ROLE OF SEDIMENT POREWATER IN THE CYCLING OF ARSENIC IN A MINE-POLLUTED LAKE

被引:23
作者
AZCUE, JM
NRIAGU, JO
SCHIFF, S
机构
[1] National Water Research Institute, Burlington, Ont. L7R 4A6
关键词
Sediment porewater - Cycling - Concentration gradient - Surficial sediments;
D O I
10.1016/0160-4120(94)90200-3
中图分类号
X [环境科学、安全科学];
学科分类号
08 ; 0830 ;
摘要
The surficial sediments of Moira Lake averaged 545 mug.g-1 of arsenic, with maximum values close to 1 mg.g-I at depths of 23-27 cm below the sediment water interface. The sediment porewater is the linking agent between the sediment solid phase and the overlying lake water. The depth distributions of total As in interstitial waters at all stations are characterized by subsurface maxima, with concentrations four to six times greater than in the lake waters. In all the porewater profiles examined. inorganic As [As(III)+As(V)] comprised most of the As. The As(III) (arsenite) percentage ranged from 66-83%. Methylated-As compounds represented <2% of the total As. The strong correlation of As with Fe and Mn together suggests that both Fe and Mn are involved in the As mobility. The elevated As concentrations in bottom sediments represent a continuous internal mining of As towards the interface all year around. The concentration gradient of total dissolved As indicates that an upward diffusion of As towards the water column with the estimated annual fluxes being 0.8-3.8 mug.cm-2.y-1.
引用
收藏
页码:517 / 527
页数:11
相关论文
共 37 条
[1]  
Aggett, O'Brien, Detailed model for the mobility of arsenic in lacustrine sediments based on measurements in Lake Ohakuri, Environ. Sci. Technol., 19, pp. 231-238, (1985)
[2]  
Allan, Heavy metals in bottom sediments of Great Slave Lake (Canada): a reconnaissance, Environ. Geol., 3, pp. 49-58, (1979)
[3]  
Allan, Ball, An overview of toxic contaminants in water and sediments of the Great Lakes, Water Pollut. Res. J. Canada, 25, pp. 387-678, (1990)
[4]  
Anderson, Bruland, Biogeochemistry of arsenic in natural waters the importance of methylated species, Environmental Science & Technology, 25, pp. 420-427, (1991)
[5]  
Andreae, Arsenic speciation in sea water and interstitial waters the influence of biological-chemical interactions on the chemistry of a trace element, Limnology and Oceanography, 24, pp. 440-452, (1979)
[6]  
Andreae, Froelich, Arsenic, antimony and germanium biogeochemistry in the Baltic Sea, Tellus, 36 B, pp. 101-117, (1984)
[7]  
Azcue, Geochemistry of Arsenic in Moira Lake (Ontario), Ph.D. Thesis, (1992)
[8]  
Azcue, Nriagu, Arsenic forms in mine-polluted sediments of Moira Lake, Ontario, Environ. Int., 19, pp. 405-415, (1993)
[9]  
Belzile, Tessier, Interactions between arsenic and iron oxyhydroxides in lacustrine sediments, Geochemin. Cosmochim. Acta, 54, pp. 103-109, (1990)
[10]  
Boyle, Jonasson, The geochemistry of arsenic and its use as an indicator element in geochemical prospecting, J. Geochem. Explor., 2, pp. 251-296, (1973)