Sediment control of facilitated transport and enhanced desorption
Laboratory column experiments examined the facilitated transport and enhanced desorption of benz(a)anthracene [B(a)A] by dissolved natural organic matter (OM) in sediments of low organic carbon content. The two-component experiments examining OM-sediment interaction and B(a)A-sediment interaction were modeled to determine the value of the linear rate constants describing transfer of B(a)A and OM between water and sediment. It was found that a two-rate approach better simulated B(a)A breakthrough and elution in the sediment relative to a one-rate approach. In contrast, OM-sediment interaction was well-simulated with a one-rate approach due to low OM sorption by sediment. The three-component experiments examining facilitated transport and enhanced desorption of B(a)A by dissolved OM, showed rapid linear reversible B(a)A-OM interaction. The value, within a factor of 2, of the equilibrium distribution constant for benz(a)anthracene distribution between water and OM was {approximately}1E6 for soil humic acid and {approximately}1E5 for Suwannee River humic acid. Simulations of the three-component experiments based on the equilibrium distribution constants for B(a)A-OM interaction and the rate constants determined from the two-component experiments were performed to determine whether rate constants differed in the two-component versus three-component systems. The simulations captured the major features of the facilitated transport and enhanced desorption data; however, discrepancies indicated that either the two-rate model for solute-sediment interaction was inappropriate, or that B(a)A transfer from sediment to dissolved OM was altered in the three-component system relative to the two-component system.
- Research Organization:
- Univ. of Utah, Salt Lake City, UT (US)
- OSTI ID:
- 20006123
- Journal Information:
- Journal of Environmental Engineering (New York), Vol. 126, Issue 1; Other Information: PBD: Jan 2000; ISSN 0733-9372
- Country of Publication:
- United States
- Language:
- English
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