Na2S对土壤中重金属离子的钝化性能

采用Na2S作为钝化剂，对人工模拟重金属污染土壤中的Cu2+，Zn2+和Cr3+三种重金属离子进行了钝化技术研究.试验结果表明，Na2S对三种重金属均具有很好的钝化效果，各重金属离子的钝化率均可达到95%以上；X射线衍射分析结果表明，Na2S与各重金属离子作用后，钝化产物分别为CuS，ZnS和Cr(OH)3；溶液化学分析表明，Na2S主要依靠S2-与重金属离子形成硫化物沉淀，或者S2-水解产生的OH-与重金属离子形成氢氧化物沉淀而将重金属除去.

Passivation Performance of Sodium Sulfide on Heavy Metal Ions in Soil

Sodium sulfide was used as passivator to deal with artificial simulation heavy metal contaminated soil with Cu2+，Zn2+ and Cr3+. The results show that sodium sulfide has effective passivation ability to the three heavy metal ions， and more than 95% passivation rates can be acquired for every heavy metal ion. X ray diffraction analysis result reveals that passivation products which contain CuS， ZnS and Cr(OH)3 can be obtained when sodium sulfide react with heavy metal ions. Solution chemistry analysis result shows that sulfide precipitation can be generated by sulfur ion reacting with heavy metal ions，or hydroxide precipitation can be generated by hydroxyl ion generated from sulfur ion hydrolysis reacting with heavy metal ions，so heavy metal ions can be removed by sodium sulfide.