Scenic road in Carmel, California

Scenic road in Carmel, California

With all the fuss about clean air, we tend to get excited about technology that prevents excessive pollution in the first place. And that's good, we need those kinds of solutions. The fact is, the air is still going to get... dirty. So, why not clean it? A special type of concrete paving stones has been designed to do exactly that, by converting nitrogen oxides back to less harmful materials.

In addition to carbon dioxide, nitrogen oxides are part of the pollution problem that results from automotive tailpipe emissions. Carbon, nitrogen, and obviously oxygen are not necessarily harmful. In fact, we need all three to survive. In the wrong form or quantity, however, they're not good for us or the environment. We'll never be able to completely prevent it, but we can at least find ways to bring balance back to our altered atmosphere.

Research and testing is already underway in the Netherlands to determine whether a special type of concrete can be used to restore the correct proportions back to the gasses in the air. Struyk Verwo Infra, a stone manufacturer, has already begun producing a new type of paving stone that contains titanium dioxide. Its composition allows it to convert nitrogen oxides to nitrate, which is less harmful.

The concrete can be poured as usual, or mixed with asphalt to create driving surfaces. Lab tests proved the initial effectiveness of the material, after which the team moved research outdoors. Measurements taken last fall showed NOx reductions of as much as 45%. They plan to continue testing later this year.

The material cost of the new concrete is estimated at about 50% higher than standard concrete, with road building costs expected to increase by about 10% with the special material. Combined with negative emissions technology found on the YeZ concept, cleaning concrete could go a long way in returning a natural balance to the air we breathe.