I-Corps: Photocatalytic Water Purification Technology for the Removal of Pollutants that are Commonly Problematic for Water Treatment Systems

Portland State University, Portland OR

Investigators

Abstract

The broader impact/commercial potential of this I-Corps project is an improvement in the current state-of-the-art water purification capability. The technology expands the range of water purification effectiveness and provides a means of preventing anthropogenic wastes from entering the environment through photocatalytic degradation. The removal of organic material from the water system has an ever-increasing role in the subject of human health. The degree to which anthropogenic water waste affects human health is ultimately tied to the ability to remove these wastes from our water supply. Unlike filtration methods, photocatalytic oxidation has the ability to destroy these contaminants without the need for chemical additives. Successful commercialization of this technology protects health by improving the capability for organic waste remediation. There also are many industrial applications requiring organic pollutant removal where this technology can have impact. The proposed system is capable of oxidizing water contaminants and can destroy contaminants that are commonly problematic for water treatment systems. This I-Corps project is based on fundamental research showing improved efficiency and scalability of photocatalytic water purification systems by optimizing the 3D geometry of the catalyst material in conjunction with the geometry of the illumination system. The result was a significant reduction in energy loss, as well as an overall improved usability and scalability of the system. The photocatalyst material itself also has been modified in order to optimize the electrical and chemical properties of the catalyst surface. Implantation of TiO2 and SiO2 nanoparticles resulted in increased degradation performance by more than 500%. The overall efficiency of the photocatalytic reactor also was considered with respect to energy usage as defined by the Electrical Energy per Order (EEO) characterization model. The lowest EEO achieved in this system was 54 kWh per cubic meter of water for each order of magnitude reduction in pollutant concentration - an improvement in EEO over previously reported thin-film based photoreactors. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.