8153

• UCREFRP Catalog Number: 8153
• Author: Jacobs, e. L. W.
• Title: Editor
• USFW Year: Series
• USFW - Doc Type: 1989
• Copyright Material: YES

54
20
15
10
5
m
d
0
-5
-10
-0.2
-0.4
-0.6
-0.8
-15L ~
0 2 4 6 8 10 12 14
pH
Fig. 3-1. Relation of oxidation-reduction potentials of Se solution species to pH.
The total Se in solution can be represented by the following equation:
[Total Se] _ [Se04-] + [HSe04 ] + [HZSe04] + [Se03-]
+ [HSe03 ] + [HZSe03] + [Se2-] + [HSe-] + [HZSe°]
Elrashidi et al. (1987) expressed the activity of each species in terms of
pH and redox (pe + pH). Then, they calculated the mole fraction (MF) of
each species in solution by the following relationship:
MF (species) _ (species)/[Total Se]
ELRASHIDI ET AL.
1.2
tis
?se ao ~ 1. o
00
.`
S~ O2/9~ 0.8
ys~ °2` y2o
o,
o.s
y?s@ ~~\
. y
'~2\0~ s
P^ ~ e02,
y 3, v 0.2
O
\ y SeO. ~ 2.
S+e \ 3 >
~` 0.0 ~ j