title: Impact of biofilm on bacterial transport and deposition in porous media.
abstract: Laboratory scale experiments were conducted to obtain insights into factors that influence bacterial transport and deposition in porous media. According to colloidal filtration theory, the removal efficiency of a filter medium is characterized by two main factors: collision efficiency and sticking efficiency. In the case of bacterial transport in porous media, bacteria attached to a solid surface can establish a thin layer of biofilm by excreting extracellular polymeric substances which can significantly influence both of these factors in a porous medium, and thus, affect the overall removal efficiency of the filter medium. However, such polymeric interactions in bacterial adhesion are not well understood and a method to calculate polymeric interactions is not yet available. Here, to determine how the migration of bacteria flowing within a porous medium is affected by the presence of surface-associated extracellular polymeric substances previously produced and deposited by the same bacterial species, a commonly used colloidal filtration model was applied to study transport and deposition of Pseudomonas fluorescens in small-scale columns packed with clean and biofilm coated glass beads. Bacterial recoveries were monitored in column effluents and used to quantify biofilm interactions and sticking efficiencies of the biofilm coated packed-beds. The results indicated that, under identical hydraulic conditions, the sticking efficiencies in packed-beds were improved consistently by 36% when covered by biofilm.
authors.affiliation: Department of Chemical and Petroleum Engineering, Schulich School of Engineering, University of Calgary, 2500 University Drive NW, Calgary, Alberta T2N 1N4, Canada.
authors.forename: Ali
authors.initials: A
authors.lastname: Bozorg
authors.affiliation: Department of Chemical and Petroleum Engineering, Schulich School of Engineering, University of Calgary, 2500 University Drive NW, Calgary, Alberta T2N 1N4, Canada.
authors.forename: Ian D
authors.initials: ID
authors.lastname: Gates
authors.affiliation: Department of Chemical and Petroleum Engineering, Schulich School of Engineering, University of Calgary, 2500 University Drive NW, Calgary, Alberta T2N 1N4, Canada. Electronic address: asen@ucalgary.ca.
authors.forename: Arindom
authors.initials: A
authors.lastname: Sen
mesh_terms: D001422:Bacterial Adhesion; D018441:Biofilms; D005374:Filtration; D005898:Glass; D060587:Groundwater / Q000382:microbiology*; D062070:Hydrology / Q000379:methods*; D007753:Laboratories; D011108:Polymers; D016062:Porosity; D011551:Pseudomonas fluorescens / Q000502:physiology*; D012988:Soil Microbiology
chemical_list: D011108:Polymers
keywords: Bacterial deposition; Biofilm; Bioluminescence; Colloidal filtration theory (CFT); Polymer interaction; Sticking efficiency