Integrated System for the Treatment of Oxides of Nitrogen from Flue Gases

Abstract

A novel and effective system was developed for the complete treatment of NOx from flue gases. The system consisted of photocatalytic or ozone oxidation of NOx, followed by scrubbing and biological denitrification. Maximum photocatalytic oxidation of NOx was achieved while using powdered TiO2 at a catalytic loading rate of 10 g/h, relative humidity of 50%, and a space time of 10 s. The used catalyst was regenerated and reused. A total of 72% of oxidized NO was recovered as HNO3/HNO2 in the regeneration process. Stoichiometrically, 10% excess ozone was able to affect 100% oxidation of NO to NO2. Presence of SO2 adversely influenced the oxidation of NO by ozone. The scrubbing of NO was effective with distilled water. Heterotrophic denitrifiers were able to denitrify the leachate with an efficiency of 90%, using sewage (COD 450 mg/L) as electron donor. The new integrated treatment system seems to be a promising alternative for complete treatment of NOx from flue gases.

Isolation of an Aerobic Denitrifying Bacterial Strain from a Biofilter for Removal of Nitrogen Oxide

“…However, this term often refers specifically to nitric oxide (NO) and nitrogen dioxide (NO 2 ), both of which are hazardous air pollutants that lead to the formation of acid rains, airborne particulates, and increase ground level ozone (Barman and Philip, 2006;Han et al, 2011). Emissions of NO x in China have undergone severe increase over the past decade, thus an effective technology is needed to decrease its concentration in the air (Chang et al, 2012).…”

Carbon Xerogel Catalyst for NO Oxidation

“…NOx is blamed for the formation of ozone in the troposphere [2], the production of acid rains and respiratory problems to mankind [3][4][5].…”

Removal of NO by simultaneous action of dielectric-barrier discharge and TiO2photocatalyst

“…Non-thermal plasma sources, such as corona discharge or dielectric barrier discharge (DBD) are considered as an efficient method for the treatment of NO x [1][2][3][4][5][6]. Another possibility for the treatment of NO x is to use photocatalysts, such as TiO 2 [6][7][8].…”

“…Another possibility for the treatment of NO x is to use photocatalysts, such as TiO 2 [6][7][8]. The main route for the removal of NO from flue gases is the oxidation of NO to NO 2 .…”