Black carbon in marine sediments : quantification and implications for the sorption of polycyclic aromatic hydrocarbons
Name
52770175-MIT.pdf
Description
Full printable version
Size
19.95 MB
Format
Adobe PDF
Checksum (MD5)
391fae4ddc0e18294cb567a2c6e90fe4
Author(s)
Accardi-Dey, AmyMarie, 1976-
Advisor(s)
Philip M. Gschwend.
Date Issued
2003
Publisher
Massachusetts Institute of Technology
Abstract
Sorption is a key factor in determining the fate of polycyclic aromatic hydrocarbons (PAHs) in the environment. Here, PAH sorption is proposed as the sum of two mechanisms: absorption into a biogenic, organic carbon (OC) fraction and adsorption onto a combustion-derived, black carbon (BC) fraction. To study BC adsorption, a 375ʻC thermal oxidation method was employed to remove OC and isolate the BC fraction. Test studies showed that nitrogen-containing macromolecules charred during this pretreatment causing a positive bias to the BC measurement. Meanwhile, the oxidation of relatively small BC particles underestimated the total BC content in non-charring samples. Models based on carbon oxidation were then proposed to estimate reasonably the total BC and OC contents of sediment samples. The adsorption of pyrene onto isolated BC particles was then studied by constructing a nonlinear isotherm, which was characterized with a BC-normalized distribution coefficient and a Freundlich exponent. Pyrene sorption to Boston Harbor sediment was then modeled as the sum of OC absorption and BC adsorption using the measured adsorption parameters and literature absorption values. Finally, literature reports of high PAH distribution coefficients from the field and nonlinear PAH isotherms from the laboratory were re-explained by considering BC adsorption.
Description
Thesis (Ph. D.)--Joint Program in Oceanography/Applied Ocean Science and Engineering (Massachusetts Institute of Technology, Dept. of Civil and Environmental Engineering; and the Woods Hole Oceanographic Institution), 2003.
Includes bibliographical references.
Subjects
/Woods Hole Oceanographic Institution. Joint Program in Oceanography/Applied Ocean Science and Engineering.
Civil and Environmental Engineering.
Woods Hole Oceanographic Institution.
MIT Department
Joint Program in Oceanography/Applied Ocean Science and Engineering
Woods Hole Oceanographic Institution
Massachusetts Institute of Technology. Department of Civil and Environmental Engineering
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