Paving the Way to Cleaner Air?

A Dutch municipality is partnering with a local university to road test pavers that purify the air.

A Dutch municipality is partnering with a local university to road test air-purifying pavers.

Car exhaust fumes contain nitrogen oxides, which cause acid rain and smog. This problem may be partly solved by using air-purifying paving stones, which were developed at the University of Twente.

Based on a Japanese invention, the paving stones featuer a top layer  made of air-purifying concrete. The concrete contains titanium dioxide, a photocatalytic material that uses sunlight to convert the nitrogen oxides in the air into harmless nitrates. The rain then washes streets clean. As an added bonus, the stones repel dirt.

The effectiveness of the stones was first demonstrated by university researchers in the school's concrete research laboratory. Now the municipality of Hengelo has made a location available for testing the stones in practice. The street will be divided into two sections, one half will be paved with conventional stones and the other half with air-purifying ones. The air quality will then be measured.

The road reconstruction is expected to be completed by the end of the year. Measurements will start early next year, with the first test results expected around the summer of 2009.