Soil humic acids may favour the persistence of hexavalent chromium in soil.
The interaction between hexavalent chromium Cr(VI), as K(2)CrO(4), and standard humic acids (HAs) in bulk solution was studied using three complementary analytical methods: UV-Visible spectroscopy, X-ray absorption spectroscopy and differential pulse stripping voltammetry. The observed UV-Vis and X-ray absorption spectra showed that, under our experimental conditions, HAs did not induce reduction of Cr(VI) to its trivalent chemical form. The interaction between Cr(VI) and HAs has rather led to the formation of Cr(VI)-HAs micelles via supramolecular chemical processes. The reported results could contribute towards explaining the relative persistence of ecotoxic hexavalent chromium in soils.
Leita
Liviana
L
A.R.C. Agricultural Research Council-Research Group on Soil-Plant Systems, Via Trieste 23, 34170 Gorizia, Italy. liviana.leita@entecra.it
Margon
Alja
A
Pastrello
Arnold
A
Arcon
Iztok
I
Contin
Marco
M
Mosetti
Davide
D
D015502:Absorptiometry, Photon / Q000379:methods; D002857:Chromium / Q000032:analysis* / Q000737:chemistry; D054750:Ecotoxicology / Q000379:methods; D004563:Electrochemistry / Q000379:methods; D006812:Humic Substances; D006863:Hydrogen-Ion Concentration; D012987:Soil / Q000032:analysis*; D012989:Soil Pollutants / Q000032:analysis* / Q000737:chemistry; D013056:Spectrophotometry, Ultraviolet / Q000379:methods; D013997:Time Factors
D006812:Humic Substances; D012987:Soil; D012989:Soil Pollutants; D002857:Chromium; C074702:chromium hexavalent ion