利用稳定化技术处理重金属复合污染土壤的研究

TREATING MULTIPLE HEAVY METAL CONTAMINATED SOIL BY STABILIZATION METHOD

稳定化是一种相对经济有效的治理重金属污染土壤的办法.以湖南某历史遗留含重金属尾砂污染的土壤为研究对象,通过正交试验向土壤中添加不同的药剂,以稳定化后土壤的浸出毒性为评价指标,确定最优的稳定化药剂配比.极差分析结果表明:氧化物的含量是控制浸出毒性的关键因素.基于标准HJ/T299—2007,加入最优配比药剂土壤的浸出液中As的稳定化率为90%以上,其他重金属的稳定化率为95%以上;基于标准GB 5086.1—1997,浸出液中As的稳定化率为88%以上,其他重金属的稳定化率为96%以上.SEM照片显示稳定化后形成了晶体,包裹重金属达到稳定化效果.

Stabilization is a cost-effective treatment method for heavy metal-contaminated soil.Mill tailings containing heavy metals in Hunan province was investigated.Stabilizing materials were added to reduce leaching toxicity of arsenic in soil impacted by heavy metals.With leaching toxicity of stabilized soil as evaluation index,the optimal medicament composition was determined.Range analysis showed that oxide content was the key factor in leaching toxicity.Optimum formula of stabilizing agents were applied.Stabilization rate of stabilized leaching toxicity of As based on HJ/T 299-2007 was 90%.Stabilization rate of other heavy metals was 95%.Stabilization rate of stabilized leaching toxicity of As based on GB 5086.1-1997 method was 88%.Stabilization rate of other heavy metals was 96%.During stabilization,SEM photos demonstrated that crystals were formed,which capsulated heavy metals and resulted in the stabilized effect.