Paving Material Laced with Titanium Dioxide Removes NOx
06 July 2010
Test results from a road surface containing titanium dioxide show that the material reduces the concentration of nitrogen oxides (NOx) by 25 to 45%, according to Professor Jos Brouwers of the Technische Universiteit Eindhoven (TU/e) in The Netherlands.
The titanium dioxide, a photocatalytic material, removes the NOx from the air and converts them with the aid of sunlight into nitrate. The nitrate is then rinsed away by rain.
The tests were carried out in the municipality of Hengelo, where the busy Castorweg road was resurfaced last fall. As part of the project, around 1,000 square meters of the road’s surface were covered with concrete paving stones containing the titanium dioxide. For comparison purposes, another area of 1.000 square meters was surfaced with normal paving stones.
Researchers at TU/e carried out three air-purity measurements on the Castorweg last spring, at heights of between a half and one-and-a-half meters. Over the area paved with air-purifying concrete the NOx content was found to 25 to 45% lower than that over the area paved with normal concrete. Further measurements are planned later this year.
Brouwers, who has been professor of building materials in the TU/e Department of Architecture, Building and Planning since September 2009, sees numerous potential applications, especially at locations where the maximum permitted NOx concentrations are now exceeded. The concrete stones used in the tests are made by, and co-developed with, paving stone manufacturer Struyk Verwo Infra, and are already available for use. For roads where an asphalt surface is preferred the air-purifying concrete can be mixed with open asphalt, according to Brouwers. It can also be used in self-cleaning and air-purifying building walls.
The use of air-purifying concrete does not have a major impact on the cost of a road, Brouwers has calculated. Although the stones themselves are 50% more expensive than normal concrete stones, the total road-building costs are only 10% higher.
Combine the titanium dioxide with embeded PV cells and those weird sound absorbing walls and change your city's name to Bizarro World.
Posted by: ToppaTom | 06 July 2010 at 08:12 PM
They put titanium dioxide in paint and not only did it absorb NOx, but it lasted much longer than regular paint.
Posted by: SJC | 07 July 2010 at 12:06 AM
Um titanum dioxide is in ALL paint as its the base white all paint starts as.
Posted by: wintermane2000 | 07 July 2010 at 03:28 AM
Perhaps not in the quantities that the article showed. I am not here to argue the point, just pointing out a story that I saw.
Posted by: SJC | 07 July 2010 at 10:58 AM
"It works by trapping NOx gases, which stick to microscopic particles of titanium dioxide embedded in the paint's base. The particles absorb sunlight, using this energy to convert NOx to nitric acid."
http://clippednews.wordpress.com/2003/02/05/new-paint-absorbs-pollution/
Posted by: SJC | 07 July 2010 at 11:25 AM
It is not necessarily in ALL paints...
"Hiding pigments, in making paint opaque, also protect the substrate from the harmful effects of ultraviolet light. Hiding pigments include titanium dioxide, phthalo blue, red iron oxide, and many others."
http://en.wikipedia.org/wiki/Paint#Pigment
Posted by: SJC | 07 July 2010 at 11:30 AM
"The polysiloxane base is porous enough to allow NOx to diffuse though it and adhere to the titanium dioxide particles."
http://www.newscientist.com/article/dn4636-smogbusting-paint-soaks-up-noxious-gases.html
I find it more beneficial to research information rather than to just make comments.
Posted by: SJC | 07 July 2010 at 05:53 PM
Well my point was there had to be something more to it then such a common thingy.
Posted by: wintermane2000 | 07 July 2010 at 11:53 PM