Title: Leachability of Trace Metal Elements from Fly Ashes, and from Concrete Incorporating Fly Ashes

Author(s): M. H. Zhang, M. C. Blanchette, and V. M. Malhotra

Publication: Symposium Paper

Volume: 199

Issue:

Appears on pages(s): 1-28

Keywords: concrete; fly ash; leachability; trace metals

DOI: 10.14359/10481

Date: 6/1/2001

Abstract:
Svnopsis:--This paper presents information on the leachability of trace metal elements from a number of fly ashes from Canadian and the U.S. sources, and from the concrete incorporating the fly ashes. The concentrations of all regulated elements Ag, As, B, Ba, Cd, Cr, Cu, Hg, Pb, and Se in the leachates from the nine fly ashes tested were within the limits of the United States Environment Protection Agency and the Transportation of Dangerous Goods Act Regulations of Canada. The leaching of As, B, Ni, and Se from the fly ashes appeared to increase with an increase in their content in the fly ash; however, there were some exceptions. In general, the concentration of As leached from the fly ashes derived from the bituminous coals was much higher than that from the lignite or sub-bituminous coals. Regardless of the type and percentage of the fly ash used, w/cm of the concrete, and curing condition, none of the trace metals in the leachates from the fly ash concrete samples exceeded the regulated concentration limits by the United States Environment Protection Agency and the Transportation of Dangerous Goods Act regulations of Canada. The concrete incorporating the fly ashes is, therefore, considered environmentally stable.