1998 Fiscal Year Final Research Report Summary
Insolubility of Hazardous Heavy Metals in Wet Fly Ashes of MSW
| Project/Area Number |
09650612
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Civil and environmental engineering
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| Research Institution | Fukuoka University |
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Principal Investigator |
SHIMAOKA Takayuki Fukuoka University, Faculty of Engineering, Associate Professor, 工学部, 助教授 (80202109)
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| Co-Investigator(Kenkyū-buntansha) |
MIYAWAKI Kentaro Fukuoka University, Faculty of Engineering, Assistant, 工学部, 助手 (00289521)
SOEDA Masashi Fukuoka University, Faculty of Engineering, Assistant, 工学部, 助手 (50148871)
HANASHIMA Masataka Fukuoka University, Faculty of Engineering, Professor, 工学部, 教授 (70078624)
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| Project Period (FY) |
1997 – 1998
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| Keywords | Fly ash / Heavy metal / Insolubility / Aging / Passing of carbon dioxide / Elution test / Dependency of pH |
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| Research Abstract |
In this research, moisturized fly ashes have been placed and left at loal tcmpeatures, and as the elution test results show, it was found that hazardous heavy metals such as Pb and Cd had become insoluble in a process we have called" Fly ashes self-stabilization". The experiments conducted with 48 diferent samples from all over Japan indicate that this stabilization dose not depend on the type of incineration plant or method of exhaust gas treatment. Under this stabilization process, as the heavy metals became insoluble, pH and alkalinity of the fly ashes solution also decreased After 30 days, from the results of the pH depended test, it was clear that the amount of released heavy metals in the wet samples was lower than the original dy samples. Therefore, we concluded that the heavy metals hal been trapped into chemical stable compounds. Also the higher the concentration of CO_2 in the air ( within a range 0*CO_2*30%), the faster the heavy metals became insoluble. As a conclusion, the expenment results suggest that the heavy metals were trapped in the carbonates formed by the reaction between CO_2 and other chemical compounds.
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