Professor of civil engineering, West Virginia University, Morgantown, W. Va.
Midwest Research Institute, Kansas City, Mo.
NUS Corporation, Pittsburgh, Pa.
University of Nebraska, Omaha, Nebr.
Louisiana State University, Baton Rouge, La.
American Electric Power Service Corporation, Canton, Ohio
Pages: 22 Published: Jan 1981
The leachability of two fly ashes was evaluated using two different proposed procedures environmental Protection Agency-Extraction Procedure (EPA-EP) and American Society for Testing and Materials method (ASTM). The EP test was also run to study the influence of contact time and the presence of dissolved oxygen. Finally, a modified EP was carried out with repeated extraction of the same ash with fresh leachate and repeated contact of the same leachate with fresh ash. Both acid and deionized water extractions were used.
The EP test was found to extract more material than the ASTM procedure on a milligrams per kilogram of ash basis, although the ASTM test gave higher concentrations. For the contact times studies (2 to 48 h), no one elution time could be chosen which would allow equilibrium for all parameters. Although certain elements evidenced sensitivity to the presence or absence of oxygen, no general pattern was found. Release during repeated extraction of the same ash with fresh leachate was found to be highly pH dependent. Most of the mobilization tended to occur in the first two extractions for the acid test, while release occurred more gradually for 5 to 7 elutions using deionized water.
leachate, fly ash, extraction, leaching tests, landfills, hazardous solid waste
Paper ID: STP28829S