Research Centre United States
Substituting road pavement and surface coatings made with nanoscale titanium dioxide (TiO2) additive can significantly improve air quality with a reduction of at least 20% in NOx emissions at little to no increase in construction and maintenance costs.
Background:
Air pollution, particularly NOx from motor vehicles on roadways, causes health and property damage. NOx is a precursor to the formation of ground-level ozone air pollution which is dangerous to human health. Any activities that involve large numbers of diesel-powered vehicles are significant point sources of NOx air pollution, especially when idled at choke points.
Quick Facts: Pollution-Absorbing Concrete
Photocatalytic TiO2 cement building materials and coverings may absorb and eliminate from 20% to 80% of air pollutants.
TiO2 is commonly used to cover surfaces that are difficult to clean by hand. The TiO2 covering functions as a self cleaning chemical to keep the surface free of accumulating air pollution.
The Challenge:
The current, approach for reducing NOx air pollution focuses primarily on reducing its emission from fixed sources (e.g., power plants) and vehicles. Reducing emissions from these sources requires either reducing usage (e.g., carpooling) or installing hardware that reduces NOx emissions. Although these can be effective solutions, they can also be expensive. Alternative solutions for reducing NOx air pollution are needed.
A Solution:
Titanium dioxide (TiO2) is a well-know catalyst able to degrade (by oxidation) several organic compounds such as NOx. Recent studies have proposed to exploit this property of TiO2 by preparing additives for construction materials based on this compound. Once the TiO2 is activated within the building material by sunlight, it reacts with NOx in the air and can thus reduce air pollution.
Since February of 2006, the centre have been working to design a study examining the effectiveness of concrete containing TiO2 to reduce NOx pollution. The partners have selected a test-site for the study.
