Zhang Shi-Han, Cai Ling-Lin, Liu Yun, Shi Yao, Li Wei
Department of Environmental Engineering, Zhejiang University (Yuquan Campus), Hangzhou, 310027, China.
Appl Microbiol Biotechnol. 2009 Mar;82(3):557-63. doi: 10.1007/s00253-008-1837-z. Epub 2009 Jan 10.
The biological reduction of Fe(III) ethylenediaminetetraacetic acid (EDTA) is a key step for NO removal in a chemical absorption-biological reduction integrated process. Since typical flue gas contain oxygen, NO(2)(-) and NO(3)(-) would be present in the absorption solution after NO absorption. In this paper, the interaction of NO(2)(-), NO(3)(-), and Fe(III)EDTA reduction was investigated. The experimental results indicate that the Fe(III)EDTA reduction rate decrease with the increase of NO(2)(-) or NO(3)(-) addition. In the presence of 10 mM NO(2)(-) or NO(3)(-), the average reduction rate of Fe(III)EDTA during the first 6-h reaction was 0.076 and 0.17 mM h(-1), respectively, compared with 1.07 mM h(-1) in the absence of NO(2)(-) and NO(3)(-). Fe(III)EDTA and either NO(2)(-) or NO(3)(-) reduction occurred simultaneously. Interestingly, the reduction rate of NO(2)(-) or NO(3)(-) was enhanced in presence of Fe(III)EDTA. The inhibition patterns observed during the effect of NO(2)(-) and NO(3)(-) on the Fe(III)EDTA reduction experiments suggest that Escherichia coli can utilize NO(2)(-), NO(3)(-), and Fe(III)EDTA as terminal electron acceptors.
乙二胺四乙酸铁（III）（EDTA）的生物还原是化学吸收 - 生物还原集成工艺中去除NO的关键步骤。由于典型的烟道气中含有氧气，NO吸收后吸收液中会存在NO2(-)和NO3(-)。本文研究了NO2(-)、NO3(-)与Fe(III)EDTA还原之间的相互作用。实验结果表明，随着NO2(-)或NO3(-)添加量的增加，Fe(III)EDTA的还原速率降低。在存在10 mM NO2(-)或NO3(-)的情况下，前6小时反应期间Fe(III)EDTA的平均还原速率分别为0.076和0.17 mM h(-1)，而在不存在NO2(-)和NO3(-)时为1.07 mM h(-1)。Fe(III)EDTA与NO2(-)或NO3(-)的还原同时发生。有趣的是，在Fe(III)EDTA存在的情况下，NO2(-)或NO3(-)的还原速率增强。在NO2(-)和NO3(-)对Fe(III)EDTA还原实验的影响中观察到的抑制模式表明，大肠杆菌可以利用NO2(-)、NO3(-)和Fe(III)EDTA作为末端电子受体。
