Estimation of Chemical Forms of Heavy Metals in Fly Ash
Project/Area Number |
08650647
|
Research Category |
Grant-in-Aid for Scientific Research (C)
|
Allocation Type | Single-year Grants |
Section | 一般 |
Research Field |
Civil and environmental engineering
|
Research Institution | KYOTO UNIVERSITY |
Principal Investigator |
TAKEDA Nobuo Kyoto University, Graduate school of Engineering, Professor, 工学研究科, 教授 (20026256)
|
Co-Investigator(Kenkyū-buntansha) |
TAKAOKA Masaki Kyoto University, Graduate school of Engineering, Instructor, 工学研究科, 助手 (80252485)
|
Project Period (FY) |
1996 – 1998
|
Project Status |
Completed (Fiscal Year 1998)
|
Budget Amount *help |
¥2,000,000 (Direct Cost: ¥2,000,000)
Fiscal Year 1998: ¥500,000 (Direct Cost: ¥500,000)
Fiscal Year 1997: ¥800,000 (Direct Cost: ¥800,000)
Fiscal Year 1996: ¥700,000 (Direct Cost: ¥700,000)
|
Keywords | XPS / Sequential Extraction Procedure / Heavy Metals / Fly Ash / Chemical Forms / 金属スズ / 塩化第一スズ / 深さ方向分析 / 亜鉛 / 鉛 |
Research Abstract |
It is very important to know chemical forms and concentration of heavy metals in fly ash from municipal solid waste incinerator in order to detoxify and reuse it or clarify complex reaction mechanism such as de novo synthesis for dioxin on it. Chemical forms of heavy metals were estimated using X-ray Photoelectron Spectroscopy (XPS), X-ray diffraction, sequential extraction procedure and thermo-dynamics study. Zinc, copper, lead and cadmium were measured for its toxicity and concentration in fly ash. The application of X-ray diffraction analysis for heavy metals in fly ash was not effective to estimate chemical forms. Chemical forms of heavy metals in many kinds of fly ash were estimated by XPS, because heavy metals concentrated onto its surface and higher intensity was obtained for XPS.Sequential extraction procedure was used for the purpose of grasping the relationship between heavy metals and the composition in fly ash keeping heavy metals. Putting the results by each analysis together, the dominant zinc compounds in fly ash were 2ZnCO_3 3Zn(OH)_2, ZnSO_4 7H_2O and ZnO.Many compounds such as PbCl_2, PbCO_3, PbO, etc., were estimated and it is impossible to determine a dominant form in it. The dominant copper compound was CuO.Chemical form of cadmium in fly ash of dry process flue-gas treatment (Cd(OH)_2, CdO) was different from that of wet process flue-gas treatment (CdSO_4, CdCl_2). Estimation of chemical form of heavy metals in fly ash is possible by XPS and sequential extraction procedure respectively, but it is considered to be able to increase the exactitude of estimation by the combination of both methods.
|
Report
(4 results)
Research Products
(4 results)