摘要
利用零价铁(ZVI,Fe0)还原技术,对受2-硝基甲苯(OMNB)和2-氯硝基苯(OCNB)这2种硝基苯类化合物污染土壤的修复进行了研究.实验结果表明,在常温常压下,ZVI可有效地将土壤中的OMNB和OCNB还原成相应的苯胺类化合物,当2种硝基苯化合物在土壤中的含量均约为2.5×10-6mo·lg-1,ZVI加入量为25mg·g-1,于25℃下反应6h,OMNB的还原率可达到97%,OCNB的还原率则高达100%;ZVI对OCNB的还原效率比OMNB稍高;这2种硝基苯类化合物的还原率均随反应时间的延长、ZVI用量的增加、温度的升高而升高,特别是当土壤初始pH值控制在偏酸性时更有利于还原反应的进行.此外,根据实验结果和相关的理论计算对ZVI还原硝基苯类化合物的反应机理进行了初步探讨.
In this paper, the zero-valent iron （ZVI,Fe^0） reduction technique was adopted to investigate the remediation of a soil contaminated by 2-methyl-nitrobenzene （OMNB） and 2-chloro-nitrobenzene （OCNB）. The experimental results indicated that ZVI was effective in reducing the OMNB and OCNB in soils to their respective anilines. At ambient temperature （25℃） and pressure, and after 6 hours of reaction, the reduction rate for OMNB was 97% and the rate for OCNB reached as high as 100% when the individual soil concentrations of these two nitrobenzens were about 2.5 × 10^-6mol·g^-1 and the dose of ZVI was 25mg·g^-1. The reduction efficiency by ZVI for OCNB was slightly higher than OMNB. Laboratory data also showed that a longer reaction time and a higher dosage of ZVI as well as a higher temperature of reaction seemed to promote the rates of reduction. An acidic initial soil pH was especially useful in facilitating the reduction reaction. In addition, a preliminary elucidation of the likely mechanisms of the reductive reactions of nitrobenzene, by ZVI in soils was given based on the experimental results and some theoretical calculations.
出处
《环境科学学报》
CAS
CSCD
北大核心
2007年第2期241-246,共6页
Acta Scientiae Circumstantiae
基金
广东省自然科学基金项目(No.04106270)~~
关键词
2-硝基甲苯
2-氯硝基苯
零价铁
土壤
还原
2-chloro-nitrobenzene （OCNB）
2-methyl-nitrobenzene （OMNB）
zero-valent iron （ZVI）
soil
reduction
