Lead and Chromium Immobilization Process Subjected to Different Freeze-Thaw Treatments in Soils of the Northeastern Qinghai-Tibet Plateau
Table 1
Freundlich and Langmuir parameters of Pb in soils under different freeze-thaw conditions.
Site area
FTCs
Pb (Freundlich)
Pb (Langmuir)
1/n
k
(mg/kg)
k
S-1
F0 + W0%
0.87 ± 0.10
2.69 ± 1.20
0.99
530.65 ± 244.75
0.003 ± 0.002
0.99
F15 + W60%
0.78 ± 0.24
4.40 ± 4.72
0.93
319.98 ± 201.15
0.009 ± 0.009
0.95
F15 + W100%
0.78 ± 0.21
3.51 ± 3.25
0.95
269.37 ± 144.31
0.008 ± 0.007
0.97
S-2
F0 + W0%
0.69 ± 0.23
6.08 ± 6.08
0.91
244.18 ± 116.17
0.01 ± 0.01
0.95
F15 + W60%
1.47 ± 0.18
0.32 ± 0.26
0.99
—
—
—
F15 + W100%
0.83 ± 0.13
3.96 ± 2.38
0.98
484.57 ± 211.89
0.005 ± 0.003
0.99
S-3
F0 + W0%
0.92 ± 0.22
4.92 ± 4.87
0.96
1181.38 ± 1453.03
0.003 ± 0.006
0.97
F15 + W60%
1.02 ± 0.01
3.41 ± 0.28
0.99
—
—
—
F15 + W100%
1.02 ± 0.08
4.68 ± 1.67
0.99
20390.80 ± 142821.15
2.54E − 4 ± 0.001
0.99
S-4
F0 + W0%
2.35 ± 0.13
0.005 ± 0.003
0.99
—
—
—
F15 + W60%
1.31 ± 0.12
0.88 ± 0.498
0.99
—
—
—
F15 + W100%
0.50 ± 0.30
11.69 ± 14.77
0.74
—
—
—
S-5
F0 + W0%
0.90 ± 0.10
4.55 ± 2.0
0.99
1158.05 ± 632.67
0.003 ± 0.002
0.99
F15 + W60%
0.64 ± 0.20
12.37 ± 10.54
0.92
353.76 ± 105.46
0.01 ± 0.01
0.96
F15 + W100%
1.08 ± 0.06
3.14 ± 0.94
0.99
—
—
—
S-6
F0 + W0%
1.57 ± 0.18
0.29 ± 0.24
0.99
—
—
—
F15 + W60%
0.89 ± 0.10
6.12 ± 2.67
0.99
1413.49 ± 734.43
0.003 ± 0.002
0.99
F15 + W100%
0.78 ± 0.16
7.81 ± 5.504
0.96
309.57 ± 1.53
0.002 ± 9.06E − 5
1.00
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).
