A methodology to predict long-term leaching potential of metals from Class F fly ash based on short-term laboratory tests

Coal fly ash is produced from the combustion of pulverized coal in electric power generation industries. In spite of its many desirable geotechnical characteristics, it contains a large number of heavy metals. These metal ions get released readily in aqueous environment, causing future threat to environment. This research was concerned with the development of a methodology for predicting long-term leaching behavior of metals from fly ash using short-term laboratory tests data.

The objectives of this study were achieved by an experimental phase and a modeling phase. The experimental phase consisted of a series of laboratory column tests on fly ash samples, collected from Hoechst Celanese plant at Pampa, using a number of controlled test conditions. The volume of leachate, equal to volume of leachate produced in landfills over 100 years, generated in the laboratory tests was analyzed for metal concentrations. A MSW model by Belvi and Baccini (1988), out of a number of models, used to simulate the laboratory test data. The same model was used for long-term prediction of metal concentrations in" the leachate.