Imagine a city
that could devour the very pollution that it creates. Such was the scenario
envisioned by scientists in the Netherlands, who have found that using
specially treated pavement on city streets can cut air pollution nearly in half.
The researchers
from Eindhoven University of Technology installed concrete paving which
included titanium dioxide – called photocatalytic pavement – on a block in the
city of Hengelo, Netherlands. Titanium oxide has the ability to remove
pollutants from the air and reduce them into less harmful components. Another
part of the street was outfitted with normal paving blocks as a control.
The study looked
at reductions in nitrogen oxides (NOx), a group of poisonous gases produced by
cars and power plants that react with other compounds in the atmosphere to form
smog.
After analyzing measurements gathered over the course of a
year, the researchers found that the treated street reduced NOx air pollution
by 19 percent on average; the figure bumped up to 28 percent during the
afternoon and a remarkable 45 percent under ideal weather conditions (high
radiation and low relative humidity).
The findings were
published in the Journal of Hazardous Materials; it is hoped the research may
lead to ways in which cities might be designed to intrinsically deal with the
air pollution they create.
Although the
application of photocatalytic surfaces has been studied for several years,
David Brown, Chief Executive of Institution of Chemical Engineers, noted in a
press release, “this latest research shows the
potential of chemically engineered surfaces to further improve our quality of
life, especially in major urban areas where traffic emissions are high.”