Leaching tests to evaluate pollution potential of combustion residues from an iron recycling industry

Three leaching tests were applied to an industrial fly ash (cupola dust) for the evaluation of its groundwater pollution potential. The tests comprised two batch shaking tests (the SLT-test and a titration test) and a column leaching test (laboratory scale). All three tests gave valuable and consistent results with respect to the leaching of lead, zinc, cadmium and organic matter. The pH of the leaching environment was the most important factor in governing the leaching process. The results of the leaching seemed to be in accordance with observations of the groundwater quality below an actual industrial fly ash disposal site. The combination of the SLT-test and the titration test appears to be a cost-effective means of evaluating the groundwater pollution potential from industrial fly ashes.