| Summary: | 碩士 === 國立臺灣大學 === 環境工程學研究所 === 92 === This study mainly examines the environmental effect of bottom ash from MSW incinerator by means of some different leaching tests along with simulated acid rain. The objectives also try to estimate the leaching potential of heavy metal in environment during a long period and to establish the fundamental data for risk assessment of the utilization of bottom ash; furthermore, to find a suitable stabilizer in order to promote the reuse of bottom ash. A mass transfer mathematical model is presented to predict quantity and quality of leachate from short-term column leaching test.
Samples used here contain high amounts of Cu, which range from 5300 to 6600 mg per kg bottom ash. As time goes by, the amount of Cu leaches are twice more than that of any other metals in column test, and may reach up to a ratio 15% of its total mass. According to the stabilization test, Na2S reacts best in processing, which may reduce a large quantity of leachate by about 85－97%. Results of sequential extraction procedures show that 1% Cu is exchangeable, fraction bounded to carbonate accounts for 10%, fraction bounded to Fe-Mn oxides accounts for 34－44%, fraction bounded to organic matters/sulfide accounts for 10－20%, and the remaining 30% is residual.
Good agreement was obtained by comparing model simulation with data of laboratory column leaching tests. This model can provide us an insight into factors that influence the physicochemical reaction and transport of leachate from bottom ash.
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