铬污染土壤的稳定化处理及其长期稳定性研究 |
摘要点击 4511 全文点击 2195 投稿时间:2013-01-15 修订日期:2013-04-28 |
查看HTML全文
查看全文 查看/发表评论 下载PDF阅读器 |
中文关键词 铬 土壤 还原 稳定化 长期效果 |
英文关键词 chromium soil reduction stabilization long term effect |
|
中文摘要 |
利用不同投加比例的FeS、FeSO4、Fe0和Na2S2O4,分别对铬污染土壤进行处理,通过土壤浸出浓度和六价铬含量的测定,考察这4种还原剂对铬污染土壤的短期(3 d、28 d)和长期(1 a)稳定作用. 结果表明,将FeS和Fe0直接用于铬污染土壤的稳定化时,由于其溶解度很低,稳定效果不好. 而FeSO4对铬污染土壤的稳定化具有很好的效果,可以在短期内降低总铬和六价铬的浸出浓度,减少土壤中的六价铬含量,且其效果随着投加浓度的增加而提高. 在长期稳定过程中,由于铁的氢氧化物的逐渐形成,其稳定化效果进一步提高. Na2S2O4同样有利于铬污染土壤的稳定化. 在适当的投加比例下,FeSO4和Na2S2O4对土壤pH值影响很小,维持在6~8. |
英文摘要 |
Short-term (3 d and 28 d) and long-term (1 a) stabilization effects of Cr contaminated soil were investigated through nature curing, using four amendments including ferrous sulfide, ferrous sulfate, zero-valent iron and sodium dithionite. The results indicated that ferrous sulfide and zero-valent iron were not helpful for the stabilization of Cr(Ⅵ) when directly used because of their poor solubility and immobility. Ferrous sulfate could effectively and rapidly decrease total leaching Cr and Cr(Ⅵ) content. The stabilization effect was further promoted by the generation of iron hydroxides after long-term curing. Sodium dithionite also had positive effect on soil stabilization. Appropriate addition ratio of the two chemicals could help maintain the soil pH in range of 6-8. |
|
|
|