Min Jee-Eun, Kim Meejeong, Pardue John H, Park Jae-Woo
Department of Civil Engineering, Hanyang University, Seoul, Korea.
J Environ Sci Health A Tox Hazard Subst Environ Eng. 2008 Feb;43(2):144-53. doi: 10.1080/10934520701781244.
The feasibility of using zero-valent iron (ZVI) and peat mixture as in situ barriers for contaminated sediments and groundwater was investigated. Trichloroethylene (TCE) and nitrate (NO(3)(-)), redox sensitive contaminants were reduced by ZVI and peat soil mixture under anaerobic condition. Peat was used to support the sorption of TCE, microbial activity for biodegradation of TCE and denitrification while TCE and nitrate were reduced by ZVI. Decreases in TCE concentrations were mainly due to ZVI, while peat supported denitrifying microbes and further affected the sorption of TCE. Due to the competition of electrons, nitrate reduction was inhibited by TCE, while TCE reduction was not affected by nitrate. From the results of peat and sterilized peat, it can be concluded that peat was involved in both dechlorination and denitrification but biological reduction of TCE was negligible compared to that of nitrate. The results from hydrogen and methane gas analyses confirmed that hydrogen utilization by microbes and methanogenic process had occurred in the ZVI-peat system. Even though effect of the peat on TCE reduction were quantitatively small, ZVI and peat contributed to the removal of TCE and nitrate independently. The 16S rRNA analysis revealed that viable bacterial diversity was narrow and the most frequently observed genera were Bacillus and Staphylococcus spp.
研究了使用零价铁（ZVI）和泥炭混合物作为污染沉积物和地下水原位屏障的可行性。在厌氧条件下，ZVI和泥炭土混合物可还原三氯乙烯（TCE）和硝酸盐（NO(3)(-)）这两种对氧化还原敏感的污染物。泥炭用于支持TCE的吸附、TCE生物降解和反硝化的微生物活性，而ZVI可还原TCE和硝酸盐。TCE浓度的降低主要归因于ZVI，而泥炭支持反硝化微生物并进一步影响TCE的吸附。由于电子竞争，TCE抑制了硝酸盐的还原，而硝酸盐对TCE的还原没有影响。从泥炭和灭菌泥炭的结果可以得出结论，泥炭参与了脱氯和反硝化过程，但与硝酸盐相比，TCE的生物还原可忽略不计。氢气和甲烷气体分析结果证实，ZVI-泥炭系统中发生了微生物对氢气的利用和产甲烷过程。尽管泥炭对TCE还原的影响在数量上较小，但ZVI和泥炭各自对TCE和硝酸盐的去除都有贡献。16S rRNA分析表明，存活细菌的多样性较窄，最常见的属是芽孢杆菌属和葡萄球菌属。
