Development of novel inexpensive adsorbents from waste concrete to mitigate NOx emissions

Mitigating NOx (NO + NO2) pollution can have result in notable improvement of public health and environmental conditions, especially in urban environments. This work is the first demonstration of applications of both fresh and aged concrete as inexpensive adsorbents for NO2 removal. The gas phase uptake experiments with fresh and aged concrete demonstrated the feasibility of this approach, while infrared spectroscopy identified a potential mechanism of NO2 adsorption on concrete surfaces. A decrease in surface basicity due to carbonation appears to be the main factor for observed decrease in NO2 uptake as a function of concrete age.