HR: 0800h
AN: H21E-1385 [Abstracts]
TI: A Comparison of Transport Parameters for Viruses and Colloidal-Sized Microspheres during Flow through
Variably-Saturated Porous Media
AU: * Anders, R
EM: randers@usgs.gov
AF: U.S. Geological Survey, 5735 Kearny Villa Rd. Ste. O, San Diego, CA 92123
United States
AU: * Anders, R
EM: randers@usgs.gov
AF: University of California, Department of Civil and Environmental Engineering, Irvine, CA 92697
United States
AU: Chrysikopoulos, C V
EM: costas@eng.uci.edu
AF: University of California, Department of Civil and Environmental Engineering, Irvine, CA 92697
United States
AU: Chrysikopoulos, C V
EM: costas@eng.uci.edu
AF: University of Patras, Department of Civil Engineering, Rio, 26500
Greece
AB:
Laboratory-scale virus transport experiments were conducted in packed sand columns under saturated and unsaturated conditions
using: (1) the male-specific RNA coliphage, MS2, and the Salmonella typhimurium phage, PRD1; (2) 0.025-, 0.1-, and
0.1-m-carboxylated fluorescent polystyrene microspheres; and (3) bromide as the non-reactive tracer. A mathematical model
developed to quantify the processes responsible for the transport of viruses in one-dimensional, unsaturated porous media was
used to analyze the data collected from the laboratory experiments. Liquid to liquid-solid and liquid to air-liquid
interface mass transfer rates for the mathematical model were obtained by fitting the experimental data with a nonlinear
least squares regression method. In addition, dynamic batch experiments were conducted to obtain time-dependent inactivation
rate coefficients for bacteriophage MS2 and PRD1 in the presence of air-liquid-solid interfaces.
The calibrated liquid to liquid-solid and liquid to air-liquid interface mass transfer rates used to simulate the
concentration histories were less for bacteriophage than for microspheres. Furthermore, the fitted liquid to air-liquid
interface mass transfer rates for microspheres decreased with a reduction in soil moisture content but changed little for
bacteriophage. These results indicate that when unfavorable conditions are established in a packed sand column (pH = 7.5;
ionic strength = 2 mM), the relative importance of saturation fluctuations on virus transport is minimal. Instead, the
presence of air-liquid-solid interfaces appear to produce the greatest damage to specific viral components that are related
to infection. In contrast, for the polystyrene microspheres saturation levels as high as 75 percent can dramatically affect
their transport through porous media. Therefore, fluctuations in water saturation of the porous media affect differently the
transport of viruses as compared with colloidal-sized microspheres.
DE: 1829 Groundwater hydrology
DE: 1831 Groundwater quality
DE: 1832 Groundwater transport
DE: 1838 Infiltration
DE: 1847 Modeling
SC: Hydrology [H]
MN: Fall Meeting 2005