TY - JOUR
T1 - Formation of Soluble Mercury Oxide Coatings
T2 - Transformation of Elemental Mercury in Soils
AU - Miller, Carrie L.
AU - Watson, David B.
AU - Lester, Brian P.
AU - Howe, Jane Y.
AU - Phillips, Debra H.
AU - He, Feng
AU - Liang, Liyuan
AU - Pierce, Eric M.
N1 - Publisher Copyright:
© 2015 American Chemical Society.
PY - 2015/10/20
Y1 - 2015/10/20
N2 - 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.
AB - 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.
UR - http://www.scopus.com/inward/record.url?scp=84945246209&partnerID=8YFLogxK
U2 - 10.1021/acs.est.5b00263
DO - 10.1021/acs.est.5b00263
M3 - Article
C2 - 26389816
AN - SCOPUS:84945246209
SN - 0013-936X
VL - 49
SP - 12105
EP - 12111
JO - Environmental Science and Technology
JF - Environmental Science and Technology
IS - 20
ER -