Can your sidewalk clean the air?
It might be able to if researchers at the
of Twente can prove that their new paving stones do what they claim. These stones, made from a variety of
non-harmful chemicals, take the nitrogen oxides given off by vehicles as a
byproduct of the combustion process (which are linked to acid rain and smog),
and convert them into completely non-harmful nitrates.
The secret ingredient is titanium dioxide, which helps to
catalyze chemical reactions when exposed to sunlight, would pull the nitrogen
oxide from the air and absorb it into the bricks, and the resulting nitrates
will simply wash away. Some are
concerned about the amount of nitrates, as too much of these can harm ground
water and soil, but the developers at Twente claim that the byproduct nitrates
are well below the “safe” level specified by the local government.
The bricks have not been put to use yet but there are plans
to produce and uses some of these eco-friendly paving stones and then study the
effects on both the air quality and the levels of pollutants in the soil and
ground water, with the results to be released some time in 2009.