Origin and speciation of major and trace PM elements in the Barcelona subway system
| Autor: | Vania Martins, Eladio de Miguel, Teresa Moreno, Marta Capdevila, Daniel Sánchez Rodas, Xavier Querol, Oriol Font |
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| Přispěvatelé: | Ministerio de Economía y Competitividad (España), Moreno, Teresa [0000-0003-3235-1027], Querol, Xavier [0000-0002-6549-9899], Moreno, Teresa, Querol, Xavier |
| Jazyk: | angličtina |
| Rok vydání: | 2019 |
| Předmět: |
Subway
Materials science PM 020209 energy Oxide Transportation 02 engineering and technology engineering.material Abrasion (geology) Brake pad Metal chemistry.chemical_compound Wear 0502 economics and business 0202 electrical engineering electronic engineering information engineering 23 Química General Environmental Science Civil and Structural Engineering 050210 logistics & transportation Trace elements 05 social sciences Metallurgy Particulates chemistry Molybdenite visual_art engineering visual_art.visual_art_medium Pyrite Stibnite Brake pads |
| Zdroj: | Arias Montano. Repositorio Institucional de la Universidad de Huelva instname Digital.CSIC. Repositorio Institucional del CSIC |
| Popis: | Wear in train and rail components in the Barcelona subway system includes brake pads, catenary wires, wheels, railways, and motor brushes. These components were characterised to evaluate their contribution to ambient particulate matter (PM) levels in two platforms (conventional F-L3 and new S-L9). The observed chemical compositions of these components were used to interpret the mineralogical, chemical, and leachability patterns of subway platform particulate matter (PM). The use of sulphides such as molybdenite (MoS 2 ), pyrite (FeS 2 ), stibnite Sb 2 S 3 ) rich in toxic elements such as in Cu, Ni, As, Hg, Cd, and Pb and abrasives such barite (BaSO 4 ) and zinzite (ZnO) in the brake pad composition, the composition of the catenary rich in Cu (98% metallic-Cu) with traces of Hg and that of the wheel/rail (98% metallic-Fe) with traces of As results in the production of fine PM particles of As, Hg, Cu, and Sb in ambient air PM in platform as a consequence of the abrasion/friction and sparking processes. The temperature reached in the aforementioned processes give rise to fine condensed and water-soluble As species (most likely As 2 O 3 and As 2 O 5 ). Moreover, the stibnite (Sb 2 S 3 ) Hg-rich lateral brake pads used in L9 also contribute to fine and relatively soluble Sb and Hg oxides. Sulphide-rich brake pads significantly increase and change the occurrence mode of the Zn, Cu, Mn, Cr, Pb, and Ni present in PM by oxidation of brake-bearing metal sulphide to relatively water-soluble sulphate and oxide species. These changes in the mode of occurrence and speciation of elements in the PM of subway platforms points to the need for in-depth PM speciation studies, as well as the need for substituting conventional friction materials with low-metal materials—such as graphite pantographs/catenaries and rubber wheels and low toxic sulphides in brake pads—to reduce exposure to metals during subway commuting. © 2019 This work was supported by the Spanish Ministry of Economy and Competitiveness, and FEDER funds within the I + D Project CGL2012-33066 (SUBWAY) and the IMPROVE LIFE project (LIFE13 ENV/ES/ 000263). Support is also acknowledged to Generalitat de Catalunya 2014 SGR33. |
| Databáze: | OpenAIRE |
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