenience; resource recovery; energy utilization.
3. What are the functions of combustion chamber overfire and underfire air? How can they be
adjusted to optimize incineration?
4. List the engineering and design factors that serve to enhance MSW combustion in an incinerator.
5. Define stoichiometric air and heat value.
6. Discuss the major types of gaseous emissions from a mass-burn incinerator and how each may
be effectively removed from the flue.
7. SO production may be controlled during mass-burn incineration by the addition of limestone
2
to the combustion chamber. What are the advantages and disadvantages of this procedure
over flue gas desulfurization?
8. An incinerator operating at a sufficiently high temperature and air inflow rate may still gener-
ate PICs. Explain how such a phenomenon may occur.
9. How do PCDDs and PCDFs form during mass-burn incineration (given that the firebox tem-
o
perature is sufficiently high, for example, > 1000 C, to destroy virtually all organic com-
pounds)? In what physical form(s) are these compounds emitted?
10. Describe “particulate matter” as relates to MSW combustion. What are its chemical and
physical properties? What size range of particulates are the most potentially damaging
when inhaled? How do certain toxins (e.g., metallic vapors, chlorinated hydrocarbons)
react with particulate matter to increase their risk of exposure?
11. Generation of atmospheric pollutants is a function of MSW charge rate and combustion
chamber conditions, among other factors. Explain.
12. Explain how the following air pollutants can be removed from stack gases: SO , particulates,
2
mercury, and PCDDs.
13. Explain why most MSW incinerators in the United States are mass-burn rather than RDF-
fired.
14. How do electrostatic precipitators and cyclone separators differ in terms of efficiency of
removal of particulate matter, SO , and PCDDs.
2
15. Cd occurring in raw MSW can become significantly more soluble (and hence more leach-
able) following MSW combustion in a mass-burn incinerator. Explain.
16. Discuss the major concern(s) with RDF storage, both indoors and outdoors.
17. Which of the following is a significant concern when considering RDF production and uti-
lization with coal: (a) dust production; (b) odor production; (c) separation of RDF and
coal during handling; (d) some plants are unable to market the RDF; (e) all of the above.