AC electric field combined with organic materials enhancing Sedum alfredii Hance phytoremediation of cadmium-contaminated soil
CHEN Ji, YAO Guihua, NI Xing, ZHAO Keli, LIU Dan, YE Zhengqian, Key Laboratory of Soil Contamination Bioremediation of Zhejiang Province, School of Environmental and Resource Sciences, Zhejiang A&F University, Hangzhou 311300, China
Abstract:To improve the phytoremediation efficiency of heavy metals contaminated soils, soil pot experiments were carried out to study the effect of alternating current (AC) electric field combining with organic materials on Sedum alfredii (hyper-accumulator) remediation efficiency of cadmium (Cd) -contaminated soil. Different AC electric field gradients (0, 0.5 and 1.0 V·cm?1) and different organic materials (potassium fulvate and milk vetch) (with application rates of 0.1%, 0.3%, 0.5%) treatments were tested. The results showed that the AC electric field could promote the growth of Sedum alfredii and its uptake of heavy metals, and 0.5 V·cm?1 AC electric field presented the best effect. After 20 d AC electric field treatment, the Cd accumulation in the aboveground part of Sedum alfredii was 48.1% higher than that without AC electric field enhancement. The combination of AC electric field and organic materials further enhanced the absorption of soil heavy metals by Sedum alfredii. The application of two organic materials (potassium fulvate and milk vetch) had positive effects on the soil heavy metal availabilities. Potassium fulvate application elevated the soil acid-extractable Cd concentration, which was 16.35% higher than that of the control. At AC electric field of 0.5 V·cm?1 and 0.3% organic material of potassium fulvate or milk vetch, the greatest enhancement on Cd accumulation in plant shoots of Sedum alfredii Hance occurred, which was 3.65 and 1.73 times higher than that of control(only with AC electric field enhancement), respectively. Consequently, heavy metal accumulation in plant shoots of Sedum alfredii was greatly promoted by the combined application of organic materials and AC electric field. Key words:soil heavy metal pollution/ organic materials/ hyper-accumulator/ phytoremediation/ AC electric field.
图1不同处理组对东南景天地上部生物量的影响 Figure1.Biomass of Sedum alfredii Hance shoots affected by different treatments
下载: 导出CSV 表2供试有机物料的基本性质 Table2.Basic properties of organic materials for test
供试物料
pH
有机碳/(g·kg?1)
全氮/(g·kg?1)
全磷/(g·kg?1)
全钾/(g·kg?1)
全Cu/(mg·kg?1)
全Zn/(mg·kg?1)
全Pb/(mg·kg?1)
全Cd/(mg·kg?1)
紫云英
6.78
463.3
37.16
0.64
27.12
10.73
30.3
0.1
0.01
黄腐酸钾
7.46
234.61
99.86
0.16
4
2.95
8.13
4.79
0.15
供试物料
pH
有机碳/(g·kg?1)
全氮/(g·kg?1)
全磷/(g·kg?1)
全钾/(g·kg?1)
全Cu/(mg·kg?1)
全Zn/(mg·kg?1)
全Pb/(mg·kg?1)
全Cd/(mg·kg?1)
紫云英
6.78
463.3
37.16
0.64
27.12
10.73
30.3
0.1
0.01
黄腐酸钾
7.46
234.61
99.86
0.16
4
2.95
8.13
4.79
0.15
下载: 导出CSV 表3不同电压梯度对东南景天地上部生物量的影响 Table3.Biomass of Sedum alfredii Hance shoots affected by different voltage gradients
通电时间/d
电压梯度/ (V·cm?1)
单株鲜重/ (g·株?1)
单株干重/ (g·株?1)
20
0
2.82a
0.17a
20
0.5
3.33a
0.17a
20
1.0
3.20a
0.18a
40
0
4.49b
0.30a
40
0.5
6.29a
0.35a
40
1.0
5.59a
0.35a
注：不同小写字母表示处理组间差异显著(P<0.05)。
通电时间/d
电压梯度/ (V·cm?1)
单株鲜重/ (g·株?1)
单株干重/ (g·株?1)
20
0
2.82a
0.17a
20
0.5
3.33a
0.17a
20
1.0
3.20a
0.18a
40
0
4.49b
0.30a
40
0.5
6.29a
0.35a
40
1.0
5.59a
0.35a
注：不同小写字母表示处理组间差异显著(P<0.05)。
下载: 导出CSV 表4不同电压梯度对东南景天地上部重金属含量的影响 Table4.Heavy metal concentrations in Sedum alfredii shoots affected by different voltage gradients
通电时间/d
电压梯度/(V·cm?1)
Cu/(mg·kg?1)
Zn/(mg·kg?1)
Pb/(mg·kg?1)
Cd/(mg·kg?1)
20
0
12.97b
10 537.27c
15.78b
208.55b
20
0.5
21.22a
12 032.64a
20.39a
297.94a
20
1.0
21.53a
11 365.41b
19.93a
207.51b
40
0
16.39b
9 837.44b
10.66b
163.61a
40
0.5
18.02ab
11 064.16a
13.99a
148.63a
40
1.0
18.42a
10 175.46b
13.68a
136.80a
注：不同小写字母表示处理组间差异显著(P<0.05)。
通电时间/d
电压梯度/(V·cm?1)
Cu/(mg·kg?1)
Zn/(mg·kg?1)
Pb/(mg·kg?1)
Cd/(mg·kg?1)
20
0
12.97b
10 537.27c
15.78b
208.55b
20
0.5
21.22a
12 032.64a
20.39a
297.94a
20
1.0
21.53a
11 365.41b
19.93a
207.51b
40
0
16.39b
9 837.44b
10.66b
163.61a
40
0.5
18.02ab
11 064.16a
13.99a
148.63a
40
1.0
18.42a
10 175.46b
13.68a
136.80a
注：不同小写字母表示处理组间差异显著(P<0.05)。
下载: 导出CSV 表5不同电压梯度对东南景天重金属积累量的影响 Table5.Effects of different voltage gradients on heavy metal accumulation in Sedum alfredii shoots
通电时间/d
电压梯度/(V·cm?1)
Cu/(mg·kg?1)
Zn/(mg·kg?1)
Pb/(mg·kg?1)
Cd/(mg·kg?1)
20
0
2.18b
1 988.39a
2.43b
33.91b
20
0.5
4.14a
2 101.06a
3.57a
50.22a
20
1.0
4.15a
2 061.23a
3.32ab
40.22b
40
0
5.22b
3 276.41b
3.58b
47.55b
40
0.5
6.57a
4 152.46a
4.90a
58.91a
40
1.0
6.73a
3 826.83ab
4.76a
46.37b
注：不同小写字母表示处理组间差异显著(P<0.05)。
通电时间/d
电压梯度/(V·cm?1)
Cu/(mg·kg?1)
Zn/(mg·kg?1)
Pb/(mg·kg?1)
Cd/(mg·kg?1)
20
0
2.18b
1 988.39a
2.43b
33.91b
20
0.5
4.14a
2 101.06a
3.57a
50.22a
20
1.0
4.15a
2 061.23a
3.32ab
40.22b
40
0
5.22b
3 276.41b
3.58b
47.55b
40
0.5
6.57a
4 152.46a
4.90a
58.91a
40
1.0
6.73a
3 826.83ab
4.76a
46.37b
注：不同小写字母表示处理组间差异显著(P<0.05)。
下载: 导出CSV 表6有机物料和交流电场对东南景天地上部生长和重金属含量的影响 Table6.Effect of organic material and AC electric field on plant growth andheavy metal concentrations in shoots of sedum alfredii
处理组
鲜重/(g·株?1)
干重/(g·株?1)
Cu/(mg·kg?1)
Zn/(mg·kg?1)
Pb/(mg·kg?1)
Cd/(mg·kg?1)
0+0HF
3.57c
0.23c
8.35a
5 503.05c
3.28c
110.35b
0+0.3HF
7.75a
0.47ab
8.78a
7 319.47a
5.45ab
123.38ab
0.5+0HF
5.81b
0.32abc
7.35a
6 010.12b
4.21bc
99.86b
0.5+0.3HF
8.56a
0.51a
7.84a
7 068.31a
6.44a
135.80a
注：不同小写字母表示处理组间差异显著(P<0.05)。
处理组
鲜重/(g·株?1)
干重/(g·株?1)
Cu/(mg·kg?1)
Zn/(mg·kg?1)
Pb/(mg·kg?1)
Cd/(mg·kg?1)
0+0HF
3.57c
0.23c
8.35a
5 503.05c
3.28c
110.35b
0+0.3HF
7.75a
0.47ab
8.78a
7 319.47a
5.45ab
123.38ab
0.5+0HF
5.81b
0.32abc
7.35a
6 010.12b
4.21bc
99.86b
0.5+0.3HF
8.56a
0.51a
7.84a
7 068.31a
6.44a
135.80a
注：不同小写字母表示处理组间差异显著(P<0.05)。
下载: 导出CSV 表7有机物料和交流电场对东南景天地上部单株重金属积累量的影响 Table7.Effect of organic material and AC electric field on the heavy metal accumulation in Sedum alfredii shoots
处理组
重金属积累量/(μg·株?1)
Cu
Zn
Pb
Cd
0+0HF
1.92b
1 225.72d
0.75b
25.31d
0+0.3HF
4.13a
3 441.26b
2.42ab
58.00b
0.5+0HF
2.31b
1 925.28c
1.33b
35.75c
0.5+0.3HF
4.07a
3 617.45a
3.29a
69.17a
处理组
重金属积累量/(μg·株?1)
Cu
Zn
Pb
Cd
0+0HF
1.92b
1 225.72d
0.75b
25.31d
0+0.3HF
4.13a
3 441.26b
2.42ab
58.00b
0.5+0HF
2.31b
1 925.28c
1.33b
35.75c
0.5+0.3HF
4.07a
3 617.45a
3.29a
69.17a
下载: 导出CSV 表8不同处理组对土壤重金属有效性的影响 Table8.Soil available heavy metal concentrations affected by different treatments
有机物料
Cu/(mg·kg?1)
Zn/(mg·kg?1)
Pb/(mg·kg?1)
Cd/(mg·kg?1)
0.1%黄腐酸钾
14.63ab
55.86a
17.43ab
0.64b
0.3%黄腐酸钾
11.55d
49.02ab
15.03b
0.72ab
0.5%黄腐酸钾
15.08ab
56.27a
17.19ab
0.68ab
0.1%紫云英
13.80ab
52.28ab
16.98ab
0.67ab
0.3%紫云英
11.48d
45.93b
15.52b
0.68ab
0.5%紫云英
15.82a
55.68a
18.84a
0.75a
CK
13.49cd
49.95ab
17.12ab
0.65b
注：不同小写字母表示处理组间差异显著(P<0.05)。
有机物料
Cu/(mg·kg?1)
Zn/(mg·kg?1)
Pb/(mg·kg?1)
Cd/(mg·kg?1)
0.1%黄腐酸钾
14.63ab
55.86a
17.43ab
0.64b
0.3%黄腐酸钾
11.55d
49.02ab
15.03b
0.72ab
0.5%黄腐酸钾
15.08ab
56.27a
17.19ab
0.68ab
0.1%紫云英
13.80ab
52.28ab
16.98ab
0.67ab
0.3%紫云英
11.48d
45.93b
15.52b
0.68ab
0.5%紫云英
15.82a
55.68a
18.84a
0.75a
CK
13.49cd
49.95ab
17.12ab
0.65b
注：不同小写字母表示处理组间差异显著(P<0.05)。
下载: 导出CSV 表9不同处理组对东南景天地上部重金属含量的影响 Table9.Effect of different treatments on heavy metal concentrations in Sedum alfredii Hance shoots
有机物料
Cu/(mg·kg?1)
Zn/(mg·kg?1)
Pb/(mg·kg?1)
Cd/(mg·kg?1)
0.1%黄腐酸钾
8.98a
5 106.16cd
4.73ab
77.87b
0.3%黄腐酸钾
10.27a
7 511.02a
7.68a
129.32a
0.5%黄腐酸钾
5.66ab
4 072.55d
5.29ab
70.46bc
0.1%紫云英
6.61ab
6 195.01b
5.31ab
84.92b
0.3%紫云英
6.93ab
5 449.83cd
5.48ab
72.00bc
0.5%紫云英
4.25b
3 479.19d
1.32c
40.32c
CK
6.11ab
4 937.66cd
3.63bc
71.07bc
注：不同小写字母表示处理组间差异显著(P<0.05)。
有机物料
Cu/(mg·kg?1)
Zn/(mg·kg?1)
Pb/(mg·kg?1)
Cd/(mg·kg?1)
0.1%黄腐酸钾
8.98a
5 106.16cd
4.73ab
77.87b
0.3%黄腐酸钾
10.27a
7 511.02a
7.68a
129.32a
0.5%黄腐酸钾
5.66ab
4 072.55d
5.29ab
70.46bc
0.1%紫云英
6.61ab
6 195.01b
5.31ab
84.92b
0.3%紫云英
6.93ab
5 449.83cd
5.48ab
72.00bc
0.5%紫云英
4.25b
3 479.19d
1.32c
40.32c
CK
6.11ab
4 937.66cd
3.63bc
71.07bc
注：不同小写字母表示处理组间差异显著(P<0.05)。
下载: 导出CSV 表10不同处理组对东南景天地上部植物重金属积累的影响 Table10.Effect of different treatments on heavy metal accumulation in Sedum alfredii Hance shoots
有机物料
Cu/(μg·株?1)
Zn/(μg·株?1)
Pb/(μg·株?1)
Cd/(μg·株?1)
0.1%黄腐酸钾
3.20ab
1 658.65b
1.94ab
23.65b
0.3%黄腐酸钾
3.83a
3 722.15a
2.56a
53.50a
0.5%黄腐酸钾
1.55c
1 315.97b
1.10bc
21.32bc
0.1%紫云英
1.82bc
1 922.73b
1.18bc
25.33b
0.3%紫云英
1.63c
1 538.79b
1.69b
25.40b
0.5%紫云英
1.12c
1 093.23b
0.57c
15.07c
CK
2.45abc
978.55b
0.55c
14.64c
注：不同小写字母表示处理组间差异显著(P<0.05)。
有机物料
Cu/(μg·株?1)
Zn/(μg·株?1)
Pb/(μg·株?1)
Cd/(μg·株?1)
0.1%黄腐酸钾
3.20ab
1 658.65b
1.94ab
23.65b
0.3%黄腐酸钾
3.83a
3 722.15a
2.56a
53.50a
0.5%黄腐酸钾
1.55c
1 315.97b
1.10bc
21.32bc
0.1%紫云英
1.82bc
1 922.73b
1.18bc
25.33b
0.3%紫云英
1.63c
1 538.79b
1.69b
25.40b
0.5%紫云英
1.12c
1 093.23b
0.57c
15.07c
CK
2.45abc
978.55b
0.55c
14.64c
注：不同小写字母表示处理组间差异显著(P<0.05)。
下载: 导出CSV 表11土壤重金属Cd不同形态与理化性质的相关关系 Table11.Correlations between different soil heavy metal Cd forms andphysicochemical properties
有机质
pH
酸可提取态Cd
可还原态Cd
可氧化态Cd
残渣态Cd
有机质
1
—
—
—
—
—
pH
?0.697**
1
—
—
—
—
酸可提取态Cd
0.093
?0.37
1
—
—
—
可还原态Cd
?0.177
0.135
?0.496*
1
—
—
可氧化态Cd
0.203
?0.466
0.249
?0.095
1
—
残渣态Cd
?0.383
0.666**
?0.33
0.199
?0.855**
1
注：*表示P<0.05；* *表示P<0.01。
有机质
pH
酸可提取态Cd
可还原态Cd
可氧化态Cd
残渣态Cd
有机质
1
—
—
—
—
—
pH
?0.697**
1
—
—
—
—
酸可提取态Cd
0.093
?0.37
1
—
—
—
可还原态Cd
?0.177
0.135
?0.496*
1
—
—
可氧化态Cd
0.203
?0.466
0.249
?0.095
1
—
残渣态Cd
?0.383
0.666**
?0.33
0.199
?0.855**
1
注：*表示P<0.05；* *表示P<0.01。
下载: 导出CSV 表12不同处理组对土壤Cd形态的影响 Table12.Effect of different treatments onsoil cadmium forms
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[10]
BI R, SCHLAAK M, SIEFERT E, et al. Influence of electrical fields (AC and DC) on phytoremediation of metal polluted soils with rapeseed (Brassica napus) and tobacco (Nicotiana tabacum)[J]. Chemosphere, 2011, 83(3): 318-326. doi: 10.1016/j.chemosphere.2010.12.052
[11]
BAKER A J M, BROOKS R R, BAKER A J M, et al. Terrestrial higher plants which hyperaccumulate metallic elements. A review of their distribution, ecology and phytochemistry[J]. Biorecovery, 1989, 1(2): 81-126.
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[18]
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Key Laboratory of Soil Contamination Bioremediation of Zhejiang Province, School of Environmental and Resource Sciences, Zhejiang A&F University, Hangzhou 311300, China Received Date: 2018-12-07 Accepted Date: 2019-05-09 Available Online: 2020-11-11 Keywords:soil heavy metal pollution/ organic materials/ hyper-accumulator/ phytoremediation/ AC electric field Abstract:To improve the phytoremediation efficiency of heavy metals contaminated soils, soil pot experiments were carried out to study the effect of alternating current (AC) electric field combining with organic materials on Sedum alfredii (hyper-accumulator) remediation efficiency of cadmium (Cd) -contaminated soil. Different AC electric field gradients (0, 0.5 and 1.0 V·cm?1) and different organic materials (potassium fulvate and milk vetch) (with application rates of 0.1%, 0.3%, 0.5%) treatments were tested. The results showed that the AC electric field could promote the growth of Sedum alfredii and its uptake of heavy metals, and 0.5 V·cm?1 AC electric field presented the best effect. After 20 d AC electric field treatment, the Cd accumulation in the aboveground part of Sedum alfredii was 48.1% higher than that without AC electric field enhancement. The combination of AC electric field and organic materials further enhanced the absorption of soil heavy metals by Sedum alfredii. The application of two organic materials (potassium fulvate and milk vetch) had positive effects on the soil heavy metal availabilities. Potassium fulvate application elevated the soil acid-extractable Cd concentration, which was 16.35% higher than that of the control. At AC electric field of 0.5 V·cm?1 and 0.3% organic material of potassium fulvate or milk vetch, the greatest enhancement on Cd accumulation in plant shoots of Sedum alfredii Hance occurred, which was 3.65 and 1.73 times higher than that of control(only with AC electric field enhancement), respectively. Consequently, heavy metal accumulation in plant shoots of Sedum alfredii was greatly promoted by the combined application of organic materials and AC electric field.
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