Correlation of Soil Organic Matter Carbon-type Distribution to the Sorption and Desorption of Hydrophobic Organic
Compounds. (S11-ding488336-poster)
Authors:
G. Ding* - South Dakota State Univ.
J.A. Rice - South Dakota State Univ.
Abstract:
Sorption and desorption to soil and sediment materials are major mechanisms affecting the fate of hydrophobic organic compounds. Sorption and desorption of naphthalene and phenanthrene on different types of soil organic matter varying in chemical composition as determined by solid-state direct-polarization magic-angle-spinning C-13 NMR techniques were examined in batch studies.
Sorption and desorption isotherms showed that the nonlinearity (N) values of a peat with a high aliphatic carbon content were larger than those of leonardite with a high aromatic carbon content. Removal of lipid fractions changes the carbon-type distribution pattern for both the peat and the leonardite. The hysteresis index, calculated from the ratio of the N values (Freundlich exponent) for desorption and sorption, was lower in lipid-extracted sorbents than that of the original material. This study demonstrates that the contribution of the lipid fraction of soil organic matter to the sorption and desorption of
hydrophobic organic compounds is significant.
Speaker Information: Guangwei Ding, South Dakota State Univ., Box 2202, SH 121Dept. Chem &
Biochem., SDSU, Brookings, SD 57007; Phone: 605-688-4782; E-mail: [email protected]
Session Information: Wednesday, November 5, 2003, 4:00 PM-6:00 PM Presentation Start: 4:00 PM (Poster Board Number: 1719)
Keywords: solid-state NMR; sorption & desorption; lipids; hysteresis
