Redox Processes Controlling Manganese Fate and Transport in a Mountain Stream
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- 作者：Durelle T. Scott ; Diane M. McKnight ; Bettina M. Voelker ; and Duane C. Hrncir
- 刊名：Environmental Science & Technology
- 出版年：2002
- 出版时间：February 1, 2002
- 年：2002
- 卷：36
- 期：3
- 页码：453 - 459
- 全文大小：114K
- 年卷期：v.36,no.3(February 1, 2002)
- ISSN：1520-5851
文摘
The biogeochemical processes controlling the speciationand transport of manganese in a Colorado mountain streamwere studied using a conservative tracer approachcombined with laboratory experiments. The study stream,Lake Fork Creek, receives manganese-rich inflows froma wetland contaminated by acid mine drainage. A conservativetracer experiment was conducted on a 1300-m reach ofthe stream. Results indicate that manganese was progressivelyremoved from the stream, resulting in a loss of 64 ± 17
mol day-1 m-1. Laboratory experiments using streamwater,mine effluent, and rocks from the stream showed theimportance of surface-catalyzed oxidation and photoreductionon the speciation of manganese. The field and modelingresults indicate that light generally promotes oxidation andremoval of manganese from the stream, presumablythrough a photosynthetically enhanced oxidation process.Differences in Mn speciation within the stream suggestthat reductive processes affect Mn speciation within thewater column. These results identify the rapid oxidation andprecipitation of MnOx as a dominant process within thisfreshwater stream.
mol day-1 m-1. Laboratory experiments using streamwater,mine effluent, and rocks from the stream showed theimportance of surface-catalyzed oxidation and photoreductionon the speciation of manganese. The field and modelingresults indicate that light generally promotes oxidation andremoval of manganese from the stream, presumablythrough a photosynthetically enhanced oxidation process.Differences in Mn speciation within the stream suggestthat reductive processes affect Mn speciation within thewater column. These results identify the rapid oxidation andprecipitation of MnOx as a dominant process within thisfreshwater stream.