| Summary: | 碩士 === 淡江大學 === 水資源及環境工程學系 === 92 === Recently, the municipal solid waste incinerator (MSWI) bottom ash was to be as useful materials after resource-technology in many developed countries. The treated ash could reduce the amount of landfill sites and increase the great value of reuse. These were very important for Taiwan, because the new landfill sites were also hard to find and the aggregate was very inadequate for construct.
This study investigated the feasibility of reuse for MSWI bottom ash. The ash of the particle size larger than 0.074 mm was washed with water to discuss the rate of removing of chloride then, stabilizing with phosphoric acid to realize the stabilization of heavy metals. The treatment processes of smaller than 0.074mm of ash was water washing, phosphoric acid stabilization, components regularization, and sintering.
The former, it was found that after water washed (L/S=2) twice and treated with 0.6 M phosphoric acid solution (L/S=0.4), the quantity of dissolve chloride was lower than 0.034% and the concentration of Pb and Cu were significantly reduced by Toxicity characteristic leaching procedure (TCLP) test. The latter had passed through the water washed twice, 0.25 M phosphoric acid solution (L/S=0.8) stabilization, mixed with 40 % coal-fired power station Flue Gas Desulfurization (FGD) sludge, and sintering at 1100 ℃, the compressive strength of sintered ash could reach 475 kgf/cm2 and this concentration of phosphoric acid solution could reduce the heavy metal evaporation during the sintering process. The sintered ash could achieve requirement for aggregate of construct.
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