Comparison of Different Methods for Redox Potential Determination in Natural Waters
In geochemical equilibrium model programs such as Phreeqe (Parkhurst et al., 1990) Phreeqc (Parkhurst, 1995) the redox potential is a major variable strictly affecting the species distribution and mineral stability of both, redoxsensitive dissolved species and solid phases. It is therefore necessary to assess the accuracy of pε determinations by redox probes. In addition, there are often inconsistencies to be found in calculated pε values. In different geochemical computer model programs, the pε may be calculated from the concentrations of various redox couples. These values often vary by hundreds of millivolts in one single water analysis. Therefore, the reliability of pε calculations is discussed.
KeywordsGraphite Sulfide Platinum Arsenic Geochemistry
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