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| Joint Center for Transportation & Air Quality |
| Project Title: | Photocatalytic Coating on Road Pavements/Structures for NOx Abatement |
| Organization: | Lamar University |
| Investigators: | Daniel H. Chen (PI), Robert Yuan, Kuyen Li |
Photocatalysis is an emerging technology that has gained much attention in air and water pollution control. Photocatalytic oxidation (PCO) uses photocatalyst under UV/visible light illumination to oxidize pollutants to innocuous compounds. Some recent applications include indoor air cleaning, process vent treatment, groundwater treatment, disinfection of hospital rooms, and self-cleaning lamp covers. Recent advancements in visible-light-responsive photocatalysts make this technology even more attractive.
In the past few years, Europe and Japan have tested photocatalytic oxidation technology in community-scale environmental remediation. There has been little or no such experiments carried out in the US. The objectives of this proposal are 1) to evaluate the costs/benefits of photocatalytic coating on pavements, sound barriers, and other road structures for the on-site destruction of NOx, 2) to develop advanced, cost-effective catalytic coatings on concrete, asphalt, and other road surfaces for NOx abatement, and 3) to transfer the developed technology to coating/concrete industry, 4) to demonstrate the developed technology with the approval of community and government agencies. The proposed photocatalytic coating has potential to economically reduce nitrogen oxides (NOx) and VOC emissions at ambient conditions nearly maintenance-free. NOx will be oxidized to nitric acid, neutralized by the alkaline base materials in concrete, and washed away by rain while VOC can be mineralized to CO2 and water. Even though the chemistry works for both NOx and VOCs, the current project will focus on NOx only. The preliminary estimate of NOx removal is very promising (50,000 ton/yr or 28% for Harris County at a cost of $200/ton assuming pavements last for 5 years). The reduction on the number of high ozone days can be significant to allow sustainable economic developments in major Texas urban areas (e.g., Houston-Galveston-Brazoria and Dallas-Ft. Worth).
Lamar University has pioneered the use of wide band gap, high transmittance, ferroelectric crystals (LiNbO3 and BaTiO3) as additives to utilize UV/visible light more efficiently. The ferroelectric opticals are believed to enhance transmission/scattering of UV/Visible light and stabilize the electron-hole pairs. Both the UV-responsive (anatase P-25) and visible-light-responsive (BA-PW25) TiO2 can be modified with ferroelectric metal oxides to enhance activities of the photocatalytic coatings.
The project scope includes:
- Technology update regarding photocatalytic coverings for pollution abatement
- Impact study based on literature removal rate and coatable area data from GIS for Houston - Galveston and Dallas-Ft. Worth areas
- Lab investigation using advanced photocatalytic composite materials (UV and visible-light responsive TiO2 plus ferroelectric optical enhancements) for NOx removal
- Technology transfer and field demonstration
The first year tasks will cover technology update, preliminary impact study, and catalytic concrete lab test for NOx. The developed technology can be transferred to the cement and coating industries to meet the tighter emission standards and will give architects and town planners a new weapon in the fight against pollution to facilitate sustainable economic growth.
Annual Project Report - Available for download
Photocatalytic Coating on Road Pavements/Structures for NOx Abatement ( 4.27 MB)
This report describes testing and results to date on catalytic coating materials that are applied to pavement surfaces to reduce NOx concentrations.
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| Page Updated/Reviewed: 03/22/2007 8:34 AM |
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