Development and resistance of a biofilm in a planar fracture during biostimulation, starvation, and varying flow conditions. Issue 4 (1st July 2007)

• Record Type: Journal Article
• Authors: Ross, Nathalie; Novakowski, Kent S; Lesage, Suzanne; Deschênes, Louise; Samson, Réjean
• Is Part Of: Journal of environmental engineering and science. Volume 6:Issue 4(2007)
• Page Start: 377
• Page End: 388
• Publication Date: 2007-07-01
• Subjects: environment; Environmental engineering -- Periodicals; Sanitary engineering -- Periodicals; Environmental engineering -- Canada -- Periodicals; Environnement, Technique de l' -- Périodiques; Technique sanitaire -- Périodiques; Environnement, Technique de l' -- Canada -- Périodiques; Environmental engineering; Sanitary engineering; Canada; Electronic journals; Computer network resources; Periodicals; 628.05
• DOI: 10.1139/s06-056
• Languages: English
• ISSNs: 1496-2551

Abstract

Abstract : Investigations of biofilms in a planar fracture are required to develop a biobarrier concept in aquifers. A glass-fracture apparatus was designed to monitor a biofilm under three phases: biostimulation, starvation, and increased flow. Direct observations were performed using a light probe whereas indirect indications were obtained by enumerating planktonic bacteria, monitoring the oxidation–reduction potential (ORP), and interpreting tracer experiments using an analytical model for two-dimensional advection-dispersion. Biofilm clusters developed along the flow lines before extending to a fully-connected biofilm, covering 500 cm 2 after 50 d. The starvation phase favoured bacterial attachment at first followed by detachment, which was accentuated by increases in groundwater velocity. The ORP declined over the three experimental phases and was significantly related to the distance from the biostimulation zone. The modeling suggested that an increase in transverse dispersion within the fracture only occurs during the biostimulation phase. Key words: fractured rock, groundwater flow, biofilms, biobarriers, advection–dispersion model, biostimulation, starvation, oxidation–reduction potential.