Spectroscopic study of volcanic ashes

JOURNAL OF HAZARDOUS MATERIALS

卷:400

Article

Bardelli, Fabrizio¹  Giuli, Gabriele²  Di Benedetto, Francesco³  Costagliola, Pilar³  Montegrossi, Giordano⁴  Rimondi, Valentina³  Romanelli, Maurizio³  Pardi, Luca A.⁵  Barone, Germana⁶  Mazzoleni, Paolo⁶ 

[1] Sapienza Univ, Dept Phys, CNR Nanotec, Piazzale Aldo Moro 5, I-00185 Rome, Italy

[2] Univ Camerino, Sch Sci & Technol, Geol Div, Via Gentile III da Varano, I-62032 Camerino, Italy

[3] Univ Firenze, Dept Earth Sci, Via G La Pira 4, I-50121 Florence, Italy

[4] CNR, Inst Geosci & Georesources, Via G Moruzzi 1, I-56124 Pisa, Italy

[5] CNR, Inst Chem Phys Proc, Via G Moruzzi 1, I-56124 Pisa, Italy

[6] Univ Catania, Dept Geol Biol & Environm Sci, Corso Italia 55, I-95129 Catania, Italy

关键词: Volcanic ash;    Explosive eruption;    Granulometry;    Iron speciation;    XAS;    EPR;   

DOI  :  10.1016/j.jhazmat.2020.123213

来源: Elsevier

【 摘 要 】

Volcanic ashes particles are subjected to substantial modification during explosive eruptions. The mineralogical and compositional changes have important consequences on the environment and human health. Nevertheless, the relationship between the speciation of iron (Fe) and the mineralogical composition and particle granulometry of the ashes, along with their interaction with water, are largely unknown. In particular, the Fe oxidation state and the possible formation of new Fe-bearing phases in presence of S, Cl, and F in the plume are key points to assess the impact of the ashes. Fragmental material ejected during volcanic activity (tephra) in 2013, was collected on the Mt. Etna (Italy) and investigated using a multi-technique approach that included conventional Electron Paramagnetic Resonance (EPR), high field EPR (HFEPR), EchoEPR, and Fe K-edge X-ray Absorption Spectroscopy (XAS). These element selective techniques allowed obtaining a detailed information on the oxidation state and coordination environment of Fe, and of its speciation in the ash samples as a function of the granulometry. A complex mineralogical assemblage, consisting of variable amounts of nanometric crystalline Fe inclusions in a glass matrix, and of Fe-oxides and Fe-sulfur phases was revealed. A risk assessment of the ashes is attempted.

【 授权许可】

Free