Enhancement of NO and CO removal via increasing of system pressure in a bio filter

The main aim of this study was the biological cleaning of waste air, especially enhancement of NO and CO removal. Pressurized bio trickling filter was chosen as bioreactor. The autotrophic culture was enriched in this laboratory reactor. The exposure to CO and NO gases were continuously carried out with a cyclic flow of nutrient medium in the reactor, which causes the enrichment of autotrophic culture. The microorganisms adhere to the rough surface of the stones. Then they catalyze the oxidation of NO and CO. The adjustment of the concentration of CO and NO gases is done with compressed air. The concentration of gaseous mixture was showed via a gas analyzer. Under atmospheric pressure in bioreactor, the elimination rate of CO was achieved by 90%, but the elimination rate of NO was very low (only 3 %). However, the results obtained were not reproducible and the system shows to be unstable. The results were improved significantly by increasing the pressure in the reactor. The removal of CO was increased to the 100 % and NO to 34 % at pressure of 4 bars.

Keywords:

Trickle bed , Bioreactor , Waste air