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
Photocatalysis
Advantages
- 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