硫化亚铁稳定化修复重金属污染湖泊底泥的效率及机理

Stabilization efficiency and mechanism of heavy metals in contaminated lake sediments by ferrous sulfide

研究了硫化亚铁(FeS)对重金属污染湖泊底泥的稳定化修复效率及作用机制。结果表明:FeS能有效稳定化湖泊底泥中的重金属Cu、Pb和Cd。当水溶液初始pH=2,FeS的添加量为5%(质量分数)时,重金属Cu、Pb和Cd的稳定化率分别达到72.83%、55.25%和48.17%。水溶液初始pH在2~7范围内逐渐增加时,FeS对重金属的稳定化效率逐渐降低。在FeS稳定化重金属的过程中,Cu的稳定化主要通过形成CuS沉淀,Pb和Cd的稳定化均包含生成金属硫化物沉淀和Fe(OH)_3共沉淀过程,但Fe(OH)_3共沉淀对Pb的稳定化贡献显著大于Pb S沉淀,而Fe(OH)_3共沉淀和CdS沉淀对Cd的稳定化贡献相当。

The stabilization mechanism of heavy metals in contaminated lake sediments by FeS was studied.The results show that heavy metals were efficiently stabilized by FeS.Under the initial pH value of 2,the stabilization ratio of Cu,Pb,and Cd could achieve 72.83%,55.25%,and 48.17%,respectively,with an addition of 5%（mass fraction） FeS.The stabilization ratio of heavy metals reduced with increased pH in the range from 2 to 7.During the stabilization of heavy metals by FeS,the formation of Cu S dominated the stabilization of Cu,while the formation of metal sulfides and coprecipitation by Fe（OH）_3 jointly contributed to the stabilization of Pb and Cd.However,for the stabilization of Pb,the contribution of coprecipitation by Fe（OH）_3 was much higher than the formation of Pb S,whereas the contribution of the formation of Cd S was close to the coprecipitation by Fe（OH）_3 for the stabilization of Cd.