柱淋洗法修复铬污染土壤的效果研究  

Study of the Effects of Column Leaching on Remediation of Chromium Contaminated Soils

作　　者：孙玉焕[1] 关峰[1] 徐小龙[1] 林云青 

机构地区：[1]青岛科技大学环境与安全工程学院,山东青岛266042 [2]青岛新天地环境保护有限责任公司,山东青岛266023

出　　处：《环境保护科学》2016年第3期113-118,共6页Environmental Protection Science

基　　金：山东省自然科学基金项目(ZR2013DQ002);青岛市民生科技计划项目(14-2-3-70-nsh/14-2-3-71-nsh)基金资助

摘　　要：以铬渣污染土壤为供试土壤,采用土柱淋洗法研究柠檬酸、草酸和盐酸单一淋洗以及复合淋洗对铬去除动态和修复效果的影响,并对淋洗前后土壤中铬形态进行分析,探讨修复机理。结果表明,各淋洗方案中,以10体积0.5 mol/L草酸溶液为淋洗剂时的修复效果最好,总Cr累计淋出量为2 304 mg/kg,上层、中层和下层土壤总Cr去除率分别为79.6%、78.1%和69.6%,Cr(VI)去除率为87.8%、86.2%和75%,且土壤Cr(VI)和总Cr随着土壤深度的增加而升高,有在底部积累的可能;淋洗后土壤明显酸化,p H值从10.5降至3左右;以酸作为淋洗剂能有效降低土壤可氧化态铬含量,将其转化为移动性较强的酸可提取态,这有助于达到预期修复效果。In this paper, chromium contaminated soils were sampled for experiment. Column leaching methods were used tostudy the influences of single leaching methods by use of citric acid, oxalic acid and hydrochloric acid respectively as well ascomposite leaching method on the dynamic removal of chromium from contaminated soils and corresponding remediation effects.Chromium speciation in soils before and after leaching was analyzed and remediation mechanism was discussed. The results showedthat with regard to the leaching methods, the one by use of 10 volumes 0.5mol/L oxalic acid as the eluent had the best remediationeffect and the total accumulative removal amount of chromium reached to 2304 mg/kg, with the total chromium removal rate in theupper, middle and lower soil layers as 79.6%, 78.1% and 69.6% and the removal rate of Cr（VI） as 87.8%, 86.2% and 75%respectively. Moreover, the contents of total chromium and chromium（VI） increased with the soil vertical depth and possiblyaccumulated in the bottom. After leaching, soils became acidic obviously with pH value dropped from 10.5 to about 3. As leachingagent, acid can effectively reduce the content of chromium existing in oxidizable form and change it into acid extractable form withstrong mobility, which was helpful to achieve the expected remediation effects.

关 键 词：铬污染土壤 酸 柱淋洗 修复效果 

分 类 号：X53[环境科学与工程—环境工程]