Characteristics of ashes from different locations at the MSW incinerator equipped with various air pollution control devices.
The characteristics of ashes from different locations at a municipal solid waste incinerator (MSWI) equipped with a water spray tower (WST) as a cooling system, and a spray dryer adsorber (SDA), a bag filter (BF) and a selective catalytic reactor (SCR) as air pollution control devices (APCD) was investigated to provide the basic data for further treatment of ashes. A commercial MSWI with a capacity of 100 tons per day was selected. Ash was sampled from different locations during the normal operation of the MSWI and was analyzed to obtain chemical composition, basicity, metal contents and leaching behavior of heavy metals. Basicity and pH of ash showed a broad range between 0.08-9.07 and 3.5-12.3, respectively. Some major inorganics in ash were identified and could affect the basicity. This could be one of the factors to determine further treatment means. Partitioning of hazardous heavy metals such as Pb, Cu, Cr, Hg and Cd was investigated. Large portions of Hg and Cd were emitted from the furnace while over 90% of Pb, Cu and Cr remained in bottom ash. However 54% of Hg was captured by WST and 41% by SDA/BF and 3.6% was emitted through the stack, while 81.5% of Cd was captured by SDA/BF. From the analysis data of various metal contents in ash and leach analysis, such capturing of metal was confirmed and some heavy metals found to be easily released from ash. Based on the overall characteristics of ash in different locations at the MSWI during the investigation, some considerations and suggestions for determining the appropriate treatment methods of ash were made as conclusions.
Song
Geum-Ju
GJ
Department of Environmental Engineering, Yonsei University, Yonsei Institute of Environmental Science & Technology, 220-710, Wonju, South Korea.
Kim
Ki-Heon
KH
Seo
Yong-Chil
YC
Kim
Sam-Cwan
SC
D000397:Air Pollution / Q000517:prevention & control*; D002244:Carbon / Q000737:chemistry*; D060729:Coal Ash; D004784:Environmental Monitoring; D004785:Environmental Pollutants / Q000032:analysis*; D004867:Equipment Design; D017745:Incineration; D019216:Metals, Heavy / Q000032:analysis*; D052638:Particulate Matter; D012037:Refuse Disposal / Q000379:methods*
D060729:Coal Ash; D004785:Environmental Pollutants; D019216:Metals, Heavy; D052638:Particulate Matter; D002244:Carbon