Na_2S对土壤中重金属离子的钝化性能

Passivation Performance of Sodium Sulfide on Heavy Metal Ions in Soil

采用Na2S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,Na2S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,Na2S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,Na2S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.

Sodium sulfide was used as passivator to deal with artificial simulation heavy metal contaminated soil w ith 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 w hich contain CuS,ZnS and Cr（OH） 3 can be obtained w hen sodium sulfide react w ith heavy metal ions.Solution chemistry analysis result show s that sulfide precipitation can be generated by sulfur ion reacting w ith heavy metal ions,or hydroxide precipitation can be generated by hydroxyl ion generated from sulfur ion hydrolysis reacting w ith heavy metal ions,so heavy metal ions can be removed by sodium sulfide.