Protection of potable water supplies demands a better understanding of the factors controlling migration of disease causing bacteria in subsurface environments. In this study, the migration behaviour of the waterborne pathogenic microorganisms Escherichia coli O157:H7 and Yersinia enterocolitica was investigated in water saturated granular systems. Both facultative bacteria were grown under aerobic and anaerobic conditions and further acclimatized to a microaerophilic or fully aerated environment for 21 h. Experiments were conducted using laboratory-scale packed columns over controlled extreme dissolved oxygen (DO) concentrations. The observed differences in the transport potential of these pathogens were found to depend strongly on the antecedent growth conditions under the tested environmental settings as well with the environmental DO in certain conditions. Further microbial characterization using cell titrations and FTIR spectroscopy gave a greater insight on the source of the surface charge that was found to dominate the attachment phenomena in sand packed columns. Techniques also revealed a probable role of other cell surface macromolecules (LPS) that could account for non-DLVO behaviour. The results illustrate the importance of considering physicochemical conditions relevant to the natural subsurface environment when designing laboratory transport experiments as evidenced by variations in microbe migration as a function of the DO under growth and acclimation. / Keywords: bacterial adhesion, bacterial transport, DLVO, physicochemical characterization, dissolved oxygen, porous media.
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:QMM.116013 |
| Date | January 2008 |
| Creators | Castro A., Felipe (Castro Arancibia), 1979- |
| Publisher | McGill University |
| Source Sets | Library and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada |
| Language | English |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Format | application/pdf |
| Coverage | Master of Engineering (Department of Chemical Engineering.) |
| Rights | All items in eScholarship@McGill are protected by copyright with all rights reserved unless otherwise indicated. |
| Relation | alephsysno: 002842129, proquestno: AAIMR66948, Theses scanned by UMI/ProQuest. |
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