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 local issue. The modular mass burning combustion units with waste heat
recovery are also popular (Figure 4-3-17B). LaRoc (1988) provides a good
description of technologies currently available in the U.S. Modular mass
burning units are probably the best choice for military installations. They
provide flexibility to meet the changing needs of a base.
4.3.17.3 Much design and operating experience on municipal solid
waste (MSW) combustion has been gained in Japan and Western Europe over the
past decade as the volume reduction of wastes has been stimulated by the
declining availability and increasing cost of landfills (Brna 1988). Nearly
2000 MSW units in Japan and several hundred in Western Europe are now
operating, with the trend now being waste-to-energy conversion rather than
simply incineration to reduce volume. Technology developed in Japan and
Western Europe has been beneficial to the U.S., where over 100 MSW combustion
systems are now operational, and a similar number are in the construction or
conceptual development phase.
4.3.17.4 The reduction of waste volume by combustion results in air
pollution, including pollutants not currently regulated by the EPA.
Pollutants/emissions and methods of control require analyses in Environmental
Assessments. Table 4-3-17B shows the U.S. standards along with those of
several states and countries (Brna and Sedman 1987). However, the EPA has
announced its intention to further regulate emissions from MSW combustors and
proposes promulgation of these regulations in December 1990. Currently,
studies are under way to determine which pollutants to regulate and to what
extent. As indicated in Table 4-3-17B, classes of pollutants currently
regulated by one or more of the entities listed include: trace organics
(dioxins, total organics), acid gases (HCl, S02), trace heavy metals (Hg, Cd,
Tl), and particulate matter. The listing in Table 4-3-17B is not intended to
be complete. For example, West Germany regulates the emissions of more trace
metals, and some U.S. states, as well as Japan and West Germany, have NOx
requirements/guidelines.
4.3.17.5 Noting the classes of pollutants that are currently
regulated and their potential for regulation in the U.S.--on a national, state,
or local level--the air pollution control strategy selected for a given plant
shall have the potential for multi-pollutant control, if costly retrofitting or
upgrading is to be minimized in meeting future regulations. Residues, although
small in volume relative to unburned wastes, contain concentrated pollutants
requiring environmentally safe disposition.
4.3.17.6 Emission Control Technologies
4.3.17.7 Historically, emission control on incinerators has focused
on particulate removal. Tables 4-3-17C and D (Tchobanoglous, Theisen, and
Eliassen 1977) show several equipment types and rate their relative performance
in removing particles.
4.3.17.8 Recent developments and perceived trends have switched the
emphasis to removal of acid gases, trace organics, and trace heavy metals.
4.3.17.9 Wet or dry scrubbers are effective for controlling
pollutants (acid gases, trace organics, trace heavy metals, and particulate
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