Iron isotopic fractionation in industrial emissions and urban aerosols.
A study on tropospheric aerosols involving Fe particles with an industrial origin is tackled here. Aerosols were collected at the largest exhausts of a major European steel metallurgy plant and around its near urban environment. A combination of bulk and individual particle analysis performed by SEM-EDX provides the chemical composition of Fe-bearing aerosols emitted within the factory process (hematite, magnetite and agglomerates of these oxides with sylvite (KCl), calcite (CaCO(3)) and graphite carbon). Fe isotopic compositions of those emissions fall within the range (0.08 per thousand<delta(56)Fe<+0.80 per thousand) of enriched ores processed by the manufacturer (-0.16 per thousand<delta(56)Fe<+1.19 per thousand). No significant evolution of Fe fractionation during steelworks processes is observed. At the industrial source, Fe is mainly present as oxide particles, to some extent in 3-4mum aggregates. In the close urban area, 5km away from the steel plant, individual particle analysis of collected aerosols presents, in addition to the industrial particle type, aluminosilicates and related natural particles (gypsum, quartz, calcite and reacted sea salt). The Fe isotopic composition (delta(56)Fe=0.14+/-0.11 per thousand) measured in the close urban environment of the steel metallurgy plant appears coherent with an external mixing of industrial and continental Fe-containing tropospheric aerosols, as evidenced by individual particle chemical analysis. Our isotopic data provide a first estimation of an anthropogenic source term as part of the study of photochemically promoted dissolution processes and related Fe fractionations in tropospheric aerosols.
UMR CNRS 8101 LPCA, Université du Littoral-Côte d'Opale, Dunkerque, France. pascal.flament@univ-littoral.fr
Pascal
P
Flament
Nadine
N
Mattielli
Laure
L
Aimoz
Marie
M
Choël
Karine
K
Deboudt
Jeroen
J
de Jong
Juliette
J
Rimetz-Planchon
Dominique
D
Weis
D005591:Chemical Fractionation / Q000379:methods*; D002947:Cities; D005602:France; D007220:Industrial Waste; D007503:Iron Isotopes / Q000032:analysis / Q000302:isolation & purification*; D052638:Particulate Matter / Q000737:chemistry*; D013232:Steel / Q000737:chemistry; D014867:Water / Q000737:chemistry
D007220:Industrial Waste; D007503:Iron Isotopes; D052638:Particulate Matter; D014867:Water; D013232:Steel