The effect of acid rain to heavy metal leaching from municipal solid waste landfill was investigated by indoor column experiments. In the experiments, synthetic acid rain (pH2.0-pH5.8) equivalent to the 16 year precipitation was flowed through the columns of bottom ash or fly ash. Main conclusions were as follows. (1) Even by the synthetic acid rain (pH4.0, which was almost same as that of real acid rain at the present time), the accumulative leached amounts of heavy metals (Pb, Zn, Fe) and Ca with bottom ash were respectively increased by 11-50% and 85% with respect to those with tap water (pH 5.8), and the accumulative leached amounts of heavy metals (Pb, Cd, Zn, Fe) with fly ash were increased by 15-90%. (2) The comparison of the results of bottom ash and fly ash indicated that the leached ratios of Pb, Zn and Fe from fly ash were greater than those from bottom ash, and that the accumulative leached amounts of Pb and Zn with fly ash were more than that with bottom ash, and that the accumulative leached amount of Fe with bottom ash was more than that with fly ash, which were not depending on pH.
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