Association of methylmercury with dissolved humic acids

被引:90
作者
Amirbahman, A [1 ]
Reid, AL
Haines, TA
Kahl, JS
Arnold, C
机构
[1] Univ Maine, Dept Civil & Environm Engn, Orono, ME 04469 USA
[2] Univ Maine, Senator George J Mitchell Ctr Environm & Watershe, Orono, ME 04469 USA
[3] US Geol Survey, Orono Field Stn, Orono, ME 04469 USA
[4] BMG Engn Ltd, CH-8952 Schlieren, Switzerland
关键词
D O I
10.1021/es011044q
中图分类号
X [环境科学、安全科学];
学科分类号
08 ; 0830 ;
摘要
Sorption of methylmercury (MeHg) to three different humic acids was investigated as a function of pH an humic concentration. The extent of sorption did not show a strong pH dependence within the pH range of 5-9. Below pH 5, a decrease in adsorption for all humic samples was observed. The experimental data for equilibrium sorption of MeHg were modeled using a discrete log K spectrum approach with three weakly acidic functional groups. The modeling parameters, which were the equilibrium binding constants and the total binding capacities, represented the data well at all MeHg and humic concentrations and pH values for a given humic sample. The estimated binding constants for complexes of MeHg with humic acids were similar in magnitude to those of MeHg with thiol-containing compounds, suggesting that binding of MeHg involves the thiol groups of humic acids. The results show that only a small fraction of the reduced sulfur species in humic substances may take part in binding MeHg, but in most natural systems, this subfraction is considerably higher in concentration than ambient MeHg. The model developed here can be incorporated into speciation models to assess the bioavailability of MeHg in the presence of dissolved organic matter and competing ligands such as chloride and sulfide.
引用
收藏
页码:690 / 695
页数:6
相关论文
共 36 条
[1]   ISOLATION OF HYDROPHILIC ORGANIC-ACIDS FROM WATER USING NONIONIC MACROPOROUS RESINS [J].
AIKEN, GR ;
MCKNIGHT, DM ;
THORN, KA ;
THURMAN, EM .
ORGANIC GEOCHEMISTRY, 1992, 18 (04) :567-573
[2]   Association of triorganotin compounds with dissolved humic acids [J].
Arnold, CG ;
Ciani, A ;
Muller, SR ;
Amirbahman, A ;
Schwarzenbach, RP .
ENVIRONMENTAL SCIENCE & TECHNOLOGY, 1998, 32 (19) :2976-2983
[3]   Sorption of methylmercury by clays and mineral oxides [J].
Desauziers, V ;
Castre, N ;
LeCloirec, P .
ENVIRONMENTAL TECHNOLOGY, 1997, 18 (10) :1009-1018
[4]  
DRISCOLL CT, 1994, ENVIRON SCI TECHNOL, V28, pA136, DOI 10.1021/es00052a721
[5]  
ESCHER BI, 1995, THESIS SWISS FEDERAL
[6]   Chemical characterization of a chelator-treated soil humate by solution-state multinuclear two-dimensional NMR with FTIR and pyrolysis-GCMS [J].
Fan, TWM ;
Higashi, RM ;
Lane, AN .
ENVIRONMENTAL SCIENCE & TECHNOLOGY, 2000, 34 (09) :1636-1646
[7]   KINETICS OF EXTREMELY FAST LIGAND-EXCHANGE REACTIONS WITH METHYLMERCURY(II) NITROTHIOPHENOLATE COMPLEXES - RATE EQUILIBRIA CORRELATIONS [J].
GEIER, G ;
GROSS, H .
INORGANICA CHIMICA ACTA, 1989, 156 (01) :91-98
[8]   SULFATE STIMULATION OF MERCURY METHYLATION IN FRESH-WATER SEDIMENTS [J].
GILMOUR, CC ;
HENRY, EA ;
MITCHELL, R .
ENVIRONMENTAL SCIENCE & TECHNOLOGY, 1992, 26 (11) :2281-2287
[9]   LAKE ACIDITY AND MERCURY CONTENT OF FISH IN DARWIN-NATIONAL-RESERVE, RUSSIA [J].
HAINES, TA ;
KOMOV, V ;
JAGOE, CH .
ENVIRONMENTAL POLLUTION, 1992, 78 (1-3) :107-112
[10]   Perch mercury content is related to acidity and color of 26 Russian lakes [J].
Haines, TA ;
Komov, VT ;
Matey, VE ;
Jagoe, CH .
WATER AIR AND SOIL POLLUTION, 1995, 85 (02) :823-828