title: Formation of Soluble Mercury Oxide Coatings: Transformation of Elemental Mercury in Soils.
abstract: The impact of mercury (Hg) on human and ecological health has been known for decades. Although a treaty signed in 2013 by 147 nations regulates future large-scale mercury emissions, legacy Hg contamination exists worldwide and small-scale releases will continue. The fate of elemental mercury, Hg(0), lost to the subsurface and its potential chemical transformation that can lead to changes in speciation and mobility are poorly understood. Here, we show that Hg(0) beads interact with soil or manganese oxide solids and X-ray spectroscopic analysis indicates that the soluble mercury coatings are HgO. Dissolution studies show that, after reacting with a composite soil, >20 times more Hg is released into water from the coated beads than from a pure liquid mercury bead. An even larger, >700 times, release occurs from coated Hg(0) beads that have been reacted with manganese oxide, suggesting that manganese oxides are involved in the transformation of the Hg(0) beads and creation of the soluble mercury coatings. Although the coatings may inhibit Hg(0) evaporation, the high solubility of the coatings can enhance Hg(II) migration away from the Hg(0)-spill site and result in potential changes in mercury speciation in the soil and increased mercury mobility.
authors.affiliation: Environmental Sciences Division, Oak Ridge National Laboratory (ORNL) , Oak Ridge, Tennessee 37831, United States.|Troy University , Troy, Alabama 36082, United States.
authors.forename: Carrie L
authors.initials: CL
authors.lastname: Miller
authors.affiliation: Environmental Sciences Division, Oak Ridge National Laboratory (ORNL) , Oak Ridge, Tennessee 37831, United States.
authors.forename: David B
authors.initials: DB
authors.lastname: Watson
authors.affiliation: Environmental Sciences Division, Oak Ridge National Laboratory (ORNL) , Oak Ridge, Tennessee 37831, United States.
authors.forename: Brian P
authors.initials: BP
authors.lastname: Lester
authors.affiliation: Environmental Sciences Division, Oak Ridge National Laboratory (ORNL) , Oak Ridge, Tennessee 37831, United States.|Hitachi High Technologies Canada, Incorporated , Toronto, Ontario M9W 6A4, Canada.
authors.forename: Jane Y
authors.initials: JY
authors.lastname: Howe
authors.affiliation: Queen's University Belfast , Belfast BT7 1NN, United Kingdom.
authors.forename: Debra H
authors.initials: DH
authors.lastname: Phillips
authors.affiliation: Environmental Sciences Division, Oak Ridge National Laboratory (ORNL) , Oak Ridge, Tennessee 37831, United States.|College of Biological and Environmental Engineering, Zhejiang University of Technology , Hangzhou, Zhejiang 310032, People's Republic of China.
authors.forename: Feng
authors.initials: F
authors.lastname: He
authors.affiliation: Environmental Sciences Division, Oak Ridge National Laboratory (ORNL) , Oak Ridge, Tennessee 37831, United States.
authors.forename: Liyuan
authors.initials: L
authors.lastname: Liang
authors.affiliation: Environmental Sciences Division, Oak Ridge National Laboratory (ORNL) , Oak Ridge, Tennessee 37831, United States.
authors.forename: Eric M
authors.initials: EM
authors.lastname: Pierce
mesh_terms: D017895:Manganese Compounds / Q000737:chemistry; D008628:Mercury / Q000032:analysis / Q000737:chemistry*; D017669:Mercury Compounds / Q000737:chemistry*; D010087:Oxides / Q000737:chemistry*; D012987:Soil / Q000737:chemistry; D012989:Soil Pollutants / Q000032:analysis / Q000737:chemistry*; D012995:Solubility; D014867:Water / Q000737:chemistry; D056928:X-Ray Absorption Spectroscopy
chemical_list: D017895:Manganese Compounds; D017669:Mercury Compounds; D010087:Oxides; D012987:Soil; D012989:Soil Pollutants; D014867:Water; C027424:manganese oxide; D008628:Mercury; C019468:mercuric oxide