淋洗法修复铬渣污染场地实验研究  

Remediation of Chromium Residue Contaminated Soil Using a Washing Technology

作　　者：李丹丹[1,2] 郝秀珍[2] 周东美[2] 占新华[1] 

机构地区：[1]南京农业大学资源与环境学院,南京210095 [2]中国科学院土壤环境与污染修复重点实验室,中国科学院南京土壤研究所,南京210008

出　　处：《农业环境科学学报》2011年第12期2451-2457,共7页Journal of Agro-Environment Science

基　　金：国家高技术研究发展计划(863)项目(2009AA063101);环保公益性行业科研专项经费(201009009)

摘　　要：铬渣污染场地已经列为我国土壤污染重点治理对象,急需修复铬渣污染土壤的关键技术。本文通过室内模拟实验,采用振荡淋洗的方法研究了水、EDTA、EDDS、柠檬酸、草酸、盐酸、磷酸、环糊精和十二烷基苯磺酸钠等淋洗剂对铬渣污染场地Cr的淋洗效果,探讨了淋洗剂浓度、淋洗时间、土水比、淋洗次数等对淋洗效果的影响,并研究了不同淋洗剂复合对Cr的淋洗效果以及不同浓度柠檬酸淋洗前后重金属形态的变化。结果表明:水、EDTA、EDDS、环糊精和十二烷基苯磺酸钠对Cr的去除率较低,柠檬酸在浓度为0.5mol·L-1、土水比1:20、反应时间为24h、淋洗次数为2次的条件下可以达到最佳淋洗效果,Cr的去除率可达到82.8%;SDBS、EDTA与柠檬酸单独组合顺序或者混合淋洗,都没有增加柠檬酸对Cr的去除率。重金属形态分析表明,柠檬酸淋洗有效地改变了Cr的形态从而达到较高的修复效果。当柠檬酸浓度小于0.25mol·L-1时,对铬的去除主要以C(rⅥ)为主;当柠檬酸浓度大于0.25mol·L-1时,对铬的去除主要以C(rⅢ)为主。本文的研究结果为异位淋洗修复铬渣污染土壤提供理论依据。Soil was contaminated by surrounding chromium residue,and quick and effective remediation technology is urgently required for remediation of metal contaminated soil.Laboratory simulation tests were conducted to examine the effects of different washing reagents（water,EDTA,EDDS,CTA,OA,HCl,H3PO4,HPCD and SDBS） on extracting Cr from contaminated soils by surrounding chromium residue discarded from chemical plant.The effects of reagent concentration,reaction time,washing time,soil and liquid ratio,and washing number on the efficiency were investigated.This paper also studied the effects of complex reagents on the efficiency and the form distribution of Cr in soil before and after CTA treated.Water,EDTA,EDDS,HPCD and SDBS had a low removal rate of Cr;while 0.5 mol·L-1 CTA obtained the highest removal rate under the optimal conditions,i.e.,soil and liquid ratio was 1：20,reaction time was 24 hours,and the soils were washed twice by CTA solution,the highest removal rate was 82.8%.The removal rate of Cr by compounding of SDBS-CTA and EDTA-CTA did not increase,no matter it was treating in order or common treating.CTA could effectively change the forms of Cr and achieved the purpose of remediation.When the concentration of CTA was below 0.25 mol·L-1,the mainly form of removed Cr was Cr（Ⅵ）,When the concentration of CTA was above 0.25 mol·L-1,the mainly form of removed Cr was Cr（Ⅲ）.The results provided the theoretical basis for the remediation of chromium contaminated soil.

关 键 词：淋洗 CR 污染土壤 修复 

分 类 号：X53[环境科学与工程—环境工程]