Oxidative dissolution of metacinnabar (β-HgS) by dissolved oxygen

被引:43
作者
Barnett, MO
Turner, RR
Singer, PC
机构
[1] Oak Ridge Natl Lab, Div Environm Sci, Oak Ridge, TN 37831 USA
[2] Univ N Carolina, Chapel Hill, NC 27599 USA
关键词
D O I
10.1016/S0883-2927(01)00026-9
中图分类号
P3 [地球物理学]; P59 [地球化学];
学科分类号
0708 ; 070902 ;
摘要
The oxidative dissolution rate of metacinnabar by dissolved O-2 was measured at pH similar to5 in batch and column reactors. In the batch reactors, the dissolution rate varied from 3.15 (+/-0.40) to 5.87 (+/-0.39) x 10(-2) mu mol/m(2)/day (I = 0.01 M, 23 degreesC) and increased with stirring speed, a characteristic normally associated with a transport-controlled reaction. However, theoretical calculations, a measured activation energy of 77 (+/-8) kJ/mol (I = 0.01 M), and the mineral dissolution literature indicate reaction rates this slow are unlikely to be transport controlled. This phenomenon was attributed to the tendency of the hydrophobic source powder to aggregate and minimize the effective outer surface area. However, in a column experiment, the steady-state dissolution rate ranged from 1.34 (+/-0.11) to 2.27 (+/-0.11) x 10(-2) mu mol/m(2)/day (I = 0.01 M, 23 degreesC) and was also influenced by flow rate, suggesting hydrodynamic conditions may influence weathering rates observed in the field. The rate of Hg release to solution, under a range of hydrogeochemical conditions that more closely approximated those in the subsurface, was I to 3 orders of magnitude lower than the dissolution rate due to the adsorption of released Hg(II) to the metacinnabar surface. The measured dissolution rates under all conditions were slow compared to the dissolution rates of minerals typically considered stable in the environment, and the adsorption of Hg(II) to the metacinnabar surface further lowered the Hg release rate. (C) 2001 Elsevier Science Ltd. All rights reserved.
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页码:1499 / 1512
页数:14
相关论文
共 38 条
[1]  
Adriano D.C., 1980, TRACE ELEMENTS AQUAT
[2]  
American Society for Testing and Materials, 1991, ANN BOOK ASTM STAND
[3]  
[Anonymous], 1986, SW846 US EPA
[4]  
[Anonymous], 2015, SUPERBOB
[5]  
Appelo C.A.J., 2004, Groundw. Pollut.
[6]   STEPWISE THERMAL-ANALYSIS TECHNIQUE FOR ESTIMATING MERCURY PHASES IN SOILS AND SEDIMENTS [J].
AZZARIA, LM ;
AFTABI, A .
WATER AIR AND SOIL POLLUTION, 1991, 56 :203-217
[7]   Formation of mercuric sulfide in soil [J].
Barnett, MO ;
Harris, LA ;
Turner, RR ;
Stevenson, RJ ;
Henson, TJ ;
Melton, RC ;
Hoffman, DP .
ENVIRONMENTAL SCIENCE & TECHNOLOGY, 1997, 31 (11) :3037-3043
[8]  
Brezonik PatrickL., 1994, CHEM KINETICS PROCES
[9]   OXIDATION OF CINNABAR BY FE(III) IN ACID MINE WATERS [J].
BURKSTALLER, JE ;
MCCARTY, PL ;
PARKS, GA .
ENVIRONMENTAL SCIENCE & TECHNOLOGY, 1975, 9 (07) :676-678
[10]  
*EPA, 1995, METHOD 1631 MERCURY