Combined Speciation Analysis by X-ray Absorption Near-Edge Structure Spectroscopy, Ion Chromatography, and Solid-Phase Microextraction Gas Chromatography-Mass Spectrometry To Evaluate Biotreatment of Concentrated Selenium Wastewaters

M. Lenz, E.D. van Hullebusch, F. Farges, S. Nikitenko, P.F.X. Corvini, P.N.L. Lens

Research output: Contribution to journalArticleAcademicpeer-review

20 Citations (Scopus)

Abstract

In this study we evaluate the potential of anaerobic granular sludge as an inoculum for the bioremediation of selenium-contaminated waters using species-specific analytical methods. Solid species formed by microbial reduction were investigated using X-ray absorption near-edge structure (XANES) spectroscopy at the selenium K-edge. Furthermore, dissolved selenium species were specifically determined by ion chromatography (IC) and solid-phase microextraction gas chromatography-mass spectrometry (SPME-GC-MS). Least-squares linear combination of the XANES spectra for samples incubated with the highest selenate/selenite concentrations (10(-3) M) show the predominance of elemental selenium and a Se(-I) selenide, such as ferroselite, the thermodynamically most stable iron selenide. In contrast, elemental selenium and Se(-II) selenides are the main species detected at the lower selenate/selenite concentrations. In each repeated fed batch incubation, most aqueous selenite anions were converted into solid selenium species, regardless of the type of electron donor used (acetate or H(2)/CO(2)) and the selenium concentration applied. On the other hand, at higher concentrations of selenate (10(-4) and 10(-3) M), significant amounts of the oxyanion remained unconverted after consecutive incubations. SPME-GC-MS demonstrated selenium alkylation with both electron donors investigated, as dimethyl selenide (DMSe) and dimethyl diselenide (DMDSe). Selenite was even more alkylated in the presence of H(2)/CO(2) (maximum 2156 µg of Se/L of DMSe + DMDSe) as compared to acetate (maximum 50 µg of Se/L). In contrast, selenate was less alkylated using both electron donors (maximum 166 and 3 µg of Se/L, respectively). The high alkylation potential for selenite limits its bioremediation in selenium laden waters involving H(2)/CO(2) as the electron donor despite the fact that nontoxic elemental selenium and thermodynamically stable metal selenide species are formed
Original languageEnglish
Pages (from-to)1067-1073
JournalEnvironmental Science and Technology
Volume45
Issue number3
DOIs
Publication statusPublished - 2011

Keywords

  • anaerobic granular sludge
  • reducing bacterial biofilms
  • agricultural drainage
  • waste-water
  • selenate
  • removal
  • bioremediation
  • reduction
  • oxyanions
  • sediments

Fingerprint Dive into the research topics of 'Combined Speciation Analysis by X-ray Absorption Near-Edge Structure Spectroscopy, Ion Chromatography, and Solid-Phase Microextraction Gas Chromatography-Mass Spectrometry To Evaluate Biotreatment of Concentrated Selenium Wastewaters'. Together they form a unique fingerprint.

  • Cite this