Scott Durelle T, McKnight Diane M, Voelker Bettina M, Hrncir Duane C
Institute of Arctic and Alpine Research, University of Colorado at Boulder, 80309-0450, USA.
Environ Sci Technol. 2002 Feb 1;36(3):453-9. doi: 10.1021/es010951s.
The biogeochemical processes controlling the speciation and transport of manganese in a Colorado mountain stream were studied using a conservative tracer approach combined with laboratory experiments. The study stream, Lake Fork Creek, receives manganese-rich inflows from a wetland contaminated by acid mine drainage. A conservative tracer experiment was conducted on a 1300-m reach of the stream. Results indicate that manganese was progressively removed from the stream, resulting in a loss of 64 +/- 17 micromol day(-1) m(-1). Laboratory experiments using streamwater, mine effluent, and rocks from the stream showed the importance of surface-catalyzed oxidation and photoreduction on the speciation of manganese. The field and modeling results indicate that light generally promotes oxidation and removal of manganese from the stream, presumably through a photosynthetically enhanced oxidation process. Differences in Mn speciation within the stream suggest that reductive processes affect Mn speciation within the water column. These results identify the rapid oxidation and precipitation of MnOx as a dominant process within this freshwater stream.
采用保守示踪剂方法并结合实验室实验，对科罗拉多山区一条溪流中控制锰形态和迁移的生物地球化学过程进行了研究。研究溪流“叉湖溪”接收来自受酸性矿山排水污染湿地的富锰水流。在该溪流1300米长的河段进行了保守示踪剂实验。结果表明，锰从溪流中逐渐去除，导致损失速率为64±17微摩尔·天⁻¹·米⁻¹。使用溪水、矿山废水和溪流中的岩石进行的实验室实验表明，表面催化氧化和光还原对锰的形态有重要影响。现场和模型结果表明，光照通常促进溪流中锰的氧化和去除，可能是通过光合增强氧化过程。溪流中锰形态的差异表明，还原过程影响水柱内的锰形态。这些结果表明，氧化锰的快速氧化和沉淀是这条淡水溪流中的主导过程。
