Effects of NO2(-) and NO3(-) on the Fe(III)EDTA reduction in a chemical absorption-biological reduction integrated NO(x) removal system.
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.
Zhang
Shi-Han
SH
Department of Environmental Engineering, Zhejiang University (Yuquan Campus), Hangzhou, 310027, China.
Cai
Ling-Lin
LL
Liu
Yun
Y
Shi
Yao
Y
Li
Wei
W
D000042:Absorption; D001673:Biodegradation, Environmental; D004492:Edetic Acid / Q000737:chemistry / Q000378:metabolism*; D004926:Escherichia coli / Q000737:chemistry / Q000378:metabolism*; D005290:Ferric Compounds / Q000737:chemistry / Q000378:metabolism*; D007700:Kinetics; D009566:Nitrates / Q000737:chemistry / Q000378:metabolism*; D009569:Nitric Oxide / Q000737:chemistry / Q000378:metabolism*; D009573:Nitrites / Q000737:chemistry / Q000378:metabolism*; D010084:Oxidation-Reduction
D005290:Ferric Compounds; D009566:Nitrates; D009573:Nitrites; D009569:Nitric Oxide; D004492:Edetic Acid