Evaluation of Adsorbed Arsenic and Potential Contribution to Shallow Groundwater in Tulare Lake Bed Area, Tulare Basin, California
S. Gao*,a,
R. Fujiib,
A. T. Chalmersc and
K. K. Tanjia
a Dep. of Land, Air, and Water Resources, Univ. of California, Davis, CA 95616
b U.S. Geological Survey, Sacramento, CA 95819
c U.S. Geological Survey, Montpelier, VT 05602

View larger version (38K):
[in a new window]
|
Fig. 1. The study site in the Tulare Lake Bed area.
|
|

View larger version (17K):
[in a new window]
|
Fig. 2. 73As(V) radioactivity decrease in solution at sediment suspension pH 7.5. Vertical bars are the standard deviation of the mean (n = 3).
|
|

View larger version (24K):
[in a new window]
|
Fig. 3. Arsenic [97 to 99% as As(V)] in successive extractions with artificial pore water at pH 7.5 and 8.5. Vertical bars are the range of duplicate values.
|
|

View larger version (18K):
[in a new window]
|
Fig. 4. The cumulative adsorbed As removed from the sediment by successive extractions at pH 7.5 and 8.5. Vertical bars are the range of duplicate values.
|
|

View larger version (18K):
[in a new window]
|
Fig. 5. Percentage of isotopically exchangeable As removed by successive extractions at pH 7.5 and 8.5. Vertical bars are the range of duplicate values.
|
|

View larger version (14K):
[in a new window]
|
Fig. 6. Arsenic [97 to 99% as As(V)] concentration in solution extracted by 0.1 M PO4 at pH 7.5. Vertical bars are the range of duplicate values.
|
|
Copyright © 2004 by the Soil Science Society of America.