Lead and Chromium Immobilization Process Subjected to Different Freeze-Thaw Treatments in Soils of the Northeastern Qinghai-Tibet Plateau
Table 2
Freundlich and Langmuir parameters of Cr in soils under different freeze-thaw conditions.
Site area
FTCs
Cr (Freundlich)
Cr (Langmuir)
1/n
k
(mg/kg)
k
S-1
F0 + W0%
0.54 ± 0.68
1.80 ± 4.39
0.40
—
—
—
F15 + W60%
0.13 ± 0.82
7.97 ± 21.32
0.02
—
—
—
F15 + W100%
1.75 ± 0.81
0.01 ± 0.02
0.80
—
—
—
S-2
F0 + W0%
0.34 ± 0.53
9.95 ± 18.12
0.27
—
—
—
F15 + W60%
0.65 ± 0.28
3.30 ± 3.37
0.84
70.98 ± 40.99
0.02 ± 0.03
0.89
F15 + W100%
—
—
—
—
—
—
S-3
F0 + W0%
0.71 ± 0.51
4.53 ± 8.33
0.65
—
—
—
F15 + W60%
0.62 ± 0.47
6.18 ± 10.43
0.63
—
—
—
F15 + W100%
0.50 ± 0.17
13.17 ± 7.78
0.88
124.76 ± 27.89
0.05 ± 0.02
0.95
S-4
F0 + W0%
0.11 ± 1.00
10.92 ± 35.26
0.01
—
—
—
F15 + W60%
1.85 ± 0.08
0.02 ± 0.01
0.99
—
—
—
F15 + W100%
0.883 ± 0.14
0.59 ± 0.32
0.97
76.20 ± 59.68
0.01 ± 0.01
0.98
S-5
F0 + W0%
0.86 ± 0.23
1.67 ± 1.45
0.93
172.81 ± 218.09
0.01 ± 0.01
0.93
F15 + W60%
1.02 ± 0.46
0.78 ± 1.36
0.85
482.39 ± 3870.92
0.001 ± 0.01
0.85
F15 + W100%
0.54 ± 0.42
7.41 ± 10.98
0.62
—
—
—
S-6
F0 + W0%
0.62 ± 0.11
12.62 ± 4.99
0.96
219.48 ± 43.91
0.03 ± 0.01
0.98
F15 + W60%
1.13 ± 0.12
2.60 ± 1.152
0.98
—
—
—
F15 + W100%
0.66 ± 0.18
11.73 ± 7.52
0.92
260.33 ± 93.79
0.02 ± 0.01
0.95
Note. “—” means that these data could not be fitted using the Freundlich and Langmuir models. F0 and F15 refer to the number of freeze-thaw cycles (0 and 15 cycles), and W0%, W60%, and W100% refer to water ratio of field capacity (0%, 60%, and 100% water ratio).
