稳定化技术对土壤重金属污染修复的试验研究.docVIP

稳定化技术对土壤重金属污染修复的试验研究 　　摘要：以两种不同性质土壤为基质，通过添加可溶性的Cd、Zn、Pb、Cu盐形成土壤重金属复合污染。采用USEPA的毒性浸出试验（Toxicity Characteristic Leaching Procedure，TCLP）对由硫化钙、过磷酸钙、氢氧化钙组成的复合修复剂进行试验研究。结果表明：（1）土壤在添加可溶性盐后pH降低。可溶性重金属盐加入越多，pH下降越多。（2）从水溶态的平均百分比来看，Cd（12.9%）Zn（7.1%）Cu（3.4%）Pb（0.7%）。 4种重金属中，除Cd的水溶态比例高于10%外，其他3种重金属的水溶态比例均低于10%。（3）试验设计的方案1为：硫化钙0.5%+过磷酸钙1%+氢氧化钙0.1%+去离子水20%。方案2为：硫化钙2%+过磷酸钙1%+氢氧化钙0.5%+去离子水20%。（4）对于Cd和Zn，方案2优于方案1。方案2对土壤重金属消减率[Cd（89.7%）、Zn（99.7%）]大于方案1的消减率[Cd（88.9%）、Zn（95.7%）]。对于Cu和Pb，方案1优于方案2。方案1消减率Cu为67.2%、Pb为53.9%。 　　关键词：稳定剂；重金属污染；TCLP；土壤修复 　　中图分类号：X53 文献标识码：A 文章编号：0439-8114（2016）12-3042-05 　　DOI：10.14088/j.cnki.issn0439-8114.2016.12.013 　　Abstract：Two different types of soil were chosen as matrix and soluble Cd， Zn， Pb and Cu salt were added to form soil heavy metal contamination. USEPA TCLP test（Toxicity Characteristic Leaching Procedure，TCLP） were used to study the effect of remediation agent which is composed of calcium sulfide，calcium phosphate and calcium hydroxide. The results showed that：（1）Addition of soluble salts to the soil made the soil pH decrease. The more soluble heavy metal salt was added， pH decreased more. （2）The average percentage of water soluble view，Cd（12.9%）Zn（7.1%）Cu（3.4%）Pb（0.7%）.（3）experimental program 1：0.5% calcium sulfide+1% calcium superphosphate+0.1% calcium hydroxide+20% water，experimental program 2 is：2% calcium sulfide+calcium phosphate or superphosphate 1%+0.5% calcium hydroxide+20% water.（4）For Cd and Zn， program 2 is superior in heavy metal reduction than project 2. Heavy metal reduction rate of is 89.7% for Cd and 99.7% for Zn in project 2，higher than project 1 with reduction rate of 88.9% for Cd and 95.7% for Zn. For Cu and Pb， program 1 is better than program 2，with reduction rate of 67.2% and 53.9% for Cu and Pb， respectively. 　　Key words：stabilizer；heavy metal pollution；TCLP；soil remediation 　　中国由铅酸电池、电镀、矿物开采以及冶炼等导致的土壤重金属污染往往引发环境群体性事件[1]。如在2009年发生的陕西凤翔儿童血铅超标、湖南浏阳镉污染及山东临沂砷污染以及在广西环江、云南会泽、湖南湘江等地土壤重金属污染引起了社会广泛关注，成为公共环境事件。作为“化学定时炸弹”