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

This Article Figures Only Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Zhang, P. Articles by Bowman, R. S. Search for Related Content PubMed PubMed Citation Articles by Zhang, P. Articles by Bowman, R. S. Agricola Articles by Zhang, P. Articles by Bowman, R. S. Related Collections Remediation Experiment Design

TECHNICAL REPORTS

Waste Management

Removal of Perchlorate from Contaminated Waters Using Surfactant-Modified Zeolite

^a Dep. of Earth and Atmospheric Sciences, City College of New York, New York, NY 10031
^b Dep. of Earth and Environmental Science, New Mexico Inst. of Mining and Technology, Socorro, NM 87801

^* Corresponding author (pzhang{at}sci.ccny.cuny.edu)

Received for publication October 6, 2006. We investigated the potential of using surfactant (hexadecyltrimethylammonium)-modified zeolite (SMZ) as an inexpensive sorbent for removing perchlorate (ClO₄^–) from contaminated waters in the presence of competing anions. In batch systems, the presence of 10 mM OH^– (i.e., pH 12), CO₃^2–, Cl^–, or SO₄^2– had little effect on the sorption of ClO₄^– by SMZ, indicating that the sorption of ClO₄^– by SMZ was very selective. The presence of 10 mM NO₃^–, however, reduced the sorption of ClO₄^– at low initial concentrations. The maximum sorption capacity for ClO₄^– by the SMZ remained relatively constant (40–47 mmol kg^–1), in the absence or presence of the competing ions. In flow-through systems, ClO₄^– broke through the SMZ columns much later than other anions present in an artificial ground water. The affinity of the anions for SMZ followed the sequence of ClO₄^– > > NO₃^– > SO₄^2– > Cl^–. Perchlorate loading under dynamic flow-through conditions was 34 mmol kg^–1, somewhat less than the maximum loading of 40 to 47 mmol kg^–1 determined by the batch method. Less than 1% of previously sorbed ClO₄^– was leached out by ultra-pure water, by extraction fluid #1 of the standard toxicity characteristic leaching procedure (TCLP), or by a solution of 0.28 M Na₂CO₃/0.5 M NaOH. About 40% of the previously sorbed ClO₄^– was leached out from SMZ by a 0.5 M NO₃^– solution. The exchange of ClO₄^– with NO₃^– corroborated results of the batch tests where NO₃^– was shown to compete with ClO₄^– sorption.

Abbreviations: HDTMA, hexadecyltrimethylammonium • PV, pore volume • SMZ, surfactant-modified zeolite