Nanotechnology Now





Heifer International

Wikipedia Affiliate Button


DHgate

Home > Press > Paving slabs that clean the air

Initial tests in the measuring chamber confirm that paving slabs coated with titanium dioxide can reduce ambient nitrogen oxide levels. (© Fraunhofer IME)
Initial tests in the measuring chamber confirm that paving slabs coated with titanium dioxide can reduce ambient nitrogen oxide levels. (© Fraunhofer IME)

Abstract:
The concentrations of toxic nitrogen oxide that are present in German cities regularly exceed the maximum permitted levels. That's now about to change, as innovative paving slabs that will help protect the environment are being introduced. Coated in titanium dioxide nanoparticles, they reduce the amount of nitrogen oxide in the air.

Paving slabs that clean the air

Germany | Posted on August 2nd, 2010

In Germany, ambient air quality is not always as good as it might be - data from the federal environment ministry makes this all too clear. In 2009, the amounts of toxic nitrogen oxide in the atmosphere exceeded the maximum permitted levels at no fewer than 55 percent of air monitoring stations in urban areas. The ministry reports that road traffi c is one of the primary sources of these emissions. In light of this fact, the Baroque city of Fulda is currently embarking on new ways to combat air pollution. Special paving slabs that will clean the air are to be laid the length of Petersberger Straße, where recorded pollution levels topped the annual mean limit of 40 micrograms per cubic meter (μg/m3) last year. These paving slabs are coated with titanium dioxide (TiO2), which converts harmful substances such as nitrogen oxides into nitrates. Titanium dioxide is a photocatalyst; it uses sunlight to accelerate a naturallyoccurring chemical reaction, the speed of which changes with exposure to light. The Air Clean nitrogen oxide-reducing paving slabs were developed by F. C. Nüdling Betonelemente. Proof of their effectiveness has subsequently been provided by the Fraunhofer Institute for Molecular Biology and Applied Ecology IME in Schmallenberg, where researchers also determined the risk to the environment posed by the resulting nitrates. Their work was funded by the German Environment Foundation.

Dr. Monika Herrchen, a scientist at the IME, says: "Experiments in Italian cities had already shown that photocatalytic paving slabs can improve the air quality. We wanted to see if they would also be effective here in Germany, where we have lower levels of light intensity and fewer hours of sunshine. Of course, the more intense the sunshine, the quicker the degradation of harmful substances, so our aim was to identify the formula with the highest photocatalytic effi ciency rating."

To begin with, concrete manufacturer F.C. Nüdling produced a range of sample slabs incorporating different surfaces, colors, types of cement and TiO2 contents. Since the nitrogen oxide degradation rates achieved using standard commercial photocatalytic cement (i.e. cement that reacts to solar radiation) proved unsatisfactory, the company ultimately had to develop its own, more effective formula. »We were able to verify the effectiveness of the optimized slabs in a variety of tests,« confi rms Herrchen. During an extended time fi eld test, the scientist and her team recorded nitrogen oxide degradation rates of 20 to 30 percent in specially-created street canyons. The measurements were taken at a height of three meters above the photocatalytic slabs, in variable wind and light conditions. When the wind was still, the experts recorded degradation rates as high as 70 percent for both nitrogen monoxide (NO) and nitrogen dioxide (NO2). Measurements likewise taken at a height of three meters above the Gothaer Platz in Erfurt, which is already paved with Air Clean paving slabs, revealed an average degradation rate of 20 percent for NO2 and 38 percent for NO.

Herrchen points out an additional benefi t of these paving slabs: "They also remain stable over the long term. Measurements recorded from 14 to 23 months after they were laid revealed no change from the initial degradation capability." Furthermore, the nitrate that is generated during the conversion process poses absolutely no risk to the environment. It runs off into the drainage system, then into a wastewater treatment plant, before fi nally ending up on a farmer's fi eld or in the groundwater. The maximum possible nitrate concentration traceable back to photocatalytic reactions is around fi ve milligrams per liter (mg/l), while the maximum permitted concentration of nitrate in groundwater is 50 mg/l. Herrchen sums up: "All in all, it's possible to say that Air Clean signifi cantly improves the air quality within a short space of time, and thus helps protect the environment."

####

For more information, please click here

Copyright © Fraunhofer-Gesellschaft

If you have a comment, please Contact us.

Issuers of news releases, not 7th Wave, Inc. or Nanotechnology Now, are solely responsible for the accuracy of the content.

Bookmark:
Delicious Digg Newsvine Google Yahoo Reddit Magnoliacom Furl Facebook

Related News Press

News and information

Stanford breakthrough heralds super-efficient light-based computers: Light can transmit more data while consuming far less power than electricity, and an engineering feat brings optical data transport closer to replacing wires May 29th, 2015

Donuts, math, and superdense teleportation of quantum information May 29th, 2015

OSU researchers prove magnetism can control heat, sound: Team leverages OSC services to help confirm, interpret experimental findings May 29th, 2015

Two UCSB Professors Receive Early Career Research Awards: The Department of Energy’s award for young scientists acknowledges UC Santa Barbara’s standing as a top tier research institution May 29th, 2015

Possible Futures

Global Carbon Nanotubes (CNT) Market Expected To Reach USD 3.42 Billion By 2022 May 29th, 2015

Global Nano-Enabled Packaging Market For Food and Beverages Will Reach $15.0 billion in 2020 May 26th, 2015

Simulations predict flat liquid May 21st, 2015

Nature inspires first artificial molecular pump: Simple design mimics pumping mechanism of life-sustaining proteins found in living cells May 19th, 2015

Academic/Education

SUNY Poly CNSE and NIOSH Launch Federal Nano Health and Safety Consortium: May 20th, 2015

New JEOL E-Beam Lithography System to Enhance Quantum NanoFab Capabilities May 6th, 2015

FEI Partners With the George Washington University to Equip New Science & Engineering Hall: Suite of new high-performance microscopes will be used for cutting-edge experiments at GW’s new research facility April 29th, 2015

Renishaw Raman systems used to study 2D materials at Boston University, Massachusetts, USA. April 28th, 2015

Announcements

Stanford breakthrough heralds super-efficient light-based computers: Light can transmit more data while consuming far less power than electricity, and an engineering feat brings optical data transport closer to replacing wires May 29th, 2015

Donuts, math, and superdense teleportation of quantum information May 29th, 2015

OSU researchers prove magnetism can control heat, sound: Team leverages OSC services to help confirm, interpret experimental findings May 29th, 2015

Two UCSB Professors Receive Early Career Research Awards: The Department of Energy’s award for young scientists acknowledges UC Santa Barbara’s standing as a top tier research institution May 29th, 2015

Environment

Collaboration could lead to biodegradable computer chips May 28th, 2015

Conversion of Greenhouse Gases to Syngas in Presence of Nanocatalysts in Iran May 22nd, 2015

Directa Plus in Barcelona to present the innovative project GEnIuS for oil spills clean-up activities: The company has created a graphene-based product for the remediation of water contaminated by oil and hydrocarbons May 21st, 2015

Nano-policing pollution May 13th, 2015

Automotive/Transportation

Chemists discover key reaction mechanism behind the highly touted sodium-oxygen battery May 28th, 2015

Controlled Release of Anticorrosive Materials in Spot by Nanocarriers May 27th, 2015

Wearables may get boost from boron-infused graphene: Rice U. researchers flex muscle of laser-written microsupercapacitors May 18th, 2015

ORNL demonstrates first large-scale graphene fabrication May 14th, 2015

Construction

Controlled Release of Anticorrosive Materials in Spot by Nanocarriers May 27th, 2015

Iranian Scientists Present Model to Study Mechanical Vibrations of Structures Containing Nanocomposites May 5th, 2015

Nanoparticles Used to Improve Mechanical, Thermal Properties of Cellulose Fibers April 23rd, 2015

Blue Star Opportunities Corp. (BSTO) Completes Major Condo Building Project in Manhattan Residential Area; Company Now Has the Resources to Service the Largest of Construction Projects April 21st, 2015

NanoNews-Digest
The latest news from around the world, FREE




  Premium Products
NanoNews-Custom
Only the news you want to read!
 Learn More
NanoTech-Transfer
University Technology Transfer & Patents
 Learn More
NanoStrategies
Full-service, expert consulting
 Learn More










ASP
Nanotechnology Now Featured Books




NNN

The Hunger Project