Effects of Organic Matter Heterogeneity on Sorption and Desorption of Hydrophobic Organic Chemicals (HOCs) by Pakokee Peat Soil

Conference · Wed Mar 31 04:00:00 EST 2004

OSTI ID:826128

Huang, Weilin; Yu, Zhiqiang; Song, Jianzhing; Peng, Pingan

Previous studies have shown that isotherm nonlinearity, varied sorption capacity and sorption-desorption hystersis relate primarily to the heterogeneity of soil organic matter (SOM). A comprehensive wet chemical isolation procedure was used to isolate and quantify into four fractions from Pahokee peat soil: (1) demineralized pahokee peat soil, (2) humic acids + kerogen + BC (HKB), (3) kerogen and (4) humic acid (HA). The major physical and chemical properties of each fraction were characterized using different techniques, such as Scanning Electron Microscopy, 13C-Nuclear Magnetic Resonance Spectroscopy, etc. The impact of SOM heterogeneity on sorption and desorption equilibria by isolated fractions and original soil was conducted using phenanthrene, naphthalene, 1,2-dichlorobenzene and 1,3,5-trichlorobenzene as sorbates. The data indicated that isolated HKB and kerogen fractions exhibit more nonlinear isotherms, greater sorption capacities and desorption hysteresis than that of HA and their original soil. The role of HA to the overall sorption by soil is less significant compared to HKB and kerogen. The sorption capacity and nonlinearity of demineralized Pahokee Peat soil is greater than original soil which suggested that SOM particle may enwrap up by the inorganic and clay materials, therefore sorbate molecules are not accessible to the surface of SOM particle. The results suggested that kerogen and BC may dominate the overall nonlinear sorption by soil and sediments. The contribution of HA in the overall sorption is different from previous studies. It may be caused by different chemical isolation procedures and needs further investigation.

• Research Organization: Rutgers University, New Brunswick, NJ (US); Chinese Academy of Sciences, Guangzhou (CN)
• Sponsoring Organization: Sponsor not identified (US)
• OSTI ID: 826128
• Country of Publication: United States
• Language: English

Related Subjects

01 COAL, LIGNITE, AND PEAT
04 OIL SHALES AND TAR SANDS
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
54 ENVIRONMENTAL SCIENCES
CAPACITY
CHEMICAL PROPERTIES
DESORPTION
HUMIC ACIDS
HYSTERESIS
ISOTHERMS
KEROGEN
MAGNETIC RESONANCE
NAPHTHALENE
ORGANIC MATTER
PEAT
PHENANTHRENE
SCANNING ELECTRON MICROSCOPY
SEDIMENTS
SOILS
SORPTION
SPECTROSCOPY