Method for Purifying Water Contaminated with Environmental Chemicals

Market Overview:

This novel water treatment uses semiconductor particles in suspended or immobilized form which are excited by light in order to induce reactions that degrade or transform chemical or microbial contaminants in water. Use of poly/perfluoroalkyl substances (PFAS) has caused widespread contamination of surface and ground waters resulting primarily from discharge by chemical plants and firefighting training practices at military installations and airfields. Methods that are effective in removing PFAS from water, and are deployable in the form of compact and integrated treatment systems, are being heavily sought by industry. PFAS are highly recalcitrant and extremely challenging to remove using existing water treatment technologies. Clemson inventors have created a method that is able to degrade perfluorosulfates (PFS), which are the most challenging subcategory of PFAS, more efficiently, and at a faster treatment rate.


Application                                                                   Stage of Development

Water Treatment, PFAS                                                    Proof of concept




  • Can be incorporated into existing commercial photo-reactor systems and is thus readily marketable at full scale
  • Faster, in terms of treatment rate, then other methods on the market
  • More robust in the presence of real water co-constituents, and simple to deploy and operate


Technical Summary

Bismuth phosphate (BiPO4) has been explored previously as a photocatalyst for advanced oxidation of organic contaminants. This method applies BiPO4, in microparticle form, as a suspension in water and reducing conditions are established in order to reduce, rather than oxidize, target contaminants - particularly recalcitrant poly/perfluoroalkyl substances. Reduction conditions are created by purging out dissolved oxygen via nitrogen bubbling, and through addition of an organic electron donor, such as methanol. The anoxic water and catalyst mixture is irradiated with ultraviolet lamps inside a photo-reactor to induce treatment. Subsequently, the catalyst particles may be removed and recycled using a membrane separation process. The key aspect of the claims of this invention is the combination of BiPO4 and reducing conditions to induce treatment of PFAS, which has not been similarly demonstrated previously.

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Inventor:                       Ezra Cates, Dawei Wang

Patent Type:                 Provisional

Serial Number:             62/879,749

CURF Ref No:               2019-038

Patent Information:
For Information, Contact:
Andy Bluvas
Technology Commercialization Officer
Clemson University Research Foundation
Ezra Cates
Dawei Wang
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