Journal article
Copper behaviour in a podosol. I: pH-dependent sorption-desorption, sorption isotherm analysis and aqueous speciation modelling
Australian Journal of Soil Research, Vol.43(4), pp.491-501
2005
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Abstract
<p>The effects of pH and Cu loading on the solid/solution partitioning of Cu in a Podosol from south-east Queensland, Australia was examined. Sorption–desorption of Cu exhibited maximum linear distribution coefficients (K<sub>D</sub>) at approximately pH 5. Observed decrease in K<sub>D</sub> values at pH >5 was attributed to increased solubility of native dissolved organic carbon (DOC) at higher pH and subsequent formation of non-sorbing Cu–DOC complexes. Speciation modelling with the MINTEQA2 code indicated that >90% of aqueous Cu was present as Cu–DOC complexes at pH >5.5. The effect of Cu loading was examined with sorption isotherm analysis at pH 5 using solid : solution ratio approaches that were both constant (1?:?2 and 1?:?10) and variable. As the solid : solution ratio increased, the proportion of Cu sorbed decreased due to the formation of Cu-DOC complexes. However, this effect was negligible once these Cu–DOC complexes were accounted for via free Cu<sup>2+</sup> sorption isotherms. This indicated that Cu<sup>2+</sup> sorption at concentrations <0.08 mg/L was described by a K<sub>D</sub> value of approximately 3000 L/kg. Despite this relatively high K<sub>D</sub> value for Cu<sup>2+</sup> sorption, the results indicate that Cu–DOC complexes significantly enhance Cu solubility in soils high in DOC</p>
Details
- Title
- Copper behaviour in a podosol. I: pH-dependent sorption-desorption, sorption isotherm analysis and aqueous speciation modelling
- Creators
- Edward D Burton - Southern Cross UniversityIan R Phillips - Southern Cross UniversityDarryl W Hawker - Southern Cross UniversityDane T Lamb - University of New England
- Publication Details
- Australian Journal of Soil Research, Vol.43(4), pp.491-501
- Identifiers
- 1351; 991012820465902368
- Academic Unit
- Science; Faculty of Science and Engineering; School of Environment, Science and Engineering; Southern Cross GeoScience
- Resource Type
- Journal article