HR: 1340h
AN: V43D-1446    [Abstracts]
TI: Surface-Specific Nucleation and Deposition (?) of Heavy and Precious Metals on Minerals and Fibers Exposed to Fumarole Gas - FESEM/EDS Studies
AU: * Obenholzner, J H
EM: obenholzner@a1.net
AF: Naturhistorisches Museum/Mineralogy, Postfach 417, Vienna, A-1014 Austria
AU: Poelt, P
EM: peter.poelt@felmi-zfe.at
AF: Zentrum fuer Elektronenmikroskopie/TU Graz, Steyrerg. 17, Graz, A-8010 Austria
AU: Reichmann, A
EM: angelika.reichmann@felmi-zfe.at
AF: Zentrum fuer Elektronenmikroskopie/TU Graz, Steyrerg. 17, Graz, A-8010 Austria
AB: Mineral grains, glass fibers and diatoms had been exposed to the F0 fumarole at Vulcano (Italy) between 2001 and 2004. On quartz grains patches of Pb-(Tl)-Cl (max.l=50 æm), Tl-(Fe)-(Br)-Cl, Al-S-Cl-(O), Al-Cl-(F)-(S)-(Mg)-(K)-(Ca)-(Fe) and needle-like Ca sulphate (+Cl-F) are growing. Pb-S nucleated on K feldspar, Ba-S-O and As-S on the surface of diatoms. Desert dust interacting with volcanic gases might transport heavy metals to environments far away from volcanoes. Si-rich glass fibers are the substratum for Tl-Cl, Hg-, As-, Tl- and Pb-bearing and Al-(S)-(O) crystals. Au-Ag alloys (l= ca. 3 æm) are detected on Si-rich fibers. These anhedral grains are embedded in an Al-O-(S)-(Ca) matrix. Available data do not indicate if deposition or nucleation are the responsible processes. Ba-S-O particles nucleated on borosilicate glass fibers. Rock wool of basaltic composition (Na-Mg-Al-Si-K-Ca-Ti-Fe-O) collected only S and shows surface modification. These preliminary results indicate that Si-rich surfaces might be useful in i.e. air conditioning systems to detoxicate volcanically polluted air. Quartz sand deployed on top of lava flows might reduce the release of heavy metals to the environment. According to the experiments utilizing glass fibers of different composition the eruptions of basaltic magma should release more heavy metals to the atmosphere relatively compared to the eruptions of rhyolitic magma.
DE: 8409 Atmospheric effects (0370)
DE: 8499 General or miscellaneous
DE: 0305 Aerosols and particles (0345, 4801)
DE: 0345 Pollution--urban and regional (0305)
DE: 0370 Volcanic effects (8409)
SC: Volcanology, Geochemistry, Petrology [V]
MN: 2004 AGU Fall Meeting