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．