摘要
以天然细砂为微生物来源,模拟研究了乳化植物油强化原位生物修复中高浓度Cr(Ⅵ)污染地下水的可行性,考察了修复效果及修复过程中地下水质变化及产物的稳定性。结果表明,反应77d后,Cr(Ⅵ)质量浓度分别从20.0、30.0、50.0、80.0、110.0mg/L降低到0.0、5.8、19.0、43.6、65.8mg/L,去除率分别为100.0%、80.7%、61.9%、45.5%、40.2%。反应后介质中Cr形态分析表明,其主要以能在自然条件下稳定存在的铁锰结合态和有机结合态形式存在。此外,随反应进行,实验体系逐渐呈弱酸性环境,pH为5.80~6.70。当Cr被完全还原后,体系会发生异化铁还原,Fe(Ⅱ)质量浓度逐渐升高,最高可达117.0mg/L,最终形成二价铁矿物。综上所述,天然细砂介质中的土著微生物能够利用乳化植物油强化并还原地下水中的中、高浓度Cr(Ⅵ),且产物能够在自然状态下稳定存在,修复过程对地下环境的影响较小。
A batch of experiments were conducted to investigate the feasibility and efficiency of in situ biostimulation for indigenous microbial community to remove Cr（Ⅵ）contamination in groundwater ranged from 20.0 to 110.0 mg/L.The results indicated that after 77 days of reaction,the Cr（Ⅵ）concentration decreased from an initial value of 20.0,30.0,50.0,80.0,110.0 mg/L to 0.0,5.8,19.0,43.6 and 65.8 mg/L respectively,with the removal efficiency of 100.0%,80.7%,61.9%,45.5%,40.2% correspondingly.The sediment analysis demonstrated that the reduced Cr was combined stably with Fe-Mn oxides and organic matter in natural environment.In addition,with the reaction progress,the reaction system was gradually changed to acid condition,and pH was 5.80-6.70.The dissimilatory iron reduction occurred after Cr（Ⅵ）was completely consumed,with an increasing of aqueous Fe（Ⅱ）concentration,and its maximum concentration of Fe（II）reached to 117.0 mg/L.Overall,the Cr（Ⅵ）that concentrated up to 110.0 mg/L can still be reduced by microorganisms in the natural fine sands through emulsified vegetable oil amendment,and the products are stable under natural conditions with little impact on a subsurface environment.
出处
《吉林大学学报（地球科学版）》
EI
CAS
CSCD
北大核心
2018年第1期234-240,共7页
Journal of Jilin University：Earth Science Edition
基金
国家自然科学基金项目(41530636)~~
关键词
地下水
铬污染
乳化植物油
异化铁还原
groundwater
Cr（Ⅵ）contamination
emulsified vegetable oil
reduction of dissimilatory iron
