A research team from Eindhoven University of Technology in the Netherlands has found that a new form of concrete paving stone made with titanium dioxide can help reduce the concentration of oxides of nitrogen (NOx) in the air by 25-45 percent. According to professor Jos Brouwers who presented news of the discovery, the first real-world test of this new air-purifying concrete material confirmed what the original lab evaluation had indicated with respect to its passive "scrubbing" prowess compared to conventional alternatives.
The titanium dioxide in these paving elements -- which are already available commercially -- acts as a photo-catalytic oxidizing material that neutralizes this fundamental component of tailpipe emissions. Energized by sunlight, it removes NOx from the air and converts it into harmless nitrates which are subsequently rinsed away by rain. If that's not enough, these enviro-friendly pavers also break down algae and dirt in a serendipitous self-cleansing process that always keeps them looking clean.
Bouwers claims that titanium dioxide-laced stones can be used in conventional building applications as well as in road paving and that powered formulations can be mixed with asphalt. While admitting that the stones currently carry about a 50-percent cost premium to produce, he calculates their implementation will add only about 10 percent to the price of a given road.