American Society of Civil Engineers


Release of Polychlorinated Biphenyls from River Sediment to Water under Low-Flow Conditions: Laboratory Assessment


by Enrique Ortiz, (Assoc. Prof., Dept. de Ingenieria Quimica, ITESM—Campus Monterrey, Sucursal de Correos J, Monterrey, NL 64849 Mexico. E-mail: eortiz@itesm.mx), Richard G. Luthy, M.ASCE, (Silas H. Palmer Prof., Dept. of Civ. and Envir. Engrg., Stanford Univ., Stanford, CA 94305. E-mail: luthy@stanford.edu), David A. Dzombak, F.ASCE, (Manager, Dept. of Civ. and Envir. Engrg., Carnegie Mellon Univ., Pittsburgh, PA 15213. E-mail: dzombak@cmu.edu), and John R. Smith, M.ASCE, (Prof., EHS Sci. and Technol., Alcoa Inc., Alcoa Tech. Ctr., 100 Technical Drive, Alcoa Ctr., PA 15069. E-mail: john.r.smith@alcoa.com)

Journal of Environmental Engineering, Vol. 130, No. 2, February 2004, pp. 126-135, (doi:  http://dx.doi.org/10.1061/(ASCE)0733-9372(2004)130:2(126))

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Document type: Journal Paper
Abstract: The diffusive release of polychlorinated biphenyls (PCBs) from sediments to water under low-flow conditions was measured for surficial sediments with different PCB concentrations collected from the Grasse River near Massena, N.Y. Data on PCB sediment-water equilibrium partitioning and PCB mass release flux from sediments were used to assess the extent and mass transfer rate of PCB release under low-flow conditions in the Grasse River. Microcosm studies were employed to evaluate the release flux of PCBs under quiescent conditions for various river sediments and sediment mixtures. The observed total-PCB release fluxes ranged from about 1 to 20 mg/m2year, showing predominantly dichloro- through tetrachlorobiphenyls. Analyses of water column samples from the Grasse River under low-flow conditions also indicated the predominance of dichloro- through tetrachlorobiphenyls as in the microcosm tests. Data on PCB equilibrium partitioning between water and sediment were used to estimate sediment porewater concentrations, and these data combined with the microcosm flux data were used to estimate average, aqueous-boundary-layer total-PCB mass transfer coefficients of 0.3.1.5 cm/day. These values are consistent with estimates of mass transfer coefficients based on aqueous-boundary-layer correlations, and with PCB mass transfer coefficients inferred from the field data for low-flow conditions in the fall and winter (approximately 2 cm/day). The correspondence of the laboratory results with the field measurements and mass transfer rates demonstrates the usefulness of the microcosm technique for estimating fluxes of PCBs from river sediments under low-flow minimum bioturbation conditions.


ASCE Subject Headings:
Desorption
Diffusion
New York
PCB
Rivers and streams
Sediment