摘要
微生物诱导碳酸盐沉积(MICP)技术可用于地基加固和污染土修复,由于其良好的效果,日益受到了人们的关注。MICP过程中通过吸附固定重金属,对污染土起修复作用,但实践中对MICP修复污染土的长期稳定性还研究较少。通过测定不同酸液、冻融循环条件下修复土中可交换态重金属的改变量发现:污染土经3次生物修复后,铜、铅可交换态含量分别降低了74.8%-79.4%和91.3%-93.2%;在冻融循环下,可交换态重金属含量仅有小幅增加,但在酸性溶液中,修复土中可交换态重金属的含量随pH值的减小而增大,在pH值为2.5的模拟硝酸型酸雨溶液中,可交换态铜、铅含量分别平均增加了27.2%和23.6%,故强酸环境对修复土的稳定性影响较大。
Microbially induced calcite precipitation( MICP) applied to improvement soil and remediation of polluted soil has increasingly been paying attentions due to the good effects of reinforcement and remediation of contaminated soil. Calcium carbonate precipitation can remediate soil contaminated by heavy metals through adsorption and immobilization. However,less research has been done on stability of bioremediated soil by MICP in practice. The changes of exchangeable heavy metal content were measured under different acidity and freezing and thawing cycle conditions. It was found that the removal efficiency of Cu-(2+)was 74. 8% - 79. 4% after bioremediation three times and the removal efficiency of Pb-(2+)was 91. 3% - 93. 2%. The exchangeable heavy metal content increased slightly under freezing and thawing cycle condition. But in acidic solution,the content of exchangeable heavy metals in the remediation soil increased with the decrease of pH value. In nitric acid rain solution( pH = 2. 5),the content of exchangeable copper increased by an average of 27. 2% and lead increased by 23. 6%. Therefore,the strongly acidic condition had a great influence on the stability of bioremediated soil.
作者
许朝阳
杨贺
黄建璋
李章彦
王海波
XU Zhaoyang;YANG He;HUANG Jianzhang;LI Zhangyan;WANG Haibo(College of Civil Science and Engineering,Yangzhou University,Yangzhou 225009,Chin)
出处
《工业建筑》
CSCD
北大核心
2018年第7期33-37,共5页
Industrial Construction
基金
国家自然科学基金项目(51278446)
江苏省前瞻性联合研究项目(BY2016069-05)