| Summary: | 碩士 === 國立中央大學 === 環境工程學系 === 86 === In this study, three municipal solid waste incinerators（MSWIs）
were selected for conducting flue gas and ashes sampling and
determination of the emissions and partitioning of metals
including lead, zinc, cadmium, chromium, copper and mercury.
MSWI-A was equipped with cyclone, dry lime scrubbing system with
fabric filter, while MSWI-B was equipped with electrostatic
precipitators（ESP）with wet scrubber, and MSWI-C was equipped
with semi-dry lime scrubbing system with fabric filter for
controlling air pollutants generated in the incineration
process. Preliminary results indicated that the average removal
efficiency of particulate was about 99.92 %, and the removal
efficiency of heavy metals could reach 98 % or higher (except
for Hg) for MSWI-A. The average removal efficiency of
particulate was about 99.52 %, and the removal efficiency of
heavy metals could reach 95 % or higher (except for Hg) for
MSWI-B. The average removal efficiencies of Hg for MSWI-A and
MSWI-B were 29.56 % and 44.70 %, respectively. Moreover, Zn,
Pb, Cr and Cu were mainly retained in the bottom ash (> 60%) in
all three MSWIs, while Cd was mainly retained in the fly ash and
reactive ash. For MSWI-A, 36.80 % of total Cd were found in fly
ash, and 24.22 % in reactive ash; in MSWI-B, 65.77% retained in
fly ash; while 77.36% retained in reactive ash for MSWI-C. As
far as Hg was concerned, about 75% of total mercury emitted from
stack of MSWI-A and MSWI-C to the atmosphere. In the MSWI-B,
50.39% of total Hg were retained in scrubber solution, and
38.98% of total mercury would emit to the atmosphere. In terms
of mercury speciation by USEPA Method 29 and Ontario Hydro
Method (OHM), oxidized mercury（Hg2+）in the flue gas was
predominant at the inlet of APCD for both incinerators. Less
than 30 % of mercury in the flue gas existed in the elemental
form（Hg0）at APCD inlet. Mercury emitted from stack also
predominated as form of Hg2+ in MSWI-A and MSWI-C. About 90 %
of total mercury emission existed in the form of Hg2+ for MSWI-A
and MSWI-C. Due to the higher removal efficiency of soluble
mercury (Hg2+) in wet scrubber, lower Hg was emitted from MSWI-B
than MSWI-A. However, the APCDs of MSWI-A (DSI+FF) have higher
removal efficiency for Hg0 than that of MSWI-B (ESP+WS).Keywords
：MSW Incinerators, Heavy Metals, Removal Efficiency, APCD, Hg
Speciation.
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