Consumption of freons CFC-11 and CFC-12 by anaerobic sediments and soils

Environmental Science & Technology
By:  and 



A variety of anaerobic sediments and soils consumed CFC-11 (CFCl3) and CFC-12 (CF2Cl2). An aerobic soil did not. Active microbial metabolism was required for CFC-12 uptake in all of the sediments examined. CFC-11 uptake was faster in the presence of microbial activity, but reduced components in the sediments also resulted in nonenzymatic CFC-11 consumption in most instances. CFC-12 uptake in a culture of Clostridium pasteurianum provided a model for the sediment uptake of CFC-11 and CFC-12 that required active microbial metabolism. Consumption of CFC-11 in the presence of reduced hematin demonstrated a potential mechanism for nonenzymatic CFC-11 consumption. These findings demonstrate that CFC-11 and CFC-12 are not biochemically inert under anaerobic conditions. This suggests that anaerobic degradation of CFC-11 and CFC-12 in anaerobic landfills might prevent some disposed CFC-11 and CFC-12 from entering the atmosphere. The results also suggest that CFC-11 and CFC-12 cannot be used as stable tracers in anaerobic environments. Furthermore, although the microbial sink for atmospheric CFC-11 and CFC-12 is much less than current anthropogenic release, this sink could have a significant long-term effect on the amount of CFC-11 and CFC-12 reaching the stratosphere.

Additional publication details

Publication type Article
Publication Subtype Journal Article
Title Consumption of freons CFC-11 and CFC-12 by anaerobic sediments and soils
Series title Environmental Science & Technology
DOI 10.1021/es00029a009
Volume 26
Issue 5
Year Published 1992
Language English
Publisher ACS
Contributing office(s) Toxic Substances Hydrology Program
Description 5 p.
First page 925
Last page 929
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