Experimental Study of the NO and NO2 Degradation by Photocatalytically Active Concrete

BALLARI, MARÍA DE LOS MILAGROS; JOS H.J.H. BROUWERS

Praga

Congreso; 6th European Meeting Solar Chemistry and Photocatalysis: Einvironmental Applications (SPEA6); 2010

Institute of Chemical Technology, Prague (ICT Prague), Jaroslav Heyrovský Institute of Physical Chemistry, Academy of Science (JH IPC)

The employment of photocatalytic concrete containing TiO2 in urban streets attempts to improve the air quality in highly polluted areas. By using this technology it is possible to degrade a wide range of air contaminants mainly emitted by automobiles, like nitric oxide (NO) and nitrogen dioxide (NO2). Currently, there are some international and national standards available to assess the photocatalytic efficiency of semiconducting materials. Some of them employ only NO as the target pollutant,1 while others use a mixture of NO and NO2 to perform the test.2,3 However, since the test is carried out in the presence of light, not only photocatalytic reactions take place. Homogenous and photolysis reactions of NOx occur as well. In the present paper, the photocatalytic degradation of NO and NO2 is experimentally studied and the homogeneous reactions involving NOx are analysed employing a photocatalytic concrete stone, and a normal concrete as a blank. In addition, the influence of different system parameters, such as inlet pollutant concentration, relative humidity, irradiance, reactor configuration and flow rate, is investigated.