The effects of transverse mixing, hydrodynamic shear, and electron acceptor concentration on microbial growth at the pore scale were studied. A micromodel was fabricated by etching a pore structure, two inlet ports, and one outlet port into a silicon wafer and sealing the etched wafer with a glass cover slip. An electron acceptor tetrachloroethylene (PCE) and an electron donor (lactate) were each delivered to one of the inlet ports with a dual syringe pump. Biomass was observed within a week after the experiment started. Over the next few days, the line of growth spread upward into the PCE zone extending over a width of up to five pore spaces. When the PCE concentration was increased to 0.5 mM, the microbial growth moved back down towards the lactate side of the micromodel. This indicated that the initial growth moved upward because PCE was the limiting growth nutrient. Tracer studies determined that the biofilm created a flow barrier between the lactate and PCE zones. Effluent analysis showed large amounts of cis-dichloroethylene and almost no PCE, indicating dechlorination activity in the micromodel pore network. This is an abstract of a paper originally presented at the 225th ACS National Meeting (New Orleans, LA 3/23-27/2003).
|Original language||English (US)|
|Number of pages||3|
|Journal||ACS, Division of Environmental Chemistry - Preprints of Extended Abstracts|
|State||Published - 2003|
|Event||225th ACS National Meeting - New Orleans, LA, United States|
Duration: Mar 23 2003 → Mar 27 2003
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