TEMPORAL AND SPATIAL CHANGES OF TERMINAL ELECTRON-ACCEPTING PROCESSESIN A PETROLEUM HYDROCARBON-CONTAMINATED AQUIFER AND THE SIGNIFICANCE FOR CONTAMINANT BIODEGRADATION
Da. Vroblesky et Fh. Chapelle, TEMPORAL AND SPATIAL CHANGES OF TERMINAL ELECTRON-ACCEPTING PROCESSESIN A PETROLEUM HYDROCARBON-CONTAMINATED AQUIFER AND THE SIGNIFICANCE FOR CONTAMINANT BIODEGRADATION, Water resources research, 30(5), 1994, pp. 1561-1570
Measurements of dissolved hydrogen and other biologically active solut
es in groundwater from a shallow petroleum hydrocarbon-contaminated aq
uifer indicate that the distribution of microbial terminal electron-ac
cepting processes (TEAPs), such as methanogenesis, sulfate reduction,
and ferric iron (Fe (III)) reduction, is highly dynamic in both time a
nd space. Delivery of sulfate to methanogenic zones by infiltrating re
charge or lateral transport can result in a TEAP shift from methanogen
esis to sulfate reduction. Conversely, lack of recharge and consumptio
n of available sulfate can result in a shift from sulfate reduction to
methanogenesis. Temporal shifts between sulfate and Fe (III) reductio
n were also observed. Time lags associated with TEAP shifts ranged fro
m less than 10 days to about 3 1/2 months. The relation between TEAP a
nd biodegradation rates of a variety of organic compounds indicate tha
t biodegradation rates of petroleum hydrocarbons probably vary tempora
lly and spatially in a contaminated aquifer.