skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Nickel speciation in several serpentine (ultramafic) topsoils via bulk synchrotron-based techniques

Authors:
ORCiD logo; ;
Publication Date:
Sponsoring Org.:
USDOE Office of Science (SC), Biological and Environmental Research (BER) (SC-23)
OSTI Identifier:
1413365
Grant/Contract Number:
AC02-98CH10886; AC02-76SF00515
Resource Type:
Journal Article: Publisher's Accepted Manuscript
Journal Name:
Geoderma
Additional Journal Information:
Journal Volume: 298; Journal Issue: C; Related Information: CHORUS Timestamp: 2017-12-14 10:39:37; Journal ID: ISSN 0016-7061
Publisher:
Elsevier
Country of Publication:
Netherlands
Language:
English

Citation Formats

Siebecker, Matthew G., Chaney, Rufus L., and Sparks, Donald L. Nickel speciation in several serpentine (ultramafic) topsoils via bulk synchrotron-based techniques. Netherlands: N. p., 2017. Web. doi:10.1016/j.geoderma.2017.03.008.
Siebecker, Matthew G., Chaney, Rufus L., & Sparks, Donald L. Nickel speciation in several serpentine (ultramafic) topsoils via bulk synchrotron-based techniques. Netherlands. doi:10.1016/j.geoderma.2017.03.008.
Siebecker, Matthew G., Chaney, Rufus L., and Sparks, Donald L. Sat . "Nickel speciation in several serpentine (ultramafic) topsoils via bulk synchrotron-based techniques". Netherlands. doi:10.1016/j.geoderma.2017.03.008.
@article{osti_1413365,
title = {Nickel speciation in several serpentine (ultramafic) topsoils via bulk synchrotron-based techniques},
author = {Siebecker, Matthew G. and Chaney, Rufus L. and Sparks, Donald L.},
abstractNote = {},
doi = {10.1016/j.geoderma.2017.03.008},
journal = {Geoderma},
number = C,
volume = 298,
place = {Netherlands},
year = {Sat Jul 01 00:00:00 EDT 2017},
month = {Sat Jul 01 00:00:00 EDT 2017}
}

Journal Article:
Free Publicly Available Full Text
Publisher's Version of Record at 10.1016/j.geoderma.2017.03.008

Citation Metrics:
Cited by: 2works
Citation information provided by
Web of Science

Save / Share:
  • Serpentine soils have elevated concentrations of trace metals including nickel, cobalt, and chromium compared to non-serpentine soils. Identifying the nickel bearing minerals allows for prediction of potential mobility of nickel. Synchrotron-based techniques can identify the solid-phase chemical forms of nickel with minimal sample treatment. Element concentrations are known to vary among soil particle sizes in serpentine soils. Sonication is a useful method to physically disperse sand, silt and clay particles in soils. Synchrotron-based techniques and sonication were employed to identify nickel species in discrete particle size fractions in several serpentine (ultramafic) topsoils to better understand solid-phase nickel geochemistry. Nickel commonlymore » resided in primary serpentine parent material such as layered-phyllosilicate and chain-inosilicate minerals and was associated with iron oxides. In the clay fractions, nickel was associated with iron oxides and primary serpentine minerals, such as lizardite. Linear combination fitting (LCF) was used to characterize nickel species. Total metal concentration did not correlate with nickel speciation and is not an indicator of the major nickel species in the soil. Differences in soil texture were related to different nickel speciation for several particle size fractionated samples. A discussion on LCF illustrates the importance of choosing standards based not only on statistical methods such as Target Transformation but also on sample mineralogy and particle size. Results from the F-test (Hamilton test), which is an underutilized tool in the literature for LCF in soils, highlight its usefulness to determine the appropriate number of standards to for LCF. EXAFS shell fitting illustrates that destructive interference commonly found for light and heavy elements in layered double hydroxides and in phyllosilicates also can occur in inosilicate minerals, causing similar structural features and leading to false positive results in LCF.« less
  • Synchrotron-based micro-X-ray fluorescence (XRF) combined with scanning electron microscopy-based energy dispersive micro-analysis (EDS) has been used to determine the elemental distribution of contaminants (e.g., Ni) and of chemical elements inherent to the cement matrix (e.g., Si, Ca, Al, S) in hardened cement paste. Detailed information on the cement microstructure was gained by using backscattered electron (BSE) imaging. The results obtained from the complementary use of micro-XRF, EDS and BSE reveal that Ni is primarily distributed around inner calcium silicate hydrates (inner-C-S-H) and that Ni is preferentially associated with Al. This suggests the formation of a Ni-Al phase and its directmore » association with inner-C-S-H. Further information on the chemical speciation of Ni in relation to Al and S was obtained at selected regions of interests in the cement matrix using synchrotron-based micro-X-ray absorption spectroscopy (XAS). Data analysis shows that Ni is predominantly immobilized in layered double hydroxides, while predominant formation of ettringite was indicated from the Al and S XAS data. The present study demonstrates that the combined use of micro-XRF, BSE, EDS and micro-XAS, opens up a powerful analytical approach to determine the distribution and the speciation of chemical elements in complex heterogeneous cementitious materials on the same region of interest with micro-scale resolution.« less
  • Here, this study investigates the early ages of hydration behavior when basaltic volcanic ash was used as a partial substitute to ordinary Portland cement using ultra-small-angle X-ray scattering and wide-angle X-ray scattering (WAXS). The mix design consisted of 10, 30 and 50% substitution of Portland cement with two different-sized volcanic ashes. The data showed that substitution of volcanic ash above 30% results in excess unreacted volcanic ash, rather than additional pozzolanic reactions along longer length scales. WAXS studies revealed that addition of finely ground volcanic ash facilitated calcium-silicate-hydrate related phases, whereas inclusion of coarser volcanic ash caused domination by calcium-aluminum-silicate-hydratemore » and unreacted MgO phases, suggesting some volcanic ash remained unreacted throughout the hydration process. Addition of more than 30% volcanic ash leads to coarser morphology along with decreased surface area and higher intensity of scattering at early-age hydration. This suggests an abrupt dissolution indicated by changes in surface area due to the retarding gel formation that can have implication on early-age setting influencing the mechanical properties of the resulting cementitious matrix. The findings from this work show that the concentration of volcanic ash influences the specific surface area and morphology of hydration products during the early age of hydration. Therefore, natural pozzolanic volcanic ashes can be a viable substitute to Portland cement by providing environmental benefits in terms of lower-carbon footprint along with long-term durability.« less