| Contents Notes |
"An ESCA/leachate analytical scheme was evaluated for its ability to characterize solid waste from combustion processes and hazardous waste incinerators. Samples were analyzed for surface elemental composition by electron spectroscopy for chemical analysis (ESCA) before and after aqueous leaching. Selected elements were subjected to oxidation state studies by ESCA, and leachates were analyzed for anions by ion chromatography and for trace metals by inductively coupled plasma spectrometry. The results of ESCA before and after leaching compared favorably with leachate data. Although aqueous leaching did not significantly affect the metal species present in the samples used in this study, it did extract considerable amounts of water-soluble ions: sodium, calcium, chloride, sulfate. Essentially all samples showed an increase in oxygen after leaching that was attributed to hydration by the aqueous extraction medium. ESCA can successfully speciate chromium, lead, and zinc when these elements are sufficiently abundant in the sample. The technique is limited, however, by its ability to detect only those elements present at greater than 0.1 to 1.0 percent atomic. Most process wastes contain very low concentrations of metals, thereby minimizing the suitability of ESCA for process waste characterization. However, municipal and hazardous waste incinerators produce bottom and baghouse ashes containing significant amounts of hazardous trace metals. ESCA in conjunction with process data could prove useful in determining metal species present and their potential for release from particulate." |
