Acceleration of the Fe(III)EDTA(-) reduction rate in BioDeNO(x) reactors by dosing electron mediating compounds.
Acceleration of the Fe(III)EDTA(-) reduction rate in BioDeNO(x) reactors by dosing electron mediating compounds.
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DOI：
10.1016/j.chemosphere.2008.04.043
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发表时间：
2009-04
期刊：
影响因子：
8.8
通讯作者：
P. V. D. Maas;P. V. D. Brink;B. Klapwijk;P. Lens
中科院分区：
文献类型：
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作者：
P. V. D. Maas;P. V. D. Brink;B. Klapwijk;P. Lens
BioDeNOx是一种从工业烟气中去除nox的新技术，其基础是将气态一氧化氮吸收到Fe(II)EDTA2 -水溶液中，然后将Fe(II)EDTA2 -络合的NO生物还原为N2。除NO还原外，高速率的生物Fe(III)EDTA−还原是BioDeNOxtechnology成功应用的关键因素，因为它决定了洗涤液中Fe(II)EDTA2−的浓度，从而决定了气相中NO的去除效率。研究了不适应厌氧产甲烷污泥与生物脱氧反应器混合液生物还原Fe(III)EDTA−的机理和动力学。在批量实验（21mM Fe(III)EDTA−,55°C, pH 7.2±0.2）中测定了不同电子给体、电子介导化合物和caso3对Fe(III)EDTA−还原速率的影响。Fe(III)EDTA−的还原速率与电子供体类型有关，葡萄糖的还原速率最高（13.9mMh−1），其次是乙醇、乙酸和氢。以甲醇为电子供体时，Fe(III)EDTA−的还原速度相对较慢（4.1mMh−1）。少量（0.5mM）硫化物、半胱氨酸或单质硫加速了Fe(III)EDTA−的还原。铁的还原量明显超过了硫化物与Fe(III)EDTA−的化学反应生成的量，这表明Fe(III)EDTA−的还原是通过一种未知的电子中介化合物（可能是由硫添加剂形成的多硫化物）的自催化过程加速的。以乙醇为电子供体时，Fe(III)EDTA−的还原率与硫化物供给量呈线性关系。CaSO3（0.5 ~ 100mM）抑制Fe(III)EDTA−还原，可能是因为so32清除了电子中介化合物。
BioDeNOx, a novel technique to remove NOxfrom industrial flue gases, is based on absorption of gaseous nitric oxide into an aqueous Fe(II)EDTA2−solution, followed by the biological reduction of Fe(II)EDTA2−complexed NO to N2. Besides NO reduction, high rate biological Fe(III)EDTA−reduction is a crucial factor for a succesful application of the BioDeNOxtechnology, as it determines the Fe(II)EDTA2−concentration in the scrubber liquor and thus the efficiency of NO removal from the gas phase. This paper investigates the mechanism and kinetics of biological Fe(III)EDTA−reduction by unadapted anaerobic methanogenic sludge and BioDeNOxreactor mixed liquor. The influence of different electron donors, electron mediating compounds and CaSO3on the Fe(III)EDTA−reduction rate was determined in batch experiments (21mM Fe(III)EDTA−, 55°C, pH 7.2±0.2). The Fe(III)EDTA−reduction rate depended on the type of electron donor, the highest rate (13.9mMh−1) was observed with glucose, followed by ethanol, acetate and hydrogen. Fe(III)EDTA−reduction occurred at a relatively slow (4.1mMh−1) rate with methanol as the electron donor. Small amounts (0.5mM) of sulfide, cysteine or elemental sulfur accelerated the Fe(III)EDTA−reduction. The amount of iron reduced significantly exceeded the amount that can be formed by the chemical reaction of sulfide with Fe(III)EDTA−, suggesting that the Fe(III)EDTA−reduction was accelerated via an auto-catalytic process with an unidentified electron mediating compound, presumably polysulfides, formed out of the sulfur additives. Using ethanol as electron donor, the specific Fe(III)EDTA−reduction rate was linearly related to the amount of sulfide supplied. CaSO3(0.5−100mM) inhibited Fe(III)EDTA−reduction, probably because SO32-scavenged the electron mediating compound.