Transport of bacteria in heterogeneous media under leaching conditions. Issue 6 (1st November 2002)

• Record Type: Journal Article
• Authors: Viraraghavan, T
• Is Part Of: Journal of environmental engineering and science. Volume 1:Issue 6(2002)
• Page Start: 383
• Page End: 395
• Publication Date: 2002-11-01
• Subjects: porous media; -- bacterial transport; -- filtration coefficient; -- unsaturated flow; -- retention; -- hydraulic conductivity; 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/s02-030
• Languages: English
• ISSNs: 1496-2551

Abstract

Abstract : Bacterial mobility under unsaturated soils play an important role in the dispersal of pathogenic microorganisms and enhancing biorestoration of contaminated soil. Experiments were conducted to evaluate the effects of bacterial retention under unsaturated flow conditions in 5% and 10% bentonite-sand mixtures. Bacterial transport and retention was investigated under different rainfall events at 22°C and 4°C. Results indicated that bacterial accumulation was predominantly at the surface of the porous media and decreased with depth. Bacterial movement was also retarded relative to the chloride tracer in all fractions of the porous media. Heterogeneity of the porous media enhanced retention through filtration, specific surface area, and reduction in permeability. Recovery of the bacteria was influenced by the air-water interface with greater bacteria recovered at 4°C compared to 22°C. The colloidal filtration model described the distribution through the experimental columns. A linear relationship was observed between the filtration coefficient and the hydraulic conductivity from the different proportions of bentonite-sand. This correlation confirms that the colloidal filtration model can be used to determine the transport of bacteria through varying hydraulic conductivities of the porous media.