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1 材料与方法
1.1 供试材料
Table 1 Basic physicochemical properties of soil samples
全氮/ (g·kg−1) | 全硫/ (g·kg−1) | pH | CEC/ (cmol·kg−1) | 有机质/ (g·kg−1) | THg/ (μg·kg−1) |
1.13±0.14 | 0.20±0.05 | 8.16 | 23.60±1.89 | 12.38±0.43 | 102.85±2.98 |
1.2 实验方法
1.2.1 人工模拟Hg污染土壤的制备
1.2.2 系列硫化物稳定剂对不同汞污染浓度紫色土中汞的稳定化效果
1.2.3 不同种类和用量硫化物稳定剂对紫色土中汞稳定化效果的影响
1.2.4 系列硫化物稳定剂对不同汞污染浓度紫色土中汞赋存形态的影响
1.2.5 系列硫化物稳定剂在紫色土中对汞的长期稳定化效果
1.3 分析测定方法
1.4 数据分析方法
E = (C0-CS)/C0 ×100%
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2 结果与分析
2.1 硫化物对紫色土不同汞污染浓度稳定化效果的比较
Fig. 1 Mercury leaching concentrations at different soil mercury contaminations by TCLP
Fig. 1 Mercury leaching concentrations at different soil mercury contaminations by TCLP

2.2 不同稳定剂种类和用量对紫色土中汞稳定化效果的影响
Fig. 2 Mercury leaching concentrations at different dosages of stabilizers by TCLP
Fig. 2 Mercury leaching concentrations at different dosages of stabilizers by TCLP

Hg2++2DTCR−→Hg(DTCR)2(s)
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Fig. 3 Structure of DTCR and its action with Hg2+

HgS+nS2-→ [HgSn] 2-
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2.3 系列硫化物对不同汞污染浓度紫色土中汞赋存形态的影响
Fig. 4 Percentages of different mercury species to total mercury contents

Table 2 Multivariate stepwise regression analysis of soil mercury concentration and morphology
稳定剂种类 | 逐步回归方程 | R值 | R2值 |
S | y=4.403+0.188x1*+0.083x2* | 0.793 | 0.628 |
Na2S | y=-0.763+0.209x1**+0.103x2** | 0.935 | 0.874 |
FeS | y=-0.736+0.183x1**+0.097x2* | 0.878 | 0.771 |
Na2S2O3 | y=0.767+0.181x1**+0.113x2* | 0.821 | 0.674 |
DTCR | y=-0.235+0.222x1**+0.101x2** | 0.971 | 0.942 |
2.4 土壤修复过程对土壤pH的影响
Fig. 5 Changes of Hg contaminated soil pH after series sulfide stabilization
Fig. 5 Changes of Hg contaminated soil pH after series sulfide stabilization

2.5 系列硫化物在紫色土中对汞的长期稳定化效果
Table 3 Stabilization efficiency of different stabilizers
稳定剂种类 | 对照组浸出浓度/ (mg·L−1) | 稳定3个月后 浸出浓度/ (mg·L−1) | 稳定9个月后 浸出浓度/ (mg·L−1) | 稳定效率/% |
S | 1.47 | 0.026 4 | 0.011 5 | 99.22 |
Na2S | 1.47 | 0.002 3 | ND | 100 |
FeS | 1.47 | 0.046 9 | 0.041 | 97.21 |
Na2S2O3 | 1.47 | 0.009 7 | 0.002 5 | 99.83 |
DTCR | 1.47 | ND | ND | 100 |