COMPARISON OF MICROELEMENTAL COMPOSITION OF OIL-SHALE ASHES EMISSIONSINTO THE ATMOSPHERE OF ESTONIA

Fly-ash from local power plants utilizing oil shale and dust outburst from cement kilns of Kunda factory am the main anthropogenic particula tes emissions into Estonian atmosphere. By means of instrumental neutr on activation analysis (INAA) more than 30 microelements have been qua ntitatively determined in waste products of Estonia [1-3] and in natur al ashes of Kamtchatka volcanoes (Russia) [5]. In this paper a quantit ative comparison of microelemental composition of anthropogenic pollut ants from the plants mentioned above and of volcaneous ashes with the composition of the American standard - coal fly-ash NRS-1633 [4] - is given. The respective enrichment factors K have been calculated and pr esented in Tables 1-5. Fly-ashes of oil shale are poorer in all elemen ts except Br, Rb, and Cs as compared to this standard. They contain 2- 5 times less toxic (Se, Sb), radioactive (Th, U), and rare elements. T he comparison of the cement kiln dust with the standard gave almost th e same results. The comparison of two local pollutants indicated that the kiln dust is enriched by Rb, Cs, Eu, Yb, Th, Lu, Ag, and Au. As th ere are no natural throw-out sources in Estonia, we cannot compare nat ural and anthropogenic throw-outs. Nevertheless, we have compared the composition of two samples of volcaneous ashes from Kamchatka with the American standard and with oil-shale fly-ash, too. The respective res ults are given in Table 5. Volcaneous ashes are poor in all elements.