Change search
ReferencesLink to record
Permanent link

Direct link
Transformation /dissolution studies on the release of iron and chromium from particles of alloys compared with their pure metals and selected metal oxides
KTH, School of Chemical Science and Engineering (CHE), Chemistry, Surface and Corrosion Science.ORCID iD: 0000-0003-2145-3650
KTH, School of Chemical Science and Engineering (CHE), Chemistry, Surface and Corrosion Science.ORCID iD: 0000-0003-2206-0082
2012 (English)In: Materials and Corrosion, ISSN 0947-5117, Vol. 63, no 6, 481-491 p.Article in journal (Refereed) Published
Abstract [en]

Transformation/dissolution (T/D) data for different Cr- and Fe-based alloys (a FeCr alloy, stainless steel AISI 316L, an alloy side product (SP) from stainless steel production) compared with their pure metals (Cr, Fe) and selected metal oxides (Cr2O3, Fe3O4) was generated and is used throughout the entire REACH assessment documentation of chromium metal and ferrochromium alloys to derive conclusions regarding their acute and chronic ecotoxicity hazard classification. Short and long term tests were conducted to assess data for acute and chronic aquatic toxicity following the recognized standardized T/D protocol. Tests were performed in media of different pH (pH 6.0 and pH 8.0), time periods, and solution composition, also investigating the effect of different experimental parameters. Generated data elucidates the complexity of the metal release process and its dependence on many interacting material-, surface-, and experimental factors as well as on the chemistry of the metalwater system being metal species specific. It is evident that the extent of metal release cannot be predicted by either the bulk or the surface composition, and that metal speciation measurements of released metals are essential to assess aquatic toxicity induced by metal/alloy particles. Observed released Fe and Cr concentrations were significantly lower than reported acute and chronic ecotoxicological endpoints.

Place, publisher, year, edition, pages
Wiley-VCH Verlag , 2012. Vol. 63, no 6, 481-491 p.
Keyword [en]
ferrochromium alloy; hazard assessment; metal particles; metal release; transformation; dissolution
National Category
Other Chemistry Topics
URN: urn:nbn:se:kth:diva-24696DOI: 10.1002/maco.201005943ISI: 000305392600004ScopusID: 2-s2.0-79954425453OAI: diva2:352864

QC 20120718

Available from: 2010-09-23 Created: 2010-09-23 Last updated: 2016-04-26Bibliographically approved
In thesis
1. Environmental and health aspects of corrosion– importance of chemical speciation
Open this publication in new window or tab >>Environmental and health aspects of corrosion– importance of chemical speciation
2010 (English)Licentiate thesis, comprehensive summary (Other academic)
Abstract [en]

During the last decades, the interest in corrosion of metals and alloys from an environmental and health perspective has increased rapidly as a consequence of stricter environmental and human exposure legislations, their extensive use as implant materials and an increasing understanding related to occupational and/or daily exposure to airborne particles. Corrosion-induced metal release, however, needs to be understood in detail and to include knowledge related to chemical speciation, i.e. the oxidation state, complexation and chemical form of released metals, parameters of high importance when considering toxicity.

In this licentiate work, corrosion-induced metal runoff from roofing materials (copper, zinc, and chromium(III)-, and chromium(VI) surface treated galvanized steel) has been investigated from an environmental perspective with focus on chemical speciation of released metals (Papers I-II). From these papers it was evident that the total concentration measured in the runoff water is not sufficient for any environmental risk assessment. The environmental fate including changes in chemical speciation and hence metal precipitation has to be considered. For example, it was shown that the copper concentration decreased by three orders of magnitude already in the internal drainage system of a shopping centre with a copper roof, to a concentration lower than storm water collected from a nearby parking space (Paper I). Also, speciation measurements can explain corrosion, metal release and surface processes of chromium surface treated galvanized steel at different sites (urban and marine). Any environmental risk assessment has to be done by considering all metal species released, and compared with ecotoxic values. For example, when most chromium(VI) (the most toxic species) was released, significantly less zinc was released at the same time which decreased the overall ecotoxicity of the runoff water significantly (Paper II).

When assessing environmental risks by standard laboratory tests, it is important to understand all mechanisms which are possibly influenced by individual experimental parameters and which often are different for different test substances. Some metals released, as seen in the case of iron, may precipitate with time and be pH-, solution- and buffering dependent. This behavior can lead to strongly underestimated measured metal concentrations (Paper III).

When particles of metals or alloys are to be investigated (Papers III-VI), it is essential to conduct a thorough particle characterization, since the surface properties cannot be defined. In addition, the surface properties (oxide layer properties) change with varying particle size (Paper VI) and with other experimental parameters such as dispersion (Paper VI).

All iron-, and chromium-based particles investigated (Papers III-VI) revealed large differences between alloy particles and pure metals. Particles of pure iron and nickel released significantly more metals compared with particles of the investigated alloys, whereas particles of pure chromium released less metals compared with the alloys. Particles of stainless steel (AISI 316L), ferro-chromium and ferro-silicon-chromium released very low amounts of metals (Papers III-VI). The released quantity increased with increased acidity (Papers III-VI) and also in the presence of complexing agents (ongoing research). The manufacturing process is of high importance, as observed for stainless steel particles when compared with a side product from stainless steel production with similar composition that released significantly more metals (Paper III). Particles of metal oxides, i.e. chromium(III)oxide and iron(II,III)oxide, released very low amounts of metals due to their thermodynamic stability.

Ongoing research activities focus on the specific influence of complexing agents and proteins on the metal release process from massive sheet and particles of metals and alloys. The applicability and the possibility to use different analytical tools are investigated and elaborated for small-sized particles. A detailed understanding of the correlation between material and particle characteristics, the metal release process, the chemical speciation in interaction with proteins and/or cells, and the particle/cell interaction is essential to enable any correlation between material/particle characteristics and toxicity.

The aim of this licentiate summary is – in contrast to the six included scientific papers – to explain the importance of chemical speciation for corrosion processes from a health and environmental perspective in a popular way to reach a broad non-academic audience. The summary is hence written as a guidance document for stakeholders and the regulatory community working with environmental and health risk assessment.

Place, publisher, year, edition, pages
Stockholm, Sweden: KTH, 2010. xvi, 36 p.
Trita-CHE-Report, ISSN 1654-1081 ; 32
urn:nbn:se:kth:diva-24701 (URN)978-91-7415-716-1 (ISBN)
2010-10-28, conference room 3, YKI, Drottning Kristinas väg 49A, Stockholm, 10:00 (English)
QC 20101006Available from: 2010-10-06 Created: 2010-09-23 Last updated: 2010-12-14Bibliographically approved

Open Access in DiVA

No full text

Other links

Publisher's full textScopus

Search in DiVA

By author/editor
Hedberg, YolandaOdnevall Wallinder, Inger
By organisation
Surface and Corrosion Science
Other Chemistry Topics

Search outside of DiVA

GoogleGoogle Scholar
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

Altmetric score

Total: 94 hits
ReferencesLink to record
Permanent link

Direct link