Arsenic speciation in surface waters and sediments in a contaminated waterway: An IC-ICP-MS and XAS based study

Andrew G. Gault, David A. Polya, Paul R. Lythgoe, Morag L. Farquhar, John M. Charnock, Roy A. Wogelius

    Research output: Contribution to journalArticlepeer-review

    Abstract

    An integrated approach involving the use of ion chromatography-inductively coupled plasma-mass spectrometry (IC-ICP-MS), X-ray absorption spectroscopy (XAS) and sequential extraction procedures has been employed to elucidate the solution and solid phase speciation and partitioning of As in a polluted urban watercourse. Dissolved As concentrations exceeding 130 μg l-1 and comprising entirely inorganic species were determined in the waters of Tinker Brook, a contaminated stream. Upon mixing with a relatively As-free stream, White Ash Brook, both the total concentration of dissolved As and the proportion of As(V) were observed to decrease dramatically below values expected for conservative mixing. This was ascribed to adsorption onto the Fe (oxyhydr)oxides that characterise White Ash Brook on the basis of sequential extraction and direct analysis of the solids via XAS. The shift in oxidation state is speculated to be due to the faster rate of adsorption of As(V) on Fe (oxyhydr)oxides than As(III) in this fast flowing stream system. During periods of reduced supply of anthropogenic As, a small, secondary input of As(III) to White Ash Brook is detectable, delivered by a small ochreous seepage. The Fe (oxyhydr)oxide As-rich deposits surrounding this discharge may also act as a significant source of As upon dissolution during stormflow conditions. © 2003 Elsevier Science Ltd. All rights reserved.
    Original languageEnglish
    Pages (from-to)1387-1397
    Number of pages10
    JournalApplied Geochemistry
    Volume18
    Issue number9
    DOIs
    Publication statusPublished - 1 Sept 2003

    Fingerprint

    Dive into the research topics of 'Arsenic speciation in surface waters and sediments in a contaminated waterway: An IC-ICP-MS and XAS based study'. Together they form a unique fingerprint.

    Cite this