Transport of Escherichia coli Through Intact and Disturbed Soil Columns

Abstract

The transport of antibiotic resistant Escherichia coli through several soils was evaluated. Up to 96% of the bacteria irrigated onto the surface of 280 mm deep intact columns were recovered in the effluent. Soil structure appeared to be related to the extent of transport. Columns prepared from mixed, repacked soil were much more effective bacterial filters than the intact soils. As rate of water input increased, the fraction of E. coli recovered in the effluent increased. The observed behavior of E. coli and the Cl− solution in which they were suspended suggests that flow through soil macropores, which bypasses the adsorptive or retentive capacities of the soil matrix, is a common phenomenon. In waste disposal systems dependent on purification in the soil profile, this could significantly increase the probability of groundwater contamination.

Bacterial transport in porous media: New aspects of the mathematical model

“…Moreover, there is probability in enhancement in the penetration of the cells through the porous medium thereby leading to earlier breakthrough. The enhancement of bacterial transport at higher water flow velocity is also reported experimentally by several other investigators [7,14].…”

Fate of a bacterium,Pseudomonas paucimobilisSS86, in Upland Field

“…Escherichia coli, poured on to intact and disturbed soil columns (Smith et al 1985), and Pseudomonas fluorescens and Bacillus subtilis introduced into the soil of field microplots (van Elsas et al 1986) were vertically transported by irrigation or water percolation. Hamdi (1970) and Wilkinson et al (1981) reported that the soil water potential affects the microbial movement in soil.…”

The Influence of Vegetation in Riparian Filterstrips on Coliform Bacteria: II. Survival in Soils

“…Gerba et al (1975) found that 92 to 97% of the Escherichia coli are filtered out in the first 4 cm as they move down through the soil. However, both laboratory and field studies have shown that enteric microorganisms can be transported long distances through soil (Huysman and Verstraete, 1993;Van Elsas et al, 1991;Chen, 1988;Smith et al, 1985). The explanation that has been given is the preferential flow of water transporting bacteria through soil macro pores, cracks, and fissures (McMurry et al, 1998;Abu-Ashour et al, 1994).…”