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Persistent organic pollutant transpo...

Venkatraman, Padma Tiruponithura.

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Persistent organic pollutant transport and fate: Assessment by molecular tracers.

Record Type:	Electronic resources : Monograph/item
Title/Author:	Persistent organic pollutant transport and fate: Assessment by molecular tracers./
Author:	Venkatraman, Padma Tiruponithura.
Description:	127 p.
Notes:	Source: Dissertation Abstracts International, Volume: 62-04, Section: B, page: 1772.
Contained By:	Dissertation Abstracts International62-04B.
Subject:	Biogeochemistry. -
Online resource:	http://pqdd.sinica.edu.tw/twdaoapp/servlet/advanced?query=3012234
ISBN:	0493208623

Persistent organic pollutant transport and fate: Assessment by molecular tracers.
Venkatraman, Padma Tiruponithura.

Persistent organic pollutant transport and fate: Assessment by molecular tracers. - 127 p.

Source: Dissertation Abstracts International, Volume: 62-04, Section: B, page: 1772.

Thesis (Ph.D.)--The College of William and Mary, 2001.

Persistent organic pollutants (POPs) such as the organochlorine pesticide hexachlorocyclohexane (HCH) may undergo atmospheric transport and accumulate in regions remote from the source. It is important to develop techniques to help apportion source and identify transport or transformation processes to which HCHs and other mobile POPs may be subjected. Molecular tracers such as compound specific stable isotope and enantiomer ratios (ERs) may prove valuable in studying POP fate and transport. The objective of this study was to further develop the use of these two novel geochemical tools to evaluate the sources, transport and environmental fate of POPs, in the context of studying the fate and transport of HCH, a globally distributed POP.

ISBN: 0493208623Subjects--Topical Terms:

545717
Biogeochemistry.

Persistent organic pollutant transport and fate: Assessment by molecular tracers.
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100 1 $a Venkatraman, Padma Tiruponithura. $3 1940054
245 1 0 $a Persistent organic pollutant transport and fate: Assessment by molecular tracers.
300 $a 127 p.
500 $a Source: Dissertation Abstracts International, Volume: 62-04, Section: B, page: 1772.
500 $a Adviser: Rebecca M. Dickhut.
502 $a Thesis (Ph.D.)--The College of William and Mary, 2001.
520 $a Persistent organic pollutants (POPs) such as the organochlorine pesticide hexachlorocyclohexane (HCH) may undergo atmospheric transport and accumulate in regions remote from the source. It is important to develop techniques to help apportion source and identify transport or transformation processes to which HCHs and other mobile POPs may be subjected. Molecular tracers such as compound specific stable isotope and enantiomer ratios (ERs) may prove valuable in studying POP fate and transport. The objective of this study was to further develop the use of these two novel geochemical tools to evaluate the sources, transport and environmental fate of POPs, in the context of studying the fate and transport of HCH, a globally distributed POP.
520 $a In the first part of my study, I evaluated the potential for using stable isotope ratios to track POP source and transport, using HCH in laboratory simulations of global distillation. I compared the relative fractionation of carbon versus deuterium isotopes during air-water gas exchange along a strong temperature gradient. The hypothesis, that perdeuterated, but not necessarily carbon-labeled compounds would show measurable and significant fractionation during air-water transfer, was validated within the confines of the experimental system. The results suggest that it may be possible to use a dual tracer approach on a larger scale, in which carbon isotopes could be used to track POP source, while fractionation of deuterium may be used to track POP transport distance. In the second part of the study, I evaluated the potential for use of ERs to evaluate HCH biodegradation. The rationale was that most enzymatic processes are stereoselective, enantiomers of pesticides may microbially degrade at significantly different rates, leading to increased environmental persistence of the non-degradable isomer. To bridge the gap between microbial and chemical information on enantioselective processes, I measured microbial activity, abundance, concentrations and enantiomer ratios of HCH in air and surface waters of the York River estuary. HCH concentrations and ERs were related with microbial activity but there were seasonal variations in enantioselectivity suggesting that seasonal as well as spatial differences in microbial communities may affect HCH ERs. The relationship between microbial parameters and enantioselective degradation appears to be complex and warrants further study before ERs can be used as effective tracers of chiral POP transport.
590 $a School code: 0261.
650 4 $a Biogeochemistry. $3 545717
650 4 $a Environmental Sciences. $3 676987
650 4 $a Biology, Oceanography. $3 783691
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690 $a 0768
690 $a 0416
710 2 0 $a The College of William and Mary. $3 1018629
773 0 $t Dissertation Abstracts International $g 62-04B.
790 1 0 $a Dickhut, Rebecca M., $e advisor
790 $a 0261
791 $a Ph.D.
792 $a 2001
856 4 0 $u http://pqdd.sinica.edu.tw/twdaoapp/servlet/advanced?query=3012234