模拟烟气中NO、NO_x的微生物净化效率强化研究

NO的脱除效率已成为微生物净化燃煤烟气NOx双塔流程的瓶颈。为了提高微生物净化烟气中NO、NOx的效率,分别研究了脱硫塔添加Fe SO4·7H2O、脱氮塔添加Na NO2对微生物净化模拟烟气中NO、NOx效率的影响作用。结果表明:脱硫塔添加0.23 g/L Fe SO4·7H2O,其NO平均脱除率为61.04%,比空白试验的35.31%提高明显;脱硫塔NOx平均脱除率为62.16%,比空白试验的31.10%提高约1倍;双塔NOx平均总脱除率从空白试验的61.8%增至86.9%。浓度梯度试验结果表明:0.23 g/L Fe SO4·7H2O是脱硫塔内较为合适的添加浓度。脱氮塔添加0.50 g/L Na NO2后,脱氮塔NO平均脱除率从空白试验的39.92%提高到52.11%;脱氮塔NOx平均脱除率从空白试验的47.67%增至58.90%;双塔NOx平均总脱除率从空白试验的70.75%增至79.32%。反复多次验证试验均证明:Fe SO4·7H2O和Na NO2的分别添加的确大幅度地强化了烟气中NO、NOx的微生物净化效率。

ENHANCEMENT RESEARCH ON MICROBIAL PURIFICATION EFFICIENCY OF NO AND NOx IN SIMULATED FLUE GAS

The removal efficiency of NO has become the bottleneck of the development of double towers system for simultaneous biological removal of SO2 and NOx ． In order to increase the microbial removal rates of NO and NOx from the flue gas，a solution of FeSO4·7H2O was added into the desulfurizing tower， and a certain concentration solution of NaNO2 was added into the denitrification tower，which were investigated on the effects on double towers system． The results demonstrated that the mean removal rates ( Abbrev． rates) of NO was 61. 04% when the dosage of FeSO4·7H2O was 0. 23 g /L， increasing by 25. 73% compared with blank test; the removal rates of NOx was 62. 16% in desulfurizing tower，which increased 31. 06% than the blank test; and the capacity of purifying NOx of double towers system improved from 61. 8% to 86. 9%． The concentration gradient experiment results showed that the suitable concentration of FeSO4·7H2O was 0. 23 g /L． Besides， the removal rate of NO by denitrification tower increased from 39. 92% to 52. 11% with the dosage of NaNO2 being 0. 5 g /L; and the NOx removal rate increased from 47. 67% to 58. 90%． Meanwhile，the removal rate of NOx in the double towers system was 79. 32%，while the blank test was 70. 75%． Verification tests for many times proved that adding FeSO4 and NaNO2 could enhance the microbial purification efficiency of NO and NOx in simulated flue gas．