USGS - science for a changing world

Environmental Health - Toxic Substances


U.S. Geological Survey Toxic Substances Hydrology Program--Proceedings of the Technical Meeting, Colorado Springs, Colorado, September 20-24, 1993, Water-Resources Investigations Report 94-4015

Previous PageTable of ContentsNext Page

Effects of Pb and Terminal-Electron-Accepting Processes on Organic Acid Concentrations in Contaminated Aquifer Sediments


Paul M. Bradley (U.S. Geological Survey, Columbia, South Carolina), Francis H. Chapelle (U.S. Geological Survey, Columbia, South Carolina), and Don A. Vroblesky (U.S. Geological Survey, Columbia, South Carolina)


The effects of terminal-electron-accepting processes (TEAPs) and dissolved Pb concentrations on carbon mineralization and organic acid accumulation in petroleum-contaminated sediments were examined under aerobic, nitrate reducing, sulfate reducing, and methanogenic conditions. Pb concentrations in the 14 to 60 µg/L range observed in the field significantly inhibited CO2 production for all TEAPs as well as CH4 production under methanogenic conditions. However, accumulation of organic acids was more closely related to the dominant TEAP. Acetic, propionic, i-butyric, and n-butyric acids accumulated in methanogenic treatments, whereas only acetic acid was detected in sulfate reducing treatments. As expected, no organic acids were detected under nitrate reducing or aerobic conditions. This pattern parallels field observations in which high concentrations of organic acids (acetic, propionic, i-butyric, and n-butyric acids) were detected in methanogenic zones, but only low concentrations of acetic acid were detected in sulfate reducing zones.

Previous PageTable of ContentsNext Page

USGS Home Water Land Resources Science Systems Ecosystems Energy and Minerals Environmental Health Hazards

Accessibility FOIA Privacy Policies and Notices logo U.S. Department of the Interior | U.S. Geological Survey
Page Contact Information:
Page Last Modified: Tuesday, 04-Aug-2015 15:15:53 EDT