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 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 ISI Web of Science (1) Citing Articles via Google Scholar Google Scholar Articles by Catallo, W. J. Articles by Junk, T. Search for Related Content PubMed PubMed Citation Articles by Catallo, W. J. Articles by Junk, T. GeoRef GeoRef Citation Agricola Articles by Catallo, W. J. Articles by Junk, T. Related Collections Bioremediation and Biodegradation

TECHNICAL REPORTS

Bioremediation and Biodegradation

Transformation of Benzothiazole in Estuarine Sediments

^a Laboratory for Ecological Chemistry, CBS Department, School of Veterinary Medicine, Louisiana State University, Baton Rouge, LA 70803
^b Department of Chemistry, University of Louisiana, Monroe, LA 71209

^* Corresponding author (jcatallo{at}mail.vetmed.lsu.edu)

Received for publication May 11, 2004. Benzothiazole (BT) is a natural and synthetic compound occurring in aquatic sediments and wastewater. The purpose of this work was to investigate BT biogeochemistry in controlled Eh/pH microcosms (CEPMs) containing estuarine sediments of different particle sizes (coarse, intermediate, fine) under oxidized and reduced conditions vs. killed controls, and tide simulation mesocosms (TSMs) containing plants and meiofauna under well-drained (oxidized), consistently saturated/flooded (reduced), and tidal (alternating oxidized/reduced) conditions. Benzothiazole was transformed into complex product mixtures under all conditions. Benzothiazole transformation rates in CEPMs were slower under reduced conditions vs. oxidized conditions in the fine- and intermediate-grain sediments, but the same in the coarse sediment. Quiescent (unstirred) CEPMs showed greatly reduced BT transformation rates in all sediments, with half-lives on the order of 2200 to >4000 h (unstirred) vs. 640 to 1000 h in the continuously stirred systems. The TSM data showed that tidal and drained systems processed BT at identical rates, far exceeding those observed in statically flooded (reduced) TSMs. Mixing was found to be a more significant variable in BT transformation rate than either Eh or sediment particle size breakdown, with constant stirring increasing observed degradation appreciably. Otherwise, BT was transformed more readily on sediments of high surface area under oxidized conditions vs. coarser sediments and those under reducing electrochemical conditions.

Abbreviations: BT, benzothiazole • CEPM, controlled Eh/pH microcosm • TSM, tide simulation mesocosm