Environmental Impact Evaluation of Heavy Metals Contained in the Fly and Bottom Ash
Kentaro Aoi*, Yoshiro Ono**, Kenji Namiki*** and Aya Yamada**Abstract
Characteristics of leaching of heavy metals from fly and bottom ash were investigated experimentally. Leaching activity was found to depend on pH, L/S ratio and ion concentration in the leaching solution. Low pH increased the elution of lead and cadmium. In order to evaluate the short- and long-term elution of landfill sites, various leaching tests are required. These include the serial batch test and/or the availability test for pH and L/S ratio. The impact analysis of heavy metals on the environment was tested using a the method which combines the results from several leaching tests and hazardous scoring techniques. As a result, it is obvious that short-term landfill cadmium and long-term lead have a more hazardous impact.
Key words: fly and bottom ash, leaching test, heavy metals, hazardousness scoring system