Bacterial transport through intact sediment cores; variability of transport parameters and controlling aquifer characteristics

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Authors:Sun, Kerang; Levy, Jonathan; Findlay, Robert H.; Schran, Heidi L.; Rossman, Anthony J.
Author Affiliations:Primary:
Miami University, Geology Department, Oxford, OH, United States
Volume Title:Geological Society of America, 1998 annual meeting
Source:Abstracts with Programs - Geological Society of America, 30(7), p.277; Geological Society of America, 1998 annual meeting, Toronto, ON, Canada, Oct. 26-29, 1998. Publisher: Geological Society of America (GSA), Boulder, CO, United States. ISSN: 0016-7592
Publication Date:1998
Note:In English
Summary:To protect groundwater aquifers from pathogenic-bacterial contamination, we need to develop the ability to predict allochthonous bacterial transport through groundwater aquifers. To make such predictions, we need good estimates of such transport parameters as die-off and sorption coefficients. These parameter values, in turn, depend on physical, chemical and biological characteristics of groundwater aquifers including grain size, mineralogy, solid organic-matter content and the nature of the autochthonous microbial community. Laboratory column experiments are often employed to study the transport behavior of allochthonous bacteria through groundwater. Most column studies use artificial aquifer sediments rather than natural sediments in intact cores. One of the drawbacks of using artificial sediment is that it fails to capture the heterogeneity inherent in natural systems. There can be substantial core-to-core variability in natural aquifer sediment, and consequently, variability in transport parameter values. Quantification of this variability is important before a predictive model of bacterial-transport through heterogeneous media can be developed. The purpose of this research is to study the variability of aquifer properties and its impact on bacterial transport. Undisturbed sediment cores were collected from a glacial outwash, buried-valley aquifer in southwestern Ohio. These cores were collected from a depth of 4.5 to 6 m within a 25 square-meter area. Bacterial breakthrough experiments were carried out on 10-cm length sections of these cores by injecting a pulse of coliform bacteria into one end and analyzing the effluent under steady-flow conditions. Bromide breakthrough experiments were also run to derive appropriate velocity and dispersivity values. Bacterial-transport parameters were found by fitting a modified advection-dispersion-reaction equation to the data. Upon completion of flow-through experiments, biotic and abiotic characterizations of the cores were conducted including analyses of the autochthonous microbial community, grain size, mineralogy and total solid organic-matter content. The variability of these properties was statistically analyzed and correlated to the variability of the transport parameters.
Subjects:Aquifer vulnerability; Aquifers; Chemical properties; Coliform bacteria; Communities; Controls; Cores; Experimental studies; Grain size; Ground water; Heterogeneity; Mineral composition; Organic compounds; Physical properties; Pollution; Properties; Protection; Quantitative analysis; Sediments; Statistical analysis; Transport; Variations; Bacteria
Record ID:1999029268
Copyright Information:GeoRef, Copyright 2018 American Geosciences Institute. Reference includes data supplied by the Geological Society of America, Boulder, CO, United States
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