Leaching behaviour of elements and evaluation of pre-treatment methods for municipal solid waste incinerator residues in column leaching tests.
Two new pre-treatment methods (water-washing/carbonation and carbonation/phosphate stabilization) of municipal solid waste (MSW) incinerator residues were evaluated by column leaching tests under aerobic conditions and anaerobic conditions (which were changed to aerobic conditions after 10 months). A mixture of bottom ash and fly ash (5:1 ratio) was pre-treated using each method. Shredded incombustible residues (SIR) were added to each ash preparation in proportions similar to the ratios present in landfills. For comparison, landfill wastes typical of Japan, namely, a mixture of bottom ash, chelating-pre-treated fly ash, and SIR, were also examined. Leachate samples were collected periodically and analysed over a 15-month period. When compared with chelating pretreatment, both water-washing/carbonation and carbonation/ phosphate stabilization reduced the leaching of Pb, Al, and Cu by about one to two orders of magnitude. Moreover, the initial concentrations of Ca and Pb in leachates from column of water-washing/carbonation were 56-57% and 84-96% less than those from the column of carbonation/phosphate stabilization. Therefore, water-washing/carbonation was considered to be a promising approach to obtain early waste stabilization and to reduce the release of heavy metals to near-negligible levels. The leaching behaviour of elements was also discussed.
Department of Environmental and Resource Engineering, Hokkaido University, Sapporo, Hokkaido, Japan. sykim@eng.hokudai.ac.jp
Sang-Yul
SY
Kim
Nobutoshi
N
Tanaka
Toshihiko
T
Matsuto
Yasumasa
Y
Tojo
D000534:Alum Compounds / Q000737:chemistry; D002244:Carbon / Q000737:chemistry*; D002245:Carbon Dioxide / Q000737:chemistry*; D002614:Chelating Agents / Q000737:chemistry; D060729:Coal Ash; D005427:Flocculation; D017745:Incineration; D007564:Japan; D008670:Metals / Q000032:analysis*; D008962:Models, Theoretical; D010100:Oxygen / Q000032:analysis; D052638:Particulate Matter; D010710:Phosphates; D010756:Phosphoric Acids / Q000737:chemistry; D012037:Refuse Disposal / Q000379:methods*; D014866:Waste Products / Q000145:classification; D014867:Water; D014872:Water Movements; D014874:Water Pollutants, Chemical / Q000032:analysis*
D000534:Alum Compounds; D002614:Chelating Agents; D060729:Coal Ash; D008670:Metals; D052638:Particulate Matter; D010710:Phosphates; D010756:Phosphoric Acids; D014866:Waste Products; D014874:Water Pollutants, Chemical; D014867:Water; D002245:Carbon Dioxide; C041524:aluminum sulfate; D002244:Carbon; C030242:phosphoric acid; D010100:Oxygen