Content of Heal Metals in Incinerated Municipal Solid Waste at Kaohsiung City, Taiwan

Abstract

Two samplings of municipal solid waste (MSW) were conducted at four MSW incineration plants at Kaohsiung City. Samplings were conducted in April and July of 2013 at different seasons. Physical composition was analyzed to find out the content of heavy metals in combustible and incombustible MSW. In 2013, the weight percentage for combustible MSW in Kaohsiung area was at 95.59%. It means that combustible MSW in Kaohsiung area is above 90%. Incombustible metals and non-metals have less content in terms of percentage. The possible reason might be valuable metals have been recycled. In 2013, the average content of heavy metals in Kaohsiung area from high to low came in this order: Pb>Zn>Cu>Cr>Cd. The average content of Pb was 155.10 mg/kg. Cd was at minimal level with average content lower than 1.00 mg/kg. The average content of Pb was 147.84 mg/kg. Cd was at minimal level in Kaohsiung area with average content lower than 1.00 mg/kg. MSW amount in Kaohsiung area for the first sampling in April 2013 and the second sampling in July 2013 were respectively at 35491 and 36062 tons. According to this research, the content of heavy metals in MSW was respectively 146.88 and 411.56 mg/kg. The content of heavy metals were calculated at 5.21 and 15.92 tons, which equal to 0.01% and 0.04% of the total amounts of MSW. After incinerating, they contain byproducts of heavy metals such as ashes, smoke emission, and dust.