ROLE OF THE SURFACE CHARGE PROPERTIES FOR BACTERIAL RETENTION IN SOILS; SIGNIFICANCE OF SOLUBLE AND COLLOIDAL ORGANIC MATTER IN SUSPENSION
Adrian Unc1, Michael J. Goss2, Susan Springthorpe1, and Syed A. Sattar1,
1University of Ottawa, 2University of Guelph
(free)
Liquid residuals deposited on tile-drained land often reach the tiles rapidly, and such contamination is facilitated by rainfall. Any predictive and risk management effort aimed at mitigating microbial contamination risk for groundwater due to tile drain discharges requires proper understanding of the transport behaviour of bacteria through soil. Retention and filtration of bacterial cells within the soil profile reduces the microbial contaminant risk associated with the land application of organic wastes. Initial retention of bacterial cells on soils is dependent on the electrostatic interactions between the microbes and mineral and organic matter surfaces.
Electrostatic retention of bacterial cells within a profile is governed by the interaction between bacterial cells and soil particles charge characteristics. Both components are characterized by having variable surface properties that are modified by the components of the soil solution. The impact of the organic wastes, which are the source of contaminant enteric bacteria, on the composition of the soil solution can be critical in determining the rate at which bacterial cells are retained or transported through soils.
KEY WORDS Bacterial cell surface properties, bacterial transport, microbial contamination, manure, microspheres, soil, surface retention
