Evaluation of environmental safety on municipal solid waste incineration bottom ash using aging method

Abstract

Since Japan does not have enough space for landfilling, the use of incineration bottom ash (IBA) from municipal solid waste (MSW) as a construction material is being explored. However IBA contains significant toxic materials, and it has to be immobilized before it can be used as a ground geo-material. This study examines aging methods to immobilize IBA by natural rain and carbon dioxide in the air at landfill sites. This paper reports the leaching properties of IBA from MSW in order to evaluate the environmental safety by means of Japanese leaching test No. 46 (Notifications No. 46 by Japanese Ministry of the Environment (JLT 46)), up-flow percolation column test, and pH-dependent test. The leaching concentrations of heavy metals from IBA were found to be influenced by the aging process. It was revealed that the concentration of lead (Pb), hexavalent chromium (Cr (VI)), cadmium (Cd) and boron (B) meet the environmental quality standard values for ground material. Also it was revealed that the possibility of leaching in the long term is low.