Theses and Dissertations at Montana State University (MSU)
Permanent URI for this collectionhttps://scholarworks.montana.edu/handle/1/733
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Item Effect of co-substrate concentration on dual-species population distribution, permeability reduction and trichloroethylene (TCE) biodegradation in porous media(Montana State University - Bozeman, College of Engineering, 2001) Komlos, JohnItem Retention of a model pathogen in a porous media biofilm(Montana State University - Bozeman, College of Engineering, 2007) Bauman, Wesley James; Chairperson, Graduate Committee: Anne CamperThe inadvertent or deliberate introduction of bacterial pathogens into drinking water systems can lead to serious public health consequences. As a result, rapid sampling opportunities within distribution systems are needed that can provide information on the source, species and fate of introduced pathogens. In this study, a porous media biofilm reactor was used to investigate the ability of an established mixed-species drinking water biofilm to immobilize cyan-labeled Escherichia coli 0157:H7 as a model pathogen. Test reactors were colonized with biofilm for two or three weeks at 0.5 mg/l C, resulting in the formation of thin and thick biofilms, respectively. Colonized reactors were then injected with slug doses of approximately 1 x 109 cfu E. coli O157:H7. Plate counts were able to successfully close a mass balance on E. coli O157:H7 around the reactor and were used measure the fractions of inocula immobilized within reactors. Compared with control reactors (0.22%), reactors colonized for two or three weeks immobilized significantly more cells (0.75% and 9.37% respectively).Item Pathogen transport and capture in a porous media biofilm reactor(Montana State University - Bozeman, College of Engineering, 2007) Grabinski, Kevin John; Chairperson, Graduate Committee: Warren JonesDrinking water distribution systems pose the potential to transport biological and chemical contaminants to the consumers' tap that can be responsible for widespread waterborne disease outbreaks (WBDO). A need exists to improve the ability to monitor contaminants that can attach to the distribution system's interior surfaces and to obtain samples for diagnosing both the cause of a WBDO and the extent of contamination within the system. In this study, a porous media reactor colonized with a mixed-species drinking water biofilm was used to study the capture of Salmonella typhimurium as a model pathogen. Parallel reactors were operated under constant flow (CF) and constant head (CH) to compare flow-regime induced spatial variations in biofilm accumulation and the resulting pathogen capture. Parallel test reactors were operated with 0.5 mg/L supplemental carbon until the accumulation of biofilm in the CH reactor reduced the flowrate to the target sampling point (CF flowrate). Both test reactors were then inoculated with slug doses of approximately 3x109 CFU S. typhimurium. Effluent water samples were collected for five pore-volumes, followed by the destructive sampling of the reactor.