Mineralogical characterization of saprolite at the FRC background site in Oak Ridge,Tennessee |
| |
| Authors: | Young-Jin Kim Ji-Won Moon Yul Roh Scott C Brooks |
| |
| Institution: | (1) Department of Civil and Environmental Engineering, Seoul National University, Seoul, 151-742, South Korea;(2) Environmental Sciences Division, Oak Ridge National Laboratory, P.O. Box 2008, Oak Ridge, TN 37831, USA;(3) Department of Earth Systems and Environmental Sciences, Chonnam National University, Gwangju, 500–757, South Korea |
| |
| Abstract: | The Field Research Center (FRC) including five contaminated sites and a clean background area was established in Oak Ridge,
Tennessee, as a part of the U.S. Department of Energy’s Natural and Accelerated Bioremediation Research (NABIR) program. This
study investigates the mineralogy and mineralogical pathways of saprolite at the FRC background site to provide a fundamental
basis for the remediation strategy for contaminated sites. The background site is underlain interbedded shales, siltstones,
and limestones with nearly identical characteristics to the contaminated sites. Bulk samples of saprolite were collected by
hand picking approximately at 1 m depth (C horizon) from the soil surface. The soil pH of 4.3 and cation exchange capacity
(CEC) of 10.5 cmol/kg measured are in the range of the typical shallow depth saprolite layer in this area. Total Fe by citrate-bicarbonate-dithionate
(CBD) and ammonium oxalate extractable (amorphous) were 17.6 and 0.61 g/kg, respectively. Total Mn extracted by NH2OH·HCl was 0.17 g/kg. X-ray diffraction (XRD) and scanning electron microscopy (SEM) analyses indicate that quartz, illite,
and microcline (K-feldspar) are the dominant minerals, occupying 95% of mineral composition. The saprolite samples analyzed
have shown characteristics of oxic conditions overall, and the degrees of weathering for three sampling locations were various,
most for S1 and least for S3, likely influenced either by the flow channels developed through saprolite or by seasonal fluctuation
of the groundwater table. The source of the manganese oxide that observed from the site is likely to be Mn-rich muscovite
in the shale or Mn-rich biotite in the blackish band in the limestone. The results such as abundant Mn and Fe contents identified
encouraging prospects for conducting remediation projects in FRC sites. |
| |
| Keywords: | Field Research Center (FRC) Saprolite Remediation Mineralogy |
| 本文献已被 SpringerLink 等数据库收录！ |
|
