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The role of organic matter in the di...

Miller, Carrie Lynn.

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The role of organic matter in the dissolved phase speciation and solid phase partitioning of mercury.

Record Type:	Language materials, printed : Monograph/item
Title/Author:	The role of organic matter in the dissolved phase speciation and solid phase partitioning of mercury./
Author:	Miller, Carrie Lynn.
Description:	173 p.
Notes:	Adviser: Robert Mason.
Contained By:	Dissertation Abstracts International67-03B.
Subject:	Environmental Sciences. -
Online resource:	http://pqdd.sinica.edu.tw/twdaoapp/servlet/advanced?query=3212032
ISBN:	9780542604485

The role of organic matter in the dissolved phase speciation and solid phase partitioning of mercury.
Miller, Carrie Lynn.

The role of organic matter in the dissolved phase speciation and solid phase partitioning of mercury. - 173 p.

Adviser: Robert Mason.

Thesis (Ph.D.)--University of Maryland, College Park, 2006.

The interaction of mercury (Hg) and methylmercury (MeHg) with organic matter is extremely important in the dissolved phase speciation and solid phase partitioning of Hg and MeHg in aquatic systems. This study shows, that under oxic conditions Hg and MeHg will likely associated with Fe oxides through an indirect association with organic matter, while under sulfidic conditions, solid phase Fe sulfide will dominate the complexation of Hg to the solid phase. As a result of the association of Hg with Fe solids, which undergo dynamic changes at redox interfaces in aquatic systems, the distribution of Hg on particles is likely changing at redox boundaries, areas that have been shown as active zones of methylation. Redox zones are also going to be important in controlling the mobility of McHg from the site of production to areas in aquatic systems in which uptake by biota occurs.

ISBN: 9780542604485Subjects--Topical Terms:

676987
Environmental Sciences.

The role of organic matter in the dissolved phase speciation and solid phase partitioning of mercury.
LDR:03143nam 2200289 a 45 001 965398
005 20110906
008 110906s2006 eng d
020 $a 9780542604485
035 $a (UMI)AAI3212032
035 $a AAI3212032
040 $a UMI $c UMI
100 1 $a Miller, Carrie Lynn. $3 1288174
245 1 4 $a The role of organic matter in the dissolved phase speciation and solid phase partitioning of mercury.
300 $a 173 p.
500 $a Adviser: Robert Mason.
500 $a Source: Dissertation Abstracts International, Volume: 67-03, Section: B, page: 1331.
502 $a Thesis (Ph.D.)--University of Maryland, College Park, 2006.
520 $a The interaction of mercury (Hg) and methylmercury (MeHg) with organic matter is extremely important in the dissolved phase speciation and solid phase partitioning of Hg and MeHg in aquatic systems. This study shows, that under oxic conditions Hg and MeHg will likely associated with Fe oxides through an indirect association with organic matter, while under sulfidic conditions, solid phase Fe sulfide will dominate the complexation of Hg to the solid phase. As a result of the association of Hg with Fe solids, which undergo dynamic changes at redox interfaces in aquatic systems, the distribution of Hg on particles is likely changing at redox boundaries, areas that have been shown as active zones of methylation. Redox zones are also going to be important in controlling the mobility of McHg from the site of production to areas in aquatic systems in which uptake by biota occurs.
520 $a Although the dissolved phase speciation of Hg has been shown as an important factor in Hg methylation, as a result of the diffusive uptake of neutral Hg-sulfide into bacterial cells, this speciation had previously not been measured. Hg forms stronger bonds with reduced sulfide relative to dissolved organic matter (DOM), therefore, it was not previously thought that DOM was important in the speciation of Hg under sulfidic conditions. Using modified octanol-water partitioning extractions and centrifugal ultrafiltration, the speciation of Hg in sulfidic natural samples and laboratory solutions was examined. It was shown that the concentration of neutral Hg-sulfide complexes are lower than predicted by thermodynamic models, as a result of an interaction of these species with DOM. It is proposed that the interaction of Hg with DOM is not a complexation, but rather, a partitioning of neutral Hg-sulfide complexes into hydrophobic portion of the DOM. Thermodynamic constants were calculated for this interaction and applied to model the speciation of Hg in natural samples. The concentration of neutral Hg-sulfide is lower than models previously predicted, as a result of the DOM interaction. Since the concentration of neutral Hg-sulfide affects methylation, DOM could impact the rate of Hg methylation in aquatic systems.
590 $a School code: 0117.
650 4 $a Environmental Sciences. $3 676987
650 4 $a Geochemistry. $3 539092
690 $a 0768
690 $a 0996
710 2 0 $a University of Maryland, College Park. $3 657686
773 0 $t Dissertation Abstracts International $g 67-03B.
790 $a 0117
790 1 0 $a Mason, Robert, $e advisor
791 $a Ph.D.
792 $a 2006
856 4 0 $u http://pqdd.sinica.edu.tw/twdaoapp/servlet/advanced?query=3212032