A conceptual model to understand the soluble and
insoluble atmospheric Cr III/VI species
Mirat Karibayev 1 and Dr. Mehdi Amouei Torkmahalleh 2
Department of Chemistry, School of Science and Technology, Nazarbayev University,
Astana, Kazakhstan (Email: [email protected])
2
Department of Chemical Engineering, School of Engineering, Nazarbayev University,
Astana, Kazakhstan (Email: [email protected])
1
Abstract
Cr(III) is crucial microelement for living organisms and exhibit important role in control of
lipids, glucose and proteins metabolism. In comparison, Cr(VI) is highly toxic and US EPA
considered as ‘Group A carcinogens’ that leads to asthma, lung cancer, bronchitis, pneumonitis,
nasal damage. Thus, it is important to be able to distinguish between these two oxidation states
in the atmosphere 1 . The majority of atmospheric chromium is insoluble and exists in solid core.
Hence, aqueous layer forms around solid core. Consequently, the interconversion between
Cr(III) and Cr(VI) can take place with atmospheric reactants and oxidants under atmospheric
PM 1 . It was found that atmospheric Cr(III) is oxidized to Cr(VI) in the presence of Mn(III) 2
at atmospheric conditions, while Cr(VI) is reduced to Cr(III) in the presence of
atmospheric metal ions such as Fe(II) 3 , and As(III) 4 . This interconversion between Cr(III)
and Cr(VI) results in some biases in measuring atmospheric Cr concentrations 5 . The
objective of this study was to develop a conceptual model to better understand the
interconversion for soluble and insoluble forms of Cr compounds at atmospheric conditions.
References:
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92-94.
3. Rai, D.; Sass, B.M.; Moore, D.A. Inorg. Chem. 1987, 26, 345-349.
4. Werner, M.; Nico, P.; Guo, B.; Kennedy, I.; Anastasio, C. Aerosol Sci. Technol. 2006, 40(7), 545-556.
5. Seigneur, C.; Constantinou, E. Environ. Sci. Technol. 1995, 29, 222-231.