Common Mineral Alters Fate of Mercury in Contaminated Sediments


Mercury (Hg) contamination is a significant environmental concern due to its toxicity and is one of the most challenging remediation challenges at DOE’s Oak Ridge site.  Ionic mercury (Hg[II]) can be transformed by anaerobic bacteria in anoxic soils and sediments to methylmercury (MeHg), a potent neurotoxin.  MeHg accumulates in ecological food chains and can be readily detected in fish tissues in contaminated streams and rivers. Reducing the levels of Hg(II) in contaminated soils decreases the potential for forming MeHg.  Researchers at Rutgers University and Pacific Northwest National Laboratory show that Hg(II) can be reduced to elemental Hg(0) by magnetite, a mineral commonly found in anoxic sediments.  The results demonstrate a potentially important mechanism of Hg(II) reduction needed to better understand the fate of Hg in contaminated environments and improve predictions of MeHg production in anoxic sediments.


Environ. Sci. Technol., 2009, 43(14): 5307-5313