ECOTOXICOLOGICAL ASSESSMENT OF ASHES AND PARTICULATE MATTER FROM FLUIDIZED-BED COMBUSTION OF COAL

Toxicity of ash and particulate matter from the gases generated in coa l fluidized bed combustion (FBC) has been determined by the Microtox a ssay according to the standard leachate procedure. Results are compare d with the polycylic aromatic hydrocarbon (PAH) content of the particu late matter, which was determined by fluorescence spectroscopy. Althou gh PAHs are considered highly toxic compounds, the low ecotoxicity val ues obtained could be explained by the low solubility of the compounds in water. The Microtox assay may underestimate the toxicity of water- insoluble compounds unless they are previously extracted with an organ ic solvent. Nevertheless, this type of assay can be very useful for me asuring the potential toxicity of residues when exposed to water sourc es such as rain water and the risk of the components being dissolved a nd transported by runoff water. (C) 1998 Academic Press