【Paper】
Experimental Studies on Leaching and Separation of Incineration Ash in Sea Area Landfill Site
Daisaburo Koga*, Takayuki Shimaoka*, Kentaro Miyawaki*, Yasukazu Toda** and Masataka Hanashima***
* Institute of Environmental Systems, Graduate School of Engineering, Kyushu University
** Penta-Ocean Construction Co, Ltd.
*** Fukuoka Research Center for Recycling Systems
† Correspondence should be addressed to Daisaburo Koga:
Institute of Environmental Systems, Graduate School of Engineering, Kyushu University
（6-10-1 Hakozaki, Higashi-ku, Fukuoka, 812-8581 Japan）


Abstract
We tried to develop a new reclamation method at a sea area landfill site. This method decreases the risk of environmental pollution from landfilled solid waste before reclamation. A safe landfill is thereby created. This method has two processes: leaching and separation. The first process is slurry transportation: soluble heavy metals in the solid waste are removed by dissolving them in seawater. The second process is separation: incineration ash is separated to reduce environmental risk.
This experiment used a machine to agitate the ash in seawater to simulate agitation by slurry transportation. As a result, the process of separating fine particles on the incineration ash surface was completed in about 5 minutes. Furthermore, increasing the L/S ratio in the slurry transportation accelerated the leaching of Cr（�Y）from the incineration ash. In addition, the upper portion of incineration ash that remained in a 2mm sieve after agitation showed heavy metal concentration in the leachate that was below the quantitative limit value. These results demonstrate that separation should be made by a 2mm sieve to develop landfills with low environmental pollution risk.


Key words: sea area landfill site, incineration ash, slurry transportation, leaching and separation, environmental pollution risk