You are here:
REDUCTIVE DEHALOGENATION OF HALOMETHANES IN IRON- AND SULFATE-REDUCING SEDIMENTS. 1. REACTIVITY PATTERN ANALYSIS
Citation:
Kenneke, J F. AND E J. Weber. REDUCTIVE DEHALOGENATION OF HALOMETHANES IN IRON- AND SULFATE-REDUCING SEDIMENTS. 1. REACTIVITY PATTERN ANALYSIS. ENVIRONMENTAL SCIENCE & TECHNOLOGY 37(4):713-720, (2003).
Impact/Purpose:
Elucidate and model the underlying processes (physical, chemical, enzymatic, biological, and geochemical) that describe the species-specific transformation and transport of organic contaminants and nutrients in environmental and biological systems. Develop and integrate chemical behavior parameterization models (e.g., SPARC), chemical-process models, and ecosystem-characterization models into reactive-transport models.
Description:
The incorporation of reductive transformations into environmental fate models requires the characterization of natural reductants in well-characterized sediments and aquifer materials. For this purpose, reactivity patterns (i.e., the range and relative order of reactivity) for a series of halogenated methanes were measured in an iron- and sulfate reducing sediment, as well as model systems representing iron sulfide and Fe(II) associated with Fe(III) containing minerals. The strong similarity in reaction patterns between the iron- and sulfate-reducing sediments suggests a common mechanism for reductive transformation. The comparison of reactivity patterns measured in the sediment and model systems, in addition to those reported for the reduction of halogenated methanes in iron porphyrin and mercaptojuglone model systems, suggests that Fe(II) adsorbed to Fe(III) containing minerals is the dominant reductant in both the iron- and sulfate-reducing sediments despite the significant formation of FeS.