HR: 13:45h
AN: B23A-02    [Abstracts]
TI: Transport of Cryptosporidium parvum in Surface Waters: Interplay of Hydrodynamic Processes, Sediments, and Biofilms
AU: * Searcy, K E
EM: k-searcy@northwestern.edu
AF: Northwestern University, Department of Civil and Environmental Engineering, 2145 Sheridan Road, Evanston, IL 60208 United States
AU: Packman, A I
EM: a-packman@northwestern.edu
AF: Northwestern University, Department of Civil and Environmental Engineering, 2145 Sheridan Road, Evanston, IL 60208 United States
AU: Atwill, E R
EM: ratwill@vmtrc.ucdavis.edu
AF: University of California-Davis, Veterinary Medicine Teaching and Research Center, School of Veterinary Medicine, 18830 Road 112, Tulare, CA 93274 United States
AU: Harter, T
EM: thharter@ucdavis.edu
AF: University of California-Davis, Department of Land, Air and Water Resources, One Shields Avenue, Davis, CA 95616 United States
AB: Understanding the movement of pathogens in the environment is necessary to ensure the safety and protection of municipal water supply systems. Cryptosporidium parvum is a human pathogen of particular concern as it is common in surface waters of the United States, it can survive for long periods of time in the environment, and it is difficult to disinfect in water treatment plants. The transport of oocysts through watersheds can be mediated by interactions with the stream channel and suspended particles in the water column. For example, the association of C. parvum oocysts with suspended particles can alter the effective physical properties of the oocysts and increase their settling velocity. The hydrodynamic coupling of the overlying water with the pore water of the sediment bed can carry oocysts from the surface water into the sediment bed. Surface-attached communities of microorganisms, called biofilms, are ubiquitous in surface water systems and can capture C. parvum oocysts. Laboratory experiments were conducted at multiple scales (flowcell, batch, and flume) to determine the association of oocysts with sediments and biofilm communities and to assess the impact of this association on C. parvum transport. The effects of flow conditions, water chemistry, sediment composition, biofilm composition, and biofilm structure on these associations were all evaluated. The experimental results demonstrate that oocyst-sediment-biofilm interactions have significant implications for the propagation of C. parvum oocysts through watersheds and should generally be considered when predicting the fate of pathogens in the environment.
DE: 1871 Surface water quality
DE: 4840 Microbiology
SC: Biogeosciences [B]
MN: 2005 Joint Assembly