烟气脱氮体系中络合吸收剂的氧化还原过程

在填料吸收塔中,考察NO和O₂共存时,NO浓度、O₂含量对脱氮效率、Fe^II(EDTA)氧化速率以及Fe^III(EDTA)生物还原速率的影响,并对该系统的主要反应过程进行了分析.结果表明,同时吸收NO可促进Fe^II(EDTA)的氧化,当进气NO浓度由0增至500cm³/m³时,表观氧化反应速率常数由0.00451min^-1增至0.00604min^-1;Fe^II(EDTA)的氧化反应对于O₂含量为1级反应,表观氧化速率常数与O₂含量成线性关系;增加气体中NO浓度或O₂含量均会使Fe^III(EDTA)的生物还原反应速率下降;微生物对氧化中间产物的还原可以减缓NO对Fe^II(EDTA)氧化的促进作用,因而气相中NO和O2共存时对Fe^III(EDTA)生物还原的影响小于各单一组分存在时的影响之和.

The oxidation reduction process of complex absorbent in the system of nitrogen removal from flue gas

The influence of NO concentration and O2 content on NO removal efficiency, FeII(EDTA) oxidation rate and FeIII(EDTA) bioreduction rate were investigated at the coexistence of NO and O2 in a stuffing absorption tower, and the main reaction process of this system was analyzed. Simultaneous NO absorption could promote the oxidation of FeII(EDTA), the apparent oxidation reaction rate constant increased from 0.00451min-1 to 0.00604min-1, when NO concentration of input gas increased from 0 to 500cm3/m3. The oxidation reaction of FeII(EDTA) by O2 was first order reaction, apparent oxidation rate constant had liner relation with O2 content. Increase of NO concentration or O2 content in gas could all lower the bioreduction reaction rate of FeIII(EDTA). The intermediates of NO2- and NO3- in NO absorption could be reduced by microorganisms, which decreased the stimulated oxidation of FeII(EDTA) caused by the intermediates, thus the influence of coexistence of O2 and NO in gas phase on FeIII(EDTA) bioreduction was smaller than the influence sum of each single component.