Removal of nitrogen oxides from waste gases by bio-filter and NRB under aerobic conditions
生物滤塔和NRB在有氧条件下去除废气中的NOx

The mass transfer mechanism of nitrogen oxides under aerobic conditions in biofilter was studied. The results showed that when oxygen content was about 20% and oxidation rate was 80%, only about 12% of NOx which were removed by biofilter were absorbed and decomposed by microorganisms, and 88% of NOx were not timely decomposed by microorganisms, but transferred into liquid phase in the form of NO-2 and NO-3. On the basis of this, the integrated process of biofilter and NRB was put forward to remove NOx from exhaust gases under aerobic conditions, a series of experimental were carried out. The results showed that the removal efficiency of NOx achieved 90.23% for the inlet NOx concentration of 1 488.92 mg/m3 when the residence time was 9.42 s, and the concentration of NO-2and NO-3 at the outlet of NRB was less than 5 mg/m3.