Location of Repository

Influence of phosphate on the oxidation kinetics of nanomolar Fe(II) in aqueous solution at circumneutral pH

By Yanpeng Mao, An Ninh Pham, Andrew L Rose and T David Waite

Abstract

The oxygenation kinetics of nanomolar concentrations of Fe(II) in aqueous solution have been studied in the absence and presence of millimolar concentrations of phosphate over the pH range 6.0–7.8. At each phosphate concentration investigated, the overall oxidation rate constant varied linearly with pH, and increased with increasing phosphate concentration. A model based on equilibrium speciation of Fe(II) was found to satisfactorily explain the results obtained. From this model, the rate constants for oxygenation of the Fe(II)-phosphate species FeH2PO4+, FeHPO4 and FePO4− have been determined for the first time. FePO4− was found to be the most kinetically reactive species at circumneutral pH with an estimated oxygenation rate constant of (2.2 � 0.2) � 10 M−1 s−1. FeH2PO4+ and FeHPO4 were found to be less reactive with oxygen, with rate constants of (3.2 � 2) � 10−2 M−1 s−1 and (1.2 � 0.8) � 10−1 M−1 s−1, respectively

Topics: Earth Sciences
Publisher: ePublications@SCU
Year: 2011
DOI identifier: 10.1016/j.gca.2011.05.031
OAI identifier: oai:epubs.scu.edu.au:geoscience_pubs-1013
Provided by: ePublications@SCU
Download PDF:
Sorry, we are unable to provide the full text but you may find it at the following location(s):
  • http://dx.doi.org/10.1016/j.gc... (external link)
  • https://epubs.scu.edu.au/geosc... (external link)
  • Suggested articles


    To submit an update or takedown request for this paper, please submit an Update/Correction/Removal Request.