HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Figures Only Full Text Free Full Text (PDF) Free Alert me when this article is cited Alert me if a correction is posted Services Related articles in JEQ Similar articles in this journal Similar articles in ISI Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via ISI Web of Science (13) Citing Articles via Google Scholar Google Scholar Articles by Phillips, D. H. Articles by Roh, Y. Search for Related Content PubMed PubMed Citation Articles by Phillips, D. H. Articles by Roh, Y. GeoRef GeoRef Citation Agricola Articles by Phillips, D. H. Articles by Roh, Y. Related Collections Remediation Water Pollution Ground Water Quality

TECHNICAL REPORTS
Ground Water Quality

Impact of Sample Preparation on Mineralogical Analysis of Zero-Valent Iron Reactive Barrier Materials

Environmental Sciences Division, Oak Ridge National Lab., P.O. Box 2008, Oak Ridge, TN 37831

^* Corresponding author (dhphillips2003{at}yahoo.com)

Received for publication March 11, 2002. Permeable reactive barriers (PRBs) of zero-valent iron (Fe⁰) are increasingly being used to remediate contaminated ground water. Corrosion of Fe⁰ filings and the formation of precipitates can occur when the PRB material comes in contact with ground water and may reduce the lifespan and effectiveness of the barrier. At present, there are no routine procedures for preparing and analyzing the mineral precipitates from Fe⁰ PRB material. These procedures are needed because mineralogical composition of corrosion products used to interpret the barrier processes can change with iron oxidation and sample preparation. The objectives of this study were (i) to investigate a method of preparing Fe⁰ reactive barrier material for mineralogical analysis by X-ray diffraction (XRD), and (ii) to identify Fe mineral phases and rates of transformations induced by different mineralogical preparation techniques. Materials from an in situ Fe⁰ PRB were collected by undisturbed coring and processed for XRD analysis after different times since sampling for three size fractions and by various drying treatments. We found that whole-sample preparation for analysis was necessary because mineral precipitates occurred within the PRB material in different size fractions of the samples. Green rusts quickly disappeared from acetone-dried samples and were not present in air-dried and oven-dried samples. Maghemite/magnetite content increased over time and in oven-dried samples, especially after heating to 105°C. We conclude that care must be taken during sample preparation of Fe⁰ PRB material, especially for detection of green rusts, to ensure accurate identification of minerals present within the barrier system.

Abbreviations: Fe⁰, zero-valent iron • PRB, permeable reactive barrier • XRD, X-ray diffraction

Related articles in JEQ:

This Issue in Journal of Environmental Quality

JEQ 2003 32: 1167-1172. [Full Text]  

This article has been cited by other articles:

				Y. Zhang, J. Wang, C. Amrhein, and W. T. Frankenberger Jr. Removal of Selenate from Water by Zerovalent Iron J. Environ. Qual., March 1, 2005; 34(2): 487 - 495. [Abstract] [Full Text] [PDF]

				D. H. Phillips, D. B. Watson, Y. Roh, and B. Gu Mineralogical Characteristics and Transformations during Long-Term Operation of a Zerovalent Iron Reactive Barrier J. Environ. Qual., November 1, 2003; 32(6): 2033 - 2045. [Abstract] [Full Text] [PDF]